644f1ed70c1b04896944f66bdfa03c16278135d6
braney
  Fri Jul 31 15:16:12 2026 -0700
quickLift: keep the difference lines from standing still during a drag

The difference lines are drawn up over a track's center label, but center
labels don't scroll with the data, so the lines sat still while the image
moved underneath them.  hgTracks now keeps each center label as text with
the color it was drawn in, and flags the label when lines were painted over
it.  While the image is being dragged hgTracks.js hides that slice and puts
the label up as text in its place, then swaps the image back on drop.
Windows with no difference lines drawn are untouched.  refs #37974

diff --git src/hg/js/hgTracks.js src/hg/js/hgTracks.js
index a3db619f33a..60cf3fc3c5c 100644
--- src/hg/js/hgTracks.js
+++ src/hg/js/hgTracks.js
@@ -1,7859 +1,7889 @@
 // hgTracks.js - Javascript for use in hgTracks CGI
 
 // Copyright (C) 2008 The Regents of the University of California
 
 // "use strict";
 // Don't complain about line break before '||' etc:
 /* jshint -W014 */
 /* jshint esversion: 8 */
 
 
 var debug = false;
 
 /* Data passed in from CGI via the hgTracks object:
  *
  * string cgiVersion      // CGI_VERSION
  * string chromName       // current chromosome
  * int winStart           // genomic start coordinate (0-based, half-open)
  * int winEnd             // genomic end coordinate
  * int newWinWidth        // new width (in bps) if user clicks on the top ruler
  * boolean revCmplDisp    // true if we are in reverse display
  * int insideX            // width of side-bar (in pixels)
  * int rulerClickHeight   // height of ruler (in pixels) - zero if ruler is hidden
  * boolean inPlaceUpdate  // true if in-place-update is turned on
  * int imgBox*            // various drag-scroll values
  * boolean measureTiming  // true if measureTiming is on
  * Object trackDb         // hash of trackDb entries for tracks which are visible on current page
  * string highlight       // highlight string, in format chrom#start#end#color|chrom2#start2#end2#color2|...
  * string prevHlColor     // the last highlight color that the user picked
  */
 
 /* IE11 compatibility - IE doesn't have string startsWith and never will */
 if (!String.prototype.startsWith) {
   String.prototype.startsWith = function(searchString, position) {
     position = position || 0;
     return this.indexOf(searchString, position) === position;
   };
 }
 
 function initVars()
 {  // There are various entry points, so we call initVars in several places to make sure all is well
     if (typeof(hgTracks) !== "undefined" && !genomePos.original) {
         // remember initial position and size so we can restore it if user cancels
         genomePos.original = genomePos.getOriginalPos();
         genomePos.originalSize = $('#size').text().replace(/,/g, ""); // strip out any commas
         dragSelect.originalCursor = jQuery('body').css('cursor');
 
         if (typeof (igv) !== "undefined") {
             igv.initIgvUcsc();
         }
 
         imageV2.imgTbl = $('#imgTbl');
         // imageV2.enabled === true unless: advancedJavascript===false, or trackSearch, or config pg
         imageV2.enabled = (imageV2.imgTbl && imageV2.imgTbl.length > 0);
 
         // jQuery load function with stuff to support drag selection in track img
         if (theClient.isSafari()) {
             // Safari has the following bug: if we update the hgTracks map dynamically,
             // the browser ignores the changes (even though if you look in the DOM the changes
             // are there). So we have to do a full form submission when the user changes
             // visibility settings or track configuration.
             // As of 5.0.4 (7533.20.27) this is problem still exists in safari.
             // As of 5.1 (7534.50) this problem appears to have been fixed - unfortunately,
             // logs for 7/2011 show vast majority of safari users are pre-5.1 (5.0.5 is by far
             // the most common).
             //
             // Early versions of Chrome had this problem too, but this problem went away
             // as of Chrome 5.0.335.1 (or possibly earlier).
             //
             // KRR/JAT 2/2016:
             // This Safari issue is likely resolved in all current versions.  However the test
             // for version had been failing, likely for some time now.
             // (As of 9.0.9, possibly earlier, the 3rd part of the version is included in the
             // user agent string, so must be accounted for in string match)
             // Consequences were that page refresh was used instead of img update (e.g. 
             // for drag-zoom).  And UI dialog was unable to update (e.g. via Apply button).
             imageV2.mapIsUpdateable = false;
             var reg = new RegExp("Version\/([0-9]+.[0-9]+)(.[0-9]+)? Safari");
             var a = reg.exec(navigator.userAgent);
             if (a && a[1]) {
                 var version = Number(a[1]);
                 if (version >= 5.1) {
                     imageV2.mapIsUpdateable = true;
                 }
             }
         }
         imageV2.inPlaceUpdate = hgTracks.inPlaceUpdate && imageV2.mapIsUpdateable;
     }
 }
 
   /////////////////////////////////////
  ////////// Genomic position /////////
 /////////////////////////////////////
 var genomePos = {
 
     original: null,
     originalSize: 0,
 
     linkFixup: function (pos, id, reg, endParamName)
     {   // fixup external links (e.g. ensembl)
         var ele = $(document.getElementById(id));
         if (ele.length) {
             var link = ele.attr('href');
             var a = reg.exec(link);
             if (a && a[1]) {
                 ele.attr('href', a[1] + pos.start + "&" + endParamName + "=" + pos.end);
             }
         }
     },
 
     setByCoordinates: function (chrom, start, end)
     {
         var newPosition = chrom + ":" + start + "-" + end;
         genomePos.set(newPosition, end - start + 1);
         return newPosition;
     },
 
     getElement: function ()
     {
     // Return position box object
         var tags = document.getElementsByName("position");
         // There are multiple tags with name === "position" (the visible position text input
         // and a hidden with id='positionHidden'); we return value of visible element.
         for (var i = 0; i < tags.length; i++) {
                 var ele = tags[i];
                 if (ele.id !== "positionHidden") {
                     return ele;
                 }
         }
         return null;
     },
 
     get: function ()
     {
     // Return current value of position box
         var ele = genomePos.getElement();
         if (ele) {
             return ele.value;
         }
         return null;
     },
 
     getOriginalPos: function ()
     {
         return genomePos.original || genomePos.get();
     },
 
     revertToOriginalPos: function ()
     {
     // undo changes to position (i.e. after user aborts a drag-and-select).
         this.set(this.original, this.originalSize);
     },
 
     undisguisePosition: function(position) // UN-DISGUISE VMODE
     {   // find the virt position
         //  position should be real chrom span
         var pos = parsePosition(position);
         if (!pos)
             return position; // some parsing error, return original
         var start = pos.start - 1;
         var end = pos.end;
         var chromName = hgTracks.windows[0].chromName;
         if (pos.chrom !== chromName)
             return position; // return original
         var newStart = -1;
         var newEnd = -1;
         var lastW = null;
         var windows = null;
         for (j=0; j < 3; ++j) {
             if (j === 0) windows = hgTracks.windowsBefore;
             if (j === 1) windows = hgTracks.windows;
             if (j === 2) windows = hgTracks.windowsAfter;
             for (i=0,len=windows.length; i < len; ++i) {
                 var w = windows[i];
                 //  double check chrom is same thoughout all windows, otherwise warning, return original value
                 if (w.chromName != chromName) {
                     return position; // return original
                 }
                 // check that the regions are ascending and non-overlapping
                 if (lastW && w.winStart < lastW.winEnd) {
                     return position; // return original
                 }
                 // overlap with position?
                 //  if intersection, 
                 if (w.winEnd > start && end > w.winStart) {
                     var s = Math.max(start, w.winStart);
                     var e = Math.min(end, w.winEnd);
                     var cs = s - w.winStart + w.virtStart;
                     var ce = e - w.winStart + w.virtStart;
                     if (newStart === -1)
                         newStart = cs;
                     newEnd = ce;
                 }
                 lastW = w;
             }
         }
         //  return new virt undisguised position as a string
         var newPos = "multi:" + (newStart+1) + "-" + newEnd;
         return newPos;
     },
 
     disguiseSize: function(position) // DISGUISE VMODE
     {   // find the real size of the windows spanned
         //  position should be a real chrom span
         var pos = parsePosition(position);
         if (!pos)
             return 0;
         var start = pos.start - 1;
         var end = pos.end;
         var newSize = 0;
         var windows = null;
         for (j=0; j < 3; ++j) {
             if (j === 0) windows = hgTracks.windowsBefore;
             if (j === 1) windows = hgTracks.windows;
             if (j === 2) windows = hgTracks.windowsAfter;
             for (i=0,len=windows.length; i < len; ++i) {
                 var w = windows[i];
                 // overlap with position?
                 //  if intersection, 
                 if (w.winEnd > start && end > w.winStart) {
                     var s = Math.max(start, w.winStart);
                     var e = Math.min(end, w.winEnd);
                     newSize += (e - s);
                 }
             }
         }
         //  return real size of the disguised position 
         return newSize;
     },
 
     disguisePosition: function(position) // DISGUISE VMODE
     {   // find the single-chrom range spanned
         //  position should be virt
         var pos = parsePosition(position);
         if (!pos)
             return position; // some parsing error, return original
         var start = pos.start - 1;
         var end = pos.end;
         var chromName = hgTracks.windows[0].chromName;
         var newStart = -1;
         var newEnd = -1;
         var lastW = null;
         var windows = null;
         for (j=0; j < 3; ++j) {
             if (j === 0) windows = hgTracks.windowsBefore;
             if (j === 1) windows = hgTracks.windows;
             if (j === 2) windows = hgTracks.windowsAfter;
             for (i=0,len=windows.length; i < len; ++i) {
                 var w = windows[i];
                 //  double check chrom is same thoughout all windows, otherwise warning, return original value
                 if (w.chromName != chromName) {
                     return position; // return undisguised original
                 }
                 // check that the regions are ascending and non-overlapping
                 if (lastW && w.winStart < lastW.winEnd) {
                     return position; // return undisguised original
                 }
                 // overlap with position?
                 //  if intersection, 
                 if (w.virtEnd > start && end > w.virtStart) {
                     var s = Math.max(start, w.virtStart);
                     var e = Math.min(end, w.virtEnd);
                     var cs = s - w.virtStart + w.winStart;
                     var ce = e - w.virtStart + w.winStart;
                     if (newStart === -1)
                         newStart = cs;
                     newEnd = ce;
                 }
                 lastW = w;
             }
         }
         //  return new non-virt disguised position as a string
         var newPos = chromName + ":" + (newStart+1) + "-" + newEnd;
         return newPos;
     },
 
     set: function (position, size)
     {   // Set value of position and size (in hiddens and input elements).
         // We assume size has already been commified.
         // Either position or size may be null.
 
         // stack dump  // DEBUG
         //console.trace();
         // NOT work on safari
         //var obj = {};
         //Error.captureStackTrace(obj);
         //warn("genomePos.set() called "+obj.stack);
 
         position = position.replace(/,/g, ""); // strip out any commas
         position.replace("virt:", "multi:");
 
         if (position) {
             // DISGUISE VMODE
             //warn("genomePos.set() called, position = "+position);
             if (hgTracks.virtualSingleChrom && (position.search("multi:")===0)) {
                 var newPosition = genomePos.disguisePosition(position);
                 //warn("genomePos.set() position = "+position+", newPosition = "+newPosition);
                 position = newPosition;
             }
         }
         if (position) {
             // There are multiple tags with name === "position"
             // (one in TrackHeaderForm and another in TrackForm).
             var tags = document.getElementsByName("position");
             for (var i = 0; i < tags.length; i++) {
                 var ele = tags[i];
                 ele.value = position;
             }
         }
         var pos = parsePosition(position);
         if ($('#positionDisplay').length) {
             // add commas to positionDisplay
             var commaPosition = position;
             if (pos)
                 commaPosition = pos.chrom+":"+commify(pos.start)+"-"+commify(pos.end);  
             $('#positionDisplay').text(commaPosition);
         }
         if (size) {
             if (hgTracks.virtualSingleChrom && (position.search("multi:")!==0)) {
                 var newSize = genomePos.disguiseSize(position);
                 //warn("genomePos.set() position = "+position+", newSize = "+newSize);
                 if (newSize > 0)
                     size = newSize;
             }
             $('#size').text(commify(size)); // add commas
         }
         if (pos) {
             // fixup external static links on page'
 
             // Example ensembl link:
             // http://www.ensembl.org/Homo_sapiens/contigview?chr=21&start=33031934&end=33041241
             genomePos.linkFixup(pos, "ensemblLink", new RegExp("(.+start=)[0-9]+"), "end");
 
             // Example NCBI Map Viewer link (obsolete):
             // https://www.ncbi.nlm.nih.gov/mapview/maps.cgi?taxid=9606&CHR=21&BEG=33031934&END=33041241
             genomePos.linkFixup(pos, "ncbiLink", new RegExp("(.+BEG=)[0-9]+"), "END");
 
             // Example NCBI Genome Data Viewer link
             // https://www.ncbi.nlm.nih.gov/genome/gdv/browser/?id=GCF_000001405.37&chr=4&from=45985744&to=45991655&context=genome
             genomePos.linkFixup(pos, "ncbiLink", new RegExp("(.+from=)[0-9]+"), "to");
 
             // Example medaka link: 
             // http://utgenome.org/medakabrowser_ens_jump.php?revision=version1.0&chr=chromosome18&start=14435198&end=14444829
             genomePos.linkFixup(pos, "medakaLink", new RegExp("(.+start=)[0-9]+"), "end");
 
             var link;
             var reg;
             var a;
             if ($('#wormbaseLink').length) {
                 // e.g. http://www.wormbase.org/db/gb2/gbrowse/c_elegans?name=II:14646301-14667800
                 link = $('#wormbaseLink').attr('href');
                 reg = new RegExp("(.+:)[0-9]+");
                 a = reg.exec(link);
                 if (a && a[1]) {
                     $('#wormbaseLink').attr('href', a[1] + pos.start + "-" + pos.end);
                 }
             }
             // Fixup DNA link; e.g.: 
             // hgc?hgsid=2999470&o=114385768&g=getDna&i=mixed&c=chr7&l=114385768&r=114651696&db=panTro2&hgsid=2999470
             if ($('#dnaLink').length) {
                 link = $('#dnaLink').attr('href');
                 reg = new RegExp("(.+&o=)[0-9]+.+&db=[^&]+(.*)");
                 a = reg.exec(link);
                 if (a && a[1]) {
                     var url = a[1] + (pos.start - 1) + "&g=getDna&i=mixed&c=" + pos.chrom;
                     url += "&l=" + (pos.start - 1) + "&r=" + pos.end + "&db=" + getDb() + a[2];
                     $('#dnaLink').attr('href', url);
                 }
             }
         }
         if (!imageV2.backSupport)
             imageV2.markAsDirtyPage();
     },
 
     getXLimits : function(img, slop) {
         // calculate the min/max x position for drag-select, such that user cannot drag into the label area
         var imgWidth = jQuery(img).width();
         var imgOfs = jQuery(img).offset();
         var leftX = hgTracks.revCmplDisp ?  imgOfs.left - slop :
                                             imgOfs.left + hgTracks.insideX - slop;
         var rightX = hgTracks.revCmplDisp ? imgOfs.left + imgWidth - hgTracks.insideX + slop :
                                             imgOfs.left + imgWidth + slop;
 
         return [leftX, rightX];
     },
 
     check: function (img, selection)
     {   // return true if user's selection is still w/n the img (including some slop).
         var imgWidth = jQuery(img).width();
         var imgHeight = jQuery(img).height();
         var imgOfs = jQuery(img).offset();
         var slop = 10;
 
         // No need to check the x limits anymore, as imgAreaSelect is doing that now.
         return  (  (selection.event.pageY >= (imgOfs.top - slop))
                 && (selection.event.pageY <  (imgOfs.top + imgHeight + slop)));
     },
 
     pixelsToBases: function (img, selStart, selEnd, winStart, winEnd, addHalfBp)
     {   // Convert image coordinates to chromosome coordinates
         var imgWidth = jQuery(img).width() - hgTracks.insideX;
         var width = hgTracks.winEnd - hgTracks.winStart;
         var mult = width / imgWidth;   // mult is bp/pixel multiplier
  
         // where does a bp position start on the screen?
         // For things like drag-select, if the user ends just before the nucleotide itself, do not count
         // the nucleotide itself as selected. But for things like clicks onto
         // a selection, if the user right-clicks just before the middle of the
         // nucleotide, we certainly want to use this position.
         var halfBpWidth = 0;
         if (addHalfBp)
             halfBpWidth = (imgWidth / width) / 2; // how many pixels does one bp take up;
 
         var startDelta;   // startDelta is how many bp's to the right/left
         var x1;
 
         // The magic number three appear at another place in the code 
         // as LEFTADD. It was originally annotated as "borders or cgi item calc
         // ?" by Larry. It has to be used when going any time when converting 
         // between pixels and coordinates.
         selStart -= 3;
         selEnd -= 3;
 
         if (hgTracks.revCmplDisp) {
             x1 = Math.min(imgWidth, selStart);
             startDelta = Math.floor(mult * (imgWidth - x1 - halfBpWidth));
         } else {
             x1 = Math.max(hgTracks.insideX, selStart);
             startDelta = Math.floor(mult * (x1 - hgTracks.insideX + halfBpWidth));
         }
         var endDelta;
         var x2;
         if (hgTracks.revCmplDisp) {
             endDelta = startDelta;
             x2 = Math.min(imgWidth, selEnd);
             startDelta = Math.floor(mult * (imgWidth - x2 + halfBpWidth));
         } else {
             x2 = Math.max(hgTracks.insideX, selEnd);
             endDelta = Math.floor(mult * (x2 - hgTracks.insideX - halfBpWidth));
         }
         var newStart = hgTracks.winStart + startDelta;
         var newEnd = hgTracks.winStart + 1 + endDelta;
 
         // if user selects space between two bases, start>end can happen
         if (newStart >= newEnd)
             newStart = newEnd-1;
 
         if (newEnd > winEnd) {
             newEnd = winEnd;
         }
         return {chromStart : newStart, chromEnd : newEnd};
     },
 
     chromToVirtChrom: function (chrom, chromStart, chromEnd)
     {   // Convert regular chromosome position to virtual chrom coordinates using hgTracks.windows list
         // Consider the first contiguous set of overlapping regions to define the match (for now).
         // only works for regions covered by the current hgTracks.windows
         var virtStart = -1, virtEnd = -1;
         var s,e;
         var i, len;
         for (i = 0, len = hgTracks.windows.length; i < len; ++i) {
             var w = hgTracks.windows[i];
             var overlap = (chrom == w.chromName && chromEnd > w.winStart && w.winEnd > chromStart);
             if (virtStart == -1) {
                 if (overlap) {
                     // when they overlap the first time
                     s = Math.max(chromStart, w.winStart);
                     e = Math.min(chromEnd, w.winEnd);
                     virtStart = w.virtStart + (s - w.winStart);
                     virtEnd   = w.virtStart + (e - w.winStart);
                 } else {
                     // until they overlap
                     // do nothing
                 }
             } else {
                 if (overlap) {
                     // while they continue to overlap, extend
                     e = Math.min(chromEnd, w.winEnd);
                     virtEnd   = w.virtStart + (e - w.winStart);
                 } else {
                     // when they do not overlap anymore, stop
                     break;
                 }
             }
         }
         return {chromStart : virtStart, chromEnd : virtEnd};
     },
 
     selectionPixelsToBases: function (img, selection)
     {   // Convert selection x1/x2 coordinates to chromStart/chromEnd.
         return genomePos.pixelsToBases(img, selection.x1, selection.x2,
                                         hgTracks.winStart, hgTracks.winEnd, true);
     },
 
     update: function (img, selection, singleClick)
     {
         // For a drag-select keep the half-base offset (addHalfBp) so an edge that
         // ends just before a base does not count that base.  For a single click turn
         // it off so both edges resolve to the same base under the pointer: with it on,
         // at single-base zoom a left click drifted one base left while a right click
         // could not move at all.
         var pos = genomePos.pixelsToBases(img, selection.x1, selection.x2,
                                             hgTracks.winStart, hgTracks.winEnd, !singleClick);
         // singleClick is true when the mouse hasn't moved (or has only moved a small amount).
         if (singleClick) {
             var center = (pos.chromStart + pos.chromEnd)/2;
             pos.chromStart = Math.floor(center - hgTracks.newWinWidth/2);
             pos.chromEnd = pos.chromStart + hgTracks.newWinWidth;
             // clip
             if (pos.chromStart < hgTracks.chromStart)
                 pos.chromStart = hgTracks.chromStart; // usually  1
             if (pos.chromEnd > hgTracks.chromEnd)
                 pos.chromEnd = hgTracks.chromEnd; // usually virt chrom size
 
             // save current position so that that it may be restored after highlight or cancel.
             genomePos.original = genomePos.getOriginalPos();
             genomePos.originalSize = $('#size').text().replace(/,/g, ""); // strip out any commas
 
         }
         var newPosition = genomePos.setByCoordinates(hgTracks.chromName,
                                                             pos.chromStart+1, pos.chromEnd);
         return newPosition;
     },
 
     handleChange: function (response, status)
     {
         var json = JSON.parse(response);
         genomePos.set(json.pos);
     },
 
     changeAssemblies: function (ele)  // UNUSED?  Larry's experimental code
     {   // code to update page when user changes assembly select list.
         $.ajax({
                 type: "GET",
                 url: "../cgi-bin/hgApi",
                 data: cart.varsToUrlData({ 'hgsid': getHgsid(), 'cmd': 'defaultPos', 'db': getDb() }),
                 dataType: "html",
                 trueSuccess: genomePos.handleChange,
                 success: catchErrorOrDispatch,
                 error: errorHandler,
                 cache: true
             });
         return false;
     },
 
 
     convertedVirtCoords : {chromStart : -1, chromEnd : -1},
 
     handleConvertChromPosToVirtCoords: function (response, status)
     {
         var virtStart = -1, virtEnd = -1;
         var newJson = scrapeVariable(response, "convertChromToVirtChrom");
         if (!newJson) {
             warn("convertChromToVirtChrom object is missing from the response");
         } else {
             virtStart = newJson.virtWinStart;
             virtEnd   = newJson.virtWinEnd;
         }
         genomePos.convertedVirtCoords = {chromStart : virtStart, chromEnd : virtEnd};
     },
 
     convertChromPosToVirtCoords: function (chrom, chromStart, chromEnd)
     {   // code to convert chrom position to virt coords
         genomePos.convertedVirtCoords = {chromStart : -1, chromEnd : -1};  // reset
         var pos = chrom+":"+(chromStart+1)+"-"+chromEnd; // easier to pass 1 parameter than 3
         $.ajax({
                 type: "GET",
                 async: false, // wait for result
                 url: "../cgi-bin/hgTracks",
                 data: cart.varsToUrlData({ 'hgt.convertChromToVirtChrom': pos, 'hgt.trackImgOnly' : 1, 'hgsid': getHgsid(), 'db': getDb() }),
                 dataType: "html",
                 trueSuccess: genomePos.handleConvertChromPosToVirtCoords,
                 success: catchErrorOrDispatch,
                 error: errorHandler,
                 cache: false
             });
         return genomePos.convertedVirtCoords;
     },
 
     positionDisplayDialog: function ()
     // Show the virtual and real positions of the windows
     {   
         var position = genomePos.get();
         position.replace("virt:", "multi:");
         var positionDialog = $("#positionDialog")[0];
         if (!positionDialog) {
             $("body").append("<div id='positionDialog'><span id='positionDisplayPosition'></span>");
             positionDialog = $("#positionDialog")[0];
         }
         if (hgTracks.windows) {
             var i, len, end;
             var matches = /^multi:[0-9]+-([0-9]+)/.exec(position);
             var modeType = (hgTracks.virtModeType === "customUrl" ? "Custom regions on virtual chromosome" :
                             (hgTracks.virtModeType === "exonMostly" ? "Exon view of" :
                             (hgTracks.virtModeType === "geneMostly" ? "Gene view of" :
                             (hgTracks.virtModeType === "singleAltHaplo" ? "Alternate haplotype as virtual chromosome" :
                                         "Unknown mode"))));
             var str = modeType + "&nbsp;" + position;
             if (matches) {
                 end = matches[1];
                 if (end < hgTracks.chromEnd) {
                     str += ". Full virtual region is multi:1-" + hgTracks.chromEnd + ". Zoom out to view.";
                 }
             }
             if (!(hgTracks.virtualSingleChrom && (hgTracks.windows.length === 1))) {
                 var w;
                 if (hgTracks.windows.length <= 10) {
                     str += "<p><table>\n";
                     for (i=0,len=hgTracks.windows.length; i < len; ++i) {
                         w = hgTracks.windows[i];
                         str += "<tr><td>" + w.chromName + ":" + (w.winStart+1) + "-" + w.winEnd + "</td><td>" + 
                                     (w.winEnd - w.winStart) + " bp" + "</td></tr>\n";
                     }
                     str += "</table></p>\n";
                 } else {
                     str += "<br><ul style='list-style-type:none; max-height:200px; padding:0; width:80%; overflow:hidden; overflow-y:scroll;'>\n";
                     for (i=0,len=hgTracks.windows.length; i < len; ++i) {
                         w = hgTracks.windows[i];
                         str += "<li>" + w.chromName + ":" + (w.winStart+1) + "-" + w.winEnd +
                                     "&nbsp;&nbsp;&nbsp;" + (w.winEnd - w.winStart) + " bp" + "</li>\n";
                     }
                     str += "</ul>\n";
                 }
             }
             $("#positionDisplayPosition").html(str);
         } else {
             $("#positionDisplayPosition").html(position);
         }
         $(positionDialog).dialog({
                 modal: true,
                 title: "Multi-Region Position Ranges",
                 closeOnEscape: true,
                 resizable: false,
                 autoOpen: false,
                 minWidth: 400,
                 minHeight: 40,
 
                 close: function() {
                     // All exits to dialog should go through this
                     $(imageV2.imgTbl).imgAreaSelect({hide:true});
                     $(this).hide();
                     $('body').css('cursor', ''); // Occasionally wait cursor got left behind
                 }
         });
         $(positionDialog).dialog('open');
     }
 
 };
 
   /////////////////////////////////////
  //// Creating items             /////
 /////////////////////////////////////
 var myVariants = {
     createBedForm: function(dialogEle) {
         // Shared top fields (visible in all manual modes)
         const commonTopFields = [
             { label: "Label", id: "name", type: "text", placeholder: "Optional item label",
               info: "A short label for this annotation, displayed in the browser" },
             { label: "Color", id: "color", type: "text" },
         ];
         // SNV-only field (between commonTop and alt/sequence)
         const snvOnlyFields = [
             { label: "Ref", id: "ref", type: "text", placeholder: "Optional reference allele sequence",
               info: "Reference allele sequence at this position" },
         ];
         // Alt/Sequence field: shown for SNV (label="Alt") and CNV (label="Sequence")
         const altField = { label: "Alt", id: "alt", type: "text",
             placeholder: "Optional alternate allele sequence",
             info: "Alternate (variant) allele sequence" };
         // Position fields: shown always for Transcript; collapsible for SNV/CNV
         const positionFields = [
             { label: "Chromosome", id: "chrom", type: "text" },
             { label: "Start", id: "start", type: "number",
               info: "1-based start position on the chromosome" },
             { label: "End", id: "end", type: "number",
               info: "1-based end position on the chromosome (inclusive)" },
             { label: "Score", id: "score", type: "number",
               info: "Score from 0-1000. Higher scores display darker" },
             { label: "Strand", id: "strand", type: "text",
               info: "Strand: + for forward, - for reverse, . for unknown" },
         ];
         // Transcript-only CDS fields (displayed as CDS Start/End; stored as thickStart/thickEnd)
         const cdsFields = [
             { label: "CDS Start", id: "thickStart", type: "number",
               info: "Start of the coding region" },
             { label: "CDS End", id: "thickEnd", type: "number",
               info: "End of the coding region" },
         ];
         // Shared bottom fields
         const commonBottomFields = [
             { label: "Mouseover", id: "mouseover", type: "text", placeholder: "Short text shown on hover",
               info: "Short text shown when hovering over this item. If empty, the label and alleles are displayed" },
             { label: "Description", id: "description", type: "textarea", placeholder: "Longer description/notes",
               info: "Longer notes or comments about this annotation. Displayed on the details page" },
             { label: "Project", id: "project", type: "text", placeholder: "Optional project name",
               info: "Group annotations by project. Projects with no annotations are automatically removed from the list" },
         ];
         // CNV vocabulary, mirrored on the server in myVariantsTrack.c:validCnvTypes
         const cnvTypeOptions = ["deletion", "duplication", "insertion", "inversion",
                                 "translocation", "complex", "breakend"];
 
         const form = document.createElement("form");
         form.className = "myVariants-form";
         form.action = "hgTracks";
         form.method = "post";
         form.id = "myVariants-form";
 
         // First: HGVS/position input box (primary interaction method)
         let quickInpDiv = document.createElement("div");
         quickInpDiv.id = "hgvsInputDiv";
         form.appendChild(quickInpDiv);
 
         let quickInp = document.createElement("input");
         let quickInpLabel = document.createElement("label");
         quickInp.type = "text";
         quickInp.id = "hgvsInput";
         quickInp.name = "myVariantsHgvsInput";
         quickInp.style.width = "300px";
         quickInpLabel.textContent = "Enter HGVS, position, or gene symbol";
         quickInpLabel.style.display = "inline-block";
         quickInpLabel.style.minWidth = "200px";
         quickInpLabel.style.marginRight = "8px";
         quickInpLabel.for = "hgvsInput";
 
         let resizeDialog = function() {
             var dialog = $("#myVariantsDialog");
             var hgvsVisible = document.getElementById("hgvsInputDiv").style.display !== "none";
             if (hgvsVisible) {
                 dialog.dialog("option", "width", 580);
                 dialog.dialog("option", "height", "auto");
                 dialog.dialog("option", "position", { my: "center", at: "center", of: window });
             } else {
                 dialog.dialog("option", "width", Math.min(1000, window.innerWidth * 0.9));
                 dialog.dialog("option", "height", Math.min(800, window.innerHeight * 0.9));
                 dialog.dialog("option", "position", { my: "top+30", at: "top", of: window });
             }
         };
 
         let updatePositionSummary = function() {
             let summaryText = document.getElementById("positionSummaryText");
             if (!summaryText) return;
             let chrom = document.getElementById("chrom");
             let start = document.getElementById("start");
             let end = document.getElementById("end");
             if (chrom && start && end) {
                 let startVal = parseInt(start.value);
                 let endVal = parseInt(end.value);
                 let startFmt = isNaN(startVal) ? start.value : startVal.toLocaleString();
                 let endFmt = isNaN(endVal) ? end.value : endVal.toLocaleString();
                 summaryText.textContent = chrom.value + ":" + startFmt + "-" + endFmt;
             }
         };
 
         // Switch the form into one of four modes and remember the choice so the
         // next dialog open restarts in the same place.
         let applyMode = function(mode) {
             const isHgvs = mode === "hgvs";
             const isTranscript = mode === "transcript";
             const isSnv = mode === "snv";
             const isCnv = mode === "cnv";
 
             document.getElementById("hgvsInputDiv").style.display = isHgvs ? "" : "none";
             document.getElementById("manualInputDiv").style.display = isHgvs ? "none" : "";
             document.getElementById("hgvsManualToggle").textContent =
                 isHgvs ? "Or edit item fields manually" : "Back to quick input mode";
 
             if (!isHgvs) {
                 document.getElementById("typeTranscript").checked = isTranscript;
                 document.getElementById("typeSnv").checked = isSnv;
                 document.getElementById("typeCnv").checked = isCnv;
             }
 
             document.getElementById("refWrapper").style.display = isSnv ? "" : "none";
             document.getElementById("altWrapper").style.display = (isSnv || isCnv) ? "" : "none";
             document.getElementById("altLabel").textContent = isCnv ? "Sequence" : "Alt";
             document.getElementById("cnvTypeWrapper").style.display = isCnv ? "" : "none";
 
             if (isTranscript) {
                 advancedDiv.style.display = "none";
                 cdsBlocksDiv.style.display = "none";
                 posWraps.forEach(function(w) { w.style.display = ""; });
                 cdsWraps.forEach(function(w) { w.style.display = ""; });
                 blocksSection.style.display = "";
                 const order = [
                     typeRadioBar, posSummary,
                     posWraps[0], posWraps[1], posWraps[2],
                     nameWrap,
                     posWraps[3], posWraps[4],
                     cdsWraps[0], cdsWraps[1],
                     colorWrap,
                     mouseoverWrap, descriptionWrap, projectWrap,
                     blocksSection,
                     advancedDiv, cdsBlocksDiv,
                     refWrapper, cnvTypeWrapper, altWrapper,
                     customFieldsSection
                 ];
                 order.forEach(function(el) { manualInpDiv.appendChild(el); });
             } else {
                 // Pack wrappers back into their collapsible containers.
                 posWraps.forEach(function(w) { advancedDiv.appendChild(w); });
                 cdsWraps.forEach(function(w) { cdsBlocksDiv.appendChild(w); });
                 cdsBlocksDiv.appendChild(blocksSection);
                 advancedDiv.style.display = "none";
                 cdsBlocksDiv.style.display = "none";
                 const order = [
                     typeRadioBar, posSummary,
                     advancedDiv,
                     nameWrap, colorWrap,
                     refWrapper, cnvTypeWrapper, altWrapper,
                     cdsBlocksDiv,
                     mouseoverWrap, descriptionWrap, projectWrap,
                     customFieldsSection
                 ];
                 order.forEach(function(el) { manualInpDiv.appendChild(el); });
             }
             document.getElementById("positionSummaryDiv").style.display = isTranscript ? "none" : "";
             if (posEditLink) posEditLink.textContent = "[edit]";
 
             try { localStorage.setItem("myVariantsLastMode", mode); } catch (e) { /* private mode */ }
             resizeDialog();
         };
 
         let currentType = function() {
             if (document.getElementById("typeTranscript").checked) return "transcript";
             if (document.getElementById("typeCnv").checked) return "cnv";
             return "snv";
         };
 
         let toggleForm = function(event) {
             event.preventDefault();
             const inHgvs = document.getElementById("hgvsInputDiv").style.display !== "none";
             applyMode(inHgvs ? currentType() : "hgvs");
         };
         let toggleContainer = document.createElement("p");
         let toggle = document.createElement("a");
         toggle.href = "#";
         toggle.id = "hgvsManualToggle";
         toggle.addEventListener("click", toggleForm);
         toggle.textContent = "Or edit item fields manually";
         toggleContainer.appendChild(toggle);
 
         quickInpDiv.appendChild(quickInpLabel);
         quickInpDiv.appendChild(quickInp);
         form.appendChild(toggleContainer);
 
         // Manual input div (contains simple + advanced fields)
         let manualInpDiv = document.createElement("div");
         manualInpDiv.id = "manualInputDiv";
         manualInpDiv.style.display = "none";
 
         let posSummary = document.createElement("div");
         posSummary.id = "positionSummaryDiv";
         posSummary.style.cssText = "margin-bottom:12px; padding:6px 10px; background:#f0f4f8; border:1px solid #d0d7de; border-radius:4px; font-size:13px;";
         let posSummaryLabel = document.createElement("b");
         posSummaryLabel.textContent = "Position: ";
         posSummary.appendChild(posSummaryLabel);
         let posSummaryText = document.createElement("span");
         posSummaryText.id = "positionSummaryText";
         posSummary.appendChild(posSummaryText);
         let posSummarySuffix = document.createElement("span");
         posSummarySuffix.style.color = "#888";
         posSummarySuffix.textContent = " (from current view)";
         posSummary.appendChild(posSummarySuffix);
         let posEditLink = document.createElement("a");
         posEditLink.href = "#";
         posEditLink.textContent = "[edit]";
         posEditLink.style.cssText = "margin-left:8px; font-size:12px;";
         posEditLink.addEventListener("click", function(event) {
             event.preventDefault();
             let advDiv = document.getElementById("advancedFieldsDiv");
             if (!advDiv) return;
             if (advDiv.style.display === "none") {
                 advDiv.style.display = "";
                 posEditLink.textContent = "[hide]";
                 let chromField = document.getElementById("chrom");
                 if (chromField) {
                     chromField.scrollIntoView({behavior: "smooth", block: "nearest"});
                     chromField.focus();
                 }
             } else {
                 advDiv.style.display = "none";
                 posEditLink.textContent = "[edit]";
             }
         });
         posSummary.appendChild(posEditLink);
         manualInpDiv.appendChild(posSummary);
 
         // Helper function to create form field (uses createInfoIcon from utils.js)
         let createField = function(field, container) {
             const wrapper = document.createElement("div");
             wrapper.style.marginBottom = "8px";
 
             const label = document.createElement("label");
             label.htmlFor = field.id;
             label.textContent = field.label;
             label.style.display = "inline-block";
             label.style.minWidth = "140px";
 
             let input;
             if (field.type === "textarea") {
                 input = document.createElement("textarea");
                 input.rows = "4";
                 input.cols = "60";
             } else {
                 input = document.createElement("input");
                 input.type = field.type;
             }
             input.id = field.id;
 
             if (field.id === "chrom") {
                 input.value = hgTracks.chromName;
             }
             if (field.type === "number") {
                 input.min = 0;
                 if (field.id === "start" || field.id === "thickStart") {
                     input.value = hgTracks.winStart;
                 }
                 if (field.id === "end" || field.id === "thickEnd") {
                     input.value = hgTracks.winEnd;
                 }
                 if (field.id === "score") {
                     input.value = 0;
                     input.max = 1000;
                 }
             }
             if (field.id === "strand") {
                 input.value = ".";
             }
             if (field.id === "color") {
                 input.value = "#000000";
                 input.style.width = "70px";
             }
             if (field.placeholder) {
                 input.placeholder = field.placeholder;
             }
 
             wrapper.appendChild(label);
             wrapper.appendChild(input);
             if (field.info) {
                 wrapper.appendChild(createInfoIcon(field.info));
             }
             container.appendChild(wrapper);
 
             return input;
         };
 
         // Helper function to create project field with dropdown if projects exist
         let createProjectField = function(container) {
             const wrapper = document.createElement("div");
             wrapper.style.marginBottom = "8px";
 
             const label = document.createElement("label");
             label.htmlFor = "project";
             label.textContent = "Project";
             label.style.display = "inline-block";
             label.style.minWidth = "140px";
             wrapper.appendChild(label);
 
             // Check if we have existing projects from the server
             let existingProjects = (typeof hgTracks !== 'undefined' && hgTracks.myVariantsProjects)
                                    ? hgTracks.myVariantsProjects : [];
 
             if (existingProjects.length > 0) {
                 // Create dropdown with existing projects
                 let select = document.createElement("select");
                 select.id = "projectSelect";
                 select.style.marginRight = "8px";
 
                 // Add empty option
                 let emptyOpt = document.createElement("option");
                 emptyOpt.value = "";
                 emptyOpt.textContent = "(none)";
                 select.appendChild(emptyOpt);
 
                 // Add existing projects
                 existingProjects.forEach(proj => {
                     let opt = document.createElement("option");
                     opt.value = proj;
                     opt.textContent = proj;
                     select.appendChild(opt);
                 });
 
                 // Add "Add new..." option
                 let newOpt = document.createElement("option");
                 newOpt.value = "__new__";
                 newOpt.textContent = "Add new...";
                 select.appendChild(newOpt);
 
                 wrapper.appendChild(select);
 
                 // Hidden text input for new project (shown when "Add new..." selected)
                 let newProjectInput = document.createElement("input");
                 newProjectInput.type = "text";
                 newProjectInput.id = "project";
                 newProjectInput.placeholder = "Enter new project name";
                 newProjectInput.style.display = "none";
                 wrapper.appendChild(newProjectInput);
 
                 // Toggle between dropdown and text input
                 select.addEventListener("change", function() {
                     if (select.value === "__new__") {
                         newProjectInput.style.display = "";
                         newProjectInput.focus();
                     } else {
                         newProjectInput.style.display = "none";
                         newProjectInput.value = select.value;
                     }
                 });
 
                 // Keep text input synced with dropdown selection
                 newProjectInput.addEventListener("blur", function() {
                     if (newProjectInput.value === "" && select.value === "__new__") {
                         select.value = "";
                         newProjectInput.style.display = "none";
                     }
                 });
             } else {
                 // No existing projects - just show text input
                 let input = document.createElement("input");
                 input.type = "text";
                 input.id = "project";
                 input.placeholder = "Optional project name";
                 wrapper.appendChild(input);
             }
 
             // Add info icon
             wrapper.appendChild(createInfoIcon("Group annotations by project. Projects with no annotations are automatically removed from the list"));
             container.appendChild(wrapper);
         };
 
         // Type radio bar: Transcript | Variant -> Short | CNV. Inserted at the very
         // top of manualInpDiv (before the existing position summary).
         let typeRadioBar = document.createElement("div");
         typeRadioBar.id = "typeRadioBar";
         typeRadioBar.style.cssText = "margin-bottom:12px; padding:8px 10px; background:#f7f7f7; border:1px solid #ddd; border-radius:4px;";
         typeRadioBar.innerHTML =
             "<div style='font-weight:bold; font-size:12px; color:#555; margin-bottom:4px;'>Annotation type</div>" +
             "<div>" +
                 "<label style='margin-right:20px;'><input type='radio' name='myVariantsType' id='typeTranscript' value='transcript'> Transcript</label>" +
                 "<label style='margin-right:20px;'><input type='radio' name='myVariantsType' id='typeSnv' value='snv' checked> Short variant (snv)</label>" +
                 "<label><input type='radio' name='myVariantsType' id='typeCnv' value='cnv'> Copy number variant (cnv)</label>" +
             "</div>";
         manualInpDiv.insertBefore(typeRadioBar, manualInpDiv.firstChild);
 
         let onTypeRadioChange = function() {
             applyMode(currentType());
         };
         // The form is not yet in the document, so query the local subtree.
         typeRadioBar.querySelectorAll("input[type=radio]").forEach(function(r) {
             r.addEventListener("change", onTypeRadioChange);
         });
 
         let colorInput = null;
         let nameWrap, colorWrap;
         commonTopFields.forEach(function(field) {
             let input = createField(field, manualInpDiv);
             if (field.id === "color") { colorInput = input; colorWrap = input.parentNode; }
             else if (field.id === "name") { nameWrap = input.parentNode; }
         });
 
         // SNV-only ref input
         let refWrapper = document.createElement("div");
         refWrapper.id = "refWrapper";
         createField(snvOnlyFields[0], refWrapper);
         manualInpDiv.appendChild(refWrapper);
 
         // CNV-only type select
         let cnvTypeWrapper = document.createElement("div");
         cnvTypeWrapper.id = "cnvTypeWrapper";
         cnvTypeWrapper.style.marginBottom = "8px";
         let cnvTypeLabel = document.createElement("label");
         cnvTypeLabel.htmlFor = "cnvType";
         cnvTypeLabel.textContent = "CNV type";
         cnvTypeLabel.style.cssText = "display:inline-block; min-width:140px;";
         let cnvTypeSelect = document.createElement("select");
         cnvTypeSelect.id = "cnvType";
         cnvTypeOptions.forEach(function(t) {
             let opt = document.createElement("option");
             opt.value = t;
             opt.textContent = t;
             cnvTypeSelect.appendChild(opt);
         });
         cnvTypeWrapper.appendChild(cnvTypeLabel);
         cnvTypeWrapper.appendChild(cnvTypeSelect);
         cnvTypeWrapper.appendChild(createInfoIcon("CNV vocabulary follows gnomAD"));
         manualInpDiv.appendChild(cnvTypeWrapper);
 
         // Alt / Sequence input (shared between SNV and CNV; label switches in applyMode)
         let altWrapper = document.createElement("div");
         altWrapper.id = "altWrapper";
         altWrapper.style.marginBottom = "8px";
         let altLabel = document.createElement("label");
         altLabel.htmlFor = "alt";
         altLabel.id = "altLabel";
         altLabel.textContent = "Alt";
         altLabel.style.cssText = "display:inline-block; min-width:140px;";
         let altInput = document.createElement("input");
         altInput.type = "text";
         altInput.id = "alt";
         altInput.placeholder = altField.placeholder;
         altWrapper.appendChild(altLabel);
         altWrapper.appendChild(altInput);
         altWrapper.appendChild(createInfoIcon(altField.info));
         manualInpDiv.appendChild(altWrapper);
 
         let advancedDiv = document.createElement("div");
         advancedDiv.id = "advancedFieldsDiv";
         advancedDiv.style.display = "none";
         let posWraps = positionFields.map(function(field) {
             return createField(field, advancedDiv).parentNode;
         });
         manualInpDiv.appendChild(advancedDiv);
 
         let cdsBlocksDiv = document.createElement("div");
         cdsBlocksDiv.id = "cdsBlocksDiv";
         cdsBlocksDiv.style.display = "none";
         let cdsWraps = cdsFields.map(function(field) {
             return createField(field, cdsBlocksDiv).parentNode;
         });
 
         let blocksSection = document.createElement("div");
         blocksSection.id = "blocksSection";
         blocksSection.style.cssText = "margin-top:12px; padding-top:10px; border-top:1px solid #ddd;";
         let blocksLabel = document.createElement("div");
         blocksLabel.style.cssText = "font-weight:bold; margin-bottom:8px; font-size:13px;";
         blocksLabel.textContent = "Blocks (optional)";
         blocksSection.appendChild(blocksLabel);
         let blocksHint = document.createElement("div");
         blocksHint.style.cssText = "font-size:12px; color:#666; margin-bottom:6px;";
         blocksHint.textContent = "Offsets are relative to Start. First offset must be 0; " +
                                  "last block must reach End. Leave empty for a single full-span block.";
         blocksSection.appendChild(blocksHint);
         let blocksContainer = document.createElement("div");
         blocksContainer.id = "blocksContainer";
         blocksSection.appendChild(blocksContainer);
         let hCount = document.createElement("input"); hCount.type = "hidden"; hCount.id = "blockCount";
         let hSizes = document.createElement("input"); hSizes.type = "hidden"; hSizes.id = "blockSizes";
         let hStarts = document.createElement("input"); hStarts.type = "hidden"; hStarts.id = "chromStarts";
         blocksSection.appendChild(hCount);
         blocksSection.appendChild(hSizes);
         blocksSection.appendChild(hStarts);
         cdsBlocksDiv.appendChild(blocksSection);
         manualInpDiv.appendChild(cdsBlocksDiv);
 
         let mouseoverWrap, descriptionWrap, projectWrap;
         commonBottomFields.forEach(function(field) {
             if (field.id === "project") {
                 createProjectField(manualInpDiv);
                 projectWrap = manualInpDiv.lastElementChild;
             } else {
                 let input = createField(field, manualInpDiv);
                 if (field.id === "mouseover") mouseoverWrap = input.parentNode;
                 else if (field.id === "description") descriptionWrap = input.parentNode;
             }
         });
 
         let customFieldsSection = document.createElement("div");
         customFieldsSection.id = "customFieldsSection";
         customFieldsSection.style.cssText = "margin-top:12px; padding-top:10px; border-top:1px solid #ddd;";
 
         let customFieldsLabel = document.createElement("div");
         customFieldsLabel.style.cssText = "font-weight:bold; margin-bottom:8px; font-size:13px;";
         customFieldsLabel.textContent = "Custom Fields";
         customFieldsSection.appendChild(customFieldsLabel);
 
         let customFieldsList = document.createElement("div");
         customFieldsList.id = "customFieldsList";
         customFieldsSection.appendChild(customFieldsList);
 
         let reservedNames = ["bin", "chrom", "chromStart", "chromEnd", "name", "score",
             "strand", "thickStart", "thickEnd", "itemRgb", "blockCount", "blockSizes",
             "chromStarts", "description", "db", "ref", "alt", "project", "mouseover",
             "itemType", "cnvType", "id"];
 
         let validateFieldName = function(nameInput) {
             let name = nameInput.value.trim();
             if (!name) return; // empty is ok, will be skipped on submit
             let valid = /^[a-zA-Z_][a-zA-Z0-9_]*$/.test(name);
             if (!valid) {
                 alert("Invalid field name: '" + name + "'. Must start with a letter or underscore, " +
                       "and contain only letters, numbers, and underscores.");
                 nameInput.focus();
                 return false;
             }
             if (name.startsWith("_hidden_")) {
                 alert("Field names cannot start with '_hidden_'.");
                 nameInput.focus();
                 return false;
             }
             if (reservedNames.indexOf(name) >= 0) {
                 alert("'" + name + "' is a reserved field name.");
                 nameInput.focus();
                 return false;
             }
             // Check for duplicates among all custom field name inputs
             let allNames = document.querySelectorAll("#customFieldsList .customFieldName");
             let count = 0;
             allNames.forEach(function(inp) {
                 if (inp.value.trim() === name) count++;
             });
             if (count > 1) {
                 alert("Duplicate field name: '" + name + "'.");
                 nameInput.focus();
                 return false;
             }
             return true;
         };
 
         let addCustomFieldRow = function(existingName) {
             // existingName: if provided, this is a pre-populated existing field (read-only name)
             let row = document.createElement("div");
             row.className = "customFieldRow";
             row.style.cssText = "display:flex; align-items:center; gap:6px; margin-bottom:6px;";
             if (existingName)
                 row.dataset.existing = "true";
 
             let nameInput = document.createElement("input");
             nameInput.type = "text";
             nameInput.className = "customFieldName";
             nameInput.placeholder = "Field name";
             nameInput.style.cssText = "width:120px;";
 
             if (existingName) {
                 nameInput.value = existingName;
                 nameInput.readOnly = true;
                 nameInput.style.cssText = "width:120px; background:#e8e8e8; color:#555;";
             } else {
                 // Add blur validation for new field names
                 nameInput.addEventListener("blur", function() {
                     if (nameInput.value.trim())
                         validateFieldName(nameInput);
                 });
             }
 
             let valueInput = document.createElement("input");
             valueInput.type = "text";
             valueInput.className = "customFieldValue";
             valueInput.placeholder = "Value (optional)";
             valueInput.style.cssText = "width:180px;";
 
             row.appendChild(nameInput);
             row.appendChild(valueInput);
 
             if (existingName) {
                 // Hide button for existing fields (soft-delete via _hidden_ prefix)
                 let hideBtn = document.createElement("button");
                 hideBtn.type = "button";
                 hideBtn.textContent = "Hide";
                 hideBtn.title = "Hide this custom field (data preserved, can be restored later)";
                 hideBtn.style.cssText = "border:1px solid #ccc; background:#f5f5f5; color:#888; font-size:11px; cursor:pointer; padding:1px 6px; border-radius:3px;";
                 hideBtn.addEventListener("click", function() {
                     if (!confirm("Hide the '" + existingName + "' field? Data will be preserved but the field will no longer appear."))
                         return;
                     // Send ALTER TABLE CHANGE COLUMN request to rename with _hidden_ prefix
                     let hideUrl = "../cgi-bin/hgTracks?hgt_doJsCommand=" +
                         encodeURIComponent("myVariants myVariants " + JSON.stringify({hideField: existingName})) +
                         "&hgt.trackImgOnly=1&hgt.ideogramToo=1&hgsid=" + getHgsid() + "&db=" + getDb();
                     fetch(hideUrl, { method: "POST", credentials: "same-origin" })
                     .then(function() {
                         row.remove();
                     })
                     .catch(function(err) {
                         alert("Error hiding field: " + err.message);
                     });
                 });
                 row.appendChild(hideBtn);
             } else {
                 // Remove button for newly added rows
                 let removeBtn = document.createElement("button");
                 removeBtn.type = "button";
                 removeBtn.textContent = "\u00D7";
                 removeBtn.title = "Remove this field";
                 removeBtn.style.cssText = "border:none; background:none; color:#c00; font-size:18px; cursor:pointer; padding:0 4px; line-height:1;";
                 removeBtn.addEventListener("click", function() {
                     row.remove();
                 });
                 row.appendChild(removeBtn);
             }
 
             customFieldsList.appendChild(row);
             if (!existingName)
                 nameInput.focus();
         };
 
         // Pre-populate existing custom fields from server
         let existingCustomFields = (typeof hgTracks !== 'undefined' && hgTracks.myVariantsCustomFields)
                                     ? hgTracks.myVariantsCustomFields : [];
         existingCustomFields.forEach(function(fieldName) {
             addCustomFieldRow(fieldName);
         });
 
         let addBtn = document.createElement("button");
         addBtn.type = "button";
         addBtn.id = "addCustomFieldBtn";
         addBtn.textContent = "+ Add Custom Field";
         addBtn.style.cssText = "margin-top:4px; padding:3px 10px; font-size:12px; cursor:pointer;";
         addBtn.addEventListener("click", function(event) {
             event.preventDefault();
             addCustomFieldRow();
         });
         customFieldsSection.appendChild(addBtn);
 
         // Hidden fields restore UI
         let hiddenFields = (typeof hgTracks !== 'undefined' && hgTracks.myVariantsHiddenFields)
                             ? hgTracks.myVariantsHiddenFields : [];
         if (hiddenFields.length > 0) {
             let hiddenSection = document.createElement("div");
             hiddenSection.id = "hiddenFieldsSection";
             hiddenSection.style.cssText = "margin-top:8px; padding:4px 8px; background:#faf8f0; border:1px solid #e0dcc8; border-radius:3px; font-size:12px;";
 
             let hiddenLabel = document.createElement("span");
             hiddenLabel.style.cssText = "color:#888; margin-right:8px;";
             hiddenLabel.textContent = "Hidden fields:";
             hiddenSection.appendChild(hiddenLabel);
 
             hiddenFields.forEach(function(fieldName) {
                 let chip = document.createElement("span");
                 chip.style.cssText = "display:inline-block; margin:2px 4px; padding:2px 6px; background:#e8e8e8; border-radius:3px;";
                 chip.textContent = fieldName + " ";
                 let restoreBtn = document.createElement("a");
                 restoreBtn.href = "#";
                 restoreBtn.textContent = "restore";
                 restoreBtn.style.cssText = "color:#36c; font-size:11px;";
                 restoreBtn.addEventListener("click", function(event) {
                     event.preventDefault();
                     // Add it back as a pre-populated existing field row
                     addCustomFieldRow(fieldName);
                     // Remove the chip
                     chip.remove();
                     // Hide the section if no more hidden fields
                     if (hiddenSection.querySelectorAll("span[style]").length <= 1)
                         hiddenSection.style.display = "none";
                 });
                 chip.appendChild(restoreBtn);
                 hiddenSection.appendChild(chip);
             });
 
             customFieldsSection.appendChild(hiddenSection);
         }
 
         manualInpDiv.appendChild(customFieldsSection);
 
         // Keep the position summary in sync when position fields change
         ["chrom", "start", "end"].forEach(function(id) {
             let el = advancedDiv.querySelector("#" + id);
             if (el) el.addEventListener("input", updatePositionSummary);
         });
         let chromEl = advancedDiv.querySelector("#chrom");
         let startEl = advancedDiv.querySelector("#start");
         let endEl = advancedDiv.querySelector("#end");
         if (chromEl && startEl && endEl) {
             let startVal = parseInt(startEl.value);
             let endVal = parseInt(endEl.value);
             let startFmt = isNaN(startVal) ? startEl.value : startVal.toLocaleString();
             let endFmt = isNaN(endVal) ? endEl.value : endVal.toLocaleString();
             posSummaryText.textContent = chromEl.value + ":" + startFmt + "-" + endFmt;
         }
 
         form.appendChild(manualInpDiv);
 
         // Add hidden field to encode form values as JSON
         const hiddenInput = document.createElement('input');
         hiddenInput.type = 'hidden';
         hiddenInput.name = 'hgt_doJsCommand';
         form.appendChild(hiddenInput);
 
         const trackNameInput = document.createElement('input');
         trackNameInput.type = 'hidden';
         trackNameInput.id = 'trackName';
         trackNameInput.name = 'trackName';
         trackNameInput.value = "myVariants";
         form.appendChild(trackNameInput);
 
         dialogEle.appendChild(form);
 
         // Initialize Spectrum color picker after form is added to DOM
         if (colorInput) {
             $(colorInput).spectrum({
                 hideAfterPaletteSelect: true,
                 color: colorInput.value,
                 showPalette: true,
                 showInput: true,
                 showSelectionPalette: true,
                 showInitial: true,
                 preferredFormat: "hex",
                 localStorageKey: "myVariantsColors"
             });
         }
 
         // Mount the block editor; reads Start/End from the chrom range fields.
         // Pass the container element directly: at this point the form is in
         // the dialog div but the dialog hasn't been appended to body yet, so
         // getElementById would still miss "blocksContainer".
         // Stash the widget handle on the form so createItem can call validate().
         if (typeof myVariantsBlocks !== "undefined") {
             form.blocksWidget = myVariantsBlocks.mount(blocksContainer, {
                 getStart: function () {
                     return parseInt(document.getElementById("start").value, 10);
                 },
                 getEnd: function () {
                     return parseInt(document.getElementById("end").value, 10);
                 },
                 hiddenCountInput: hCount,
                 hiddenSizesInput: hSizes,
                 hiddenStartsInput: hStarts
             });
         }
 
         // Stash applyMode on the form so init() can restore last-used mode.
         form.applyMode = applyMode;
         return form;
     },
 
     init: function () {
         // show a jquery-ui dialog when a user clicks on the 'Add Annotation' button
         let dialog = document.getElementById('myVariantsDialog');
         if (!dialog) {
             dialog = document.createElement("div");
             dialog.id = "myVariantsDialog";
             dialog.style = "display: none";
 
             dialogButtons = {};
             // Call the function to build the form, but only if logged in already
             if (!userIsLoggedIn) {
                 let msg = document.createElement("div");
                 msg.id = "logInMessage";
                 let href = (typeof myVariantsLoginUrl !== "undefined" && myVariantsLoginUrl)
                            ? myVariantsLoginUrl : "./hgSession";
                 let link = document.createElement("a");
                 link.href = href;
                 link.textContent = "log in";
                 msg.appendChild(document.createTextNode("Please "));
                 msg.appendChild(link);
                 msg.appendChild(document.createTextNode(" to use this feature."));
                 dialog.appendChild(msg);
             } else {
                 let form = this.createBedForm(dialog);
 
                 document.body.append(dialog);
                 dialogButtons.Submit = function() {
                     // extract the form elements and check
                     myVariants.createItem(form);
                 };
             }
             dialogButtons.Cancel = function(){
                 $(this).dialog("close");
             };
             $(dialog).dialog({
                 title: "My Annotations",
                 resizable: false,
                 height: "auto",
                 width: 580,
                 modal: true,
                 closeOnEscape: true,
                 autoOpen: false,
                 buttons: dialogButtons,
                 open: function() {
                     // Restore the last input mode the user picked (or default to HGVS).
                     let form = document.getElementById("myVariants-form");
                     if (form && form.applyMode) {
                         let saved;
                         try { saved = localStorage.getItem("myVariantsLastMode"); } catch (e) { saved = null; }
                         const validModes = ["hgvs", "transcript", "snv", "cnv"];
                         form.applyMode(validModes.indexOf(saved) >= 0 ? saved : "hgvs");
                     }
                 },
                 close: function() {
                     // Reset block rows so the next open starts clean.
                     let form = document.getElementById("myVariants-form");
                     if (form && form.blocksWidget) {
                         form.blocksWidget.clear();
                     }
                 }
             });
         } else {
             // Reopening after an async image update; refresh the position fields.
             // The dialog's open callback re-applies the last-used mode.
             let form = document.getElementById("myVariants-form");
             if (form) {
                 let start = form.elements.start;
                 let end = form.elements.end;
                 let thickStart = form.elements.thickStart;
                 let thickEnd = form.elements.thickEnd;
                 if (start) start.value = hgTracks.winStart;
                 if (end) end.value = hgTracks.winEnd;
                 if (thickStart) thickStart.value = hgTracks.winStart;
                 if (thickEnd) thickEnd.value = hgTracks.winEnd;
             }
             let summaryText = document.getElementById("positionSummaryText");
             if (summaryText) {
                 let chromEl = document.getElementById("chrom");
                 let startFmt = parseInt(hgTracks.winStart).toLocaleString();
                 let endFmt = parseInt(hgTracks.winEnd).toLocaleString();
                 summaryText.textContent =
                     (chromEl ? chromEl.value : hgTracks.chromName) + ":" + startFmt + "-" + endFmt;
             }
         }
 
         // if we clicked outside of the pop up, close the popup:
         document.addEventListener('click', (e) => {
             let dialogEl = document.getElementById("myVariantsDialog");
             if (!dialogEl) return;
             // If the click handler that ran first removed its own target from
             // the document (eg a row remove button, or a Grammarly/extension
             // DOM swap on the description field), e.target is now detached
             // and `.contains(e.target)` would falsely report "outside". Skip.
             if (!document.contains(e.target)) return;
             let dialogContainer = dialogEl.parentElement;
             // Check if click target is inside the dialog (handles native dropdowns that render outside bounds)
             if (dialogContainer && !dialogContainer.contains(e.target)) {
                 $("#myVariantsDialog").dialog("close");
             }
         });
     },
 
     createItem: function(form) {
         // sends a post to hgTracks that adds a new item to the users custom track
         // and updates the image to include this track if it wasn't already there
         // Block validation only matters for the transcript path; SNV/CNV don't carry blocks.
         let blockResult = {ok: true, noBlocks: true};
         const isTranscript = !!(document.getElementById("typeTranscript") &&
                                 document.getElementById("typeTranscript").checked);
         if (isTranscript && form.blocksWidget && form.blocksWidget.getRowCount() > 0) {
             blockResult = form.blocksWidget.validate();
             if (!blockResult.ok) {
                 alert("Block error: " + blockResult.msg);
                 return;
             }
         }
         const data = {};
         if (form.elements.hgvsInput.value) {
             data.hgvsInput = form.elements.hgvsInput.value;
         } else {
             const itemType = isTranscript ? "transcript"
                 : (document.getElementById("typeCnv").checked ? "cnv" : "snv");
             Array.from(form.elements).forEach( (ele) => {
                 if (ele.name === "myVariantsHgvsInput" || ele.name === "hgt_doJsCommand" ||
                         ele.name === "myVariantsType" ||
                         (ele.tagName !== "INPUT" && ele.tagName !== "TEXTAREA")) {return;}
                 const key = ele.id;
                 let value = ele.value;
                 // Handle Spectrum color picker - get the value from spectrum if available
                 if (ele.id === "color" && $(ele).spectrum) {
                     let spectrumColor = $(ele).spectrum("get");
                     if (spectrumColor) {
                         value = spectrumColor.toHexString();
                     }
                 }
                 data[key] = value;
             });
             data.itemType = itemType;
             data.cnvType = (itemType === "cnv") ? document.getElementById("cnvType").value : "";
             if (itemType === "cnv") data.ref = "";
             else if (itemType === "transcript") { data.ref = ""; data.alt = ""; }
             // Collect custom fields from the dynamic rows
             let customRows = document.querySelectorAll("#customFieldsList .customFieldRow");
             if (customRows.length > 0) {
                 let customFields = [];
                 customRows.forEach(function(row) {
                     let name = row.querySelector(".customFieldName").value.trim();
                     if (name) {
                         let value = row.querySelector(".customFieldValue").value;
                         customFields.push({name: name, value: value});
                     }
                 });
                 if (customFields.length > 0) {
                     data.extraFields = customFields;
                 }
             }
             // Convert hidden block fields from CSV strings to arrays of ints.
             // Drop blocks entirely for SNV/CNV; server synthesizes a single full-span
             // block. For transcript with noBlocks (rows added but every size empty),
             // also drop and let the server synthesize.
             let bc = parseInt(data.blockCount, 10);
             if (!isTranscript || !bc || blockResult.noBlocks) {
                 delete data.blockCount;
                 delete data.blockSizes;
                 delete data.chromStarts;
             } else {
                 data.blockCount = bc;
                 data.blockSizes = data.blockSizes.split(",").map(Number);
                 data.chromStarts = data.chromStarts.split(",").map(Number);
             }
         }
 
         // Show loading indicator
         const loadingId = showLoadingImage("imgTbl");
         document.body.style.cursor = "wait";
 
         // Build request - use fetch() instead of form.submit()
         const trackName = form.elements.namedItem("trackName").value;
         const req = encodeURIComponent(`myVariants ${trackName} ${JSON.stringify(data)}`);
         const url = cart.addUpdatesToUrl(`../cgi-bin/hgTracks?hgt_doJsCommand=${req}&trackName=${trackName}&hgt.trackImgOnly=1&hgt.ideogramToo=1&hgsid=${getHgsid()}&db=${getDb()}`);
 
         fetch(url, {
             method: "POST",
             credentials: "same-origin"
         })
         .then(response => {
             if (!response.ok) {
                 throw new Error("Network response was not ok: " + response.status);
             }
             return response.text();
         })
         .then(html => {
             hideLoadingImage(loadingId);
             document.body.style.cursor = "";
             myVariants.handleCreateSuccess(html, data);
         })
         .catch(error => {
             hideLoadingImage(loadingId);
             document.body.style.cursor = "";
             warn("Error creating annotation: " + error.message);
             console.error("Fetch error:", error);
         });
     },
 
     handleCreateSuccess: function(response, data) {
         // Close the create dialog
         $("#myVariantsDialog").dialog("close");
 
         // Update the image using the existing pattern
         imageV2.updateImgAndMap.call({cmd: 'wholeImage'}, response, 'success');
 
         // Extract new item coordinates from server response
         const newItemPos = scrapeVariable(response, "newItemPos");
         let variantChrom, variantStart, variantEnd;
 
         if (newItemPos) {
             // Server returned the coordinates
             variantChrom = newItemPos.chrom;
             variantStart = newItemPos.start;
             variantEnd = newItemPos.end;
         } else {
             // Fallback: try to get from form data (manual entry)
             variantChrom = data.chrom || hgTracks.chromName;
             variantStart = parseInt(data.start, 10) || hgTracks.winStart;
             variantEnd = parseInt(data.end, 10) || hgTracks.winEnd;
         }
 
         // Check if variant is in current window
         const inCurrentWindow = (variantChrom === hgTracks.chromName &&
                                 variantStart < hgTracks.winEnd &&
                                 variantEnd > hgTracks.winStart);
 
         if (inCurrentWindow) {
             // Already visible - just show brief success message
             return;
         }
 
         // Check stored preference
         const navPref = localStorage.getItem("myVariants_navPref");
         if (navPref === "jump") {
             // Auto-navigate to variant
             myVariants.navigateToVariant(variantChrom, variantStart, variantEnd);
             return;
         } else if (navPref === "stay") {
             // Stay here, just show message
             warn("Annotation created at " + variantChrom + ":" +
                  (variantStart+1).toLocaleString() + "-" + variantEnd.toLocaleString());
             return;
         }
 
         // No preference saved - show dialog
         myVariants.showNavigationDialog(variantChrom, variantStart, variantEnd);
     },
 
     showNavigationDialog: function(chrom, start, end) {
         const posStr = chrom + ":" + (start+1).toLocaleString() + "-" + end.toLocaleString();
 
         // Create dialog content
         const content = document.createElement("div");
 
         // Build message with position
         const msg = document.createElement("p");
         msg.style.marginBottom = "0.5em";
         msg.innerHTML = "Annotation created at <strong>" + posStr + "</strong>";
         content.appendChild(msg);
 
         // Show dialog with buttons
         $(content).dialog({
             title: "Annotation Created",
             modal: true,
             width: 600,
             buttons: {
                 "Go to Annotation": function() {
                     if (document.getElementById("myVariantsRememberNav").checked) {
                         localStorage.setItem("myVariants_navPref", "jump");
                     }
                     $(this).dialog("close");
                     myVariants.navigateToVariant(chrom, start, end);
                 },
                 "Stay Here": function() {
                     if (document.getElementById("myVariantsRememberNav").checked) {
                         localStorage.setItem("myVariants_navPref", "stay");
                     }
                     $(this).dialog("close");
                 }
             },
             open: function() {
                 // Add checkbox to button pane, inline with buttons
                 const dialog = $(this);
                 const buttonPane = dialog.closest(".ui-dialog").find(".ui-dialog-buttonpane");
                 const checkboxSpan = document.createElement("span");
                 checkboxSpan.style.cssText = "display: inline-block; vertical-align: middle; margin-right: 1em;";
                 checkboxSpan.innerHTML = "<label><input type='checkbox' id='myVariantsRememberNav'> Remember this choice </label>";
                 checkboxSpan.appendChild(createInfoIcon(
                     "Save your preference. Future annotations outside the current view will automatically " +
                     "use this choice. Reset via Configure page or cartReset."
                 ));
                 // Insert before the button set
                 buttonPane.find(".ui-dialog-buttonset").before(checkboxSpan);
                 // Force dialog to recalculate its size
                 dialog.dialog("option", "height", "auto");
             }
         });
     },
 
     navigateToVariant: function(chrom, start, end) {
         // Add small padding around the variant (max 100bp)
         const padding = 100;
         const paddedStart = Math.max(0, start - padding);
         const paddedEnd = end + padding;
 
         // Navigate using existing mechanism
         const pos = chrom + ":" + paddedStart + "-" + paddedEnd;
         imageV2.navigateInPlace("position=" + pos, null, true);
     },
 
     showDialog: function() {
         let dialog = document.getElementById('myVariantsDialog');
         // Clear dynamically-added custom field rows; for existing fields, just clear the value
         let customFieldsList = document.getElementById("customFieldsList");
         if (customFieldsList) {
             let rows = customFieldsList.querySelectorAll(".customFieldRow");
             rows.forEach(function(row) {
                 if (row.dataset.existing === "true") {
                     // Existing field - just clear the value input
                     let valInput = row.querySelector(".customFieldValue");
                     if (valInput) valInput.value = "";
                 } else {
                     // Dynamically added row - remove it
                     row.remove();
                 }
             });
         }
         $(dialog).dialog("open");
     },
 };
 
   /////////////////
  //// posting ////
 /////////////////
 var posting = {
 
     blockUseMap: false,
 
     blockMapClicks: function () 
     // Blocks clicking on map items when in effect. Drag opperations frequently call this.
     { 
         posting.blockUseMap=true;  
     },
     
     allowMapClicks:function ()  
     // reallows map clicks.  Called after operations that compete with clicks (e.g. dragging) 
     { 
         $('body').css('cursor', ''); // Explicitly remove wait cursor.
         posting.blockUseMap=false; 
     },
 
     mapClicksAllowed: function () 
     // Verify that click-competing operation (e.g. dragging) isn't currently occurring.
     { 
         return (posting.blockUseMap === false); 
     },
 
     blockTheMapOnMouseMove: function (ev)
     {
         if (!posting.blockUseMap && mouse.hasMoved(ev)) {
             posting.blockUseMap=true;
         }
     },
 
     mapClk: function ()
     {
         var done = false;
         // if we clicked on a merged item then show all the items, similar to clicking a
         // dense track to turn it to pack
         if (!(this && this.href)) {
             writeToApacheLog(`no href for mapClk, this = `);
         }
         let parsedUrl = parseUrl(this.href);
         let cgi = parsedUrl.cgi;
 
         // for some reason, '-' characters are encoded here? unencode them so lookups into
         // hgTracks.trackDb will work
         let id = "";
         if (typeof parsedUrl.queryArgs.g !== "undefined") {
             id = parsedUrl.queryArgs.g.replace("%2D", "-");
         }
         if (parsedUrl.queryArgs.i === "mergedItem") {
             updateObj={};
             updateObj[id+".doMergeItems"] = 0;
             hgTracks.trackDb[id][id+".doMergeItems"] = 0;
             cart.setVarsObj(updateObj,null,false);
             imageV2.requestImgUpdate(id, id + ".doMergeItems=0");
             return false;
         }
 
         if (done)
             return false;
         else {
             // first check if we are allowed to click, we could be in the middle
             // of a drag select
             if (posting.blockUseMap === true) {
                 return false;
             } else if (cgi === "hgGene") {
                 window.hgcOrHgGeneArgs = parsedUrl.queryArgs;
                 id = parsedUrl.queryArgs.hgg_type;
                 popUpHgcOrHgGene.hgc(id, this.href);
                 return false;
             } else if (cgi === "hgTrackUi") {
                 rec = hgTracks.trackDb[id];
                 if (rec && tdbIsLeaf(rec)) {
                     popUp.hgTrackUi(id, false);
                 } else {
                     location.assign(href);
                 }
             } else if (cgi === "hgc") {
                 if (id.startsWith("multiz") || id.startsWith("tabulaSapiens") || id.startsWith("crossTissue")) {
                     // multiz tracks have a form that lets you change highlighted bases
                     // that does not play well in a pop up
                     // the faceted bar charts have a custom hgc page that resubmits on most clicks
                     // so we need to overhaul the page before allowing them in popups
                     location.assign(href);
                     return false;
                 }
                 popUpHgcOrHgGene.hgc(id, this.href);
                 return false;
             } else {
                 // must be changing the density of a track, save the settings and post the form:
                 return posting.saveSettings(this);
             }
         }
     },
 
     saveSettings: function (obj)
     {
         if (posting.blockUseMap === true) {
             return false;
         }
         if (!obj || !obj.href) // called directly with obj
             obj = this;                               // and from callback without obj
 
         if ($(obj).hasClass('noLink'))  // TITLE_BUT_NO_LINK
             return false;
 
         if (obj.href.match('#') || obj.target.length > 0) {
             //alert("Matched # ["+obj.href+"] or has target:"+obj.target);
             return true;
         }
         var thisForm = normed($(obj).parents('form').first());
         if (!thisForm)
             thisForm = normed($("FORM").first());
         if (thisForm) {
             //alert("posting form:"+$(thisForm).attr('name'));
             return postTheForm($(thisForm).attr('name'),cart.addUpdatesToUrl(obj.href));
         }
         return true;
     }
 };
 
 /////////////////////////
 //// cart updating /////
 ///////////////////////
 var cart = {
     // Controls queuing and ultimately updating cart variables vis ajax or submit. Queued vars
     // are held in an object with unique keys preventing duplicate updates and ensuring last update 
     // takes precedence.  WARNING: be careful creating an object with variables on the fly:
     // cart.setVarsObj({track: vis}) is invalid but cart.setVarsObj({'knownGene': vis}) is ok! 
 
     updateQueue: {},
     
     updatesWaiting: function ()
     {   // returns TRUE if updates are waiting.
         return objNotEmpty(cart.updateQueue);
     },
     
     addUpdatesToUrl: function (url)
     {   // adds any outstanding cart updates to the url, then clears the queue
         if (cart.updatesWaiting()) {
             //console.log('cart.addUpdatesToUrl: '+objKeyCount(cart.updateQueue)+' vars');
             var updates = cart.varsToUrlData(); // clears the queue
             if (!url || url.length === 0)
                 return updates;
 
             if (updates.length > 0) {
                 var dataOnly = (url.indexOf("cgi-bin") === -1); // all urls should be to our cgis
                 if (!dataOnly && url.lastIndexOf("?") === -1)
                     url += "?" + updates;
                 else
                     url += '&' + updates;
             }
         }
         return url;
     },
     
     varsToUrlData: function (varsObj)
     {   // creates a url data (var1=val1&var2=val2...) string from vars object and queue
         // The queue will be emptied by this call.
         cart.queueVarsObj(varsObj); // lay ontop of queue, to give new values precedence
         
         // Now convert to url data and clear queue
         var urlData = '';
         if (cart.updatesWaiting()) {
             //console.log('cart.varsToUrlData: '+objKeyCount(cart.updateQueue)+' vars');
             urlData = varHashToQueryString(cart.updateQueue);
             cart.updateQueue = {};
         }
         return urlData;
     },
     
     setVarsObj: function (varsObj, errFunc, async)
     {   // Set all vars in a var hash, appending any queued updates
         // The default behavior is async = true
         //console.log('cart.setVarsObj: were:'+objKeyCount(cart.updateQueue) + 
         //            ' new:'+objKeyCount(varsObj);
         cart.queueVarsObj(varsObj); // lay ontop of queue, to give new values precedence
         
         // Now ajax update all in queue and clear queue
         if (cart.updatesWaiting()) {
             setVarsFromHash(cart.updateQueue, errFunc, async);
             cart.updateQueue = {};
         }
     },
     
     setVars: function (names, values, errFunc, async)
     {   // ajax updates the cart, and includes any queued updates.
         cart.updateSessionPanel();      // handles hide from left minibutton
         cart.setVarsObj(arysToObj(names, values), errFunc, async);
     },
 
     queueVarsObj: function (varsObj)
     {   // Add object worth of cart updates to the 'to be updated' queue, so they can be sent to
         // the server later. Note: hash allows overwriting previous updates to the same variable.
         if (typeof varsObj !== 'undefined' && objNotEmpty(varsObj)) {
             //console.log('cart.queueVarsObj: were:'+objKeyCount(cart.updateQueue) + 
             //            ' new:'+objKeyCount(varsObj));
             for (var name in varsObj) {
                 cart.updateQueue[name] = varsObj[name];
             }
         }
     },
 
     addVarsToQueue: function (names,values)
     {   // creates a string of updates to save for ajax batch or a submit
         cart.queueVarsObj(arysToObj(names,values));
     },
 
     updateSessionPanel: function()
     /* This function tries to find out if the current cart changed enough. It is not used anymore, as the 
      * current active rec. track set name is not shown anymore */
     {
     // this is never set anymore
     if (typeof recTrackSetsDetectChanges === 'undefined' || recTrackSetsDetectChanges === null)
         return;
 
     // change color of text
     $('span.gbSessionChangeIndicator').addClass('gbSessionChanged');
 
     // change mouseover on the panel.  A bit fragile here inserting text in the mouseover specified in
     // hgTracks.js, so depends on match with text there, and should present same message as C code
     // (Perhaps this could be added as a script tag, so not duplicated)
     var txt = $('span.gbSessionLabelPanel').attr('title');
     if (txt && !txt.match(/with changes/)) {
         $('span.gbSessionLabelPanel').attr('title', txt.replace(
                                    "track set", 
                                    "track set, with changes (added or removed tracks) you have requested"));
         }
     }
 };
 
   ///////////////////////////////////////////////
  //// visibility (mixed with group toggle) /////
 ///////////////////////////////////////////////
 var vis = {
 
     // map cgi enum visibility codes to strings
     enumOrder: new Array("hide", "dense", "full", "pack", "squish"),  
 
     update: function (track, visibility)
     {   // Updates visibility state in hgTracks.trackDb and any visible elements on the page.
         // returns true if we modify at least one select in the group list
         var rec = hgTracks.trackDb[track];
         var selectUpdated = false;
         $("select[name=" + escapeJQuerySelectorChars(track) + "]").each(function(t) {
             $(this).attr('class', visibility === 'hide' ? 'hiddenText' : 'normalText');
             $(this).val(visibility);
             selectUpdated = true;
         });
         if (rec) {
             rec.localVisibility = visibility;
         }
         return selectUpdated;
     },
 
     get: function (track)
     {   // return current visibility for given track
         var rec = hgTracks.trackDb[track];
         if (rec) {
             if (rec.localVisibility) {
                 return rec.localVisibility;
             } else {
                 return vis.enumOrder[rec.visibility];
             }
         } else {
             return null;
         }
     },
 
     makeTrackVisible: function (track)
     {   // Sets the vis box to visible, and ques a cart update, but does not update the image
         // Trusts that the cart update will be submitted later.
         if (track && vis.get(track) !== "full") {
             vis.update(track, 'pack');
             cart.addVarsToQueue([track], ['pack']);
         }
     },
 
     toggleForGroup: function (button, prefix)
     {   // toggle visibility of a track group; prefix is the prefix of all the id's of tr's in the
         // relevant group. This code also modifies the corresponding hidden fields and the gif
         // of the +/- img tag.
         imageV2.markAsDirtyPage();
         if (arguments.length > 2)
             return setTableRowVisibility(button, prefix, "hgtgroup", "group",false,arguments[2]);
         else
             return setTableRowVisibility(button, prefix, "hgtgroup", "group", true);
     },
 
     expandAllGroups: function (newState)
     {   // Set visibility of all track groups to newState (true means expanded).
         // This code also modifies the corresponding hidden fields and the gif's of the +/- img tag.
         imageV2.markAsDirtyPage();
         $(".toggleButton[id$='_button']").each( function (i) {  
             // works for old img type AND new BUTTONS_BY_CSS      // - 7: clip '_button' suffix
             vis.toggleForGroup(this,this.id.substring(0,this.id.length - 7),newState);
         });
         return false;
     },
     
     initForAjax: function()
     {   // To better support the back-button, it is good to eliminate extraneous form puts
         // Towards that end, we support visBoxes making ajax calls to update cart.
         var sels = $('select.normalText,select.hiddenText');
         $(sels).on("change", function() {
             var track = $(this).attr('name');
             let newVis = $(this).val();
             if (newVis === 'hide') {
                 var rec = hgTracks.trackDb[track];
                 if (rec)
                     rec.visibility = 0;
                 // else Would be nice to hide subtracks as well but that may be overkill
                 $(document.getElementById('tr_' + track)).remove();
                 cart.updateSessionPanel();
                 imageV2.drawHighlights();
                 $(this).attr('class', 'hiddenText');
             } else
                 $(this).attr('class', 'normalText');
             document.querySelectorAll('[name="'+track+'"]').forEach( (sel) => {
                 sel.value = newVis;
             });
             
             cart.setVars([track], [$(this).val()]);
             imageV2.markAsDirtyPage();
             return false;
         });
         // Now we can rid the submt of the burden of all those vis boxes
         var form = $('form#TrackForm');
         $(form).on("submit", function () {
             $('select.normalText,select.hiddenText').prop('disabled',true);
         });
         $(form).attr('method','get');
     },
 
     restoreFromBackButton: function()
     // Re-enabling vis dropdowns is necessary because initForAjax() disables them on submit.
     {
         $('select.normalText,select.hiddenText').prop('disabled',false);
     }
 };
 
   ////////////////////////////////////////////////////////////
  // dragSelect is also known as dragZoom or shift-dragZoom //
 ////////////////////////////////////////////////////////////
 var dragSelect = {
 
     hlColor :       '#aac6ff', // current highlight color
     hlColorDefault: '#aac6ff', // default highlight color, if nothing specified
     areaSelector:    null, // formerly "imgAreaSelect". jQuery element used for imgAreaSelect
     originalCursor:  null,
     startTime:       null,
     escPressed :     false,  // flag is set when user presses Escape
 
     selectStart: function (img, selection)
     {
         initVars();
         dragSelect.escPressed = false;
         if (rightClick.menu) {
             rightClick.menu.hide();
         }
         var now = new Date();
         dragSelect.startTime = now.getTime();
         posting.blockMapClicks();
     },
 
     selectChange: function (img, selection)
     {
         if (selection.x1 !== selection.x2) {
             if (genomePos.check(img, selection)) {
                 genomePos.update(img, selection, false);
                 jQuery('body').css('cursor', dragSelect.originalCursor);
             } else {
                 jQuery('body').css('cursor', 'not-allowed');
             }
         }
         return true;
     },
 
     findHighlightIdxForPos : function(findPos) {
         // return the index of the highlight string e.g. hg19.chrom1:123-345#AABBDCC that includes a chrom range findPos
         // mostly copied from drawHighlights()
         var currDb = getDb();
         if (hgTracks.highlight) {
             var hlArray = hgTracks.highlight.split("|"); // support multiple highlight items
             for (var i = 0; i < hlArray.length; i++) {
                 hlString = hlArray[i];
                 pos = parsePositionWithDb(hlString);
                 imageV2.undisguiseHighlight(pos);
 
                 if (!pos) 
                     continue; // ignore invalid position strings
                 pos.start--;
 
                 if (pos.chrom === hgTracks.chromName && pos.db === currDb
                 &&  pos.start <= findPos.chromStart && pos.end >= findPos.chromEnd) {
                     return i;
                 }
             }
         }
         return null;
     },
 
     saveHlColor : function (hlColor) 
     // save the current hlColor to the object and also the cart variable hlColor and return it.
     // hlColor is a 6-character hex string prefixed by #
     {
             dragSelect.hlColor = hlColor;
             cart.setVars(["prevHlColor"], [dragSelect.hlColor], null, false);
             hgTracks.prevHlColor = hlColor; // cart.setVars does not update the hgTracks-variables. The cart-variable system is a problem.
             return hlColor;
     },
 
     loadHlColor : function () 
     // load hlColor from prevHlColor in the cart, or use default color, set and return it
     // color is a 6-char hex string prefixed by #
     {
         if (hgTracks.prevHlColor)
             dragSelect.hlColor = hgTracks.prevHlColor;
         else
             dragSelect.hlColor = dragSelect.hlColorDefault;
         return dragSelect.hlColor;
     },
 
     highlightThisRegion: function(newPosition, doAdd, hlColor)
     // set highlighting newPosition in server-side cart and apply the highlighting in local UI.
     // hlColor can be undefined, in which case it defaults to the last used color or the default light blue
     // if hlColor is set, it is also saved into the cart.
     // if doAdd is true, the highlight is added to the current list. If it is false, all old highlights are deleted.
     {
         newPosition.replace("virt:", "multi:");
         var hlColorName = null;
         if (hlColor==="" || hlColor===null || hlColor===undefined)
             hlColorName = dragSelect.loadHlColor();
         else
             hlColorName = dragSelect.saveHlColor( hlColor );
 
         var pos = parsePosition(newPosition);
         var start = pos.start;
         var end = pos.end;
         var newHighlight = makeHighlightString(getDb(), pos.chrom, start, end, hlColorName);
         newHighlight = imageV2.disguiseHighlight(newHighlight);
         var oldHighlight = hgTracks.highlight;
         if (oldHighlight===undefined || doAdd===undefined || doAdd===false || oldHighlight==="") {
             // just set/overwrite the old highlight position, this used to be the default
             hgTracks.highlight = newHighlight;
         }
         else {
             // add to the end of a |-separated list
             hgTracks.highlight = oldHighlight+"|"+newHighlight;
         }
         // we include enableHighlightingDialog because it may have been changed by the dialog
         var cartSettings = {             'highlight': hgTracks.highlight, 
                           'enableHighlightingDialog': hgTracks.enableHighlightingDialog ? 1 : 0 };
 
         if (hgTracks.windows && !hgTracks.virtualSingleChrom) {
             var nonVirtChrom = "";
             var nonVirtStart = -1; 
             var nonVirtEnd   = -1; 
             for (i=0,len=hgTracks.windows.length; i < len; ++i) {
                 var w = hgTracks.windows[i];
                 // overlap with new position?
                 if (w.virtEnd > start && end > w.virtStart) {
                     var s = Math.max(start, w.virtStart);
                     var e = Math.min(end, w.virtEnd);
                     var cs = s - w.virtStart + w.winStart;
                     var ce = e - w.virtStart + w.winStart;
                     if (nonVirtChrom === "") {
                         nonVirtChrom = w.chromName;
                         nonVirtStart = cs; 
                         nonVirtEnd   = ce;
                     } else {
                         if (w.chromName === nonVirtChrom) {
                             nonVirtEnd = Math.max(ce, nonVirtEnd);
                         } else {
                             break;
                         }
                     }
                 }
             }
             if (nonVirtChrom !== "")
                 cartSettings.nonVirtHighlight = makeHighlightString(getDb(), nonVirtChrom, nonVirtStart, (nonVirtEnd+1), hlColorName);
         } else if (hgTracks.windows && hgTracks.virtualSingleChrom) {
                 cartSettings.nonVirtHighlight = hgTracks.highlight;
         }
         // TODO if not virt, do we need to erase cart nonVirtHighlight ?
         cart.setVarsObj(cartSettings);
         imageV2.drawHighlights();
     },
 
     selectionEndDialog: function (newPosition)
     // Let user choose between zoom-in and highlighting.
     {   
         newPosition.replace("virt:", "multi:");
         // if the user hit Escape just before, do not show this dialo
         if (dragSelect.startTime===null)
             return;
         var dragSelectDialog = $("#dragSelectDialog")[0];
         if (!dragSelectDialog) {
             $("body").append("<div id='dragSelectDialog'>" + 
                              "<p><ul>"+
                              "<li>Hold <b>Shift+drag</b> to show this dialog" +
                              "<li>Hold <b>Alt+drag</b> (Windows) or <b>Option+drag</b> (Mac) to add a highlight" +
                              "<li>Hold <b>Ctrl+drag</b> (Windows) or <b>Cmd+drag</b> (Mac) to zoom" +
                              "<li>To cancel, press <tt>Esc</tt> anytime during the drag" +
                              "<li>Using the keyboard, highlight the current position with <tt>h then m</tt>" +
                              "<li>Clear all highlights with View - Clear Highlights or <tt>h then c</tt>" +
                              "<li>Clear specific highlights with right click &gt; Remove highlight" +
                              "<li>To merely save the color for the next keyboard or right-click &gt; Highlight operations, click 'Save Color' below" +
                              "</ul></p>");
             makeHighlightPicker("hlColor", document.getElementById("dragSelectDialog"), null);
             $("#dragSelectDialog").append("<div style='padding-top: 4px'><input style='float:left' type='checkbox' id='disableDragHighlight'>" + 
                              "<span style='border:solid 1px #DDDDDD; padding:3px;display:inline-block' id='hlNotShowAgainMsg'>Don't show this again and always zoom with shift.<br>" + 
                              "Re-enable via 'View - Configure Browser' (<tt>c then f</tt>)</span></div>"+ 
                              "Selected chromosome position: <span id='dragSelectPosition'></span>");
             dragSelectDialog = $("#dragSelectDialog")[0];
             // reset value
             // allow to click checkbox by clicking on the label
             $('#hlNotShowAgainMsg').on("click", function() { $('#disableDragHighlight').trigger("click");});
             // click "add highlight" when enter is pressed in color input box
             $("#hlColorInput").on("keyup", function(event){
                 if(event.keyCode == 13){
                     $(".ui-dialog-buttonset button:nth-child(3)").trigger("click");
                 }
             });
         }
 
         if (hgTracks.windows) {
             var i,len;
             var newerPosition = newPosition;
             if (hgTracks.virtualSingleChrom && (newPosition.search("multi:")===0)) {
                 newerPosition = genomePos.disguisePosition(newPosition);
             }
             var str = newerPosition + "<br>\n";
             var str2 = "<br>\n";
             str2 += "<ul style='list-style-type:none; max-height:200px; padding:0; width:80%; overflow:hidden; overflow-y:scroll;'>\n";
             var pos = parsePosition(newPosition);
             var start = pos.start - 1;
             var end = pos.end;
             var selectedRegions = 0;
             for (i=0,len=hgTracks.windows.length; i < len; ++i) {
                 var w = hgTracks.windows[i];
                 // overlap with new position?
                 if (w.virtEnd > start && end > w.virtStart) {
                     var s = Math.max(start, w.virtStart);
                     var e = Math.min(end, w.virtEnd);
                     var cs = s - w.virtStart + w.winStart;
                     var ce = e - w.virtStart + w.winStart;
                     str2 += "<li>" + w.chromName + ":" + (cs+1) + "-" + ce + "</li>\n";
                     selectedRegions += 1;
                 }
             }
             str2 += "</ul>\n";
             if (!(hgTracks.virtualSingleChrom && (selectedRegions === 1))) {
                 str += str2;
             }
             $("#dragSelectPosition").html(str);
         } else {
             $("#dragSelectPosition").html(newPosition);
         }
         // Build the button set in two passes so that "Create Item" only
         // appears when myVariants is enabled in hg.conf.  doMyVariants is
         // emitted by the server only inside the gated hg.conf block, so on
         // a server with the feature off the variable is undefined and the
         // button is omitted entirely.
         let dragSelectButtons = {
             "Zoom In": function() {
                 // Zoom to selection
                 $(this).dialog("option", "revertToOriginalPos", false);
                 if ($("#disableDragHighlight").prop('checked'))
                     hgTracks.enableHighlightingDialog = false;
                 if (imageV2.inPlaceUpdate) {
                     if (hgTracks.virtualSingleChrom && (newPosition.search("multi:")===0)) {
                         newPosition = genomePos.disguisePosition(newPosition); // DISGUISE
                     }
                     var params = "db=" + getDb() + "&position=" + newPosition;
                     if (!hgTracks.enableHighlightingDialog)
                         params += "&enableHighlightingDialog=0";
                     imageV2.navigateInPlace(params, null, true);
                 } else {
                     $('body').css('cursor', 'wait');
                     if (!hgTracks.enableHighlightingDialog)
                         cart.setVarsObj({'enableHighlightingDialog': 0 },null,false); // async=false
                     document.TrackHeaderForm.submit();
                 }
                 $(this).dialog("close");
             },
             "Single Highlight": function() {
                 // Clear old highlight and Highlight selection
                 $(imageV2.imgTbl).imgAreaSelect({hide:true});
                 if ($("#disableDragHighlight").prop('checked'))
                     hgTracks.enableHighlightingDialog = false;
                 var hlColor = $("#hlColorInput").val();
                 dragSelect.highlightThisRegion(newPosition, false, hlColor);
                 $(this).dialog("close");
             },
             "Add Highlight": function() {
                 // Highlight selection
                 if ($("#disableDragHighlight").prop('checked'))
                     hgTracks.enableHighlightingDialog = false;
                 var hlColor = $("#hlColorInput").val();
                 dragSelect.highlightThisRegion(newPosition, true, hlColor);
                 $(this).dialog("close");
             },
             "Save Color": function() {
                 var hlColor = $("#hlColorInput").val();
                 dragSelect.saveHlColor( hlColor );
                 $(this).dialog("close");
             }
         };
         if (typeof doMyVariants !== 'undefined' && doMyVariants) {
             dragSelectButtons["Add Annotation"] = function() {
                 let data = {};
                 let pos = parsePosition(newPosition);
                 data.chrom = pos.chrom;
                 data.start = data.thickStart = pos.start.toString();
                 data.end = data.thickEnd = pos.end.toString();
                 data.score = "0";
                 data.strand = ".";
                 data.color = $("#hlColorInput").val();
                 data.name = "";
                 data.description = "";
                 data.ref = "";
                 data.alt = "";
                 data.trackName = "myVariants";
                 $(this).dialog("close");
                 let req = encodeURIComponent(`myVariants myVariants ${JSON.stringify(data)}`);
                 jQuery('body').css('cursor', 'wait');
                 $.ajax({
                         type: "POST",
                         url: "../cgi-bin/hgTracks",
                         data: cart.addUpdatesToUrl(`hgt_doJsCommand=${req}&trackName=myVariants&hgsid=${getHgsid()}`),
                         dataType: "html",
                         trueSuccess: imageV2.updateImgAndMap,
                         success: catchErrorOrDispatch,
                         error: errorHandler,
                         cmd: 'wholeImage',
                         loadingId: showLoadingImage("imgTbl"),
                         cache: false
                     });
             };
         }
         dragSelectButtons.Cancel = function() {
             $(this).dialog("close");
         };
         $(dragSelectDialog).dialog({
                 modal: true,
                 title: "Drag-and-select",
                 closeOnEscape: true,
                 resizable: false,
                 autoOpen: false,
                 revertToOriginalPos: true,
                 minWidth: 750,
                 buttons: dragSelectButtons,
 
                 open: function () { // Make zoom the focus/default action
                    $(this).parents('.ui-dialog-buttonpane button:eq(0)').trigger("focus");
                 },
 
                 close: function() {
                     // All exits to dialog should go through this
                     $(imageV2.imgTbl).imgAreaSelect({hide:true});
                     if ($(this).dialog("option", "revertToOriginalPos"))
                         genomePos.revertToOriginalPos();
                     if ($("#disableDragHighlight").prop('checked'))
                         $(this).remove();
                     else
                         $(this).hide();
                     $('body').css('cursor', ''); // Occasionally wait cursor got left behind
                     $("#hlColorPicker").spectrum("hide");
                 }
         });
         $(dragSelectDialog).dialog('open');
         
     },
 
     selectEnd: function (img, selection, event)
     {
         var now = new Date();
         var doIt = false;
         var rulerClicked = selection.y1 <= hgTracks.rulerClickHeight; // = drag on base position track (no shift)
         // A single click on the grey side-label/config strip has its x clamped into the
         // data area by imgAreaSelect, so without this test it looks like a ruler click and
         // performs the zoom instead of opening the base-position track's config popup (#27113).
         // Use the raw mouse x (getXLimits gives the data-area bounds) to spot a label-strip
         // click and let it fall through to the normal config handler.
         if (rulerClicked && selection.event) {
             var dataXLimits = genomePos.getXLimits($(img), 0);
             if (selection.event.pageX < dataXLimits[0] || selection.event.pageX > dataXLimits[1])
                 rulerClicked = false;
         }
         if (dragSelect.originalCursor)
             jQuery('body').css('cursor', dragSelect.originalCursor);
         if (dragSelect.escPressed)
             return false;
         // ignore releases outside of the image rectangle (allowing a 10 pixel slop)
         if (genomePos.check(img, selection)) {
             // ignore single clicks that aren't in the top of the image
             // (this happens b/c the clickClipHeight test in dragSelect.selectStart
             // doesn't occur when the user single clicks).
             doIt = (dragSelect.startTime !== null || rulerClicked);
         }
 
         if (doIt) {
             // dragSelect.startTime is null if mouse has never been moved
             var singleClick = (  (selection.x2 === selection.x1)
                               || dragSelect.startTime === null
                               || (now.getTime() - dragSelect.startTime) < 100);
             var newPosition = genomePos.update(img, selection, singleClick);
             newPosition.replace("virt:", "multi:");
             if (newPosition) {
                 if (event.altKey) {
                     // with the alt-key, only highlight the region, do not zoom
                     dragSelect.highlightThisRegion(newPosition, true);
                     $(imageV2.imgTbl).imgAreaSelect({hide:true});
                 } else {
                     if (hgTracks.enableHighlightingDialog && !(event.metaKey || event.ctrlKey) && !(rulerClicked && singleClick))
                         // don't show the dialog if: single-clicked on ruler, if dialog deactivated or meta/ctrl was pressed
                         dragSelect.selectionEndDialog(newPosition);
                     else {
                         // in every other case, show the dialog
                         $(imageV2.imgTbl).imgAreaSelect({hide:true});
                         if (imageV2.inPlaceUpdate) {
                             if (hgTracks.virtualSingleChrom && (newPosition.search("multi:")===0)) {
                                 newPosition = genomePos.disguisePosition(newPosition); // DISGUISE
                             }
                             imageV2.navigateInPlace("db=" + getDb() + "&position=" + newPosition, null, true);
                         } else {
                             jQuery('body').css('cursor', 'wait');
                             document.TrackHeaderForm.submit();
                         }
                     }
                 }
             } else {
                 $(imageV2.imgTbl).imgAreaSelect({hide:true});
                 genomePos.revertToOriginalPos();
             }
             dragSelect.startTime = null;
             // blockMapClicks/allowMapClicks() is necessary if selectEnd was over a map item.
             setTimeout(posting.allowMapClicks,50);
             return true;
         }
     },
 
     load: function (firstTime)
     {
         var imgHeight = 0;
         if (imageV2.enabled)
             imgHeight = imageV2.imgTbl.innerHeight() - 1; // last little bit makes border look ok
         
 
         // No longer disable without ruler, because shift-drag still works
         if (typeof(hgTracks) !== "undefined") {
 
             if (hgTracks.rulerClickHeight === undefined || hgTracks.rulerClickHeight === null)
                 hgTracks.rulerClickHeight = 0; // will be zero if no ruler track
             var heights = hgTracks.rulerClickHeight;
 
             var xLimits = genomePos.getXLimits($(imageV2.imgTbl), 0);
 
             dragSelect.areaSelector = jQuery((imageV2.imgTbl).imgAreaSelect({
                 minX : xLimits[0],
                 maxX : xLimits[1],
                 selectionColor:  'blue',
                 outerColor:      '',
                 minHeight:       imgHeight,
                 maxHeight:       imgHeight,
                 onSelectStart:   dragSelect.selectStart,
                 onSelectChange:  dragSelect.selectChange,
                 onSelectEnd:     dragSelect.selectEnd,
                 autoHide:        false, // gets hidden after possible dialog
                 movable:         false,
                 clickClipHeight: heights
             }));
 
             // remove any ongoing drag-selects when the esc key is pressed anywhere for this document
             // This allows to abort zooming / highlighting
             $(document).on("keyup", function(e){
                 if(e.keyCode === 27) {
                     $(imageV2.imgTbl).imgAreaSelect({hide:true});
                     dragSelect.escPressed = true;
                 }
             });
 
             // hide and redraw all current highlights when the browser window is resized
             $(window).on("resize", function() {
                 $(imageV2.imgTbl).imgAreaSelect({hide:true});
                 imageV2.drawHighlights();
             });
 
         }
     }
 };
 
   /////////////////////////////////////
  //// Chrom Drag/Zoom/Expand code ////
 /////////////////////////////////////
 jQuery.fn.chromDrag = function(){
 this.each(function(){
     // Plan:
     // mouseDown: determine where in map: convert to img location: pxDown
     // mouseMove: flag drag
     // mouseUp: if no drag, then create href centered on bpDown loc with current span
     //          if drag, then create href from bpDown to bpUp
     //          if ctrlKey then expand selection to containing cytoBand(s)
 
     // Image dimensions all in pix
     var img = { top: -1, scrolledTop: -1, height: -1, left: -1, scrolledLeft: -1, width: -1 };  
     // chrom Dimensions beg,end,size in bases, rest in pix
     var chr = { name: "", reverse: false, beg: -1, end: -1, size: -1,
                 top: -1, bottom: -1, left: -1, right: -1, width: -1 };   
     var pxDown = 0;     // pix X location of mouseDown
     var chrImg = $(this);
     var mouseIsDown   = false;
     var mouseHasMoved = false;
     var hilite = null;
 
     initialize();
 
     function initialize(){
 
         findDimensions();
 
         if (chr.top === -1)
             warn("chromIdeo(): failed to register "+this.id);
         else {
             hiliteSetup();
 
             $('area.cytoBand').off('mousedown');  // Make sure this is only bound once
             $('area.cytoBand').on("mousedown", function(e)
             {   // mousedown on chrom portion of image only (map items)
                 updateImgOffsets();
                 pxDown = e.clientX - img.scrolledLeft;
                 var pxY = e.clientY - img.scrolledTop;
                 if (mouseIsDown === false
                 && isWithin(chr.left,pxDown,chr.right) && isWithin(chr.top,pxY,chr.bottom)) {
                     mouseIsDown = true;
                     mouseHasMoved = false;
 
                     $(document).on('mousemove',chromMove);
                     $(document).on( 'mouseup', chromUp);
                     hiliteShow(pxDown,pxDown);
                     return false;
                 }
             });
         }
     }
 
     function chromMove(e)
     {   // If mouse was down, determine if dragged, then show hilite
         if ( mouseIsDown ) {
             var pxX = e.clientX - img.scrolledLeft;
             var relativeX = (pxX - pxDown);
             if (mouseHasMoved || (mouseHasMoved === false && Math.abs(relativeX) > 2)) {
                 mouseHasMoved = true;
                 if (isWithin(chr.left,pxX,chr.right))
                     hiliteShow(pxDown,pxX);
                 else if (pxX < chr.left)
                     hiliteShow(pxDown,chr.left);
                 else
                     hiliteShow(pxDown,chr.right);
             }
         }
     }
     function chromUp(e)
     {   // If mouse was down, handle final selection
         $(document).off('mousemove',chromMove);
         $(document).off('mouseup',chromUp);
         chromMove(e); // Just in case
         if (mouseIsDown) {
             updateImgOffsets();
             var bands;
             var pxUp = e.clientX - img.scrolledLeft;
             var pxY  = e.clientY - img.scrolledTop;
             if (isWithin(0,pxY,img.height)) {  // within vertical range or else cancel
                 var selRange = { beg: -1, end: -1, width: -1 };
                 var dontAsk = true;
 
                 if (e.ctrlKey) {
                     bands = findCytoBand(pxDown,pxUp);
                     if (bands.end > -1) {
                         pxDown = bands.left;
                         pxUp   = bands.right;
                         mouseHasMoved = true;
                         dontAsk = false;
                         selRange.beg = bands.beg;
                         selRange.end = bands.end;
                         hiliteShow(pxDown,pxUp);
                     }
                 }
                 else if (mouseHasMoved) {
                     // bounded by chrom dimensions: but must remain within image!
                     if (isWithin(-20,pxUp,chr.left)) 
                         pxUp = chr.left;
                     if (isWithin(chr.right,pxUp,img.width + 20))
                         pxUp = chr.right;
 
                     if ( isWithin(chr.left,pxUp,chr.right+1) ) {
 
                         selRange.beg = convertToBases(pxDown);
                         selRange.end = convertToBases(pxUp);
 
                         if (Math.abs(selRange.end - selRange.beg) < 20)
                             mouseHasMoved = false; // Drag so small: treat as simple click
                         else
                             dontAsk = false;
                     }
                 }
                 if (mouseHasMoved === false) { // Not else because small drag turns this off
 
                     hiliteShow(pxUp,pxUp);
                     var curWidth = hgTracks.winEnd - hgTracks.winStart;
                     // Notice that beg is based upon up position
                     selRange.beg = convertToBases(pxUp) - Math.round(curWidth/2); 
                     selRange.end  = selRange.beg + curWidth;
                 }
                 if (selRange.end > -1) {
                     // prompt, then submit for new position
                     selRange = rangeNormalizeToChrom(selRange,chr);
                     if (mouseHasMoved === false) { // Update highlight by converting bp back to pix
                         pxDown = convertFromBases(selRange.beg);
                         pxUp = convertFromBases(selRange.end);
                         hiliteShow(pxDown,pxUp);
                     }
                     //if ((selRange.end - selRange.beg) < 50000)
                     //    dontAsk = true;
                     if (dontAsk
                     || confirm("Jump to new position:\n\n"+chr.name+":"+commify(selRange.beg)+
                                "-"+commify(selRange.end)+" size:"+commify(selRange.width)) ) {
                         genomePos.setByCoordinates(chr.name, selRange.beg, selRange.end);
                         // Stop the presses :0)
                         $('area.cytoBand').on("mousedown",  function(e) { return false; });
                         if (imageV2.backSupport) {
                             imageV2.navigateInPlace("db=" + getDb() + "&position=" +
                                     encodeURIComponent(genomePos.get().replace(/,/g,'')) + 
                                     "&findNearest=1",null,true);
                             hiliteCancel();
                         } else
                             document.TrackHeaderForm.submit();
                         return true; // Make sure the setTimeout below is not called.
                     }
                 }
             }
             hiliteCancel();
             setTimeout(posting.allowMapClicks,50);
         }
         mouseIsDown = false;
         mouseHasMoved = false;
     }
 
     function isWithin(beg,here,end)
     {   // Simple utility
         return ( beg <= here && here < end );
     }
     function convertToBases(pxX)
     {   // Simple utility to convert pix to bases
         var offset = (pxX - chr.left)/chr.width;
         if (chr.reverse)
             offset = 1 - offset;
         return Math.round(offset * chr.size);
     }
     function convertFromBases(bases)
     {   // Simple utility to convert bases to pix
         var offset = bases/chr.size;
         if (chr.reverse)
             offset = 1 - offset;
         return Math.round(offset * chr.width) + chr.left;
     }
 
     function findDimensions()
     {   // Called at init: determine the dimensions of chrom from 'cytoband' map items
         var lastX = -1;
         $('area.cytoBand').each(function(ix) {
             var loc = this.coords.split(",");
             if (loc.length === 4) {
                 var myLeft  = parseInt(loc[0]);
                 var myRight = parseInt(loc[2]);
                 if (chr.top === -1) {
                     chr.left   = myLeft;
                     chr.right  = myRight;
                     chr.top    = parseInt(loc[1]);
                     chr.bottom = parseInt(loc[3]);
                 } else {
                     if (chr.left  > myLeft)
                         chr.left  = myLeft;
                     if (chr.right < parseInt(loc[2]))
                         chr.right = parseInt(loc[2]);
                 }
 
                 let title = this.getAttribute("data-tooltip") || this.getAttribute("title");
                 var range = title.substr(title.lastIndexOf(':')+1);
                 var pos = range.split('-');
                 if (pos.length === 2) {
                     if (chr.name.length === 0) {
                         chr.beg = parseInt(pos[0]);
                         //chr.end = parseInt(pos[1]);
                         chr.name = title.substring(title.lastIndexOf(' ')+1,
                                                         title.lastIndexOf(':'));
                     } else {
                         if (chr.beg > parseInt(pos[0]))
                             chr.beg = parseInt(pos[0]);
                     }
                     if (chr.end < parseInt(pos[1])) {
                         chr.end = parseInt(pos[1]);
                         if (lastX === -1)
                             lastX = myRight;
                         else if (lastX > myRight)
                             chr.reverse = true;  // end is advancing, but X is not, so reverse
                     } else if (lastX !== -1 && lastX < myRight)
                         chr.reverse = true;      // end is not advancing, but X is, so reverse
 
                 }
                 $(this).css( 'cursor', 'text');
                 $(this).attr("href","");
             }
         });
         chr.size  = (chr.end   - chr.beg );
         chr.width = (chr.right - chr.left);
     }
 
     function findCytoBand(pxDown,pxUp)
     {   // Called when mouseup and ctrl: Find the bounding cytoband dimensions (in pix and bases)
         var cyto = { left: -1, right: -1, beg: -1, end: -1 };
         $('area.cytoBand').each(function(ix) {
             var loc = this.coords.split(",");
             if (loc.length === 4) {
                 var myLeft  = parseInt(loc[0]);
                 var myRight = parseInt(loc[2]);
                 var range;
                 var pos;
                 if (cyto.left === -1 || cyto.left > myLeft) {
                     if ( isWithin(myLeft,pxDown,myRight) || isWithin(myLeft,pxUp,myRight) ) {
                         cyto.left  = myLeft;
                         range = this.title.substr(this.title.lastIndexOf(':')+1);
                         pos = range.split('-');
                         if (pos.length === 2) {
                             cyto.beg  = (chr.reverse ? parseInt(pos[1]) : parseInt(pos[0]));
                         }
                     }
                 }
                 if (cyto.right === -1 || cyto.right < myRight) {
                     if ( isWithin(myLeft,pxDown,myRight) || isWithin(myLeft,pxUp,myRight) ) {
                         cyto.right = myRight;
                         range = this.title.substr(this.title.lastIndexOf(':')+1);
                         pos = range.split('-');
                         if (pos.length === 2) {
                             cyto.end  = (chr.reverse ? parseInt(pos[0]) : parseInt(pos[1]));
                         }
                     }
                 }
             }
         });
         return cyto;
     }
     function rangeNormalizeToChrom(selection,chrom)
     {   // Called before presenting or using base range: make sure chrom selection
         // is within chrom range
         if (selection.end < selection.beg) {
             var tmp = selection.end;
             selection.end = selection.beg;
             selection.beg = tmp;
         }
         selection.width = (selection.end - selection.beg);
         selection.beg += 1;
         if (selection.beg < chrom.beg) {
             selection.beg = chrom.beg;
             selection.end = chrom.beg + selection.width;
         }
         if (selection.end > chrom.end) {
             selection.end = chrom.end;
             selection.beg = chrom.end - selection.width;
             if (selection.beg < chrom.beg) { // spans whole chrom
                 selection.width = (selection.end - chrom.beg);
                 selection.beg = chrom.beg + 1;
             }
         }
         return selection;
     }
 
     function hiliteShow(down,cur)
     {   // Called on mousemove, mouseup: set drag hilite dimensions
         var topY = img.top;
         var high = img.height;
         var begX = -1;
         var wide = -1;
         if (cur < down) {
             begX = cur + img.left;
             wide = (down - cur);
         } else {
             begX = down + img.left;
             wide = (cur - down);
         }
         $(hilite).css({ left: begX + 'px', width: wide + 'px', top: topY + 'px',
                         height: high + 'px', display:'' });
         $(hilite).show();
     }
     function hiliteCancel(left,width,top,height)
     {   // Called on mouseup: Make green drag hilite disappear when no longer wanted
         $(hilite).hide();
         $(hilite).css({ left: '0px', width: '0px', top: '0px', height: '0px' });
     }
 
     function hiliteSetup()
     {   // Called on init: setup of drag region hilite (but don't show yet)
         if (hilite === null) {  // setup only once
             hilite = jQuery("<div id='chrHi'></div>");
             $(hilite).css({ backgroundColor: 'green', opacity: 0.4, borderStyle: 'solid',
                             borderWidth: '1px', bordercolor: '#0000FF' });
             $(hilite).css({ display: 'none', position: 'absolute', overflow: 'hidden', zIndex: 1 });
             jQuery($(chrImg).parents('body')).append($(hilite));
         }
         return hilite;
     }
 
     function updateImgOffsets()
     {   // Called on mousedown: Gets the current offsets
         var offs = $(chrImg).offset();
         img.top  = Math.round(offs.top );
         img.left = Math.round(offs.left);
         img.scrolledTop  = img.top  - $("body").scrollTop();
         img.scrolledLeft = img.left - $("body").scrollLeft();
         if (theClient.isIePre11()) {
             img.height = $(chrImg).outerHeight();
             img.width  = $(chrImg).outerWidth();
         } else {
             img.height = $(chrImg).height();
             img.width  = $(chrImg).width();
         }
         return img;
     }
 });
 };
 
 
 
   //////////////////////////
  //// Drag Scroll code ////
 //////////////////////////
 jQuery.fn.panImages = function(){
     // globals across all panImages
     genomePos.original = genomePos.getOriginalPos(); // redundant but makes certain original is set.
     var leftLimit   = hgTracks.imgBoxLeftLabel * -1;
     var rightLimit  = (hgTracks.imgBoxPortalWidth - hgTracks.imgBoxWidth + leftLimit);
     var only1xScrolling = ((hgTracks.imgBoxWidth - hgTracks.imgBoxPortalWidth) === 0);
     var prevX       = (hgTracks.imgBoxPortalOffsetX + hgTracks.imgBoxLeftLabel) * -1;
     var portalWidth = 0;
     var portalAbsoluteX = 0;
     var savedPosition;
     var highlightAreas  = null; // Used to ensure dragSelect highlight will scroll.
+    // quickLift draws its difference lines up into the center labels, but center labels do
+    // not scroll with the data.  Rather than leave the lines standing still over an image
+    // that is moving underneath them, these slices are swapped for a text stand-in of the
+    // center label (written by hgTracks) while the image is being dragged.
+    var cntrLabLines    = null;
+
+    function cntrLabDragSwap(dragging) {
+        if (cntrLabLines === null || cntrLabLines.length === 0)
+            return;
+        cntrLabLines.css( {'display': (dragging ? 'none' : '')} );
+        cntrLabLines.siblings('.cntrLabStandIn').css( {'display': (dragging ? 'block':'none')});
+    }
 
     this.each(function(){
 
     var pic;
     var pan;
 
     if ( $(this).is("img") ) {
         pan = $(this).parent("div");
         pic = $(this);
     }
     else if ( $(this).is("div.scroller")  ) {
         pan = $(this);
         pic = $(this).children("img#panImg"); // Get the real pic
     }
 
     if (!pan || !pic) {
         throw "Not a div with child image! 'panImages' can only be used with divs contain images.";
     }
 
     // globals across all panImages
     portalWidth     = $(pan).width();
     portalAbsoluteX = $(pan).offset().left;
     // globals to one panImage
     var newX        = 0;
     var mouseDownX  = 0;
     var mouseIsDown = false;
     var beyondImage = false;
     var atEdge      = false;
 
     initialize();
 
     function initialize(){
 
         $(pan).parents('td.tdData').on("mousemove", function(e) {
             if (e.shiftKey)
                 $(this).css('cursor',"crosshair");  // shift-dragZoom
             else if ( theClient.isIePre11() )     // IE will override map item cursors if this gets set
                 $(this).css('cursor',"");  // normal pointer when not over clickable item
         });
 
         panAdjustHeight(prevX);
 
         pan.on("mousedown", function(e){
              if (e.which > 1 || e.button > 1 || e.shiftKey || e.metaKey || e.altKey || e.ctrlKey)
                  return true;
             if (mouseIsDown === false) {
                 if (rightClick.menu) {
                     rightClick.menu.hide();
                 }
                 mouseIsDown = true;
                 mouseDownX = e.clientX;
                 highlightAreas = $('.highlightItem');
+                // quickLift lines in center labels.  ':visible' so that turning center
+                // labels off leaves drag scrolling exactly as it was.
+                cntrLabLines = $('img.cntrLabLines:visible');
                 atEdge = (!beyondImage && (prevX >= leftLimit || prevX <= rightLimit));
                 $(document).on('mousemove',panner);
                 $(document).on('mouseup', panMouseUp);  // Will exec only once
                 return false;
             }
         });
     }
 
     function panner(e) {
         //if (!e) e = window.event;
         if ( mouseIsDown ) {
             var relativeX = (e.clientX - mouseDownX);
 
             if (relativeX !== 0) {
                 if (posting.mapClicksAllowed()) {
                     // need to throw up a z-index div.  Wait mask?
                     savedPosition = genomePos.get();
                     dragMaskShow();
                     posting.blockMapClicks();
                 }
                 var decelerator = 1;
                 //var wingSize    = 1000; // 0 stops the scroll at the edges.
                 // Remeber that offsetX (prevX) is negative
                 newX = prevX + relativeX;
                 if ( newX >= leftLimit ) { // scrolled all the way to the left
                     if (atEdge) {  // Do not drag straight off edge.  Force second drag
                         beyondImage = true;
                         newX = leftLimit + (newX - leftLimit)/decelerator;// slower
                         //if (newX >= leftLimit + wingSize) // Don't go too far over the edge!
                         //    newX =  leftLimit + wingSize;
                     } else
                         newX = leftLimit;
 
                 } else if ( newX < rightLimit ) { // scrolled all the way to the right
                     if (atEdge) {  // Do not drag straight off edge.  Force second drag
                         beyondImage = true;
                         newX = rightLimit - (rightLimit - newX)/decelerator;// slower
                         //if (newX < rightLimit - wingSize) // Don't go too far over the edge!
                         //    newX = rightLimit - wingSize;
                     } else
                         newX = rightLimit;
 
                 } else if (newX >= rightLimit && newX < leftLimit)
                     beyondImage = false; // could have scrolled back without mouse up
 
                 posStatus = panUpdatePosition(newX,true);
                 newX = posStatus.newX;
                 // do not update highlights if we are at the end of a chromsome
                 if (!posStatus.isOutsideChrom)
                     scrollHighlight(relativeX);
 
+                cntrLabDragSwap(true);  // center label lines can't scroll: use the text
                 var nowPos = newX.toString() + "px";
                 $(".panImg").css( {'left': nowPos });
                 $('.tdData').css( {'backgroundPosition': nowPos } );
                 if (!only1xScrolling)
                     panAdjustHeight(newX);  // Will dynamically resize image while scrolling.
             }
         }
     }
     function panMouseUp(e) {  // Must be a separate function instead of pan.mouseup event.
         //if (!e) e = window.event;
         if (mouseIsDown) {
 
             dragMaskClear();
             $(document).off('mousemove',panner);
             $(document).off('mouseup',panMouseUp);
             mouseIsDown = false;
             // timeout incase the dragSelect.selectEnd was over a map item. select takes precedence.
             setTimeout(posting.allowMapClicks,50); 
 
             // Outside image?  Then abandon.
             var curY = e.pageY;
             var imgTbl = $('#imgTbl');
             var north = $(imgTbl).offset().top;
             var south = north + $(imgTbl).height();
             if (curY < north || curY > south) {
                 atEdge = false;
                 beyondImage = false;
                 if (savedPosition)
                     genomePos.set(savedPosition);
                 var oldPos = prevX.toString() + "px";
                 $(".panImg").css( {'left': oldPos });
                 $('.tdData').css( {'backgroundPosition': oldPos } );
+                cntrLabDragSwap(false);  // image is back where it started, lines line up
                 if (highlightAreas)
                     imageV2.drawHighlights();
                 return true;
             }
 
             // Do we need to fetch anything?
             if (beyondImage) {
                 if (imageV2.inPlaceUpdate) {
                     var pos = parsePosition(genomePos.get());
                     imageV2.navigateInPlace("db=" + getDb() + "&position=" +
                             encodeURIComponent(pos.chrom + ":" + pos.start + "-" + pos.end),
                             null, true);
                 } else {
                     document.TrackHeaderForm.submit();
                 }
                 return true; // Make sure the setTimeout below is not called.
             }
 
             // Just a normal scroll within a >1X image
             if (prevX !== newX) {
                 prevX = newX;
                 if (!only1xScrolling) {
                     //panAdjustHeight(newX); // Will resize image AFTER scrolling.
                     // Important, since AJAX could lead to reinit after this within bounds scroll
                     hgTracks.imgBoxPortalOffsetX = (prevX * -1) - hgTracks.imgBoxLeftLabel;
                     hgTracks.imgBoxPortalLeft = newX.toString() + "px";
                 }
+                // No new image is coming, but the center label slices didn't move with the
+                // data, so the quickLift lines hidden above can only come back in the right
+                // place with a redraw.  Ask for one.
+                if (cntrLabLines && cntrLabLines.length > 0) {
+                    if (imageV2.inPlaceUpdate) {
+                        var newPos = parsePosition(genomePos.get());
+                        imageV2.navigateInPlace("db=" + getDb() + "&position=" +
+                                encodeURIComponent(newPos.chrom + ":" + newPos.start + "-" +
+                                                   newPos.end), null, true);
+                    } else
+                        cntrLabDragSwap(false);
                 }
+            } else
+                cntrLabDragSwap(false);  // drag ended where it started, nothing moved
         }
     }
     });  // end of this.each(function(){
 
     function panUpdatePosition(newOffsetX,bounded)
     {
         // Updates the 'position/search" display with change due to panning
         var closedPortalStart = hgTracks.imgBoxPortalStart + 1;   // Correction for half open
         var portalWidthBases = hgTracks.imgBoxPortalEnd - closedPortalStart;
         var portalScrolledX  = hgTracks.imgBoxPortalOffsetX+hgTracks.imgBoxLeftLabel + newOffsetX;
         var recalculate = false;
 
         var newPortalStart = 0;
         if (hgTracks.revCmplDisp)
             newPortalStart = closedPortalStart +     // As offset goes down, so do bases seen.
                                 Math.round(portalScrolledX*hgTracks.imgBoxBasesPerPixel);
         else
             newPortalStart = closedPortalStart -     // As offset goes down, bases seen goes up!
                                 Math.round(portalScrolledX*hgTracks.imgBoxBasesPerPixel);
         if (newPortalStart < hgTracks.chromStart && bounded) {     // Stay within bounds
             newPortalStart = hgTracks.chromStart;
             recalculate = true;
         }
         var newPortalEnd = newPortalStart + portalWidthBases;
         if (newPortalEnd > hgTracks.chromEnd && bounded) {
             newPortalEnd = hgTracks.chromEnd;
             newPortalStart = newPortalEnd - portalWidthBases;
             recalculate = true;
         }
         if (newPortalStart > 0) {
             var newPos = hgTracks.chromName + ":" + newPortalStart + "-" + newPortalEnd;
             genomePos.set(newPos); // no need to change the size
         }
         if (recalculate && hgTracks.imgBoxBasesPerPixel > 0) { 
             // Need to recalculate X for bounding drag
             portalScrolledX = (closedPortalStart - newPortalStart) / hgTracks.imgBoxBasesPerPixel;
             newOffsetX = portalScrolledX - (hgTracks.imgBoxPortalOffsetX+hgTracks.imgBoxLeftLabel);
         }
 
         if (typeof (igv) !== "undefined") {
            igv.updateIgvStartPosition(newPortalStart);
         }
 
 
         ret = {};
         ret.newX = newOffsetX;
         ret.isOutsideChrom = recalculate;
         return ret;
     }
     function mapTopAndBottom(mapName,east,west)
     {
     // Find the top and bottom px given left and right boundaries
         var mapPortal = { top: -10, bottom: -10 };
         var items = $("map[name='"+mapName+"']").children();
         if ($(items).length>0) {
             $(items).each(function(t) {
                 var loc = this.coords.split(",");
                 var aleft   = parseInt(loc[0]);
                 var aright  = parseInt(loc[2]);
                 if (aleft < west && aright >= east) {
                     var atop    = parseInt(loc[1]);
                     var abottom = parseInt(loc[3]);
                     if (mapPortal.top    < 0 ) {
                         mapPortal.top    = atop;
                         mapPortal.bottom = abottom;
                     } else if (mapPortal.top > atop) {
                             mapPortal.top = atop;
                     } else if (mapPortal.bottom < abottom) {
                             mapPortal.bottom = abottom;
                     }
                 }
             });
         }
         return mapPortal;
     }
     function panAdjustHeight(newOffsetX) {
         // Adjust the height of the track data images so that bed items scrolled off screen
         // do not waste vertical real estate
 
         // Is the > 1x?
         if (only1xScrolling)
             return;
 
         var east = newOffsetX * -1;
         var west = east + portalWidth;
         $(".panImg").each(function(t) {
             var mapid  = this.id.replace('img_','map_');
             var hDiv   = $(this).parent();
             var north  = parseInt($(this).css("top")) * -1;
             var south  = north + $(hDiv).height();
 
             var mapPortal = mapTopAndBottom(mapid,east,west);
             if (mapPortal.top > 0) {
                 var topdif = Math.abs(mapPortal.top - north);
                 var botdif = Math.abs(mapPortal.bottom - south);
                 if (topdif > 2 || botdif > 2) {
                     $(hDiv).height( mapPortal.bottom - mapPortal.top );
                     north = mapPortal.top * -1;
                     $(this).css( {'top': north.toString() + "px" });
 
                     // Need to adjust side label height as well!
                     var imgId = this.id.split("_");
                     var titlePx = 0;
                     var center = $("#img_center_"+imgId[2]);
                     if (center.length > 0) {
                         titlePx = $(center).parent().height();
                         north += titlePx;
                     }
                     var side = $("#img_side_"+imgId[2]);
                     if (side.length > 0) {
                         $(side).parent().height( mapPortal.bottom - mapPortal.top + titlePx);
                         $(side).css( {'top': north.toString() + "px" });
                     }
                     var btn = $("#p_btn_"+imgId[2]);
                     if (btn.length > 0) {
                         $(btn).height( mapPortal.bottom - mapPortal.top + titlePx);
                     } else {
                         btn = $("#img_btn_"+imgId[2]);
                         if (btn.length > 0) {
                             $(btn).parent().height( mapPortal.bottom - mapPortal.top + titlePx);
                             $(btn).css( {'top': top.toString() + "px" });
                         }
                     }
                 }
             }
         });
         dragMaskResize();  // Resizes the dragMask to match current image size
     }
 
     function dragMaskShow() 
     {   // Sets up the dragMask to show grabbing cursor within image
         // and not allowed north and south of image
         var imgTbl = $('#imgTbl');
         // Find or create the waitMask (which masks the whole page)
         var dragMask = normed($('div#dragMask'));
         if (!dragMask) {
             $("body").prepend("<div id='dragMask' class='waitMask'></div>");
             dragMask = $('div#dragMask');
         }
 
         $('body').css('cursor','not-allowed');
         $(dragMask).css('cursor',"url(../images/grabbing.cur),w-resize");
         $(dragMask).css({opacity:0.0,display:'block',
                         top: $(imgTbl).position().top.toString() + 'px',
                         height: $(imgTbl).height().toString() + 'px' });
     }
 
     function dragMaskResize() 
     {   // Resizes dragMask (called when image is dynamically resized in >1x scrolling)
         var imgTbl = $('#imgTbl');
         // Find or create the waitMask (which masks the whole page)
         var dragMask = normed($('div#dragMask'));
         if (dragMask) {
             $(dragMask).height( $(imgTbl).height() );
         }
     }
 
     function dragMaskClear() {        // Clears the dragMask
         $('body').css('cursor','auto');
         var  dragMask = normed($('#dragMask'));
         if (dragMask)
             $(dragMask).hide();
     }
 
     function scrollHighlight(relativeX) 
     // Scrolls the highlight region if one exists
     {        
         if (highlightAreas) {
             for (i=0; i<highlightAreas.length; i++) {
                 highlightArea = highlightAreas[i];
                 // Best to have a left and right, then min/max the edges, then set width
                 var hiOffset = $(highlightArea).offset();
                 var hiDefinedLeft  = $(highlightArea).data('leftPixels');
                 var hiDefinedWidth = $(highlightArea).data('widthPixels');
                 hiOffset.left = Math.max(hiDefinedLeft + relativeX,
                                          portalAbsoluteX);
                 var right     = Math.min(hiDefinedLeft + hiDefinedWidth + relativeX,
                                          portalAbsoluteX + portalWidth);
                 var newWidth = Math.max(right - hiOffset.left,0);
                 if (hiDefinedWidth !== newWidth)
                     $(highlightArea).width(newWidth);
                 $(highlightArea).offset(hiOffset);
             }
         }
     }
 
 };
 
   ///////////////////////////////////////
  //// rightClick (aka context menu) ////
 ///////////////////////////////////////
 var rightClick = {
 
     menu: null,
     selectedMenuItem: null,   // currently choosen context menu item (via context menu).
     floatingMenuItem: null,
     currentMapItem:   null,
     supportZoomCodon: true,  // add zoom to exon and zoom to codon to right click menu
     clickedHighlightIdx : null,  // the index (0,1,...) of the highlight item that overlaps the last right-click
 
     moveTo : function(id, topOrBottom) {
         /* move a track to either "top" or "bottom" position */
         let newPos = "0.5";
         if (hgTracks.trackDb[0]!=="ruler")
             newPos = 0;
 
         if (topOrBottom==="bottom") {
             newPos = String(parseInt($(".imgOrd").last().attr("abbr"))+1);
         }
 
         let trEl = $(document.getElementById('tr_' + id));
         trEl.attr('abbr', newPos);
 
         dragReorder.sort($("#imgTbl"));
         dragReorder.setOrder($("#imgTbl"));
     },
     hideLegends : function() {
         /* if no pliBy track is shown, hide the pli legend */
         hasPliTracks = false;
         for (var trDomEl of $(".imgOrd")){
             var trackName = trDomEl.id.split("_")[1];
             if (trackName.startsWith("pliBy"))
                 hasPliTracks = true;
         }
         if (!hasPliTracks)
             $("#gnomadColorKeyLegend").hide();
     },
     hideTracks: function (ids)
         /* hide specified list of tracks, take care to hide parents rather than children, whenever possible. This is
          * addressing a basic problem of how we handle container tracks: if you right-click hide the last child, the container is still 
          * in the track list on the screen as not-hidden, but there are no
          * tracks shown of this container. This is confusing for the user. The
          * code below analyzes the track hierarchy and finds out if hiding a
          * track would lead to a container becoming empty and instead of hiding
          * just this track, will hide the container. It does this does both on
          * screen and in the cart. This means that you cannot end up with a container that is
          * not hidden but no tracks shown of this container, at least not with right-click. */
     {
         var cartVars = [];
         var cartVals = [];
 
         // find parent tracks that are losing all their children (lone parents)
         var familyAnalysis = tdbFindChildless(hgTracks.trackDb, ids);
 
         // lone parents get special treatment
         for (var delFam of familyAnalysis.loneParents) {
             var loneParent = delFam[0];
             var loneParentChildren = delFam[1];
 
             // remove all the lone parent children now from the track image
             // and also unselect them, if they are children of a composite
             for (var childName of loneParentChildren) {
                 $(document.getElementById('tr_' + childName)).remove();
                 var rec = hgTracks.trackDb[childName];
                 // the following means that all composite children are always unselected, so you cannot get the
                 // current selection easily back, since we always hide them all, instead of just hiding the parent.
                 // The problem is that it's not easy to find out if there is an easier way to hide them, the code
                 // would have to go over all possible parents, not just topParents. Maybe one day.
                 //if (tdbIsSubtrack(rec)) {
                  //  cartVars.push(childName+"_sel");
                  //   cartVals.push('0');
                 //}
             }
 
             // and set the lone parent to hide in the cart
             cartVars.push(loneParent);
             cartVals.push('hide');  // need to explicitely set to "hide", not "[]", to hide the default tracks
              
             // update the track list below the image
             vis.update(loneParent, 'hide');
             rightClick.hideLegends();
             delete hgTracks.trackDb[loneParent]; // for the next right-click
         }
 
         // handle all other tracks, they are either not parents or parents with at least one child left
         var delIds = familyAnalysis.others;
         for (var i = 0; i<delIds.length; i++) {
             var id = delIds[i];
             cartHideAnyTrack(id, cartVars, cartVals);
             $(document.getElementById('tr_' + id)).remove();
             delete hgTracks.trackDb[id]; // for the next right-click
         }
         imageV2.afterImgChange(true);
         cart.setVars( cartVars, cartVals );
     },
 
     hideOthers: function (id) {
         /* hide all tracks but 'id'. Hide parents of composites/folders, rather than their children */
         var myParent = hgTracks.trackDb[id].parentTrack;
 
         var hideList = [];
         for (var otherId in hgTracks.trackDb) {
             if (otherId===id || otherId==="ruler")
                 continue;
 
             hideList.push(otherId);
         }
         rightClick.hideTracks(hideList);
     },
     makeMapItem: function (id)
     {   // Create a dummy mapItem on the fly
         // (for objects that don't have corresponding entry in the map).
         if (id && id.length > 0 && hgTracks.trackDb) {
             var title;
             var rec = hgTracks.trackDb[id];
             if (rec) {
                 title = rec.shortLabel;
             } else {
                 title = id;
             }
             return {id: id, title: "configure " + title};
         } else {
             return null;
         }
     },
 
     findMapItem: function (e)
     {   // Find mapItem for given event; returns item object or null if none found.
 
         if (rightClick.currentMapItem) {
             return rightClick.currentMapItem;
         }
 
         // rightClick for non-map items that can be resolved to their parent tr and
         // then trackName (e.g. items in gray bar)
         var tr = $( e.target ).parents('tr.imgOrd');
         if ($(tr).length === 1) {
             var a = /tr_(.*)/.exec($(tr).attr('id'));  // voodoo
             if (a && a[1]) {
                 var id = a[1];
                 return rightClick.makeMapItem(id);
             }
         }
         return null;
     },
 
     windowOpenFailedMsg: function ()
     {
         warn("Your web browser prevented us from opening a new window.\n\n" +
              "Please change your browser settings to allow pop-up windows from " +
              document.domain + ".");
     },
 
     handleZoomCodon: function (response, status)
     {
         var json = JSON.parse(response);
         if (json.pos) {
             imageV2.navigateInPlace("db=" + getDb() + "&position="+json.pos);
         } else {
             alert(json.error);
         }
     },
 
     handleViewImg: function (response, status)
     {   // handles view image response, which must get new image without imageV2 gimmickery
         jQuery('body').css('cursor', '');
         var str = "<IMG[^>]*SRC='([^']+)'";
         var reg = new RegExp(str);
         var a = reg.exec(response);
         if (a && a[1]) {
             if ( ! window.open(a[1]) ) {
                 rightClick.windowOpenFailedMsg();
             }
             return;
         }
         warn("Couldn't parse out img src");
     },
 
     myPrompt: function (msg, callback)
     {   // replacement for prompt; avoids misleading/confusing security warnings which are caused
         // by prompt in IE 7+.   Callback is called if user presses "OK".
         $("body").append("<div id = 'myPrompt'><div id='dialog' title='Basic dialog'><form>" +
                             msg + "<input id='myPromptText' value=''></form>");
         $('#myPromptText').on('keypress', function(e) {
             if (e.which === 13) {  // listens for return key
                 e.preventDefault();   // prevents return from also submitting whole form
                 $("#myPrompt").dialog("close");
                 callback($("#myPromptText").val());
             }
         });
         $("#myPrompt").dialog({
                                 modal: true,
                                 closeOnEscape: true,
                                 buttons: { "OK": function() {
                                                     var myPromptText = $("#myPromptText").val();
                                                     $(this).dialog("close");
                                                     callback(myPromptText);
                                                 }
                                         }
                             });
     },
 
     hit: function (menuItemClicked, menuObject, cmd, args)
     {
         setTimeout( function() {
                         rightClick.hitFinish(menuItemClicked, menuObject, cmd, args);
                     }, 1);
     },
 
     hitFinish: function (menuItemClicked, menuObject, cmd, args)
     {   // dispatcher for context menu hits
         var id = rightClick.selectedMenuItem.id;
         var url = null;  // TODO: Break this giant routine with shared vars into some sub-functions
         var href = null;
         var rec = null;
         var row = null;
         var rows = null;
         var selectUpdated = null;
                 function mySuccess() {}
         if (menuObject.shown) {
             // warn("Spinning: menu is still shown");
             setTimeout(function() { rightClick.hitFinish(menuItemClicked, menuObject, cmd); }, 10);
             return;
         }
         if (cmd === 'selectWholeGene' || cmd === 'getDna' || cmd === 'highlightItem' || cmd === 'highlightThisRegion') {
                 // bring whole gene into view or redirect to DNA screen.
                 let href = rightClick.selectedMenuItem.href;
                 let url = URL.parse(rightClick.selectedMenuItem.href);
                 let chrom = url.searchParams.get('hgg_chrom');
                 if (!chrom)
                     chrom = url.searchParams.get('c');
                 let chromStart = url.searchParams.get('hgg_start');
                 if (!chromStart)
                     chromStart = url.searchParams.get('o');
                 let chromEnd = url.searchParams.get('hgg_end');
                 if (!chromEnd)
                     chromEnd = url.searchParams.get('t');
                 chromStart = parseInt(chromStart) + 1;
                 chromEnd = parseInt(chromEnd);
                 // Many links leave out the chrom (b/c it's in the server side cart as "c")
                 // var chrom = hgTracks.chromName; // This is no longer acceptable
                 // with multi-window capability drawing multiple positions on multiple chroms.
                 if (!chrom || chrom.length === 0 || !chromStart || !chromEnd) {// 1-based chromStart
                     warn("couldn't parse out genomic coordinates");
                 } else {
                     if (cmd === 'getDna') {
                         // NOTE: this should be shared with URL generation for getDna blue bar menu
                         url = "../cgi-bin/hgc?g=getDna&i=mixed&c=" + chrom;
                         url += "&l=" + (chromStart - 1) + "&r=" + chromEnd;
                         url += "&db=" + getDb() + "&hgsid=" + getHgsid();
                         if ( ! window.open(url) ) {
                             rightClick.windowOpenFailedMsg();
                         }
                     } else if (cmd === 'highlightItem') {
                         if (hgTracks.windows && !hgTracks.virtualSingleChrom) {
                             // orig way only worked if the entire item was visible in the windows.
                             //var result = genomePos.chromToVirtChrom(chrom, parseInt(chromStart-1), parseInt(chromEnd));
 
                             var result = genomePos.convertChromPosToVirtCoords(chrom, parseInt(chromStart-1), parseInt(chromEnd));
 
                             if (result.chromStart != -1)
                                 {
                                 var newPos2 = hgTracks.chromName+":"+(result.chromStart+1)+"-"+result.chromEnd;
                                 dragSelect.highlightThisRegion(newPos2, true);
                                 }
 
                         } else {
                             var newChrom = hgTracks.chromName;
                             if (hgTracks.windows && hgTracks.virtualSingleChrom) {
                                 newChrom = hgTracks.windows[0].chromName;
                             }
                             var newPos3 = newChrom+":"+(parseInt(chromStart))+"-"+parseInt(chromEnd);
                             dragSelect.highlightThisRegion(newPos3, true);
                         }
                     } else if (cmd === 'highlightThisItem') {
 
                     } else {
                         var newPosition = genomePos.setByCoordinates(chrom, chromStart, chromEnd);
                         var reg = new RegExp("hgg_gene=([^&]+)");
                         var b = reg.exec(href);
                         var name;
                         // pull item name out of the url so we can set hgFind.matches (redmine 3062)
                         if (b && b[1]) {
                             name = b[1];
                         } else {
                             reg = new RegExp("[&?]i=([^&]+)");
                             b = reg.exec(href);
                             if (b && b[1]) {
                                 name = b[1];
                             }
                         }
                         if (imageV2.inPlaceUpdate) {
                             // XXXX This attempt to "update whole track image in place" didn't work
                             // for a variety of reasons (e.g. safari doesn't parse map when we
                             // update on the client side), so this is currently dead code.
                             // However, this now works in all other browsers, so we may turn this
                             // on for non-safari browsers (see redmine #4667).
                             jQuery('body').css('cursor', '');
                             var data = "hgt.trackImgOnly=1&hgt.ideogramToo=1&position=" +
                                        newPosition + "&hgsid=" + getHgsid() + "&db=" + getDb();
                             if (name)
                                 data += "&hgFind.matches=" + name;
                             $.ajax({
                                     type: "GET",
                                     url: "../cgi-bin/hgTracks",
                                     data: cart.addUpdatesToUrl(data),
                                     dataType: "html",
                                     trueSuccess: imageV2.updateImgAndMap,
                                     success: catchErrorOrDispatch,
                                     error: errorHandler,
                                     cmd: cmd,
                                     loadingId: showLoadingImage("imgTbl"),
                                     cache: false
                                 });
                         } else {
                             // do a full page refresh to update hgTracks image
                             jQuery('body').css('cursor', 'wait');
                             var ele;
                             if (document.TrackForm)
                                 ele = document.TrackForm;
                             else
                                 ele = document.TrackHeaderForm;
                             if (name)
                                 // Add or update form input with gene to highlight
                                 suggestBox.updateFindMatches(name);
                             ele.submit();
                         }
                     }
                 }
         } else if (cmd === 'zoomCodon' || cmd === 'zoomExon') {
             var num, ajaxCmd, msg;
             if (cmd === 'zoomCodon') {
                 msg = "Please enter the codon number to zoom to:";
                 ajaxCmd = 'codonToPos';
             } else {
                 msg = "Please enter the exon number to zoom to:";
                 ajaxCmd = 'exonToPos';
             }
             rightClick.myPrompt(msg, function(results) {
                 $.ajax({
                         type: "GET",
                         url: "../cgi-bin/hgApi",
                         data: cart.varsToUrlData({ 'hgsid': getHgsid(), 'db': getDb(), 'cmd': ajaxCmd, 'num': results,
                               'table': args.table, 'name': args.name, 'chrom': hgTracks.chromName}),
                         trueSuccess: rightClick.handleZoomCodon,
                         success: catchErrorOrDispatch,
                         error: errorHandler,
                         cache: true
                     });
                     });
         } else if (cmd === 'hgTrackUi_popup') {
 
             // Launches the popup but shields the ajax with a waitOnFunction
             popUp.hgTrackUi( rightClick.selectedMenuItem.id, false );  
 
         } else if (cmd === 'hgTrackUi_popup_description') {
 
             // Launches the popup but shields the ajax with a waitOnFunction
             popUp.hgTrackUi( rightClick.selectedMenuItem.id, true );
 
         } else if (cmd === 'changeTrackColor') {
 
             rightClick.showColorPicker(id);
 
         } else if (cmd === 'colorThisItem') {
 
             rightClick.colorThisItem();
 
         } else if (cmd === 'removeItemColor') {
 
             var itemToRemove = rightClick.itemFromHref(rightClick.selectedMenuItem.href);
             if (itemToRemove)
                 rightClick.removeItemColor(itemToRemove.track, itemToRemove.name);
 
         } else if (cmd === 'clearItemColors') {
 
             rightClick.clearItemColors();
 
         } else if (cmd === 'hgTrackUi_follow') {
 
             url = "hgTrackUi?hgsid=" + getHgsid() + "&g=";
             rec = hgTracks.trackDb[id];
             if (tdbHasParent(rec) && tdbIsLeaf(rec))
                 url += rec.parentTrack;
             else if (tdbHasParent(rec) && tdbIsContainer(rec))
                 // A container (e.g. multiWig) nested in a composite configures itself,
                 // not its parent (whose link is on the shared row button).
                 url += id;
             else {
                 // The button already has the ref
                 var link = normed($( 'td#td_btn_'+ rightClick.selectedMenuItem.id ).children('a'));
                 if (link)
                     url = $(link).attr('href');
                 else
                     url += rightClick.selectedMenuItem.id;
             }
             location.assign(url);
 
         } else if (cmd === 'hgTrackUi_followParent') {
 
             // Configure the parent container (e.g. the composite) of a nested container track.
             rec = hgTracks.trackDb[id];
             url = "hgTrackUi?hgsid=" + getHgsid() + "&g=" + rec.parentTrack;
             location.assign(url);
 
         } else if (cmd === 'newCollection') {
             $.ajax({
                 type: "PUT",
                 async: false,
                 url: "../cgi-bin/hgCollection",
                 data:  "cmd=newCollection&track=" + id + "&hgsid=" + getHgsid(),
                 trueSuccess: mySuccess,
                 success: catchErrorOrDispatch,
                 error: errorHandler,
             });
 
             imageV2.fullReload();
         } else if (cmd === 'addCollection') {
             var shortLabel = $(menuItemClicked).text().substring(9).slice(0,-1); 
             var ii;
             var collectionName;
             for(ii=0; ii < hgTracks.collections.length; ii++) {
                 if ( hgTracks.collections[ii].shortLabel === shortLabel) {
                     collectionName = hgTracks.collections[ii].track;
                     break;
                 }
             }
 
             $.ajax({
                 type: "PUT",
                 async: false,
                 url: "../cgi-bin/hgCollection",
                 data: "cmd=addTrack&track=" + id + "&collection=" + collectionName + "&hgsid=" + getHgsid(),
                 trueSuccess: mySuccess,
                 success: catchErrorOrDispatch,
                 error: errorHandler,
             });
 
             imageV2.fullReload();
         } else if (cmd === "hideOthers") {
             rightClick.hideOthers(id);
         } else if (cmd === "moveTop") {
             rightClick.moveTo(id, "top");
         } else if (cmd === "moveBottom") {
             rightClick.moveTo(id, "bottom");
         } else if ((cmd === 'sortExp') || (cmd === 'sortSim')) {
             url = "hgTracks?hgsid=" + getHgsid() + "&" + cmd + "=";
             rec = hgTracks.trackDb[id];
             if (tdbHasParent(rec) && tdbIsLeaf(rec))
                 url += rec.parentTrack;
             else {
                 // The button already has the ref
                 var link2 = normed($( 'td#td_btn_'+ rightClick.selectedMenuItem.id ).children('a')); 
                 if (link2)
                     url = $(link2).attr('href');
                 else
                     url += rightClick.selectedMenuItem.id;
             }
             location.assign(url);
 
         } else if (cmd === 'viewImg') {
             // Fetch a new copy of track img and show it to the user in another window. This code
             // assume we have updated remote cart with all relevant chages (e.g. drag-reorder).
             jQuery('body').css('cursor', 'wait');
             $.ajax({
                     type: "GET",
                     url: "../cgi-bin/hgTracks",
                     data: cart.varsToUrlData({ 'hgt.imageV1': '1','hgt.trackImgOnly': '1', 
                                                'hgsid': getHgsid(), 'db': getDb() }),
                     dataType: "html",
                     trueSuccess: rightClick.handleViewImg,
                     success: catchErrorOrDispatch,
                     error: errorHandler,
                     cmd: cmd,
                     cache: false
                 });
         } else if (cmd === 'openLink' || cmd === 'followLink') {
             href = rightClick.selectedMenuItem.href;
             var vars = new Array("c", "l", "r", "db");
             var valNames = new Array("chromName", "winStart", "winEnd");
             for (var i in vars) {
                 // make sure the link contains chrom and window width info
                 // (necessary b/c we are stripping hgsid and/or the cart may be empty);
                 // but don't add chrom to wikiTrack links (see redmine #2476).
                 var v = vars[i];
                 var val;
                 if (v === "db") {
                     val = getDb();
                 } else {
                     val = hgTracks[valNames[i]];
                 }
                 if (val
                 && id !== "wikiTrack"
                 && (href.indexOf("?" + v + "=") === -1)
                 && (href.indexOf("&" + v + "=") === -1)) {
                     href = href + "&" + v + "=" + val;
                 }
             }
             if (cmd === 'followLink') {
                 popUpHgcOrHgGene.hgc(rightClick.selectedMenuItem.id, href);
             } else {
                 // XXXX This is blocked by Safari's popup blocker (without any warning message).
                 href = removeHgsid(href);
                 if ( ! window.open(href) ) {
                     rightClick.windowOpenFailedMsg();
                 }
             }
         } else if (cmd === 'float') {
             if (rightClick.floatingMenuItem && rightClick.floatingMenuItem === id) {
                 $.floatMgr.FOArray = [];
                 rightClick.floatingMenuItem = null;
             } else {
                 if (rightClick.floatingMenuItem) {
                     // This doesn't work.
                     $('#img_data_' + rightClick.floatingMenuItem).parent().restartFloat();
                     // This does work
                     $.floatMgr.FOArray = [];
                 }
                 rightClick.floatingMenuItem = id;
                 rightClick.reloadFloatingItem();
                 imageV2.requestImgUpdate(id, "hgt.transparentImage=0", "");
             }
         } else if (cmd === 'hideSet') {
             row = $( 'tr#tr_' + id );
             rows = dragReorder.getContiguousRowSet(row);
             if (rows && rows.length > 0) {
                 var varsToUpdate = {};
                 // from bottom up, just in case remove screws with us
                 for (var ix=rows.length - 1; ix >= 0; ix--) { 
                     var rowId = $(rows[ix]).attr('id').substring('tr_'.length);
                     // Remove subtrack level vis and explicitly uncheck.
                     varsToUpdate[rowId]        = '[]';
                     varsToUpdate[rowId+'_sel'] = 0;
                     $(rows[ix]).remove();
                 }
                 if (objNotEmpty(varsToUpdate)) {
                     cart.setVarsObj(varsToUpdate);
                 }
                 imageV2.afterImgChange(true);
             }
         } else if (cmd === 'hideComposite') {
             rec = hgTracks.trackDb[id];
             if (tdbIsSubtrack(rec)) {
                 let trid = id.replaceAll(".","\\.");
                 row = $( 'tr#tr_' + trid );
                 rows = dragReorder.getCompositeSet(row);
                 // from bottom up, just in case remove screws with us
                 if (rows && rows.length > 0) {
                     for (var rIx=rows.length - 1; rIx >= 0; rIx--) {
                         $(rows[rIx]).remove();
                     }
                 selectUpdated = vis.update(rec.parentTrack, 'hide');
                 cart.setVars( [rec.parentTrack], ['hide']);
                 imageV2.afterImgChange(true);
                 }
             }
         } else if (cmd === 'jumpToHighlight') { // If highlight exists for this assembly, jump to it
             if (hgTracks.highlight && rightClick.clickedHighlightIdx!==null) {
                 var newPos = getHighlight(hgTracks.highlight, rightClick.clickedHighlightIdx);
                 if (newPos && newPos.db === getDb()) {
                     if ( $('#highlightItem').length === 0) { // not visible? jump to it
                         var curPos = parsePosition(genomePos.get());
                         var diff = ((curPos.end - curPos.start) - (newPos.end - newPos.start));
                         if (diff > 0) { // new position is smaller then current, then center it
                             newPos.start = Math.max( Math.floor(newPos.start - (diff/2) ), 0 );
                             newPos.end   = newPos.start + (curPos.end - curPos.start);
                         }
                     }
                     if (imageV2.inPlaceUpdate) {
                         var params = "db=" + getDb() + "&position=" + newPos.chrom+':'+newPos.start+'-'+newPos.end;
                         imageV2.navigateInPlace(params, null, true);
                     } else {
                         genomePos.setByCoordinates(newPos.chrom, newPos.start, newPos.end);
                         jQuery('body').css('cursor', 'wait');
                         document.TrackHeaderForm.submit();
                     }
                 }
             }
 
         } else if (cmd === 'removeHighlight') {
 
             var highlights = hgTracks.highlight.split("|");
             highlights.splice(rightClick.clickedHighlightIdx, 1); // splice = remove element from array
             hgTracks.highlight = highlights.join("|");
             cart.setVarsObj({'highlight' : hgTracks.highlight});
             imageV2.drawHighlights();
         } else if (cmd === 'toggleMerge') {
             // toggle both the cart (if the user goes to trackUi)
             // and toggle args[key], if the user doesn't leave hgTracks
             var key = id + ".doMergeItems";
             var updateObj = {};
             if (args[key] === 1) {
                 args[key] = 0;
                 updateObj[key] = 0;
                 cart.setVarsObj(updateObj,null,false);
                 imageV2.requestImgUpdate(id, id + ".doMergeItems=0");
             } else {
                 args[key] = 1;
                 updateObj[key] = 1;
                 cart.setVarsObj(updateObj,null,false);
                 imageV2.requestImgUpdate(id, id + ".doMergeItems=1");
             }
         } else {   // if ( cmd in 'hide','dense','squish','pack','full','show' )
             // Change visibility settings:
             //
             // First change the select on our form:
             rec = hgTracks.trackDb[id];
             selectUpdated = vis.update(id, cmd);
 
             // Now change the track image
             if (imageV2.enabled && cmd === 'hide') {
                 // Hide local display of this track and update server side cart.
                 // Subtracks controlled by 2 settings so del vis and set sel=0.
                 rightClick.hideTracks([id]);
             } else if (!imageV2.mapIsUpdateable) {
                 jQuery('body').css('cursor', 'wait');
                 if (selectUpdated) {
                     // assert(document.TrackForm);
                     document.TrackForm.submit();
                 } else {
                         // Add vis update to queue then submit
                         cart.setVars([id], [cmd], null, false); // synchronous
                         document.TrackHeaderForm.submit();
                 }
             } else {
                 imageV2.requestImgUpdate(id, id + "=" + cmd, "", cmd);
             }
         }
     },
 
     makeHitCallback: function (title)
     {   // stub to avoid problem with a function closure w/n a loop
         return function(menuItemClicked, menuObject) {
             rightClick.hit(menuItemClicked, menuObject, title); return true;
         };
     },
 
     reloadFloatingItem: function ()
     {   // currently dead (experimental code)
         if (rightClick.floatingMenuItem) {
             $('#img_data_' + rightClick.floatingMenuItem).parent().makeFloat(
                 {x:"current",y:"current", speed: 'fast', alwaysVisible: true, alwaysTop: true});
         }
     },
 
     makeImgTag: function (img)
     {   // Return img tag with explicit dimensions for img (dimensions are currently hardwired).
         // This fixes the "weird shadow problem when first loading the right-click menu"
         // seen in FireFox 3.X, which occurred b/c FF doesn't actually fetch the image until
         // the menu is being shown.
         return "<img style='width:16px; height:16px; border-style:none;' src='../images/" +
                 img + "' />";
     },
 
     showColorPicker: function (trackName)
     {   // Show a small dialog with a spectrum color picker for changing track color
         var rec = hgTracks.trackDb[trackName];
         if (!rec || !rec.defaultColor)
             return;
         var currentColor = (rec.colorOverrideOn && rec.colorOverride) ?
                            rec.colorOverride : rec.defaultColor;
         var dialogId = "trackColorDialog";
         $("#" + dialogId).remove();
         // Build with static template + data injected via .text()/.val()/.prop() so that
         // hub-provided shortLabel cannot inject HTML.
         var $dlg = $("<div>").attr("id", dialogId).html(
             "<p>Pick a new color for <b></b>:</p>" +
             "<input type='text' id='trackColorText' size='8' />" +
             "&nbsp;<input id='trackColorPicker' />" +
             "<br><br><label><input type='checkbox' id='trackColorOn' /> " +
             "Enable color override</label>");
         $dlg.find("p b").text(rec.shortLabel);
         $dlg.find("#trackColorText").val(currentColor);
         $dlg.find("#trackColorOn").prop("checked", !!rec.colorOverrideOn);
         $("body").append($dlg);
         var hexColorRe = /^#[0-9a-fA-F]{6}$/;
         $("#trackColorPicker").spectrum({
             color: currentColor,
             showPalette: true,
             showSelectionPalette: true,
             showInitial: true,
             showInput: true,
             preferredFormat: "hex",
             localStorageKey: "genomebrowser",
             hideAfterPaletteSelect: true,
             change: function(color) {
                 $("#trackColorText").val(color.toHexString());
                 $("#trackColorOn").prop("checked", true);
             }
         });
         $("#trackColorText").on("change", function() {
             var val = $(this).val();
             if (!hexColorRe.test(val))
                 return;
             $("#trackColorPicker").spectrum("set", val);
             $("#trackColorOn").prop("checked", true);
         });
         var applyColor = function() {
             var color = $("#trackColorText").val();
             if (!hexColorRe.test(color)) {
                 warn("Invalid color '" + color + "'. Expected hex format like #1a2b3c.");
                 return false;
             }
             var isOn = $("#trackColorOn").is(":checked") ? "1" : "0";
             rec.colorOverride = color;
             rec.colorOverrideOn = (isOn === "1");
             cart.setVars(
                 [trackName + ".colorOverride", trackName + ".colorOverrideOn"],
                 [color, isOn], null, false);
             imageV2.requestImgUpdate(trackName,
                 trackName + ".colorOverride=" + encodeURIComponent(color) +
                 "&" + trackName + ".colorOverrideOn=" + isOn);
             return true;
         };
         $("#" + dialogId).dialog({
             modal: true,
             title: "Change Track Color",
             closeOnEscape: true,
             resizable: false,
             minWidth: 400,
             buttons: {
                 "Apply": function() { applyColor(); },
                 "Ok": function() {
                     if (applyColor())
                         $(this).dialog("close");
                 }
             },
             close: function() {
                 $("#trackColorPicker").spectrum("destroy");
                 $(this).remove();
             }
         });
     },
 
     // ---- Per-item color (right-click "Color this item") ----
     // The itemColors cart variable holds db#track#mode#itemName#hexColor records joined by '|',
     // where mode is "item" (recolor the glyph) or "bg" (background highlight). db, track and mode
     // are the leading fields and the color is the last '#' field, so item names containing '#'
     // are tolerated.
 
     getItemColors: function ()
     {   // Current itemColors cart string, cached and seeded from the page's hgTracks json.
         if (rightClick.itemColorsCache === undefined) {
             rightClick.itemColorsCache =
                 (typeof hgTracks !== "undefined" && typeof hgTracks.itemColors === "string") ?
                 hgTracks.itemColors : "";
         }
         return rightClick.itemColorsCache;
     },
 
     parseItemColors: function (str)
     {   // Parse the itemColors string into an array of {db, track, mode, name, hex} records.
         var records = [];
         if (!str)
             return records;
         str.split("|").forEach(function (rec) {
             if (!rec)
                 return;
             var firstHash = rec.indexOf("#");
             var secondHash = rec.indexOf("#", firstHash + 1);
             var thirdHash = rec.indexOf("#", secondHash + 1);
             var lastHash = rec.lastIndexOf("#");
             if (firstHash < 0 || secondHash < 0 || thirdHash < 0 || lastHash <= thirdHash)
                 return;
             records.push({
                 db:    rec.substring(0, firstHash),
                 track: rec.substring(firstHash + 1, secondHash),
                 mode:  rec.substring(secondHash + 1, thirdHash),
                 name:  rec.substring(thirdHash + 1, lastHash),
                 hex:   rec.substring(lastHash + 1)   // bare hex, no leading '#'
             });
         });
         return records;
     },
 
     serializeItemColors: function (records)
     {
         return records.map(function (r) {
             return r.db + "#" + r.track + "#" + r.mode + "#" + r.name + "#" + r.hex;
         }).join("|");
     },
 
     itemFromHref: function (href)
     {   // Identify the clicked item from its hgc/hgGene link. Use the real name when it has a usable
         // one (name field of the returned object), otherwise fall back to genomic position
         // ("pos:chrom:start-end"). Nameless items (e.g. bed3) all share a placeholder name, so
         // position - which both the link (c=/o=/t=) and the draw code can produce - identifies them.
         if (!href)
             return null;
         var track, name, m;
         m = /[&?]g=([^&]+)/.exec(href);
         if (m && m[1])
             track = decodeURIComponent(m[1]);
         m = /[&?]i=([^&]+)/.exec(href);
         if (m && m[1])
             name = decodeURIComponent(m[1].replace(/\+/g, " "));
         if (!name) {   // knownGene-style links
             m = /[&?]hgg_gene=([^&]+)/.exec(href);
             if (m && m[1])
                 name = decodeURIComponent(m[1]);
             if (!track) {
                 m = /[&?]hgg_type=([^&]+)/.exec(href);
                 if (m && m[1])
                     track = decodeURIComponent(m[1]);
             }
         }
         if (!track)
             return null;
         // Custom tracks prefix the bed file path before the item name ("<path> <name>") and use the
         // literal "NoItemName" when the row has no name; treat empty or "NoItemName" as nameless.
         var nameless = !name || /(^|\s)NoItemName$/.test(name);
         if (!nameless)
             return {track: track, name: name};
         // o=/t= are 0-based start/end, matching tg->itemStart/itemEnd in the draw code
         var chrom, start, end;
         m = /[&?]c=([^&]+)/.exec(href);
         if (m && m[1]) chrom = decodeURIComponent(m[1]);
         m = /[&?]o=([^&]+)/.exec(href);
         if (m && m[1]) start = m[1];
         m = /[&?]t=([^&]+)/.exec(href);
         if (m && m[1]) end = m[1];
         if (chrom && start && end)
             return {track: track, name: "pos:" + chrom + ":" + start + "-" + end};
         return null;
     },
 
     findItemColor: function (track, name)
     {   // Return {hex (with leading '#'), mode} stored for this item, or null.
         var db = getDb();
         var records = rightClick.parseItemColors(rightClick.getItemColors());
         for (var i = 0; i < records.length; i++) {
             if (records[i].db === db && records[i].track === track && records[i].name === name)
                 return {hex: "#" + records[i].hex, mode: records[i].mode};
         }
         return null;
     },
 
     updateItemColorsVar: function (newStr)
     {   // Persist the itemColors cart variable and keep the local cache in sync.
         rightClick.itemColorsCache = newStr;
         if (typeof hgTracks !== "undefined" && hgTracks)
             hgTracks.itemColors = newStr;
         cart.setVars(["itemColors"], [newStr], null, false);
     },
 
     setItemColor: function (track, name, hexWithHash, mode)
     {
         var db = getDb();
         var hex = hexWithHash.replace(/^#/, "");
         var records = rightClick.parseItemColors(rightClick.getItemColors());
         var found = false;
         for (var i = 0; i < records.length; i++) {
             if (records[i].db === db && records[i].track === track && records[i].name === name) {
                 records[i].hex = hex;
                 records[i].mode = mode;
                 found = true;
                 break;
             }
         }
         if (!found)
             records.push({db: db, track: track, mode: mode, name: name, hex: hex});
         rightClick.updateItemColorsVar(rightClick.serializeItemColors(records));
         imageV2.requestImgUpdate(track,
             "itemColors=" + encodeURIComponent(rightClick.getItemColors()));
     },
 
     removeItemColor: function (track, name)
     {
         var db = getDb();
         var records = rightClick.parseItemColors(rightClick.getItemColors()).filter(function (r) {
             return !(r.db === db && r.track === track && r.name === name);
         });
         rightClick.updateItemColorsVar(rightClick.serializeItemColors(records));
         imageV2.requestImgUpdate(track,
             "itemColors=" + encodeURIComponent(rightClick.getItemColors()));
     },
 
     hasItemColorsForCurrentDb: function ()
     {   // Are any item colors set for the database currently shown?
         var db = getDb();
         return rightClick.parseItemColors(rightClick.getItemColors()).some(function (r) {
             return r.db === db;
         });
     },
 
     clearItemColors: function ()
     {   // Clear item colors for the current database only, leaving other assemblies' colors alone.
         var db = getDb();
         var records = rightClick.parseItemColors(rightClick.getItemColors()).filter(function (r) {
             return r.db !== db;
         });
         var newStr = rightClick.serializeItemColors(records);
         rightClick.updateItemColorsVar(newStr);
         imageV2.fullReload("itemColors=" + encodeURIComponent(newStr));
     },
 
     colorThisItem: function ()
     {   // Open the per-item color dialog for the right-clicked item.
         var sel = rightClick.selectedMenuItem;
         var item = sel ? rightClick.itemFromHref(sel.href) : null;
         if (!item) {
             warn("Couldn't identify the item to color.");
             return;
         }
         var existing = rightClick.findItemColor(item.track, item.name);
         var currentColor = existing ? existing.hex : "#ff0000";
         var currentMode = existing ? existing.mode : "item";
         rightClick.showItemColorPicker(item.track, item.name, currentColor, currentMode);
     },
 
     showItemColorPicker: function (track, itemName, currentColor, currentMode)
     {   // Spectrum dialog to recolor a single item's glyph or draw a colored background behind it.
         var dialogId = "itemColorDialog";
         $("#" + dialogId).remove();
         var $dlg = $("<div>").attr("id", dialogId).html(
             "<p>Pick a color for <b></b>:</p>" +
             "<input type='text' id='itemColorText' size='8' />" +
             "&nbsp;<input id='itemColorPicker' />" +
             "<br><br><label><input type='radio' name='itemColorMode' value='item'> " +
             "Color whole item</label>" +
             "<br><label><input type='radio' name='itemColorMode' value='bg'> " +
             "Background highlight</label>");
         $dlg.find("p b").text(itemName);
         $dlg.find("#itemColorText").val(currentColor);
         $dlg.find("input[name='itemColorMode'][value='" +
                   (currentMode === "bg" ? "bg" : "item") + "']").prop("checked", true);
         $("body").append($dlg);
         var hexColorRe = /^#[0-9a-fA-F]{6}$/;
         $("#itemColorPicker").spectrum({
             color: currentColor,
             showPalette: true,
             showSelectionPalette: true,
             showInitial: true,
             showInput: true,
             preferredFormat: "hex",
             localStorageKey: "genomebrowser",
             hideAfterPaletteSelect: true,
             change: function(color) {
                 $("#itemColorText").val(color.toHexString());
             }
         });
         $("#itemColorText").on("change", function() {
             var val = $(this).val();
             if (hexColorRe.test(val))
                 $("#itemColorPicker").spectrum("set", val);
         });
         var applyColor = function() {
             var color = $("#itemColorText").val();
             if (!hexColorRe.test(color)) {
                 warn("Invalid color '" + color + "'. Expected hex format like #1a2b3c.");
                 return false;
             }
             var mode = $("input[name='itemColorMode']:checked").val() || "item";
             rightClick.setItemColor(track, itemName, color, mode);
             return true;
         };
         $("#" + dialogId).dialog({
             modal: true,
             title: "Color this item",
             closeOnEscape: true,
             resizable: false,
             minWidth: 400,
             buttons: {
                 "Apply": function() { applyColor(); },
                 "Ok": function() {
                     if (applyColor())
                         $(this).dialog("close");
                 }
             },
             close: function() {
                 $("#itemColorPicker").spectrum("destroy");
                 $(this).remove();
             }
         });
     },
 
     // CGIs now use HTML tags, e.g. "<b>Transcript:</b> ENST00000297261.7<br><b>Strand:</b>"
     mouseOverToLabel: function(title)
     {
         if (title.search(/<b>Transcript: ?<[/]b>/) !== -1) {
             title = title.split("<br>")[0].split("</b>")[1];
         }
         // for older UCSC genes tracks, the protein name is forced onto the item name
         if (title.search(/&hgg_prot=/) !== -1) {
             title = title.split("&hgg_prot=")[0];
         }
         return title;
     },
 
     // when "exonNumbers on", the mouse over text is not a good item description for the right-click menu
     // "exonNumbers on" is the default for genePred/bigGenePred tracks but can also be actived for bigBed and others
     // We don't have the value of the tdb variable "exonNumbers" here, so just use a heuristic to see if it's on
     mouseOverToExon: function(title)
     {
         var exonNum = 0;
         var exonRe = /(Exon) (\d+) /;
         var matches = exonRe.exec(title);
         if (matches !== null && matches[2].length > 0)
             exonNum = matches[2];
         return exonNum;
     },
 
     load: function (img)
     {
         rightClick.menu = img.contextMenu(function() {
             popUp.cleanup();   // Popup box is not getting closed properly so must do it here
             if ( ! rightClick.selectedMenuItem )  // This is literally an edge case so ignore
                 return;
 
             var o; // TODO: Break this giant routine with shared vars into some sub-functions
             var str;
             var rec = null;
             var menu = [];
             var selectedImg = rightClick.makeImgTag("greenChecksm.png");
             var blankImg    = rightClick.makeImgTag("invisible16.png");
             var done = false;
             if (rightClick.selectedMenuItem && rightClick.selectedMenuItem.id) {
                 var href = rightClick.selectedMenuItem.href;
                 var isHgc, isGene;
                 if (href) {
                     isGene = href.match("hgGene");
                     isHgc = href.match("hgc");
                 }
                 var id = rightClick.selectedMenuItem.id;
                 rec = hgTracks.trackDb[id];
                 var offerHideSubset    = false;
                 var offerHideComposite = false;
                 var offerSingles       = true;
                 let trid = id.replaceAll(".","\\.");
                 var row = $( 'tr#tr_' + trid );
                 if (row) {
                     var btn = $(row).find('p.btnBlue'); // btnBlue means cursor over left button
                     if (btn.length === 1) {
                         var compositeSet = dragReorder.getCompositeSet(row);
                         if (compositeSet && compositeSet.length > 0) {  // There is composite set
                             offerHideComposite = true;
                             $( compositeSet ).find('p.btn').addClass('blueButtons');// blue persists
 
                             var subSet = dragReorder.getContiguousRowSet(row);
                             if (subSet && subSet.length > 1) {
                                 offerSingles = false;
                                 if (subSet.length < compositeSet.length) {
                                     offerHideSubset = true;
                                     $( subSet ).addClass("greenRows"); // green persists
                                 }
                             }
                         }
                     }
                 }
 
                 // First option is hide sets
                 if (offerHideComposite) {
                     if (offerHideSubset) {
                         o = {};
                         o[blankImg + " hide track subset (green)"] = {
                                             onclick: rightClick.makeHitCallback('hideSet')};
                         menu.push(o);
                     }
 
                     o = {};
                     str = blankImg + " hide track set";
                     if (offerHideSubset)
                         str += " (blue)";
                     o[str] = {onclick: rightClick.makeHitCallback('hideComposite')};
                     menu.push(o);
                 }
 
                 // Second set of options: visibility for single track
                 if (offerSingles) {
                     if (offerHideComposite)
                         menu.push($.contextMenu.separator);
 
                     // XXXX what if select is not available (b/c trackControlsOnMain is off)?
                     // Move functionality to a hidden variable?
                     var select = $("select[name=" + escapeJQuerySelectorChars(id) + "]");
                     if (select.length > 1)  
                         // Not really needed if $('#hgTrackUiDialog').html(""); has worked
                         select =  [ $(select)[0] ];
                     var cur = $(select).val();
                     if (cur) {
                         $(select).children().each(function(index, o) {
                             var title = $(this).val();
                             str = blankImg + " " + title;
                             if (title === cur)
                                 str = selectedImg + " " + title;
                             o = {};
                             o[str] = {onclick: function (menuItemClicked, menuObject) {
                                         rightClick.hit(menuItemClicked, menuObject, title);
                                         return true;}};
                             menu.push(o);
                         });
                         done = true;
                     } else {
                         if (rec) {
                             // XXXX check current state from a hidden variable.
                             var visStrings = new Array("hide","dense","squish","pack","full");
                             for (var i in visStrings) {
                                 // use maxVisibility and change hgTracks so it can hide subtracks
                                 o = {};
                                 str = blankImg + " " + visStrings[i];
                                 if (rec.onlyVisibility) {
                                     if (visStrings[i] == "hide" || visStrings[i] === rec.onlyVisibility) {
 
                                         if (rec.localVisibility) {
                                             if (visStrings[i] === rec.localVisibility) {
                                                 str = selectedImg + " " + visStrings[i];
                                             }
                                         } else if (visStrings[i] === vis.enumOrder[rec.visibility]) {
                                             str = selectedImg + " " + visStrings[i];
                                         }
                                         o[str] = { onclick:
                                                     rightClick.makeHitCallback(visStrings[i])
                                                  };
                                         menu.push(o);
 
 
                                     }
                                 }
                                 else {
                                     if (rec.canPack
                                     || (visStrings[i] !== "pack" && visStrings[i] !== "squish")) {
                                         if (rec.localVisibility) {
                                             if (visStrings[i] === rec.localVisibility) {
                                                 str = selectedImg + " " + visStrings[i];
                                             }
                                         } else if (visStrings[i] === vis.enumOrder[rec.visibility]) {
                                             str = selectedImg + " " + visStrings[i];
                                         }
                                         o[str] = { onclick:
                                                     rightClick.makeHitCallback(visStrings[i])
                                                  };
                                         menu.push(o);
                                     }
                                 }
                             }
                             done = true;
                         }
                     }
                 }
 
                 if (done) {
                     o = {};
                     var any = false;
                     var title = rightClick.selectedMenuItem.title || "feature";
                     var maxLength = 60;
 
                     if ((isGene || isHgc || id === "wikiTrack") && href.indexOf("i=mergedItem") === -1) {
                         // Add "Open details..." item
                         var displayItemFunctions = false;
                         if (rec) {
                             if (rec.type.indexOf("wig") === 0
                             ||  rec.type.indexOf("bigWig") === 0
                             ||  id === "wikiTrack") {
                                 displayItemFunctions = false;
                             } else if (rec.type.indexOf("expRatio") === 0) {
                                 displayItemFunctions = title !== "zoomInMore";
                             } else {
                                 displayItemFunctions = true;
                             }
                             // For barChart mouseovers, replace title (which may be a category 
                             // name+value) with item name
                             if (rec.type.indexOf("barChart") === 0
                             || rec.type.indexOf("bigBarChart") === 0) {
                                 let a = /i=([^&]+)/.exec(href);
                                 if (a && a[1]) {
                                     title = a[1];
                                 }
                             }
                         }
 
                         // pick out the exon number from the mouseover text
                         // Probably should be a data-exonNum tag on the DOM element
                         var exonNum = rightClick.mouseOverToExon(title);
 
                         // remove special genePred exon mouseover html text
                         // CGIs now use HTML tags, e.g. "<b>Transcript:</b> ENST00000297261.7<br><b>Strand:</b>"
                         title = rightClick.mouseOverToLabel(decodeURIComponent(title));
 
                         if (title.length > maxLength) {
                             title = title.substring(0, maxLength) + "...";
                         }
 
                         if (isHgc) {
                             // For GTEx gene and UniProt mouseovers, replace title (which may be a tissue name) with 
                             // item (gene) name. Also need to unescape the urlencoded characters and the + sign.
                             let a = /i=([^&]+)/.exec(href);
                             if (a && a[1]) {
                                 title = decodeURIComponent(a[1].replace(/\+/g, " "));
                             }
                         }
 
                         if (displayItemFunctions) {
                             o[rightClick.makeImgTag("magnify.png") + " Zoom to " +  title] = {
                                 onclick: function(menuItemClicked, menuObject) {
                                             rightClick.hit(menuItemClicked, menuObject,
                                                     "selectWholeGene"); return true;
                                           }
                                 };
                             o[rightClick.makeImgTag("highlight.png") + " Highlight " + title] =
                                 {   onclick: function(menuItemClicked, menuObject) {
                                         rightClick.hit(menuItemClicked, menuObject,
                                                        "highlightItem");
                                         return true;
                                     }
                                 };
                             var itemForColor = rightClick.itemFromHref(href);
                             if (hgTracks.canColorItems && itemForColor) {
                                 o[rightClick.makeImgTag("palette.png") + " Color " + title + "..."] =
                                     {   onclick: function(menuItemClicked, menuObject) {
                                             rightClick.hit(menuItemClicked, menuObject,
                                                            "colorThisItem");
                                             return true;
                                         }
                                     };
                                 if (rightClick.findItemColor(itemForColor.track,
                                                              itemForColor.name)) {
                                     o[rightClick.makeImgTag("palette.png") +
                                             " Remove color from " + title] =
                                         {   onclick: function(menuItemClicked, menuObject) {
                                                 rightClick.hit(menuItemClicked, menuObject,
                                                                "removeItemColor");
                                                 return true;
                                             }
                                         };
                                 }
                             }
                             //o[rightClick.makeImgTag("highlight.png") + " Highlight THIS item"] = 
                             //    {   onclick: function(menuItemClicked, menuObject) {
                             //            rightClick.hit(menuItemClicked, menuObject,
                             //                           "highlightThisItem"); 
                             //            return true;
                             //        }
                             //    };
                             if (rightClick.supportZoomCodon &&
                                     (rec.type.indexOf("genePred") !== -1 || rec.type.indexOf("bigGenePred") !== -1)) {
                                 // http://hgwdev-larrym.gi.ucsc.edu/cgi-bin/hgGene?hgg_gene=uc003tqk.2&hgg_prot=P00533&hgg_chrom=chr7&hgg_start=55086724&hgg_end=55275030&hgg_type=knownGene&db=hg19&c=chr7
                                 var name, table;
                                 var reg = new RegExp("hgg_gene=([^&]+)");
                                 let a = reg.exec(href);
                                 if (a && a[1]) {
                                     name = a[1];
                                     reg = new RegExp("hgg_type=([^&]+)");
                                     a = reg.exec(href);
                                     if (a && a[1]) {
                                         table = a[1];
                                     }
                                 } else {
                                     // http://hgwdev-larrym.gi.ucsc.edu/cgi-bin/hgc?o=55086724&t=55275031&g=refGene&i=NM_005228&c=chr7
                                     // http://hgwdev-larrym.gi.ucsc.edu/cgi-bin/hgc?o=55086713&t=55270769&g=wgEncodeGencodeManualV4&i=ENST00000455089&c=chr7
                                     reg = new RegExp("i=([^&]+)");
                                     a = reg.exec(href);
                                     if (a && a[1]) {
                                         name = a[1];
                                         reg = new RegExp("g=([^&]+)");
                                         a = reg.exec(href);
                                         if (a && a[1]) {
                                             table = a[1];
                                         }
                                     }
                                 }
                                 if (name && table) {
                                     if (exonNum > 0) {
                                         o[rightClick.makeImgTag("magnify.png")+" Zoom to this exon"] = {
                                             onclick: function(menuItemClicked, menuObject) {
                                                 $.ajax({
                                                         type: "GET",
                                                         url: "../cgi-bin/hgApi",
                                                         data: cart.varsToUrlData({ 'hgsid': getHgsid(), 'db': getDb(),
                                                                 'cmd': "exonToPos", 'num': exonNum,
                                                                 'table': table, 'name': name, 'chrom': hgTracks.chromName}),
                                                         trueSuccess: rightClick.handleZoomCodon,
                                                         success: catchErrorOrDispatch,
                                                         error: errorHandler,
                                                         cache: true
                                                     });
                                                 return true; }
                                         };
                                     o[rightClick.makeImgTag("magnify.png")+" Enter codon to zoom to..."] =
                                     {   onclick: function(menuItemClicked, menuObject) {
                                             rightClick.hit(menuItemClicked, menuObject,
                                                         "zoomCodon",
                                                         {name: name, table: table, 'chrom': hgTracks.chromName});
                                             return true;}
                                     };
                                         o[rightClick.makeImgTag("magnify.png")+" Enter exon to zoom to..."] =
                                         {   onclick: function(menuItemClicked, menuObject) {
                                                 rightClick.hit(menuItemClicked, menuObject,
                                                             "zoomExon",
                                                             {name: name, table: table, 'chrom': hgTracks.chromName});
                                                 return true;}
                                         };
                                     }
                                 }
                             }
                             o[rightClick.makeImgTag("dnaIcon.png")+" Get DNA for "+title] = {
                                 onclick: function(menuItemClicked, menuObject) {
                                     rightClick.hit(menuItemClicked, menuObject, "getDna");
                                     return true; }
                             };
                         }
                         o[rightClick.makeImgTag("bookOut.png")+
                                                 " Open details page in new window..."] = {
                             onclick: function(menuItemClicked, menuObject) {
                                 rightClick.hit(menuItemClicked, menuObject, "openLink");
                                 return true; }
                         };
                         any = true;
                     }
                     if (href && href.length  > 0 && href.indexOf("i=mergedItem") === -1) {
                         // Add "Show details..." item
                         if (title.indexOf("Click to alter ") === 0) {
                             // suppress the "Click to alter..." items
                         } else if (rightClick.selectedMenuItem.href.indexOf("cgi-bin/hgTracks")
                                                                                         !== -1) {
                             // suppress menu items for hgTracks links (e.g. Next/Prev map items).
                         } else {
                             var item;
                             if (title === "zoomInMore")
                                 // avoid showing menu item that says
                                 // "Show details for zoomInMore..." (redmine 2447)
                                 item = rightClick.makeImgTag("book.png") + " Show details...";
                             else
                                 item = rightClick.makeImgTag("book.png")+" Show details for "+
                                        title + "...";
                             o[item] = {onclick: function(menuItemClicked, menuObject) {
                                        rightClick.hit(menuItemClicked,menuObject,"followLink");
                                        return true; }
                             };
                             any = true;
                         }
                     }
                     if (any) {
                         menu.push($.contextMenu.separator);
                         menu.push(o);
                     }
                 }
             }
 
 
             menu.push($.contextMenu.separator);
             o = {};
             o[rightClick.makeImgTag("hiddenIcon.png") + " Hide all other tracks "] = {
                 onclick: function(menuItemClicked, menuObject) {
                     rightClick.hit(menuItemClicked, menuObject, "hideOthers");
                     return true; }
             };  
             menu.push(o);
 
             //o = {};
             //o[" Float "] = {
                 //onclick: function(menuItemClicked, menuObject) {
                     //rightClick.hit(menuItemClicked, menuObject, "float");
                     //return true; }
             //};  
             //menu.push(o);
 
             o = {};
             o[rightClick.makeImgTag("ab_up.gif") + " Move to top "] = {
                 onclick: function(menuItemClicked, menuObject) {
                     rightClick.hit(menuItemClicked, menuObject, "moveTop");
                     return true; }
             };  
             menu.push(o);
 
             o = {};
             o[rightClick.makeImgTag("ab_down.gif") + " Move to bottom "] = {
                 onclick: function(menuItemClicked, menuObject) {
                     rightClick.hit(menuItemClicked, menuObject, "moveBottom");
                     return true; }
             };  
             menu.push(o);
 
             if (rightClick.selectedMenuItem && rec) {
                 // Add cfg options at just shy of end...
                 o = {};
                 if (tdbIsLeaf(rec)) {
 
                     if (rec.configureBy !== 'none'
                     && (!tdbIsCompositeSubtrack(rec) || rec.configureBy !== 'clickThrough')) {
                         // Note that subtracks never do clickThrough because
                         // parentTrack cfg is the desired clickThrough
                         o[rightClick.makeImgTag("wrench.png")+" Configure "+rec.shortLabel] = {
                             onclick: function(menuItemClicked, menuObject) {
                                 rightClick.hit(menuItemClicked, menuObject, "hgTrackUi_popup");
                                 return true; }
                         };
 
                     }
                     if (rec.parentTrack) {
                         o[rightClick.makeImgTag("folderWrench.png")+" Configure "+
                           rec.parentLabel + " track set..."] = {
                             onclick: function(menuItemClicked, menuObject) {
                                 rightClick.hit(menuItemClicked,menuObject,"hgTrackUi_follow");
                                 return true; }
                           };
                     }
                 } else {
 
                     o[rightClick.makeImgTag("folderWrench.png")+" Configure "+rec.shortLabel +
                       " track set..."] = {
                         onclick: function(menuItemClicked, menuObject) {
                             rightClick.hit(menuItemClicked, menuObject, "hgTrackUi_follow");
                             return true; }
                       };
                     if (rec.parentTrack) {
                         // A container (e.g. multiWig) nested in a composite: also offer
                         // the parent composite's configuration.
                         o[rightClick.makeImgTag("folderWrench.png")+" Configure "+
                           rec.parentLabel + " track set..."] = {
                             onclick: function(menuItemClicked, menuObject) {
                                 rightClick.hit(menuItemClicked,menuObject,"hgTrackUi_followParent");
                                 return true; }
                           };
                     }
                 }
                 if (jQuery.floatMgr) {
                     o[(rightClick.selectedMenuItem.id === rightClick.floatingMenuItem ?
                             selectedImg : blankImg) + " float"] = {
                         onclick: function(menuItemClicked, menuObject) {
                             rightClick.hit(menuItemClicked, menuObject, "float");
                             return true; }
                     };
                 }
                 // add a toggle to hide/show the merged item(s)
                 mergeTrack = rightClick.selectedMenuItem.id + ".doMergeItems";
                 if (rec.hasOwnProperty(mergeTrack)) {
                     var hasMergedItems = rec[mergeTrack] === 1;
                     titleStr = rightClick.makeImgTag("wrench.png") + " ";
                     if (hasMergedItems) {
                         titleStr += "Show merged items";
                     } else {
                         titleStr += "Merge items that span the current region";
                     }
                     o[titleStr] = {onclick: function(menuItemClick, menuObject) {
                         rightClick.hit(menuItemClick, menuObject, "toggleMerge", rec);
                         return true; }
                     };
                 }
 
 		o[rightClick.makeImgTag("book.png")+" Track Description "+rec.shortLabel] = {
 		    onclick: function(menuItemClicked, menuObject) {
 			rightClick.hit(menuItemClicked, menuObject, "hgTrackUi_popup_description");
 			return true; }
 		    };
 
                 if (rec.defaultColor) {
                     o[rightClick.makeImgTag("palette.png")+" Change Track Color"] = {
                         onclick: function(menuItemClicked, menuObject) {
                             rightClick.hit(menuItemClicked, menuObject, "changeTrackColor");
                             return true; }
                     };
                 }
                 if (hgTracks.canColorItems && rightClick.hasItemColorsForCurrentDb()) {
                     o[rightClick.makeImgTag("palette.png")+" Clear all item colors"] = {
                         onclick: function(menuItemClicked, menuObject) {
                             rightClick.hit(menuItemClicked, menuObject, "clearItemColors");
                             return true; }
                     };
                 }
 
                 menu.push($.contextMenu.separator);
                 menu.push(o);
             }
 
             menu.push($.contextMenu.separator);
             if (hgTracks.highlight && rightClick.clickedHighlightIdx!==null) {
                 var currentlySeen = ($('#highlightItem').length > 0); 
                 o = {};
                 // Jumps to highlight when not currently seen in image
                 var text = (currentlySeen ? " Zoom" : " Jump") + " to highlight";
                 o[rightClick.makeImgTag("highlightZoom.png") + text] = {
                     onclick: rightClick.makeHitCallback('jumpToHighlight')
                 };
 
                 if ( currentlySeen ) {   // Remove only when seen
                     o[rightClick.makeImgTag("highlightRemove.png") + 
                                                                " Remove highlight"] = {
                         onclick: rightClick.makeHitCallback('removeHighlight')
                     };
                 }
                 menu.push(o);
             }
 
             if (rec.isCustomComposite)
                 {
                 // add delete from composite
                 }
             else if ((!rec.type.startsWith("wigMaf")) &&
                 (rec.type.startsWith("bigWig") || rec.type.startsWith("multiWig") || rec.type.startsWith("wig") || rec.type.startsWith("bedGraph"))) {
                 o = {};
                 o[" Make a New Collection with \"" + rec.shortLabel + "\""] = {
                     onclick: rightClick.makeHitCallback("newCollection")
                 };  
                 menu.push(o);
 
                 if (hgTracks.collections) {
                     var ii;
                     for(ii=0; ii < hgTracks.collections.length; ii++) {
                         o = {};
                         o[" Add to \"" + hgTracks.collections[ii].shortLabel + "\""] = {
                             onclick: rightClick.makeHitCallback("addCollection")
                         };  
                         menu.push(o);
                     }
                 }
                 menu.push($.contextMenu.separator);
             }
 
             // add sort options if this is a custom composite or a wiggle-only composite
             if ((rec.isCustomComposite || parentIsAllWiggle(rec)) && tdbHasParent(rec) && tdbIsLeaf(rec)) {
 
                 o = {};
                 o[" Sort by Magnitude "] = {
                     onclick: function(menuItemClicked, menuObject) {
                         rightClick.hit(menuItemClicked, menuObject, "sortExp");
                         return true; }
                 };  
                 menu.push(o);
 
                 o = {};
                 o[" Sort by Similarity "] = {
                     onclick: function(menuItemClicked, menuObject) {
                         rightClick.hit(menuItemClicked, menuObject, "sortSim");
                         return true; }
                 };  
                 menu.push(o);
 
                 menu.push($.contextMenu.separator);
             }
 
             // Add view image at end
             o = {};
             o[rightClick.makeImgTag("eye.png") + " View image"] = {
                 onclick: function(menuItemClicked, menuObject) {
                     rightClick.hit(menuItemClicked, menuObject, "viewImg");
                     return true; }
             };
             menu.push(o);
 
             return menu;
         },
         {
             beforeShow: function(e) {
                 // console.log(mapItems[rightClick.selectedMenuItem]);
                 rightClick.selectedMenuItem = rightClick.findMapItem(e);
                 
                 // find the highlight that was clicked
                 var imageX = (imageV2.imgTbl[0].getBoundingClientRect().left) + imageV2.LEFTADD;
                 var xDiff = (e.clientX) - imageX;
                 var clickPos = genomePos.pixelsToBases(img, xDiff, xDiff+1, hgTracks.winStart, hgTracks.winEnd, false);
                 rightClick.clickedHighlightIdx = dragSelect.findHighlightIdxForPos(clickPos);
 
                 // XXXX? posting.blockUseMap = true;
                 return true;
             },
             hideTransition:'hide', // hideCallback fails if these are not defined.
             hideSpeed:10,
             hideCallback: function() {
                 $('p.btn.blueButtons').removeClass('blueButtons');
                 $('tr.trDraggable.greenRows').removeClass('greenRows');
             }
         });
         return;
     }
 };
 
   //////////////////////////////////
  //// external tools           ////
 //////////////////////////////////
 
 function showExtToolDialog() {
         /* show the 'send to external tool' dialog */
         // information about external tools is stored in the extTools global list
         // defined by a <script> at the end of the body
 
         // remove an existing dialog box
         var extToolDialog = $("#extToolDialog").remove();
 
         // construct the contents
         var htmlLines = ["<ul class='indent'>"];
         var winSize = hgTracks.winEnd - hgTracks.winStart;
         for (i = 0; i < extTools.length; i++) {
             var tool = extTools[i];
             var toolId = tool[0];
             var shortLabel = tool[1];
             var longLabel = tool[2];
             var maxSize = tool[3];
             if ((maxSize===0) || (winSize < maxSize))
                 {
                 var url = "hgTracks?hgsid="+getHgsid()+"&hgt.redirectTool="+toolId;
                 //var onclick = "$('#extToolDialog').dialog('close');";
                 //htmlLines.push("<li><a onclick="+'"'+onclick+'"'+"id='extToolLink' target='_BLANK' href='"+url+"'>"+shortLabel+"</a>: <small>"+longLabel+"</small></li>");
 		// onclick js code moved to jsInline
                 htmlLines.push("<li><a class='extToolLink2' target='_BLANK' href='"+url+"'>"+shortLabel+"</a>: <small>"+longLabel+"</small></li>");
                 }
             else
                 {
                 note = "<br><b>Needs zoom to &lt; "+maxSize/1000+" kbp.</b></small></span></li>";
                 htmlLines.push('<li><span style="color:grey">'+shortLabel+": <small>"+longLabel+note);
                 }
         }
         htmlLines.push("</ul>");
         content = htmlLines.join("");
             
         var title = hgTracks.chromName + ":" + (hgTracks.winStart+1) + "-" + hgTracks.winEnd;
         if (hgTracks.nonVirtPosition)
             title = hgTracks.nonVirtPosition;
         title += " on another website";
         $("body").append("<div id='extToolDialog' title='"+title+"'><p>" + content + "</p>");
 
 	$('a.extToolLink2').on("click", function(){$('#extToolDialog').dialog('close');});
 
         // copied from the hgTrackUi function below
         var popMaxHeight = ($(window).height() - 40);
         var popMaxWidth  = ($(window).width() - 40);
         var popWidth     = 600;
         if (popWidth > popMaxWidth)
             popWidth = popMaxWidth;
 
         // also copied from the hgTrackUi code below
         $('#extToolDialog').dialog({
             resizable: false,
             height: popMaxHeight,
             width: popWidth,
             minHeight: 200,
             minWidth: 600,
             maxHeight: popMaxHeight,
             maxWidth: popMaxWidth,
             modal: true,
             closeOnEscape: true,
             autoOpen: false,
             buttons: { "Close": function() {
                     $(this).dialog("close");
             }},
         });
         
         $('#extToolDialog').dialog('open');
 }
 
   /////////////////////////////////////////////////////////
  //// popupHgt popup for hgTracks  (aka modal dialog) ////
 /////////////////////////////////////////////////////////
 var popUpHgt = {
 
     whichHgTracksMethod: "",
     title: "",
 
     cleanup: function ()
     {  // Clean out the popup box on close
         if ($('#hgTracksDialog').html().length > 0 ) {
             // clear out html after close to prevent problems caused by duplicate html elements
             $('#hgTracksDialog').html("");
             popUpHgt.whichHgTracksMethod = "";
             popUpHgt.title = "";
         }
     },
 
     _uiDialogRequest: function (whichHgTracksMethod)
     { // popup cfg dialog
         popUpHgt.whichHgTracksMethod = whichHgTracksMethod;
         var myLink = "../cgi-bin/hgTracks?hgsid=" + getHgsid() + "&db=" + getDb();
         if (popUpHgt.whichHgTracksMethod === "multi-region config") {
             myLink += "&hgTracksConfigMultiRegionPage=multi-region";
             popUpHgt.title = "Configure Multi-Region View";
         }
 
         $.ajax({
                     type: "GET",
                     url: cart.addUpdatesToUrl(myLink),
                     dataType: "html",
                     trueSuccess: popUpHgt.uiDialog,
                     success: catchErrorOrDispatch,
                     error: errorHandler,
                     cache: false
                 });
     },
 
     hgTracks: function (whichHgTracksMethod)
     {   // Launches the popup but shields the ajax with a waitOnFunction
         waitOnFunction( popUpHgt._uiDialogRequest, whichHgTracksMethod);
     },
 
     uiDialogOk: function (popObj)
     {   // When popup closes with ok
 
     },
 
     uiDialog: function (response, status)
     {
     // Take html from hgTracks and put it up as a modal dialog.
 
         // make sure all links (e.g. help links) open up in a new window
         response = response.replace(/<a /ig, "<a target='_blank' ");
 
         var cleanHtml = response;
         //cleanHtml = stripCspHeader(cleanHtml,false); // DEBUG msg with true
         cleanHtml = stripJsFiles(cleanHtml,false);   // DEBUG msg with true
         cleanHtml = stripCssFiles(cleanHtml,false);  // DEBUG msg with true
         //cleanHtml = stripJsEmbedded(cleanHtml,false);// DEBUG msg with true // Obsolete by CSP2?
         var nonceJs = {};
         cleanHtml = stripCSPAndNonceJs(cleanHtml, false, nonceJs); // DEBUG msg with true
 
         cleanHtml = stripMainMenu(cleanHtml,false);  // DEBUG msg with true
 
         $('#hgTracksDialog').html("<div id='pop' style='font-size:.9em;'>"+ cleanHtml +"</div>");
 
         appendNonceJsToPage(nonceJs);
 
 
         // Strategy for popups with js:
         // - jsFiles and CSS should not be included in html.  Here they are shluped out.
         // - The resulting files ought to be loadable dynamically (with getScript()), 
         //   but this was not working nicely with the modal dialog
         //   Therefore include files must be included with hgTracks CGI !
         // - embedded js should not be in the popup box.
         // - Somethings should be in a popup.ready() function, and this is emulated below, 
         //   as soon as the cleanHtml is added
         //   Since there are many possible popup cfg dialogs, the ready should be all inclusive.
 
         // -- popup.ready() -- Here is the place to do things that might otherwise go
         //                     into a $('#pop').ready() routine!
 
         // Searching for some semblance of size suitability
         var popMaxHeight = ($(window).height() - 40);
         var popMaxWidth  = ($(window).width() - 40);
         var popWidth     = 700;
         if (popWidth > popMaxWidth)
             popWidth = popMaxWidth;
 
         $('#hgTracksDialog').dialog({
             ajaxOptions: {
                 // This doesn't work
                 cache: true
             },
             resizable: false,
             height: 'auto',
             width: popWidth,
             minHeight: 200,
             minWidth: 400,
             maxHeight: popMaxHeight,
             maxWidth: popMaxWidth,
             modal: true,
             closeOnEscape: true,
             autoOpen: false,
             buttons: { 
                 /* NOT NOW
                 "OK": function() {
                     popUpHgt.uiDialogOk($('#pop'));
                     $(this).dialog("close");
                 }
                 */
             },
             // popup.ready() doesn't seem to work in open.
 
             //create: function () { 
                 //$(this).siblings().find(".ui-dialog-title").html('<span style="">Test </span>'); 
                 //$(this).siblings().find(".ui-dialog-title").html('<span style="       visibility: hidden;"></span>'); 
             //},
             
             open: function () {
                 $('#hgTracksDialog').find('.filterBy,.filterComp').each(
                     function(i) {  // ddcl.js is dropdown checklist lib support
                         if ($(this).hasClass('filterComp'))
                             ddcl.setup(this);
                         else
                             ddcl.setup(this, 'noneIsAll');
                     }
                 );
 
             },
 
             close: function() {
                 popUpHgt.cleanup();
             }
         });
         
     
         $('#hgTracksDialog').dialog('option' , 'title' , popUpHgt.title);
         $('#hgTracksDialog').dialog('open');
 
         // Initialize autocomplete for alt/fix sequence names
         autocompleteCat.init($('#singleAltHaploId'),
                              { baseUrl: 'hgSuggest?db=' + getDb() + '&type=altOrPatch&prefix=',
                                enterSelectsIdentical: true });
         // Make multi-region option inputs select their associated radio buttons
         $('input[name="emPadding"]').on("keyup", function() {
             $('#virtModeType[value="exonMostly"]').prop('checked', true); });
         $('input[name="gmPadding"]').on("keyup", function() {
             $('#virtModeType[value="geneMostly"]').prop('checked', true); });
         $('#multiRegionsBedInput').on("keyup", function() {
             $('#virtModeType[value="customUrl"]').prop('checked', true); });
         $('#singleAltHaploId').on("keyup", function() {
             $('#virtModeType[value="singleAltHaplo"]').prop('checked', true); });
 
         // Customize message based on current mode
         var msg = "<em>Select a multi-region viewing mode below.</em>";  // default
         if (hgTracks.virtModeType) {
             msg = "The display is currently in <em><b> ";
             var mode = "unknown";
             if (hgTracks.virtModeType === "exonMostly") {
                 msg += "exon";
             } else if (hgTracks.virtModeType == "geneMostly") {
                 msg += "gene";
             } else if (hgTracks.virtModeType == "customUrl") {
                 msg += "custom regions";
             } else if (hgTracks.virtModeType == "singleAltHaplo") {
                 msg += "alt haplotype";
             } 
             msg += " </b></em> view. &nbsp;&nbsp;"
                 + "<em>Select a different viewing mode, or exit and return to normal view</em>.";
         }
         $('#multiRegionConfigStatusMsg').html(msg);
 
         // Make 'Cancel' button close dialog
         $('input[name="Cancel"]').on("click", function() {
             $('#hgTracksDialog').dialog('close');
         });
     }
 };
 
 var popUpHgcOrHgGene = {
 
     whichHgcMethod: "", // either hgc or hgGene or whatever else
     table: "", // the g= parameter
     title: "",
     saveAllVars: null, // when a click brings up hgTrackUi or something else with a form
     loadingId: null, // the id of the loading overlay
     href: "", // the link we're populating the pop up with
 
     cleanup: function ()
     {  // Clean out the popup box on close
         if ($('#hgcDialog').html().length > 0 ) {
             // clear out html after close to prevent problems caused by duplicate html elements
             $('#hgcDialog').html("");
             popUpHgcOrHgGene.whichHgcMethod = "";
             popUpHgcOrHgGene.title = "";
             popUpHgcOrHgGene.table = "";
             if (loadingId) {
                 hideLoadingImage(loadingId);
             }
         }
     },
 
     _uiDialogRequest: function (table, href)
     { // popup cfg dialog
         let cgi = parseUrl(href).pathInfo.split('/')[1];
         popUpHgcOrHgGene.whichHgcMethod = cgi;
         // the table name gets passed in
         popUpHgcOrHgGene.table = table;
         popUpHgcOrHgGene.title  = hgTracks.trackDb[table].shortLabel;
         popUpHgcOrHgGene.href = href;
         var rec = hgTracks.trackDb[table];
         if (popUpHgcOrHgGene.whichHgcMethod === "hgTrackUi" && rec && rec.configureBy) {
             if (rec.configureBy === 'none')
                 return;
             else if (rec.configureBy === 'clickThrough') {
                 window.location = cart.addUpdatesToUrl(href);
                 return;
             }  // default falls through to configureBy popup
         }
         loadingId = showLoadingImage("imgTbl");
         $.ajax({
                     type: "GET",
                     url: cart.addUpdatesToUrl(href),
                     dataType: "html",
                     trueSuccess: popUpHgcOrHgGene.uiDialog,
                     success: catchErrorOrDispatch,
                     error: errorHandler,
                     loadingId: loadingId,
                     cache: true
                 });
     },
 
     hgc: function (table, url)
     {   // Launches the popup but shields the ajax with a waitOnFunction
         if (typeof doHgcInPopUp !== 'undefined' && doHgcInPopUp === true) {
             waitOnFunction(popUpHgcOrHgGene._uiDialogRequest, table, url);
         } else {
             window.location = cart.addUpdatesToUrl(url);
         }
     },
 
     uiDialogOk: function (trackName)
     {
         // See popUp.uiDialogOk for a detailed explanation of the below vis-setting
         // code
         var rec = hgTracks.trackDb[trackName];
         var subtrack = tdbIsSubtrack(rec) ? trackName : undefined;  // subtrack vis rules differ
         var allVars = getAllVars($('#hgcDialog'), subtrack );
         var changedVars = varHashChanges(allVars,popUpHgcOrHgGene.saveAllVars);
 
         // special case these hprc tracks that allow you to turn on different tracks
         if (trackName.startsWith("hprcDeletions") || trackName.startsWith("hprcInserts") ||
                 trackName.startsWith("hprcArr") || trackName.startsWith("hprcDouble")) {
             trackName = "chainHprc";
         }
         var newVis = changedVars[trackName];
         // subtracks do not have "hide", thus '[]'
         var hide = (newVis && (newVis === 'hide' || newVis === '[]'));
         if ( ! normed($('#imgTbl')) ) { // On findTracks or config page
             if (objNotEmpty(changedVars))
                 cart.setVarsObj(changedVars);
         }
         else {  // On image page
             if (hide) {
                 if (objNotEmpty(changedVars))
                     cart.setVarsObj(changedVars);
                 $(document.getElementById('tr_' + trackName)).remove();
                 imageV2.afterImgChange(true);
                 cart.updateSessionPanel();
             } else {
                 // Keep local state in sync if user changed visibility
                 if (newVis) {
                     vis.update(trackName, newVis);
                 }
                 if (objNotEmpty(changedVars)) {
                     var urlData = cart.varsToUrlData(changedVars);
                     if (imageV2.mapIsUpdateable) {
                         imageV2.requestImgUpdate(trackName,urlData,"fake");
                     } else {
                         window.location = "../cgi-bin/hgTracks?" + urlData + "&hgsid=" + getHgsid();
                     }
                 }
             }
         }
     },
 
     uiDialog: function (response, status)
     {
     // Take html from hgc/hgGene and put it up as a modal dialog.
 
         // make sure all links (e.g. help links) open up in a new window
         //response = response.replace(/<a /ig, "<a target='_blank' ");
 
         var cleanHtml = response;
         cleanHtml = stripJsFiles(cleanHtml,false);   // DEBUG msg with true
         cleanHtml = stripCssFiles(cleanHtml,false);  // DEBUG msg with true
         var nonceJs = {};
         cleanHtml = stripCSPAndNonceJs(cleanHtml, false, nonceJs); // DEBUG msg with true
         cleanHtml = stripMainMenu(cleanHtml, false, nonceJs); // DEBUG msg with true
 
         // this is dumb but all relative links need to be stripped of _target = blank so we
         // can jump down the page rather than out to a new tab
         cleanHtml = cleanHtml.replace(/_target ?= ?["']blank["']/g,"");
 
         // "Share a link" at the top of the popup: shares a link to this details page
         // (the hgc URL with the hgsid stripped), handled by topLinks.js.
         var shareBar = "<div id='hgcShareBar' style='margin:0 0 8px 0; text-align:right;'>" +
             "<a id='hgcShareLink' href='#'>Share a link</a></div>";
         $('#hgcDialog').html("<div id='pop' style='font-size:1.1em;'>"+ shareBar + cleanHtml +"</div>");
         $('#hgcShareLink').on("click", function(e) {
             e.preventDefault();
             // Share the details-page URL with hgsid stripped; keep (or add) db so it opens
             // standalone, and note that the link shows the page, not the user's active tracks.
             if (window.topLinks && window.topLinks.shareUrl)
                 window.topLinks.shareUrl(popUpHgcOrHgGene.href, {ensureDb: getDb(), pageNote: true});
         });
         appendNonceJsToPage(nonceJs);
         let subtrack = tdbIsSubtrack(hgTracks.trackDb[popUpHgcOrHgGene.table]) ? popUpHgcOrHgGene.table : "";
         popUpHgcOrHgGene.saveAllVars = getAllVars( $('#hgcDialog'), subtrack );
 
 
 
         // Strategy for popups with js:
         // - jsFiles and CSS should not be included in html.  Here they are shluped out.
         // - The resulting files ought to be loadable dynamically (with getScript()),
         //   but this was not working nicely with the modal dialog
         //   Therefore include files must be included with hgc CGI !
         // - embedded js should not be in the popup box.
         // - Somethings should be in a popup.ready() function, and this is emulated below,
         //   as soon as the cleanHtml is added
         //   Since there are many possible popup cfg dialogs, the ready should be all inclusive.
 
         // -- popup.ready() -- Here is the place to do things that might otherwise go
         //                     into a $('#pop').ready() routine!
 
         // Searching for some semblance of size suitability
         var popMaxHeight = (window.innerHeight - (window.innerHeight * 0.15)); // make 15% of the bottom of the screen still visible
         var popMaxWidth     = (window.innerWidth - (window.innerWidth * 0.1)); // take up 90% of the window
 
         // Create dialog buttons for UI popup
         // this could be more buttons later
         var uiDialogButtons = {};
         uiDialogButtons.Close = function() {
             // if there was a form to submit, submit it:
             popUpHgcOrHgGene.uiDialogOk(popUpHgcOrHgGene.table);
             $(this).dialog("close");
         };
 
         let openIcon = "<a class='dialogNewWindowIcon' target='_blank' href='" + popUpHgcOrHgGene.href + "'><svg xmlns='http://www.w3.org/2000/svg' width='15' height='15' viewBox='0 0 512 512'><!--!Font Awesome Free 6.5.2 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free Copyright 2024 Fonticons, Inc.--><path d='M320 0c-17.7 0-32 14.3-32 32s14.3 32 32 32h82.7L201.4 265.4c-12.5 12.5-12.5 32.8 0 45.3s32.8 12.5 45.3 0L448 109.3V192c0 17.7 14.3 32 32 32s32-14.3 32-32V32c0-17.7-14.3-32-32-32H320zM80 32C35.8 32 0 67.8 0 112V432c0 44.2 35.8 80 80 80H400c44.2 0 80-35.8 80-80V320c0-17.7-14.3-32-32-32s-32 14.3-32 32V432c0 8.8-7.2 16-16 16H80c-8.8 0-16-7.2-16-16V112c0-8.8 7.2-16 16-16H192c17.7 0 32-14.3 32-32s-14.3-32-32-32H80z'/></svg></a>";
         let titleText = hgTracks.trackDb[popUpHgcOrHgGene.table].shortLabel + " (Item Details)" + openIcon;
 
         $('#hgcDialog').dialog({
             resizable: false,
             height: popMaxHeight,
             width: popMaxWidth,
             minHeight: 200,
             minWidth: 400,
             modal: true,
             closeOnEscape: true,
             autoOpen: false,
             buttons: uiDialogButtons,
 
             open: function (event) {
                 // fix popup to a location -- near the top and somewhat centered on the browser image
                 $(event.target).parent().css('position', 'fixed');
                 $(event.target).parent().css('top', '10%');
                 $('#hgcDialog').find('.filterBy,.filterComp').each(
                     function(i) {  // ddcl.js is dropdown checklist lib support
                         if ($(this).hasClass('filterComp'))
                             ddcl.setup(this);
                         else
                             ddcl.setup(this, 'noneIsAll');
                     }
                 );
             },
 
             close: function() {
                 popUpHgcOrHgGene.cleanup();
             },
             title: function() {
                 this.innerHTML = titleText;
             }
         });
 
         // override the _title function to show custom html:
         //$('#hgcDialog').dialog('option' , 'title', titleText);
         $('#hgcDialog').dialog('open');
         // if there is anything on the hgc page that would normally run
         // on document.ready, run it now
         hgc.initPage();
         document.addEventListener('click', e => {
             // if we clicked outside of the pop up, close the popup
             // Use contains() instead of coordinates because native browser
             // dropdowns (select elements) render outside the dialog bounds
             let dialogEl = document.getElementById("hgcDialog");
             if (!dialogEl) return;
             let dialogContainer = dialogEl.parentElement;
             if (dialogContainer && !dialogContainer.contains(e.target)) {
                 $("#hgcDialog").dialog("close");
             }
         });
 
         // Customize message based on current mode
         // Make 'Cancel' button close dialog
         $('input[name="Cancel"]').on("click", function() {
             $('#hgcDialog').dialog('close');
         });
     }
 };
 
 // Show the exported data hubs popup
 function showExportedDataHubsPopup() {
     let popUp = document.getElementById("exportedDataHubsPopup");
     title = popUp.title;
     if (title.length === 0 && popUp.getAttribute("mouseovertext") !== "") {title = popUp.getAttribute("mouseovertext");}
     $('#exportedDataHubsPopup').dialog({resizable: false, width:'650', title: title});
 }
 
 // Show the recommended track sets popup
 function showRecTrackSetsPopup() {
     // Update links with current position
     $('a.recTrackSetLink').each(function() {
         var $this = $(this);
         var link = $this.attr("href").replace(/position=.*/, 'position=');
         $this.attr("href", link + genomePos.original);
     });
     $('#recTrackSetsPopup').dialog({resizable: false, width:'650'});
 }
 
 function removeSessionPanel() {
     $('#recTrackSetsPanel').remove();
     setCartVar("hgS_otherUserSessionLabel", "off", null, false);
 }
 
 // A function to show the keyboard help dialog box, bound to ? and called from the menu bar
 function showHotkeyHelp() {
     $("#hotkeyHelp").dialog({width:'600', resizable: false});
 }
 
 // A function to add an entry for the keyboard help dialog box to the menubar 
 // and add text that indicates the shortcuts to many static menubar items as suggested by good old IBM CUA/SAA
 function addKeyboardHelpEntries() {
     var html = '<li><a id="keybShorts" title="List all possible keyboard shortcuts" href="#">Keyboard Shortcuts</a><span class="shortcut">?</span></li>';
     $('#help .last').before(html);
     $("#keybShorts").on("click", function(){showHotkeyHelp();} );
 
     html = '<span class="shortcut">s s</span>';
     $('#sessionsMenuLink').after(html);
 
     html = '<span class="shortcut">p s</span>';
     $('#publicSessionsMenuLink').after(html);
 
     html = '<span class="shortcut">c t</span>';
     $('#customTracksMenuLink').after(html);
 
     html = '<span class="shortcut">t c</span>';
     $('#customCompositeMenuLink').after(html);
 
     html = '<span class="shortcut">t h</span>';
     $('#trackHubsMenuLink').after(html);
 
     html = '<span class="shortcut">t b</span>';
     $('#blatMenuLink').after(html);
 
     html = '<span class="shortcut">t t</span>';
     $('#tableBrowserMenuLink').after(html);
 
     html = '<span class="shortcut">t i</span>';
     $('#ispMenuLink').after(html);
 
     html = '<span class="shortcut">t s</span>';
     $('#trackSearchMenuLink').after(html);
 
     html = '<span class="shortcut">c f</span>';
     $('#configureMenuLink').after(html);
 
     html = '<span class="shortcut">c r</span>';
     $('#cartResetMenuLink').after(html);
 }
 
 // A function for the keyboard shortcut:
 // View DNA
 function gotoGetDnaPage() {
     var position = hgTracks.chromName+":"+hgTracks.winStart+"-"+hgTracks.winEnd;
     if (hgTracks.virtualSingleChrom && (pos.chrom.search("multi") === 0)) {
         position = genomePos.get().replace(/,/g,'');
     } else if (hgTracks.windows && hgTracks.nonVirtPosition) {
         position = hgTracks.nonVirtPosition;
     }
     var pos = parsePosition(position);
     if (pos) {
         var url = "hgc?hgsid="+getHgsid()+"&g=getDna&i=mixed&c="+pos.chrom+"&l="+pos.start+"&r="+pos.end+"&db="+getDb();
         window.location.href = url;
     }
     return false;
 }
 
 function hubQuickConnect() {
     /* open a little dialog window that accepts a URL to a hub.txt file */
     const dialogHtml = 
         '<div id="hubQuickDialog" title="Track hub quick connect">'+
         '<b>Track hub URL:</b><br>'+
         '<form action="hgTracks" method="GET">'+
         '<input type="text" name="hubUrl" maxlength="1024" size="60" />'+
         '<input type="hidden" hgsid="'+getHgsid()+'"/>'+
         '<input type="submit" value="OK" />'+
         '</form>'+
         'To connect to public hubs, more options when connecting via URL or hub development tools, select from the menu My Data &gt; Track Hubs.'+
         '</div>';
     $('body').append(dialogHtml);
 
     // Initialize the dialog
     $("#hubQuickDialog").dialog({
         autoOpen: false,
         width: 600,
         height: 400,
         modal: true,
         // not showing a Cancel button, the standard X should be sufficient and the user can always use Esc
     });
 
     // Show dialog
     $("#hubQuickDialog").dialog("open");
 }
 
 function gotoConfigurePage() {
     let inp = $('input[name="hgTracksConfigPage"]');
     if (inp.length) {
         inp.submit().click();
     } else {
         // form a url to go there manually
         let url = window.location.href;
         url += "&hgTracksConfigPage=configure";
         window.location.assign(url);
     }
 }
 
 function onHideAllGroupButtonClick(ev) {
     /* called when 'hide all' button is clicked on group blue bar menu */
     let groupName = ev.target.getAttribute("data-group-name");
     let visSelects = document.querySelectorAll(`tr[id^="${groupName}"] select`);
     let trackNames = [];
     let values = [];
     for (let sel of visSelects) {
         sel.value = "hide";
         trackNames.push(sel.name);
         values.push("hide");
     }
     cart.setVars(trackNames, values, null, false);
     imageV2.fullReload();
 }
 
 // A function for the keyboard shortcuts "zoom to x bp"
 function zoomTo(zoomSize) {
     var flankSize = Math.floor(zoomSize/2);
     var posStr = genomePos.get();
     posStr = posStr.replace("virt:", "multi:");
     var pos = parsePosition(posStr);
     var mid = pos.start+(Math.floor((pos.end-pos.start)/2));
     var newStart = Math.max(mid - flankSize, 0);
     var newEnd = mid + flankSize - 1;
     var newPos = genomePos.setByCoordinates(pos.chrom, newStart, newEnd);
     if (hgTracks.virtualSingleChrom && (newPos.search("multi:")===0))
         newPos = genomePos.disguisePosition(newPosition); // DISGUISE?
     imageV2.navigateInPlace("db=" + getDb() + "&position="+newPos, null, true);
 }
 
 // A function for the keyboard shortcuts "highlight add/clear/new"
 function highlightCurrentPosition(mode) {
     var pos = genomePos.get();
     if (mode=="new")
         dragSelect.highlightThisRegion(pos, false);
     else if (mode=="add")
         dragSelect.highlightThisRegion(pos, true);
     else {
         hgTracks.highlight = "";
         var cartSettings = {'highlight': ""};
         cart.setVarsObj(cartSettings);
         imageV2.drawHighlights();
     }
 }
 
 function onTrackDelIconClick (ev) {
     /* delete custom track if user clicks its trash icon */
     // https://genome.ucsc.edu/cgi-bin/hgCustom?hgsid=1645697744_i0Yp2Di71NytSDdb6r0vUbupIvKO&hgct_do_delete=delete&hgct_del_ct_UserTrack_3545=on
     var divEl = ev.target.closest("div"); // must use .closest(), as user can click on either the SVG or the DIV space.
     var trackName = divEl.getAttribute("data-track");
     var hgsid = getHgsid();
     var url = 'hgCustom?hgsid='+hgsid+'&hgct_do_delete=delete&hgct_del_'+trackName+'=on';
     xhttp = new XMLHttpRequest();
     // this cannot be asyncronous, as users can click quickly here and the hgCustom calls above cannot run in parallel
     // since we store custom tracks as a text file, not mysql tables
     xhttp.open("GET", url, false);
     xhttp.send();
     divEl.closest("td").remove();
 }
 
 function onQuickLiftDelIconClick (ev) {
     /* Remove this track's stanza from the quickLift hub in trash, and
      * remove all rows referencing it from the page (it can appear both in
      * its hub group and in the Visible Tracks group). */
     var divEl = ev.target.closest("div");
     var trackName = divEl.getAttribute("data-track");
     var sourceDb = divEl.getAttribute("data-sourcedb");
     var hgsid = getHgsid();
     var url = 'hgTrackUi?hgsid=' + hgsid +
               '&hgTrackUi_op=quickLiftRemove' +
               '&g=' + encodeURIComponent(trackName) +
               '&qlSourceDb=' + encodeURIComponent(sourceDb);
     var xhttp = new XMLHttpRequest();
     // synchronous: the hub file is a shared text file, parallel rewrites would race
     xhttp.open("GET", url, false);
     xhttp.send();
     var selector = 'div.quickLiftDelIcon[data-track="' + trackName + '"]';
     document.querySelectorAll(selector).forEach(function(d) {
         var td = d.closest("td");
         if (td) td.remove();
     });
 }
 
 
   //////////////////////////////////
  //// popup (aka modal dialog) ////
 //////////////////////////////////
 var popUp = {
 
     trackName:            "",
     trackDescriptionOnly: false,
     saveAllVars:          null,
 
     cleanup: function ()
     {  // Clean out the popup box on close
         if ($('#hgTrackUiDialog').html().length > 0 ) {
             // clear out html after close to prevent problems caused by duplicate html elements
             $('#hgTrackUiDialog').html("");
             popUp.trackName = ""; //set to defaults
             popUp.trackDescriptionOnly = false;
             popUp.saveAllVars = null;
         }
     },
 
     _uiDialogRequest: function (trackName,descriptionOnly)
     { // popup cfg dialog
         popUp.trackName = trackName;
         var myLink = "../cgi-bin/hgTrackUi?g=" + trackName + "&hgsid=" + getHgsid() +
                      "&db=" + getDb();
         popUp.trackDescriptionOnly = descriptionOnly;
         if (popUp.trackDescriptionOnly)
             myLink += "&descriptionOnly=1";
 
         var rec = hgTracks.trackDb[trackName];
         if (!descriptionOnly && rec && rec.configureBy) {
             if (rec.configureBy === 'none')
                 return;
             else if (rec.configureBy === 'clickThrough') {
                 jQuery('body').css('cursor', 'wait');
                 window.location = cart.addUpdatesToUrl(myLink);
                 return;
             }  // default falls through to configureBy popup
         }
         myLink += "&ajax=1";
         $.ajax({
                     type: "GET",
                     url: cart.addUpdatesToUrl(myLink),
                     dataType: "html",
                     trueSuccess: popUp.uiDialog,
                     success: catchErrorOrDispatch,
                     error: errorHandler,
                     cmd: rightClick.selectedMenuItem,
                     cache: false
                 });
     },
 
     hgTrackUi: function (trackName,descriptionOnly)
     {   // Launches the popup but shields the ajax with a waitOnFunction
         waitOnFunction( popUp._uiDialogRequest, trackName, descriptionOnly );  
     },
 
     uiDialogOk: function (popObj, trackName)
     {   // When hgTrackUi Cfg popup closes with ok, then update cart and refresh parts of page
         var rec = hgTracks.trackDb[trackName];
         var subtrack = tdbIsSubtrack(rec) ? trackName : undefined;  // subtrack vis rules differ
         // For unknown reasons IE8 fails to find $('#pop'), occasionally
         var allVars = getAllVars($('#hgTrackUiDialog'), subtrack );
         //  Since 2010, when Tim changed this to only report changed vars instead of all form vars,
         // it no longer matches the behavior of hgTrackUi when called the non-popup way.
         // A few places in the hgTracks C code have been patched to explicitly set the cart vars
         // for some default checkboxes. So now this still means that QA must explicitly test
         // both paths through the code: as a separate full hgTracksUi page, and as a popup config window.
         // hgTrackUi always sends in its form all variables causing them to be explicitly set in the cart.  
         // The popup only sends things that have changed, causing those changes to appear explicitly
         // and even then it skips over disabled form items.
         // There is some C code that was written before the popup config, 
         // and it expects all the variables are set or none are.
         // If just some are set, and not the default ones, it gets confused.
         // I fixed just such a bug in the code that handles refSeq.
         // See commit daf92c0f9eb331ea60740e6802aabd241d4be363.
         var changedVars = varHashChanges(allVars,popUp.saveAllVars);
          // DEBUG Examples:
         //debugDumpFormCollection("saveAllVars", popUp.saveAllVars);
         //debugDumpFormCollection("allVars", allVars);
         //debugDumpFormCollection("changedVars", changedVars);
         var newVis = changedVars[trackName];
         // subtracks do not have "hide", thus '[]'
         var hide = (newVis && (newVis === 'hide' || newVis === '[]'));  
         if ( ! normed($('#imgTbl')) ) { // On findTracks or config page
             if (objNotEmpty(changedVars))
                 cart.setVarsObj(changedVars);
         }
         else {  // On image page
             if (hide) {
                 if (objNotEmpty(changedVars))
                     cart.setVarsObj(changedVars);
                 $(document.getElementById('tr_' + trackName)).remove();
                 imageV2.afterImgChange(true);
                 cart.updateSessionPanel();
             } else {
                 // Keep local state in sync if user changed visibility
                 if (newVis) {
                     vis.update(trackName, newVis);
                 }
                 if (objNotEmpty(changedVars)) {
                     var urlData = cart.varsToUrlData(changedVars);
                     if (imageV2.mapIsUpdateable) {
                         imageV2.requestImgUpdate(trackName,urlData,"");
                     } else {
                         window.location = "../cgi-bin/hgTracks?" + urlData + "&hgsid=" + getHgsid();
                     }
                 }
             }
         }
     },
 
     uiDialog: function (response, status)
     {
     // Take html from hgTrackUi and put it up as a modal dialog.
 
         // make sure all links (e.g. help links) open up in a new window
         response = response.replace(/<a /ig, "<a target='_blank' ");
 
         var cleanHtml = response;
         cleanHtml = stripJsFiles(cleanHtml,false);   // DEBUG msg with true
         cleanHtml = stripCssFiles(cleanHtml,false);  // DEBUG msg with true
         //cleanHtml = stripJsEmbedded(cleanHtml,false);// DEBUG msg with true // OBSOLETE BY CSP2?
 	var nonceJs = {};
 	cleanHtml = stripCSPAndNonceJs(cleanHtml, false, nonceJs); // DEBUG msg with true
 
 	//alert(cleanHtml);  // DEBUG REMOVE
         $('#hgTrackUiDialog').html("<div id='pop' style='font-size:.9em;'>"+ cleanHtml +"</div>");
 
 	appendNonceJsToPage(nonceJs);
 
         // Strategy for popups with js:
         // - jsFiles and CSS should not be included in html.  Here they are shluped out.
         // - The resulting files ought to be loadable dynamically (with getScript()), 
         //   but this was not working nicely with the modal dialog
         //   Therefore include files must be included with hgTracks CGI !
         // - embedded js should not be in the popup box.
         // - Somethings should be in a popup.ready() function, and this is emulated below, 
         //   as soon as the cleanHtml is added
         //   Since there are many possible popup cfg dialogs, the ready should be all inclusive.
 
         if ( ! popUp.trackDescriptionOnly ) {
             // If subtrack then vis rules differ
             var subtrack = tdbIsSubtrack(hgTracks.trackDb[popUp.trackName]) ? popUp.trackName :"";  
             // Saves the original vars (and vals) that may get changed by the popup cfg.
             popUp.saveAllVars = getAllVars( $('#hgTrackUiDialog'), subtrack ); 
 
             // -- popup.ready() -- Here is the place to do things that might otherwise go
             //                     into a $('#pop').ready() routine!
         }
 
         // Searching for some semblance of size suitability
         var popMaxHeight = ($(window).height() - 40);
         var popMaxWidth  = ($(window).width() - 40);
         var popWidth     = 640;
         if (popWidth > popMaxWidth)
             popWidth = popMaxWidth;
 
         // Create dialog buttons for UI popup
         var uiDialogButtons = {};
         if (popUp.trackDescriptionOnly) {
             uiDialogButtons.OK = function() {
                 $(this).dialog("close");
             };
         } else {
             uiDialogButtons.Apply = function() {
                  popUp.uiDialogOk($('#pop'), popUp.trackName);
                  // thanks to JAT for this cleverness to keep button functioning
                  popUp.saveAllVars = getAllVars( $('#hgTrackUiDialog'), popUp.trackName);
                  if (popUp.saveAllVars[popUp.trackName+"_sel"] === 0) {       // hide
                     // NOTE: once hidden, can't be unhidden by popup, so shut it down
                     $(this).dialog("close");
                 }
             };
             uiDialogButtons.OK = function() {
                 popUp.uiDialogOk($('#pop'), popUp.trackName);
                 $(this).dialog("close");
             };
         }
 
         $('#hgTrackUiDialog').dialog({
             resizable: true,               // Let description scroll vertically
             height: (popUp.trackDescriptionOnly ? popMaxHeight : 'auto'),
             width: popWidth,
             minHeight: 200,
             minWidth: 400,
             maxHeight: popMaxHeight,
             maxWidth: popMaxWidth,
             modal: true,
             closeOnEscape: true,
             autoOpen: false,
             buttons: uiDialogButtons,
 
             // popup.ready() doesn't seem to work in open.
             open: function(event) {
                 // fix popup to a location -- near the top and somewhat centered on the browser image
                 $(event.target).parent().css('position', 'fixed');
                 $(event.target).parent().css('top', '18%');
                 if (popUp.trackDescriptionOnly) {
                     $(event.target).parent().css('left', '15%');
                 } else {
                     $(event.target).parent().css('left', '30%');
                 }
                 var offsetTop = $(event.target).parent()[0].offsetTop;
                 // from popMaxHeight calculation above:
                 var offsetBottom = 40;
                 var maxContainerHeight = $(window).height() - offsetTop - offsetBottom;
                 $(event.target).css('max-height', maxContainerHeight - 100);
 
                 if (!popUp.trackDescriptionOnly) {
                     $('#hgTrackUiDialog').find('.filterBy,.filterComp').each(
                         function(i) {
                             if ($(this).hasClass('filterComp'))
                                 ddcl.setup(this);
                             else
                                 ddcl.setup(this, 'noneIsAll');
                         }
                     );
                 }
             },
             close: function() {
                 popUp.cleanup();
             }
         });
         
         $(".ui-dialog").on("keypress", function(e) {
             var key = e.charCode || e.keyCode || 0;     
             if (key == 13) {
                 e.preventDefault();
                 $(".ui-button:contains('OK')").click();
             }
         });
 
         // FIXME: Why are open and close no longer working!!!
         if (popUp.trackDescriptionOnly) {
             var myWidth =  $(window).width() - 300;
             if (myWidth > 900)
                 myWidth = 900;
             $('#hgTrackUiDialog').dialog("option", "maxWidth", myWidth);
             $('#hgTrackUiDialog').dialog("option", "width", myWidth);
             $('#hgTrackUiDialog').dialog('option' , 'title' ,
                                hgTracks.trackDb[popUp.trackName].shortLabel+" Track Description");
             $('#hgTrackUiDialog').dialog('open');
         } else {
             $('#hgTrackUiDialog').dialog('option' , 'title' ,
                                   hgTracks.trackDb[popUp.trackName].shortLabel+" Track Settings");
             $('#hgTrackUiDialog').dialog('open');
         }
         var buttOk = $('button.ui-state-default');
         $(buttOk).trigger("focus");
     }
 };
 
   ///////////////////////////////
  //// imageV2  (aka imgTbl) ////
 ///////////////////////////////
 var imageV2 = {
 
     enabled:        false,  // Will be set to true unless advancedJavascriptFeatures
                             // is turned off OR if track search of config page
     imgTbl:         null,   // formerly "trackImgTbl"  The imgTbl or null if non-imageV2.
     inPlaceUpdate:  false,  // modified based on value of hgTracks.inPlaceUpdate & mapIsUpdateable
     mapIsUpdateable:true,
     lastTrack:      null,   // formerly (lastMapItem) this is used to try to keep what the
                             // last track the cursor passed.
 
     LEFTADD: 3,             // when going from pixels to chrom coords, these 3 pixels
                             // are somehow used for "borders or cgi item calc ?" (original comment)
 
     markAsDirtyPage: function ()
     {   // Page is marked as dirty so that the back-button knows page doesn't match cart
         var dirty = normed($('#dirty'));
         if (dirty)
             $(dirty).val('true');
     },
 
     markAsCleanPage: function ()
     {   // Clears signal that history may be out of sync with cart.
         var dirty = normed($('#dirty'));
         if (dirty)
             $(dirty).val('false');
     },
 
     isDirtyPage: function ()
     { // returns true if page was marked as dirty
     // This will allow the backbutton to be overridden
 
         var dirty = normed($('#dirty'));
         if (dirty && $(dirty).val() === 'true')
             return true;
         return false;
     },
     
     manyTracks: function ()
     {   // image-reload is slower than whole page reload when there are too many tracks
         if (!hgTracks || !hgTracks.trackDb || objKeyCount(hgTracks.trackDb) > 50)
             return true;
         return false;
     },
 
     moveTiming: function() 
     {    // move measure timing messages to the end of the page
         if ($(".timing").length > 0) {
             $("body").append("<div id='timingDiv'></div>");
             $(".timing").detach().appendTo('#timingDiv');
         }
     },
 
     updateTiming: function (response)
     {   // update measureTiming text on current page based on what's in the response
         var reg = new RegExp("(<span class='timing'>.+?</span>)", "g");
         var strs = [];
         for (var a = reg.exec(response); a && a[1]; a = reg.exec(response)) {
             strs.push(a[1]);
         }
         if (strs.length > 0) {
             $('.timing').remove();
             for (var ix = strs.length; ix > 0; ix--) {
                 $('#timingDiv').append(strs[ix - 1]);
             }
         }
         reg = new RegExp("(<span class='trackTiming'>[\\S\\s]+?</span>)");
         a = reg.exec(response);
         if (a && a[1]) {
             $('.trackTiming').replaceWith(a[1]);
         }
     },
 
     loadSuggestBox: function ()
     {
         if ($('#positionInput').length) {
             if (!suggestBox.initialized) { // only call init once
                 suggestBox.init(getDb(),
                             $("#suggestTrack").length > 0,
                             function (item) {
                                 if (item.type === "geneExon") {
                                     // Complete "GENE exon N" — resolve via hgApi and navigate
                                     $.ajax({
                                         type: "GET",
                                         url: "../cgi-bin/hgApi",
                                         data: cart.varsToUrlData({ 'hgsid': getHgsid(), 'db': getDb(),
                                               'cmd': 'geneExonToPos', 'symbol': item.symbol,
                                               'num': item.num, 'offset': item.offset || 0 }),
                                         trueSuccess: rightClick.handleZoomCodon,
                                         success: catchErrorOrDispatch,
                                         error: function() {
                                             window.location.assign("../cgi-bin/hgSearch?search=" +
                                                 encodeURIComponent(item.value.trim()) + "&hgsid=" + getHgsid());
                                         },
                                         cache: false
                                     });
                                     return;
                                 } else if (item.type === "geneExonHint") {
                                     // Partial — input is now "GENE exon "; keep focus so user types the number
                                     $('#positionInput').focus();
                                     return;
                                 } else if (["helpDocs", "publicHubs", "trackDb"].includes(item.type) ||
                                         item.id.startsWith("hgc")) {
                                     if (item.geneSymbol) {
                                         selectedGene = item.geneSymbol;
                                         // Overwrite item's long value with symbol after the autocomplete plugin is done:
                                         window.setTimeout($('#positionInput').val(item.geneSymbol), 0);
                                     } else {
                                         selectedGene = item.value;
                                     }
                                     window.location.assign(item.id);
                                 } else if (item.type === "hgvs") {
                                     let newPos = genomePos.setByCoordinates(item.chrom, item.start, item.end);
                                     dragSelect.highlightThisRegion(newPos, true, "#fcfcac");
                                     let withPadding = genomePos.setByCoordinates(item.chrom, item.start-5, item.end+5);
                                     $("#goButton").trigger("click");
                                 } else {
                                     genomePos.set(item.id, getSizeFromCoordinates(item.id));
                                     if ($("#suggestTrack").length && $('#hgFindMatches').length) {
                                         // Set cart variables to open the hgSuggest gene track and highlight
                                         // the chosen transcript.  These variables will be submittted by the goButton
                                         // click handler.
                                         vis.makeTrackVisible($("#suggestTrack").val());
                                         cart.addVarsToQueue(["hgFind.matches"],[$('#hgFindMatches').val()]);
                                     }
                                     $("#goButton").trigger("click");
                                 }
                             },
                             function (position) {
                                 genomePos.set(position, getSizeFromCoordinates(position));
                             }
                 );
             }
         }
     },
     
     afterImgChange: function (dirty)
     {   // Standard things to do when manipulations change image without ajax update.
         dragReorder.init();
         dragSelect.load(false);
         imageV2.drawHighlights();
         if (dirty)
             imageV2.markAsDirtyPage();
     },
     
     afterReload: function (id)
     {   // Reload various UI widgets after updating imgTbl map.
         dragReorder.init();
         dragSelect.load(false);
         // Do NOT reload context menu (otherwise we get the "context menu sticks" problem).
         // rightClick.load($('#tr_' + id));
         if (imageV2.imgTbl.tableDnDUpdate)
             imageV2.imgTbl.tableDnDUpdate();
         rightClick.reloadFloatingItem();
         // Turn on drag scrolling.
         if (hgTracks.imgBoxPortal) {
             $("div.scroller").panImages();
         }
         if (imageV2.backSupport) {
             if (id) { // The remainder is only needed for full reload
                 imageV2.markAsDirtyPage(); // vis of cfg change
                 imageV2.drawHighlights();
                 if (typeof showMouseovers !== 'undefined' && showMouseovers) {
                     convertTitleTagsToMouseovers();
                 }
                 return;
             }
         }
         
         imageV2.loadRemoteTracks();
         imageV2.loadSuggestBox();
         imageV2.drawHighlights();
 
         if (imageV2.backSupport) {
             // try/catch: browser extensions that proxy history.pushState can throw
             // "Permission denied to access property apply" under Firefox cross-origin
             // security. Swallow it so zoom/drag still complete; only the URL-bar
             // position update is lost.
             try {
                 imageV2.setInHistory(false);    // Set this new position into History stack
             } catch (e) {
                 console.warn("setInHistory failed, continuing:", e);
             }
         } else {
             imageV2.markAsDirtyPage();
         }
         if (typeof showMouseovers !== 'undefined' && showMouseovers) {
             convertTitleTagsToMouseovers();
         }
         if(typeof window.igvBrowser !== "undefined") {
            window.igvBrowser.search(genomePos.get());
         }
 
         if (typeof doMyVariants !== 'undefined' && doMyVariants) {
             myVariants.init();
         }
     },
 
     updateImgForId: function (html, id, fullImageReload, newJsonRec)
     {   // update row in imgTbl for given id.
         // return true if we successfully pull slice for id and update it in imgTrack.
         var newTr = $(html).find("tr[id='tr_" + id + "']");
         if (newTr.length > 0) {
             var tr = $(document.getElementById("tr_" + id));
             if (tr.length > 0) {
                 $(tr).html(newTr.children());
 
                 // Need to update tr class list too
                 var classes = $(html).find("tr[id='tr_"+ id + "']")[0].className;
                 if (classes && classes.length > 0) {
                     $(tr).removeClass();
                     $(tr).addClass(classes);
                 }
 
                 // NOTE: Want to examine the png? Uncomment:
                 //var img = $('#tr_' + id).find("img[id^='img_data_']").attr('src');
                 //warn("Just parsed image:<BR>"+img);
 
                 // >1x dragScrolling needs some extra care.
                 if (hgTracks.imgBoxPortal && (hgTracks.imgBoxWidth > hgTracks.imgBoxPortalWidth)) {
                     if (hgTracks.imgBoxPortalLeft !== undefined
                     &&  hgTracks.imgBoxPortalLeft !== null) {
                         $(tr).find('.panImg').css({'left': hgTracks.imgBoxPortalLeft });
                         $(tr).find('.tdData').css(
                                 {'backgroundPosition': hgTracks.imgBoxPortalLeft});
                     }
                 }
 
                 // Need to update vis box (in case this is reached via back-button)
                 if (imageV2.backSupport && fullImageReload) {
                     // Update abbr so that rows can be resorted properly
                     var abbr = $(newTr).attr('abbr');
 
                     if (abbr) {
                         $(tr).attr('abbr', abbr);
                     }
 
                     if (newJsonRec)
                         vis.update(id, vis.enumOrder[newJsonRec.visibility]);
                 }
                 // hg.conf will turn this on 2020-10 - Hiram
                 if (window.mouseOverEnabled) { mouseOver.updateMouseOver(id, newJsonRec); }
                 return true;
             }
         }
         return false;
     },
 
     updateImgForAllIds: function (response, oldJson, newJson)
     {   // update all rows in imgTbl based upon navigateInPlace response.
         var imgTbl = $('#imgTbl');
 
         // We update rows one at a time 
         // (b/c updating the whole imgTbl at one time doesn't work in IE).
         var id;
         for (id in newJson.trackDb) {
             var newJsonRec = newJson.trackDb[id];
             var oldJsonRec = oldJson.trackDb[id];
             
             // use limitedVis as visibility if set
             if (newJsonRec.limitedVis !== undefined)
                 newJsonRec.visibility = newJsonRec.limitedVis;
             if (newJsonRec.visibility === 0)  // hidden 'ruler' is in newJson.trackDb!
                 continue;
             if (newJsonRec.type === "remote")
                 continue;
             var escapedId = id.replace('.', '\\.');
             if (oldJsonRec &&  oldJsonRec.visibility !== 0 && $('tr#tr_' + escapedId).length === 1) {
                 // New track replacing old:
                 if (!imageV2.updateImgForId(response, id, true, newJsonRec))
                     warn("Couldn't parse out new image for id: " + id);
             } else { //if (!oldJsonRec || oldJsonRec.visibility === 0)
                 // New track seen for the first time
                 if (imageV2.backSupport) {
                     $(imgTbl).append("<tr id='tr_" + id + "' abbr='0'" + // abbr gets filled in
                                         " class='imgOrd trDraggable'></tr>");
                     if (!imageV2.updateImgForId(response, id, true, newJsonRec)) {
                         warn("Couldn't insert new image for id: " + id);
                     } else {
                         cart.updateSessionPanel();
                     }
                 }
             }
         }
         if (imageV2.backSupport) {
             // Removes OLD: those in oldJson but not in newJson
             for (id in oldJson.trackDb) {
                 if ( ! newJson.trackDb[id] )
                     $(document.getElementById('tr_' + id)).remove();
             }
             
             // Need to reorder the rows based upon abbr
             dragReorder.sort($(imgTbl));
         }
     },
     
     updateChromImg: function (response)
     {   // Parse out new chrom 'ideoGram' (if available)
         // e.g.: <IMG SRC = "../trash/hgtIdeo/hgtIdeo_hgwdev_larrym_61d1_8b4a80.gif"
         //                BORDER=1 WIDTH=1039 HEIGHT=21 USEMAP=#ideoMap id='chrom' style='display: inline;'>
         // If the ideo is hidden or missing, we supply a place-holder for dynamic update later.
         // e.g.: <IMG SRC = ""
         //                BORDER=1 WIDTH=1039 HEIGHT=0 USEMAP=#ideoMap id='chrom' style='display: none'>
         // Larry's regex voodoo:
         var a = /<IMG([^>]+SRC[^>]+id='chrom'[^>]*)>/.exec(response);
         if (a && a[1]) {
             var b = /SRC\s*=\s*"([^")]*)"/.exec(a[1]);
             if (b) { // tolerate empty SRC= string when no ideo
                 $('#chrom').attr('src', b[1]);
                 var c = /style\s*=\s*'([^')]+)'/.exec(a[1]);
                 if (c && c[1]) {
                     $('#chrom').attr('style', c[1]);
                 }
                 var d = /HEIGHT\s*=\s*(\d*)/.exec(a[1]);
                 if (d && d[1]) {
                     $('#chrom').attr('HEIGHT', d[1]);
                 }
                 // Even if we're on the same chrom, ideoMap may change because the label
                 // on the left changes width depending on band name, and that changes px scaling.
                 var ideoMapMatch = /<MAP Name=ideoMap>[\s\S]+?<\/MAP>/.exec(response);
                 if (ideoMapMatch) {
                     var $oldMap = $("map[name='ideoMap']");
                     var $container = $oldMap.parent();
                     $oldMap.remove();
                     $container.append(ideoMapMatch[0]);
                 }
                 if (imageV2.backSupport) {
                     // Reinit chrom dragging.
                     if ($('area.cytoBand').length >= 1) {
                         $('img#chrom').chromDrag();
                     }
                 }
             }
         }
     },
 
     updateBackground: function (response)
     {
         // Added by galt to update window separators
         // Parse out background image url
         // background-image:url("../trash/hgt/blueLines1563-118-12_hgwdev_galt_9df9_e33b30.png")
         // background-image:url("../trash/hgt/winSeparators_hgwdev_galt_5bcb_baff60.png")
         // This will only need to update when multi-region is on and is using winSeparators.
 
         var a = /background-image:url\("(..\/trash\/hgt\/winSeparators[^"]+[.]png)"\)/.exec(response);
         if (a && a[1]) {
             $('td.tdData').css("background-image", "url("+a[1]+")");
         }
 
     },
 
         
     requestImgUpdate: function (trackName,extraData,loadingId,newVisibility)
     {
         // extraData, loadingId and newVisibility are optional
         var data = "hgt.trackImgOnly=1&hgsid=" + getHgsid() + "&hgt.trackNameFilter=" + trackName + "&db=" + getDb();
         if (extraData && extraData !== "")
             data += "&" + extraData;
         if (!loadingId || loadingId === "")
             loadingId = showLoadingImage("tr_" + trackName);
         var getOrPost = "GET";
         if ((data.length) > 2000) // extraData could contain a bunch of changes from the cfg dialog
             getOrPost = "POST";
         $.ajax({
                     type: getOrPost,
                     url: "../cgi-bin/hgTracks",
                     data: cart.addUpdatesToUrl(data),
                     dataType: "html",
                     trueSuccess: imageV2.updateImgAndMap,
                     success: catchErrorOrDispatch,
                     error: errorHandler,
                     cmd: 'refresh',
                     loadingId: loadingId,
                     id: trackName,
                     newVisibility: newVisibility,
                     cache: false
                 });
     },
 
     fullReload: function(extraData)
     {
         // force reload of whole page via trackform submit
         // This function does not return
         jQuery('body').css('cursor', 'wait');
         if (extraData || cart.updatesWaiting()) {
             var url = cart.addUpdatesToUrl(window.location.href);
             if (extraData) {
                 if ( url.lastIndexOf("?") === -1)
                     url += "?" + extraData;
                 else
                     url += '&' + extraData;
             }
             window.location.assign(url);
             return false;
         }
         document.TrackHeaderForm.submit();
         window.igv.initUcsc();
     },
 
     updateImgAndMap: function (response, status)
     {   // Handle ajax response with an updated trackMap image, map and optional ideogram. 
         //    and maybe the redLines background too.
         // this.cmd can be used to figure out which menu item triggered this.
         // this.id === appropriate track if we are retrieving just a single track.
 
         // update local hgTracks.trackDb to reflect possible side-effects of ajax request.
 
         var newJson = scrapeVariable(response, "hgTracks");
 
         //alert(JSON.stringify(newJson)); // DEBUG Example
 
         var oldJson = hgTracks;
         var valid = false;
         var stripped = {};
         if (!newJson) {
             stripJsEmbedded(response, true, stripped);
             if ( ! stripped.warnMsg )
                 warn("An unexpected error has occurred. Please consider letting us know " +
                      "by emailing genome-www@soe.ucsc.edu with the steps that resulted in " +
                      "this state and any info on how we could reproduce it. Using the " +
                      "sessions (My Data > My Sessions) tool can simplify the process by " +
                      "saving all configuration settings.");
         } else {
             if (this.id) {
                 if (newJson.trackDb[this.id]) {
                     var visibility = vis.enumOrder[newJson.trackDb[this.id].visibility];
                     var limitedVis;
                     if (newJson.trackDb[this.id].limitedVis)
                         limitedVis = vis.enumOrder[newJson.trackDb[this.id].limitedVis];
                     if (this.newVisibility && limitedVis && this.newVisibility !== limitedVis)
                         // see redmine 1333#note-9
                         alert("There are too many items to display the track in " +
                                 this.newVisibility + " mode.");
                     var rec = oldJson.trackDb[this.id];
                     rec.limitedVis = newJson.trackDb[this.id].limitedVis;
                     rec.imgOffsetY = newJson.trackDb[this.id].imgOffsetY;
                     vis.update(this.id, visibility);
                     if (visibility === "hide")
                         cart.updateSessionPanel(); // notify when vis change to hide track
                     valid = true;
                 } else {
                     // what got returned from the AJAX request was a different
                     // set of tracks.  Let's do a reload and hope for the best
                     imageV2.fullReload();
                 }
             } else {
                 valid = true;
             }
 
             suggestBox.restoreWatermark(getDb(), $("#suggestTrack").length > 0);
 
             // the ajax request may have generated an error or warning in the warnbox
             // so make sure those warnings still get to the user
             stripJsEmbedded(response, false, stripped);
         }
         if (valid) {
             if (imageV2.enabled
             && this.id
             && this.cmd
             && this.cmd !== 'wholeImage'
             && this.cmd !== 'selectWholeGene'
             && !newJson.virtChromChanged) {
                 // Extract <TR id='tr_ID'>...</TR> and update appropriate row in imgTbl;
                 // this updates src in img_left_ID, img_center_ID and img_data_ID
                 // and map in map_data_ID
                 var id = this.id;
                 if (imageV2.updateImgForId(response, id, false, newJson)) {
                     imageV2.afterReload(id);
                     imageV2.updateBackground(response);  // Added by galt to update window separators
                 } else {
                     warn("Couldn't parse out new image for id: " + id);
                     // Very helpful when debugging and alert doesn't render the html:
                     //alert("Couldn't parse out new image for id: " + id+"BR"+response);
                 }
             } else {
                 if (imageV2.enabled) {
                     // Implement in-place updating of hgTracks image
                     // GALT delaying this until after newJson updated in hgTracks so disguising works
                     //genomePos.setByCoordinates(newJson.chromName, newJson.winStart + 1, newJson.winEnd);
                     $("input[name='c']").val(newJson.chromName);
                     $("input[name='l']").val(newJson.winStart);
                     $("input[name='r']").val(newJson.winEnd);
 
                     if (newJson.cgiVersion !== oldJson.cgiVersion || newJson.virtChromChanged) {
                         // Must reload whole page because of a new version on the server;
                         // this should happen very rarely. Note that we have already updated 
                         // position based on the user's action.
                         imageV2.fullReload();
                     } else {
                         // Will rebuild image adding new, removing old and resorting tracks
                         imageV2.updateImgForAllIds(response,oldJson,newJson);
                         imageV2.updateChromImg(response);
                         imageV2.updateBackground(response);  // Added by galt to update window separators
                         hgTracks = newJson;
                         genomePos.original = undefined;
                         genomePos.setByCoordinates(hgTracks.chromName, hgTracks.winStart + 1, hgTracks.winEnd); // MOVED HERE GALT
                         initVars();
                         imageV2.afterReload();
                     }
                 } else {
                     warn("ASSERT: Attempt to update track without advanced javascript features.");
                 }
             }
             if (hgTracks.measureTiming) {
                 imageV2.updateTiming(response);
             }
         }
         if (this.disabledEle) {
             this.disabledEle.prop('disabled', false);
         }
         if (this.loadingId) {
             hideLoadingImage(this.loadingId);
         }
         jQuery('body').css('cursor', '');
         if (valid && this.currentId) {
             var top = $(document.getElementById("tr_" + this.currentId)).position().top;
             $(window).scrollTop(top - this.currentIdYOffset);
         }
     },
 
     loadRemoteTracks: function ()
     {
         if (hgTracks.trackDb) {
             for (var id in hgTracks.trackDb) {
                 var rec = hgTracks.trackDb[id];
                 if (rec.type === "remote") {
                     if ($("#img_data_" + id).length > 0) {
                         // load the remote track renderer via jsonp
                         rec.loadingId = showLoadingImage("tr_" + id);
                         var script = document.createElement('script');
                         var pos = parsePosition(genomePos.get());
                         var name = rec.remoteTrack || id;
                         script.setAttribute('src',
                                 rec.url + "?track=" + name +
                                 "&jsonp=imageV2.remoteTrackCallback&position=" +
                                 encodeURIComponent(pos.chrom + ":" + pos.start + "-" + pos.end) +
                                 "&pix=" + $('#imgTbl').width()
                         );
                         document.getElementsByTagName('head')[0].appendChild(script);
                     }
                 }
             }
         }
     },
 
     remoteTrackCallback: function (rec)
     // jsonp callback to load a remote track.
     {
         if (rec.error) {
             alert("retrieval from remote site failed with error: " + rec.error);
         } else {
             var remoteTrack = rec.track;
             for (var track in hgTracks.trackDb) {
                 if (hgTracks.trackDb[track].remoteTrack === remoteTrack) {
                     $('#img_data_' + track).attr('style', "left:-116px; top: -23px;");
                     $('#img_data_' + track).attr('height', rec.height);
                     // XXXX use width in some way?
            //       $('#img_data_' + track).attr('width', rec.width);
                     $('#img_data_' + track).attr('width', $('#img_data_ruler').width());
                     $('#img_data_' + track).attr('src', rec.img);
           /* jshint loopfunc: true */// function inside loop works and replacement is awkward.
                     $('#td_data_' + track + ' > div').each(function(index) {
                         if (index === 1) {
                             var style = $(this).attr('style');
                             style = style.replace(/height:\s*\d+/i, "height:" + rec.height);
                             $(this).attr('style', style);
                         }
                     });
                     var style = $('#p_btn_' + track).attr('style');
                     style = style.replace(/height:\s*\d+/i, "height:" + rec.height);
                     $('#p_btn_' + track).attr('style', style);
                     if (hgTracks.trackDb[track].loadingId) {
                         hideLoadingImage(hgTracks.trackDb[track].loadingId);
                     }
                 }
             }
         }
     },
 
     navigateButtonClick: function (ele) // called from hgTracks.c
     {   // code to update just the imgTbl in response to navigation buttons (zoom-out etc.).
         if (imageV2.inPlaceUpdate) {
             var params = ele.name + "=" + ele.value;
             $(ele).prop('disabled', 'disabled');
             // dinking navigation needs additional data
             if (ele.name === "hgt.dinkLL" || ele.name === "hgt.dinkLR") {
                 params += "&dinkL=" + $("input[name='dinkL']").val();
             } else if (ele.name === "hgt.dinkRL" || ele.name === "hgt.dinkRR") {
                 params += "&dinkR=" + $("input[name='dinkR']").val();
             }
             if (ele.name !== "db") {
                 params += "&db=" + getDb();
             }
             imageV2.navigateInPlace(params, $(ele), false);
             return false;
         } else {
             return true;
         }
     },
 
     updateButtonClick: function (ele) // UNUSED?
     {   // code to update the imgTbl based on changes in the track controls.
         // This is currently experimental code and is dead in the main branch.
         if (imageV2.mapIsUpdateable) {
             var data = "";
             $("select").each(function(index, o) {
                 var cmd = $(this).val();
                 if (cmd === "hide") {
                     if (hgTracks.trackDb[this.name]) {
                         alert("Need to implement hide");
                     }
                 } else {
                     if ( ! hgTracks.trackDb[this.name]
                     ||  cmd !== vis.enumOrder[hgTracks.trackDb[this.name].visibility]) {
                         if (data.length > 0) {
                             data = data + "&";
                         }
                         data = data + this.name + "=" + cmd;
                     }
             }
             });
             if (data.length > 0) {
                 imageV2.navigateInPlace("db=" + getDb() + "&" + data, null, false);
             }
             return false;
         } else {
             return true;
         }
     },
 
     navigateInPlace: function (params, disabledEle, keepCurrentTrackVisible)
     {   // request an hgTracks image, using params
         // disabledEle is optional; this element will be enabled when update is complete
         // If keepCurrentTrackVisible is true, we try to maintain relative position of the item
         // under the mouse after the in-place update.
         // Tim thinks we should consider disabling all UI input while we are doing in-place update.
         // TODO: waitOnFuction?
     
         // No ajax image update if there are too many tracks!
         if (imageV2.manyTracks()) {
             imageV2.fullReload(params);
             return false;  // Shouldn't return from fullReload but I have seen it in FF
         }
     
         jQuery('body').css('cursor', 'wait');
         var currentId, currentIdYOffset;
         if (keepCurrentTrackVisible) {
             var item = rightClick.currentMapItem || imageV2.lastTrack;
             if (item) {
                 var top = $(document.getElementById("tr_" + item.id)).position().top;
                 if (top >= $(window).scrollTop()
                 || top < $(window).scrollTop() + $(window).height()) {
                     // don't bother if the item is not currently visible.
                     currentId = item.id;
                     currentIdYOffset = top - $(window).scrollTop();
                 }
             }
         }
         $.ajax({
                 type: "GET",
                 url: "../cgi-bin/hgTracks",
                 data: cart.addUpdatesToUrl(params + 
                                       "&hgt.trackImgOnly=1&hgt.ideogramToo=1&hgsid=" + getHgsid() + "&db=" + getDb()),
                 dataType: "html",
                 trueSuccess: imageV2.updateImgAndMap,
                 success: catchErrorOrDispatch,
                 error: errorHandler,
                 cmd: 'wholeImage',
                 loadingId: showLoadingImage("imgTbl"),
                 disabledEle: disabledEle,
                 currentId: currentId,
                 currentIdYOffset: currentIdYOffset,
                 cache: false
             });
     },
 
     disguiseHighlight: function(position)
     // disguise highlight position
     {
         pos = parsePositionWithDb(position);
         // DISGUISE
         if (hgTracks.virtualSingleChrom && (pos.chrom.search("multi") === 0)) {
             var positionStr = pos.chrom+":"+pos.start+"-"+pos.end;
             var newPosition = genomePos.disguisePosition(positionStr);
             var newPos = parsePosition(newPosition);
             pos.chrom = newPos.chrom;
             pos.start = newPos.start;
             pos.end   = newPos.end;
         }
         return makeHighlightString(pos.db, pos.chrom, pos.start, pos.end, pos.color);
     },
 
     undisguiseHighlight: function(pos)
     // undisguise highlight pos
     {
         // UN-DISGUISE
         if (hgTracks.virtualSingleChrom && (pos.chrom.search("multi") !== 0)) {
             var position = pos.chrom+":"+pos.start+"-"+pos.end;
             var newPosition = genomePos.undisguisePosition(position);
             var newPos = parsePosition(newPosition);
             if (newPos) {
                 pos.chrom = newPos.chrom;
                 pos.start = newPos.start;
                 pos.end   = newPos.end;
             }
         }
     },
 
     drawHighlights: function()
     // highlight vertical region in imgTbl based on hgTracks.highlight (#709).
     // For PDF/hgRenderTracks output, the highlights are drawn by hgTracks.c:drawHighlights()
     {
         var pos;
         var hexColor = dragSelect.hlColorDefault;
         // if possible, re-use the color that the user picked last time
         if (hgTracks.prevHlColor)
             hexColor = hgTracks.prevHlColor;
         var defHexColor = hexColor;
 
         $('.highlightItem').remove();
         var db = getDb();
 
         if (hgTracks.highlight) {
             var hlArray = hgTracks.highlight.split("|"); // support multiple highlight items
             for (var i = 0; i < hlArray.length; i++) {
                 hlString = hlArray[i];
                 pos = parsePositionWithDb(hlString);
                 // UN-DISGUISE
                 imageV2.undisguiseHighlight(pos);
 
                 if (pos && pos.db===db && pos.chrom === hgTracks.chromName
                 &&  (pos.start-1) <= hgTracks.imgBoxPortalEnd && pos.end >= hgTracks.imgBoxPortalStart) {
                     pos.start--;  // make start 0-based to match hgTracks.winStart
                     var portalWidthBases = hgTracks.imgBoxPortalEnd - hgTracks.imgBoxPortalStart;
                     var portal = $('#imgTbl td.tdData')[0];
                     var leftPixels = $(portal).offset().left + imageV2.LEFTADD;
                     var pixelsPerBase = ($(portal).width() - 2) / portalWidthBases;
                     var clippedStartBases = Math.max(pos.start, hgTracks.imgBoxPortalStart);
                     var clippedEndBases = Math.min(pos.end, hgTracks.imgBoxPortalEnd);
                     var widthPixels = (clippedEndBases - clippedStartBases) * pixelsPerBase;
                     if (hgTracks.revCmplDisp)
                         leftPixels += (hgTracks.imgBoxPortalEnd - clippedEndBases) * pixelsPerBase - 1;
                     else
                         leftPixels += (clippedStartBases - hgTracks.imgBoxPortalStart) * pixelsPerBase;
                     // Impossible to get perfect... Okay to overrun by a pixel on each side
                     leftPixels  = Math.floor(leftPixels);
                     widthPixels = Math.ceil(widthPixels);
                     if (widthPixels < 2) {
                         widthPixels = 3;
                         leftPixels -= 1;
                     }
     
                     var area = jQuery("<div id='highlightItem' class='highlightItem'></div>");
                     if (pos.color)
                         hexColor = pos.color;
                     else
                         hexColor = defHexColor;
 
                     $(area).css({ backgroundColor: hexColor,
                                 left: leftPixels + 'px', top: $('#imgTbl').offset().top + 1 + 'px',
                                 width: widthPixels + 'px',
                                 height: $('#imgTbl').css('height') });
                     $(area).data({leftPixels: leftPixels, widthPixels: widthPixels});// needed by dragScroll
     
                     // Larry originally appended to imgTbl, but discovered that doesn't work on IE 8 and 9.
                     $('body').append($(area)); 
                     // z-index is done in css class, so highlight is beneath transparent data images.
                     // NOTE: ideally highlight would be below transparent blue-lines, but THAT is a  
                     // background-image so z-index can't get below it!  PS/PDF looks better for blue-lines!
                 }
             }
         }
     },
 
     backSupport: (window.History.enabled !== undefined), // support of our back button via: 
     history: null,                                     //  jquery.history.js and HTML5 history API
     
     setupHistory: function ()
     {   // Support for back-button using jquery.history.js.
         // Sets up the history and initializes a state.
     
         // Since ajax updates leave the browser cached pages different from the server state, 
         // simple back-button fails.  Using a 'dirty flag' we had forced an update from server,
         // whenever the back button was hit, meaning there was no going back from server-state!
         // NOW using the history API, the back-button triggers a 'statechange' event which can 
         // contain data.  We save the position in the data and ajax update the image when the
         // back-button is pressed.  This works great for going back through ajax-updated position
         // changes, but is a bit messier when going back past a full-page retrieved state (as
         // described below).
     
         // NOTE: many things besides position could be ajax updated (e.g. track visibility). We are
         // using the back-button to keep track of position only.  Since the image should be updated
         // every-time the back button is pressed, all track settings should persist (not go back).
         // What will occasionally fail is vis box state and group expansion state. This is because
         // the back-button goes to a browser cached page and then the image alone is updated.
     
         imageV2.history = window.History;
         
         // The 'statechange' function triggerd by the back-button.
         // Whenever the position changes, then use ajax-update to refetch the position
         imageV2.history.Adapter._bind(window, 'statechange',function(){
             var prevDbPos = imageV2.history.getState().data.lastDbPos;
             var prevPos = imageV2.history.getState().data.position;
             var curDbPos = hgTracks.lastDbPos;
             if (prevDbPos && prevDbPos !== curDbPos) {
                 // NOTE: this function is NOT called when backing past a full retrieval boundary
                 genomePos.set(decodeURIComponent(prevPos));
                 imageV2.navigateInPlace("db=" + getDb() + "&" + prevDbPos, null, false);
             }
         });
         
         // With history support it is best that most position changes will ajax-update the image
         // This ensures that the 'go' and 'refresh' button will do so unless the chrom changes.
         $("#goButton,input[value='refresh']").on("click", function () {
             var newPos = genomePos.get().replace(/,/g,'');
             if (newPos.length > 2000) {
                alert("Sorry, you cannot paste identifiers or sequences with more than 2000 characters into this box.");
                $('input[name="hgt.positionInput"]').val("");
                return false;
             }
 
             var newDbPos = hgTracks.lastDbPos;
             if ( ! imageV2.manyTracks() ) {
                 var newChrom = newPos.split(':')[0];
                 var oldChrom  = genomePos.getOriginalPos().split(':')[0];
                 if (newChrom === oldChrom) {
                     imageV2.markAsDirtyPage();
                     imageV2.navigateInPlace("db=" + getDb() + "&position=" + encodeURIComponent(newPos), null, false);
                     window.scrollTo(0,0);
                     return false;
                 }
             }
             
             // If not just image update AND there are vis updates waiting...
             if (cart.updatesWaiting()) {
                 var url = "../cgi-bin/hgTracks?position=" + newPos + "&" + cart.varsToUrlData({ 'db': getDb(), 'hgsid': getHgsid() });
                 window.location.assign(url);
                 return false;
             }
 
             // redirect to hgBlat if the input looks like a DNA sequence
             // minimum length=19 so we do not accidentally redirect to hgBlat for a gene identifier 
             // like ATG5
             var dnaRe = new RegExp("^(>[^\n\r ]+[\n\r ]+)?(\\s*[actgnACTGN \n\r]{19,}\\s*)$");
             if (dnaRe.test(newPos)) {
                 var blatUrl = "hgBlat?type=BLAT%27s+guess&userSeq="+newPos;
                 window.location.href = blatUrl;
                 return false;
             }
 
             // helper functions for checking whether a plain chrom name was searched for
             term = genomePos.get().replace(/[\u200b-\u200d\u2060\uFEFF]/g,''); // remove 0-width chars
             term = encodeURIComponent(term.replace(/^[\s]*/,'').replace(/[\s]*$/,''));
             function onSuccess(jqXHR, textStatus) {
                 if (jqXHR.chromName !== null) {
                     imageV2.markAsDirtyPage();
                     imageV2.navigateInPlace("db=" + getDb() + "&position=" + encodeURIComponent(newPos), null, false);
                     window.scrollTo(0,0);
                 } else  {
                     window.location.assign("../cgi-bin/hgSearch?search=" + term  + "&hgsid="+ getHgsid());
                 }
             }
             function onFail(jqXHR, textStatus) {
                 window.location.assign("../cgi-bin/hgSearch?search=" + term  + "&hgsid="+ getHgsid());
             }
 
             // redirect to search disambiguation page if it looks like we didn't enter a regular position:
             // "BRCA1 exon 5" or "BRCA1:e.5+2" — resolve via hgApi and navigate in place
             var exonMatch = newPos.match(geneExonExp) || newPos.match(geneExonCoordExp);
             if (exonMatch) {
                 var symbol, num, offset = 0;
                 var m = newPos.match(geneExonExp);
                 if (m) {
                     symbol = m[1]; num = parseInt(m[2], 10);
                 } else {
                     m = newPos.match(geneExonCoordExp);
                     symbol = m[1]; num = parseInt(m[2], 10);
                     if (m[3]) offset = parseInt(m[3], 10);
                 }
                 $.ajax({
                     type: "GET",
                     url: "../cgi-bin/hgApi",
                     data: cart.varsToUrlData({ 'hgsid': getHgsid(), 'db': getDb(),
                           'cmd': 'geneExonToPos', 'symbol': symbol, 'num': num, 'offset': offset }),
                     trueSuccess: rightClick.handleZoomCodon,
                     success: catchErrorOrDispatch,
                     error: function() { window.location.assign("../cgi-bin/hgSearch?search=" + term + "&hgsid=" + getHgsid()); },
                     cache: false
                 });
                 return false;
             }
 
             var canonMatch = newPos.match(canonicalRangeExp);
             var gbrowserMatch = newPos.match(gbrowserRangeExp);
             var lengthMatch = newPos.match(lengthRangeExp);
             var bedMatch = newPos.match(bedRangeExp);
             var sqlMatch = newPos.match(sqlRangeExp);
             var singleMatch = newPos.match(singleBaseExp);
             var gnomadRangeMatch = newPos.match(gnomadRangeExp);
             var gnomadVarMatch = newPos.match(gnomadVarExp);
             var positionMatch = canonMatch || gbrowserMatch || lengthMatch || bedMatch || sqlMatch || singleMatch || gnomadRangeMatch || gnomadVarMatch;
             if (positionMatch === null) {
                 // user may have entered a full chromosome name, check for that asynchronosly:
                 $.ajax({
                     type: "GET",
                     url: "../cgi-bin/hgSearch",
                     data: cart.varsToUrlData({ 'cjCmd': '{"getChromName": {"db": "' + getDb() + '", "searchTerm": "' + term + '"}}' }),
                     dataType: "json",
                     trueSuccess: onSuccess,
                     success: onSuccess,
                     error: onFail,
                     cache: true
                 });
                 return false;
             } else {
                 // about to do a form submit with a regular position range, save this to the recents stack
                 // strip any html content first
                 newPos = newPos.replace(/<[^>]*>/g, '');
                 addRecentSearch(getDb(), newPos, {id: newPos, value: newPos, label: newPos});
             }
                 
             return true;
         });
         // Have vis box changes update cart through ajax.  This helps keep page/cart in sync.
         vis.initForAjax();
 
         // We reach here from these possible paths:
         // A) Forward: Full page retrieval: hgTracks is first navigated to (or chrom change)
         // B) Back-button past a full retrieval (B in: ->A,->b,->c(full page),->d,<-c,<-B(again))
         //    B1) Dirty page: at least one non-position change (e.g. 1 track vis changed in b)
         //    B2) Clean page: only position changes from A->b->| 
         var curPos = encodeURIComponent(genomePos.get().replace(/,/g,''));
         var curDbPos = hgTracks.lastDbPos;
         var cachedPos = imageV2.history.getState().data.position;
         var cachedDbPos = imageV2.history.getState().data.lastDbPos;
         // A) Forward: Full page retrieval: hgTracks is first navigated to (or chrom change)
         if (!cachedDbPos) { // Not a back-button operation
             // set the current position into history outright (will replace). No img update needed
             // try/catch: see comment on the other setInHistory call site.
             try {
                 imageV2.setInHistory(true);
             } catch (e) {
                 console.warn("setInHistory failed, continuing:", e);
             }
         } else { // B) Back-button past a full retrieval
             genomePos.set(decodeURIComponent(cachedPos));
             // B1) Dirty page: at least one non-position change 
             if (imageV2.isDirtyPage()) {
                 imageV2.markAsCleanPage();
                 // Only forcing a full page refresh if chrom changes
                 var cachedChrom = decodeURIComponent(cachedPos).split(':')[0];
                 var curChrom    = decodeURIComponent(   curPos).split(':')[0];
                 if (cachedChrom === curChrom) {
                     imageV2.navigateInPlace("db="+getDb()+"&"+cachedDbPos, null, false);
                 } else {
                     imageV2.fullReload();
                 }
             } else {
                 // B2) Clean page: only position changes from a->b 
                 if (cachedDbPos !== curDbPos) {
                     imageV2.navigateInPlace("db="+getDb()+"&"+cachedDbPos, null, false);
                 }
             }
             // Special because FF is leaving vis drop-downs disabled
             vis.restoreFromBackButton();
         }
     },
     
     setInHistory: function (fullPageLoad)
     {   // Keep a position history and allow the back-button to work (sort of)
         // replaceState on initial page load, pushState on each advance
         // When call triggered by back button, the lastPos===newPos, so no action.
         var lastDbPos = imageV2.history.getState().data.lastDbPos;
         var newPos  = encodeURIComponent(genomePos.get().replace(/,/g,''));  // no commas
         var newDbPos  = hgTracks.lastDbPos;
         
         // A full page load could be triggered by back-button, but then there will be a lastPos
         // if this is the case then don't set the position in history again!
         if (fullPageLoad && lastDbPos)
             return;
 
         if (!lastDbPos || lastDbPos !== newDbPos) {
             // Swap the position into the title
             var title = $('TITLE')[0].text;
             var ttlWords = title.split(' ');
             if (ttlWords.length >= 2) {
                 for (var i=1; i < ttlWords.length; i++) {
                     if (ttlWords[i].indexOf(':') >= 0) {
                         ttlWords[i] = genomePos.get();
                     }
                 }
                 title = ttlWords.join(' ');
             } else
                 title = genomePos.get();
 
             var sid = getHgsid();
             if (fullPageLoad) { 
                 // Should only be on initial set-up: first navigation to page
                 imageV2.history.replaceState({lastDbPos: newDbPos, position: newPos, hgsid: + sid },title,
                                  "hgTracks?db="+getDb()+"&"+newDbPos+"&hgsid="+sid);
             } else {  
                 // Should be when advancing (not-back-button)
                 imageV2.history.pushState({lastDbPos: newDbPos, position: newPos, hgsid: + sid },title,
                                  "hgTracks?db="+getDb()+"&"+newDbPos+"&hgsid="+sid);
             }
         }
     }
 };
 
   ///////////////////////////////////////
  //// mouseOver data display 2020-10 ///
 ///////////////////////////////////////
 var mouseOver = {
 
     items: {},  // items[trackName][] - data for each item in this track
     visible: false,     // keeping track of popUp window visibility
     tracks: {}, // tracks[trackName] - number of data items for this track
     trackType: {},	// key is track name, value is track type from hgTracks
     mouseOverFunction: {}, // key is track name, value mouseOverFunction string
     jsonUrl: {},       // list of json files from hidden DIV elements
     maximumWidth: {},   // maximumWidth[trackName] - largest string to display
     popUpDelay: 200,   // 0.2 second delay before popUp appears
     popUpTimer: null,// handle from setTimeout to use in clearTimout(popUpTimer)
     delayDone: true,   // mouse has not left element, still receiving move evts
     delayInProgress: false,        // true while waiting for delay timer
     mostRecentMouseEvt: null,   // to use when mouse delay is finished
     browserTextSize: 12,        // default if not found otherwise
     measureTextBox: null,
     noDataString: "no&nbsp;data",	// message for no data at this position
     noDataSize: 0,	// will be set to size of text 'no data'
     noAverageString: "&nbsp;zoom&nbsp;in&nbsp;to&nbsp;see&nbsp;values&nbsp;",	// "noAverage" function
 
     // items{} - key name is track name, value is an array of data items
     //           where the format of each item can be different for different
     //           data tracks.  For example, the wiggle track is an array of:
     //                   objects: {x1, x2, v, c}
     //           where [x1..x2) is the array index where the value 'v'
     //           is found, and 'c' is the data value count in this value
     //           i.e. when c > 1 the value is a 'mean' of 'c' data values
     // visible - keep track of window visible or not, value: true|false
     //           shouldn't need to do this here, the window knows if it
     //           is visible or not, just ask it for status
     // tracks{}  - tracks that were set up initially, key is track name
     //             value is the number of items (for debugging)
     // maximumWidth{} - key is track name, value is length of longest
     //                  number string as measured when rendered
 
     // given hgt_....png file name, change to hgt_....json file name
     jsonFileName: function(imgDataId)
     {
       var jsonFile=imgDataId.src.replace(".png", ".json");
       return jsonFile;
     },
 
     // called from: updateImgForId when it has updated a track in place
     // need to refresh the event handlers and json data
     updateMouseOver: function (trackName, newJson)
     {
       if (! newJson ) { return; }
       // this newJson object appears to be a single trackDb, not
       //  an array of them
       var trackDb = null;
       // so, if the type attribute exists, then it is the trackDb
       if (newJson.type) {
          trackDb = newJson;
       } else {	// otherwise, search through the array
         for ( var id in newJson.trackDb ) {
            if (id === trackName) {
               trackDb = newJson.trackDb[id];
               break;
            }
         }
       }
       var trackType = null;
       var hasChildren = null;
       if (trackDb) {
 	trackType = trackDb.type;
 	hasChildren = trackDb.hasChildren;
       } else if (hgTracks.trackDb && hgTracks.trackDb[trackName]) {
 	trackType = hgTracks.trackDb[trackName].type;
       } else if (mouseOver.trackType[trackName]) {
 	trackType = mouseOver.trackType[trackName];
       }
       var validType = false;
       if (trackType) {
 	if (trackType.indexOf("wig") === 0) { validType = true; }
 	if (trackType.indexOf("bigWig") === 0) { validType = true; }
 	if (trackType.indexOf("wigMaf") === 0) { validType = false; }
 	if (hasChildren) { validType = false; }
       }
       if (! validType ) { return; }
       var tdData = "td_data_" + trackName;
       var tdDataId  = document.getElementById(tdData);
       var imgData = "img_data_" + trackName;
       var imgDataId  = document.getElementById(imgData);
       if (imgDataId && tdDataId) {
 	var url = mouseOver.jsonFileName(imgDataId);
         $( tdDataId ).on("mousemove", mouseOver.mouseMoveDelay);
         $( tdDataId ).on("mouseout", mouseOver.popUpDisappear);
         mouseOver.fetchJsonData(url);  // may be a refresh, don't know
       }
     },
 
     // given an X coordinate: x, find the index idx
     // in the rects[idx] array where rects[idx].x1 <= x < rects[idx].x2
     // returning -1 when not found
     // if we knew the array was sorted on x1 we could get out early
     //   when x < x1
     // Note, different track types could have different intersection
     //       procedures.  For example, the HiC track will need to intersect
     //       the mouse position within the diamond/square defined by the
     //       items in the display.
     findRange: function (x, rects)
     {
       var answer = -1;  // assmume not found
       var idx = 0;
       if (hgTracks.revCmplDisp) {
         var rectsLen = rects.length - 1;
         for ( idx in rects ) {
            if ((rects[rectsLen-idx].x1 <= x) && (x < rects[rectsLen-idx].x2)) {
              answer = rectsLen-idx;
              break;
            }
         }
       } else {
         for ( idx in rects ) {
            if ((rects[idx].x1 <= x) && (x < rects[idx].x2)) {
              answer = idx;
              break;
            }
         }
       }
       return answer;
     },
 
     popUpDisappear: function () {
       if (mouseOver.visible) {        // should *NOT* have to keep track !*!
         mouseOver.visible = false;
         $('#mouseOverText').css('display','none');
         $('#mouseOverVerticalLine').css('display','none');
       }
       if (mouseOver.popUpTimer) {
          clearTimeout(mouseOver.popUpTimer);
          mouseOver.popUpTimer = null;
       }
       mouseOver.delayDone = true;
       mouseOver.delayInProgress = false;
     },
 
     popUpVisible: function () {
       if (! mouseOver.visible) {        // should *NOT* have to keep track !*!
         mouseOver.visible = true;
         $('#mouseOverText').css('display','block');
         $('#mouseOverVerticalLine').css('display','block');
       }
     },
 
     //  the evt.currentTarget.id is the td_data_<trackName> element of
     //     the track graphic.  There doesn't seem to be a evt.target.id ?
     mouseInTrackImage: function (evt)
     {
     // the center label also events here, can't use that
     //  plus there is a one pixel line under the center label that has no
     //   id name at all, so verify we are getting the event from the correct
     //   element.
     if (! evt.currentTarget.id.includes("td_data_")) { return; }
     var trackName = evt.currentTarget.id.replace("td_data_", "");
     if (trackName.length < 1) { return; }	// verify valid trackName
 
     // location of mouse relative to the whole page
     //     even when the top of page has scolled off
     var evtX = Math.floor(evt.pageX);
 //  var evtY = Math.floor(evt.pageY);
 //  var offX = Math.floor(evt.offsetX);       // no need for evtY or offX
 
     // find location of this <td> slice in the image, this is the track
     //   image in the graphic, including left margin and center label
     //   This location follows the window scrolling, could go negative
     var tdId  = document.getElementById(evt.currentTarget.id);
     var tdRect = tdId.getBoundingClientRect();
     var tdLeft = Math.floor(tdRect.left);
     var tdTop = Math.floor(tdRect.top);
 //    if (tdTop < 0) { return; }  // track is scrolled off top of screen
     var tdWidth = Math.floor(tdRect.width);
     var tdHeight = Math.floor(tdRect.height);
     var tdRight = tdLeft + tdWidth;
     // clientX is the X coordinate of the mouse hot spot
     var clientX = Math.floor(evt.clientX);
     var clientY = Math.floor(evt.clientY);
     // the graphOffset is the index (x coordinate) into the 'items' definitions
     //  of the data value boxes for the graph.  The magic number three
     //   is used elsewhere in this code, note the comment on the constant
     //   LEFTADD.
     var graphOffset = Math.max(0, clientX - tdLeft - 3);
     if (hgTracks.revCmplDisp) {
        graphOffset = Math.max(0, tdRight - clientX);
     }
 
     var windowUp = false;     // see if window is supposed to become visible
     var foundIdx = -1;
     if (mouseOver.items[trackName]) {
        foundIdx = mouseOver.findRange(graphOffset, mouseOver.items[trackName]);
     }
     // can show 'no data' when not found
     var mouseOverValue = mouseOver.noDataString;
     if (mouseOver.mouseOverFunction[trackName] === "noAverage") {
        mouseOverValue = mouseOver.noAverageString;
     }
     if (foundIdx > -1) { // value to display
         mouseOverValue = "&nbsp;" + mouseOver.items[trackName][foundIdx].v + "&nbsp;";
     }
     $('#mouseOverText').html(mouseOverValue);
     var msgWidth = mouseOver.maximumWidth[trackName];
     $('#mouseOverText').width(msgWidth);
     var msgHeight = Math.ceil($('#mouseOverText').height());
     var lineHeight = Math.max(0, tdHeight - msgHeight);
     if (tdTop < 0) {
        lineHeight = Math.max(0, tdHeight + tdTop - msgHeight);
     }
     var msgLeft = Math.max(tdLeft, clientX - (msgWidth/2) - 3); // with magic 3
     var msgTop = Math.max(0, tdTop);
     var lineTop = Math.max(0, msgTop + msgHeight);
     var lineLeft = Math.max(0, clientX - 1);  // magic 3 +  2 for width of indicator box
     if (clientY < msgTop + msgHeight) {	// cursor overlaps with the msg box
       msgLeft = clientX - msgWidth - 6;     // to the left of the cursor
       if (msgLeft < tdLeft || msgLeft < 0) {   // hits left edge, switch
         msgLeft = clientX;         // to right of cursor
       }
     } else {	// apply limits to left and right edges, window or image
       msgLeft = Math.min(msgLeft, tdRight - msgWidth);  // image right limit
       msgLeft = Math.min(msgLeft, $(window).width() - msgWidth); // window right
       msgLeft = Math.max(0, msgLeft);  // left window edge limit
     }
     $('#mouseOverText').css('top',msgTop + "px");
     $('#mouseOverText').css('left',msgLeft + "px");
     $('#mouseOverVerticalLine').css('left',lineLeft + "px");
     $('#mouseOverVerticalLine').css('top',lineTop + "px");
     $('#mouseOverVerticalLine').css('height',lineHeight + "px");
     windowUp = true;      // yes, window is to become visible
 
     if (windowUp) {     // the window should become visible
       mouseOver.popUpVisible();
     } else {    // the window should disappear
       mouseOver.popUpDisappear();
     } //      window visible/not visible
     },  //      mouseInTrackImage function (evt)
 
     // timeout calls here upon completion
     delayCompleted: function()
     {
        mouseOver.delayDone = true;
        // mouse could just be sitting there with no events, if there
        // have been events during the timer, the evt has been recorded
        // so the popUp appears where the mouse is while it moved during the
        // time delay since mostRecentMouseEvt is up to date to now
        // If mouse has moved out of element during timeout, the
        // delayInProgress will be false and nothing happens.
        if (mouseOver.delayInProgress) {
           mouseOver.mouseInTrackImage(mouseOver.mostRecentMouseEvt);
        }
     },
 
     // all mouse move events come here even during timeout
     mouseMoveDelay: function (evt)
     {
       mouseOver.mostRecentMouseEvt = evt;   // record evt for delayCompleted
 
       if (mouseOver.delayInProgress) {
         if (mouseOver.delayDone) {
           mouseOver.mouseInTrackImage(evt);	// OK to trigger event now
           return;
         } else {
           return; // wait for delay to be done
         }
       }
       mouseOver.delayDone = false;
       mouseOver.delayInProgress = true;
       if (mouseOver.popUpTimer) {
          clearTimeout(mouseOver.popUpTimer);
          mouseOver.popUpTimer = null;
       }
       mouseOver.popUpTimer = setTimeout(mouseOver.delayCompleted, mouseOver.popUpDelay);
     },
 
     // given a string of text, return width of rendered text size
     // using an off-screen span element that is created here first time through
     getWidthOfText: function (measureThis)
     {
     if(mouseOver.measureTextBox === null){  // set up first time only
         mouseOver.measureTextBox = document.createElement('span');
         var cssText = "position: fixed; width: auto; display: block; text-align: right; left:-999px; top:-999px; font-style:normal; font-size:" + mouseOver.browserTextSize + "px; font-family:" + jQuery('body').css('font-family');
         mouseOver.measureTextBox.style.cssText = cssText;
         document.body.appendChild(mouseOver.measureTextBox);
     }
     mouseOver.measureTextBox.innerHTML = measureThis;
     return Math.ceil(mouseOver.measureTextBox.clientWidth);
     },
 
     // =======================================================================
     // receiveData() callback for successful JSON request, receives incoming
     //             JSON data and gets it into global variables for use here.
     //  The incoming 'arr' is a a set of objects where the object key name is
     //      the track name, used here as an array reference: arr[trackName]
     //        (currently only one object per json file, one file for each track,
     //           this may change to have multiple tracks in one json file.)
     //  The value associated with each track name
     //  is an array of span definitions, where each element in the array is a
     //     mapBox definition object:
     //        {x1:n, x2:n, value:s}
     //        where n is an integer in the range: 0..width,
     //        and s is the value string to display
     //     Will need to get them sorted on x1 for efficient searching as
     //     they accumulate in the local data structure here.
     //  2020-11-24 more generalized incoming data structure, don't care
     //             what the structure is for each item, this will vary
     //             depending upon the type of track.  trackType now remembered
     //             in mouseOver.trackType[trackName]
     // =======================================================================
     receiveData: function (arr)
     {
       mouseOver.popUpDisappear();
       for (var trackName in arr) {
 	// clear these variables if they existed before
       if (mouseOver.trackType[trackName]) {mouseOver.trackType[trackName] = undefined;}
       if (mouseOver.items[trackName]) {mouseOver.items[trackName] = undefined;}
       if (mouseOver.tracks[trackName]) {mouseOver.tracks[trackName] = 0;}
       mouseOver.items[trackName] = [];      // start array
       mouseOver.trackType[trackName] = arr[trackName].t;
       if (arr[trackName].hasOwnProperty('mo')) {
          mouseOver.mouseOverFunction[trackName] = arr[trackName].mo;
       } else {
          delete mouseOver.mouseOverFunction[trackName];
       }
       // add a 'mousemove' and 'mouseout' event listener to each track
       //     display object
       var tdData = "td_data_" + trackName;
       var tdDataId  = document.getElementById(tdData);
 // from jQuery doc:
 //  As the .mousemove() method is just a shorthand
 //    for .on( "mousemove", handler ), detaching is possible
 //      using .off( "mousemove" ).
       $( tdDataId ).on("mousemove", mouseOver.mouseMoveDelay);
       $( tdDataId ).on("mouseout", mouseOver.popUpDisappear);
       var itemCount = 0;	// just for monitoring purposes
       // save incoming x1,x2,v data into the mouseOver.items[trackName][] array
       var lengthLongestNumberString = 0;
       var longestNumber = 0;
       var hasMean = false;
       for (var datum in arr[trackName].d) {      // .d is the data array
          if (arr[trackName].d[datum].c > 1) { hasMean = true; }
          var lenV = arr[trackName].d[datum].v.toString().length;
          if (lenV > lengthLongestNumberString) {
 	   lengthLongestNumberString = lenV;
 	   longestNumber = arr[trackName].d[datum].v;
          }
         mouseOver.items[trackName].push(arr[trackName].d[datum]);
        ++itemCount;
       }
       mouseOver.tracks[trackName] = itemCount;	// != 0 -> indicates valid track
       var mouseOverValue = "";
       if (hasMean) {
          mouseOverValue = "&nbsp;~&nbsp;" + longestNumber + "&nbsp;";
       } else {
          mouseOverValue = "&nbsp;" + longestNumber + "&nbsp;";
       }
       if (mouseOver.mouseOverFunction[trackName] === "noAverage") {
          mouseOverValue = mouseOver.noAverageString;
       }
       $('#mouseOverText').css('fontSize',mouseOver.browserTextSize + "px");
       var maximumWidth = mouseOver.getWidthOfText(mouseOverValue);
       if ( 0 === mouseOver.noDataSize) {  // only need to do this once
         mouseOver.noDataSize = mouseOver.getWidthOfText(mouseOver.noDataString);
       }
       if (mouseOver.noDataSize > maximumWidth) {
           maximumWidth = mouseOver.noDataSize;
       }
       mouseOver.maximumWidth[trackName] = maximumWidth;
       }
     },  //      receiveData: function (arr)
 
     failedRequest: function(url)
     {   // failed request to get json data, remove it from the URL list
       if (mouseOver.jsonUrl[url]) {
         delete mouseOver.jsonUrl[url];
       }
     },
 
     // =========================================================================
     // fetchJsonData() sends JSON request, callback to receiveData() upon return
     // =========================================================================
     fetchJsonData: function (url)
     {
        // avoid fetching the same URL multiple times.  Multiple track data
        // can be in a single json file
        if (mouseOver.jsonUrl[url]) {
           mouseOver.jsonUrl[url] += 1;
           return;
        }
        mouseOver.jsonUrl[url] = 1;     // remember already done this one
        var xmlhttp = new XMLHttpRequest();
        xmlhttp.onreadystatechange = function() {
          if (4 === this.readyState && 200 === this.status) {
             var mapData = JSON.parse(this.responseText);
             mouseOver.receiveData(mapData);
          } else {
             if (4 === this.readyState && 404 === this.status) {
                mouseOver.failedRequest(url);
             }
          }
        };
     xmlhttp.open("GET", url, true);
     xmlhttp.send();  // sends request and exits this function
                      // the onreadystatechange callback above will trigger
                      // when the data has safely arrived
     },
 
     getData: function ()
     {
       // check for the hidden div elements for mouseOverData
       // single file version can find many trackNames, but will all
       // be the same URL
       var trackList = document.getElementsByClassName("mouseOverData");
       for (var i = 0; i < trackList.length; i++) {
         var trackName = trackList[i].getAttribute('name');
         var jsonFileUrl = trackList[i].getAttribute('jsonUrl');
         if (jsonFileUrl) { mouseOver.fetchJsonData(jsonFileUrl); }
       }
     },
 
     // any scrolling turns the popUp message off
     scroll: function()
     {
     if (mouseOver.visible) { mouseOver.popUpDisappear(); }
     },
 
     addListener: function () {
         mouseOver.visible = false;
         if (window.browserTextSize) {
            mouseOver.browserTextSize = window.browserTextSize;
         }
         window.addEventListener('scroll', mouseOver.scroll, false);
         // Call getData directly since the DOM is already parsed by the time
         // $(document).ready() calls addListener.
         mouseOver.getData();
     }
 };	//	var mouseOver
 
   //////////////////////
  //// track search ////
 //////////////////////
 var trackSearch = {
 
     searchKeydown: function (event)
     {
         if (event.which === 13) {
             // Required to fix problem on IE and Safari where value of hgt_tSearch is "-"
             //    (i.e. not "Search").
             // NOTE: must match TRACK_SEARCH_PAGER in hg/inc/searchTracks.h
             $("input[name=hgt_tsPage]").val(0);  
             $('#trackSearch').submit();
             // This doesn't work with IE or Safari.
             // $('#searchSubmit').trigger("click");
         }
     },
 
     init: function ()
     {
         // Track search uses tabs
         if ($("#tabs").length > 0) {
             // Search page specific code
 
             var val = $('#currentTab').val();
             $("#tabs").tabs({
                                 show: function(event, ui) {
                                     $('#currentTab').val(ui.newPanel[0].id);
                                 },
                                 activate: function(event, ui) { findTracks.switchTabs(ui); }
                             });
             $('#tabs').show();
             if (val === 'simpleTab' && $('div#found').length < 1) {
                 $('input#simpleSearch').trigger("focus");
             }
             $("#tabs").css('font-family', jQuery('body').css('font-family'));
             $("#tabs").css('font-size', jQuery('body').css('font-size'));
             $('.submitOnEnter').on("keydown", trackSearch.searchKeydown);
             findTracks.normalize();
             findTracks.updateMdbHelp(0);
         }
     }
 };
 
 ////////
 // Download Current Tracks in window Dialog
 ////////
 var downloadCurrentTrackData = {
     downloadData: {}, // container for holding data while it comes in from the api
     currentRequests: {}, // pending requests
     intervalId: null, // the id of the timer that waits on the api
 
     failedTrackDataRequest: function(msg) {
         msgJson = JSON.parse(msg);
         alert("Download failed. Error message: '" + msgJson.error);
     },
 
     receiveTrackData: function(track, data) {
         downloadCurrentTrackData.downloadData[track] = data;
     },
 
     convertJson: function(data, outType, withHeaders) {
         if (outType !== "tsv" && outType !== "csv") {
             alert("ERROR: incorrect output format option");
             return null;
         }
         let outSep = outType === "tsv" ? '\t' : ',';
         // TODO: someday we will probably want to include some of these fields
         // for each track downloaded, perhaps as an option
         let ignoredKeys = new Set(["chrom", "dataTime", "dataTimeStamp", "downloadTime", "downloadTimeStamp",
             "start", "end", "track", "trackType", "genome", "itemsReturned", "columnTypes",
             "bigDataUrl", "chromSize", "hubUrl"]);
         let columnTypes;
         let cleanData = {};
         // first get rid of top level non track object keys
         _.each(data, function(val, key) {
             if (ignoredKeys.has(key)) {
                 // squirrel away the columnTypes if requested
                 if (key === "columnTypes") {
                     columnTypes = data[key];
                 }
             } else {
                 cleanData[key] = data[key];
             }
         });
         // now go through each track and format it correctly
         let str = "";
         _.each(cleanData, function(val, track) {
             str += "track name=\"" + track + "\"\n";
             if (withHeaders) {
                 let headers = [];
                 if (columnTypes) {
                     for (let i of columnTypes[track]) {
                         headers.push(i.name);
                     }
                     if (headers.length) {
                         str += headers.join(outSep) + "\n";
                     }
                 }
             }
             for (let row of val) {
                 for (let i = 0; i < row.length; i++) {
                     str += JSON.stringify(row[i]);
                     if (i+1 < row.length) { str += outSep; }
                 }
                 str += "\n";
             }
             str += "\n"; // extra new line after each track oh well
         });
         return new Blob([str], {type: "text/plain"});
     },
 
     makeDownloadFile: function(key) {
         if (_.keys(downloadCurrentTrackData.currentRequests).length === 0) {
             // first stop the timer so we don't execute again
             clearInterval(downloadCurrentTrackData.intervalId);
             let outType = $("#outputFormat")[0].selectedOptions[0].value;
             let withHeaders = document.getElementById("downloadTrackHeaders").checked;
             var blob = null;
             if (outType === 'json') {
                 blob = new Blob([JSON.stringify(downloadCurrentTrackData.downloadData[key])], {type: "text/plain"});
             } else {
                 blob = downloadCurrentTrackData.convertJson(downloadCurrentTrackData.downloadData[key], outType, withHeaders);
             }
             if (blob) {
                 anchor = document.createElement("a");
                 anchor.href = URL.createObjectURL(blob);
                 fname = $("#downloadFileName")[0].value;
                 if (fname.length === 0) {
                     fname = "trackDownload.txt";
                 }
                 switch (outType) {
                     case "tsv":
                         if (!fname.endsWith(".tsv")) {fname += ".tsv";}
                         break;
                     case "csv":
                         if (!fname.endsWith(".csv")) {fname += ".csv";}
                         break;
                     default:
                         if (!fname.endsWith(".txt")) {fname += ".txt";}
                         break;
                 }
                 anchor.download = fname;
                 anchor.click();
                 window.URL.revokeObjectURL(anchor.href);
                 downloadCurrentTrackData.downloadData = {};
             }
         }
     },
 
     startDownload: function() {
         trackList = [];
         $(".downloadTrackName:checked").each(function(i, elem) {
             trackName = elem.id;
             if (getDb().startsWith("hub_")) {
                 // when we are working with assembly hubs, we undecorate the name
                 trackName = undecoratedTrack(elem.id);
             }
             trackList.push(trackName);
         });
         if (trackList.length == 0) {
             alert("At least one track must be selected");
             return;
         } else if (trackList.length > 100) {
             alert("Too many tracks requested. Please limit requests to 100 tracks or less");
             return;
         } else if (trackList.join(',').length > 7000) {
             // tracks with too long of names and we hit the max URI length allowed
             // by Apache, I doubt this could happen without requesting more than the
             // 100 tracks allowed above, but just in case:
             alert("Too many tracks requested");
             return;
         }
         chrom = hgTracks.chromName;
         start = hgTracks.winStart;
         end = hgTracks.winEnd;
         db = getDb();
         apiUrl = "../cgi-bin/hubApi/getData/track?";
         apiUrl += "chrom=" + chrom;
         apiUrl += ";start=" + start;
         apiUrl += ";end=" + end;
         apiUrl += ";genome=" + db;
         apiUrl += ";jsonOutputArrays=1";
         apiUrl += ";track=" + trackList.join(',');
         var xmlhttp = new XMLHttpRequest();
         downloadCurrentTrackData.currentRequests[apiUrl] = true;
         xmlhttp.onreadystatechange = function() {
             if (4 === this.readyState && 200 === this.status) {
                 var mapData = JSON.parse(this.responseText);
                 downloadCurrentTrackData.receiveTrackData(apiUrl, mapData);
                 delete downloadCurrentTrackData.currentRequests[apiUrl];
             } else {
                 if (4 === this.readyState && this.status >= 400) {
                     clearInterval(downloadCurrentTrackData.intervalId);
                     downloadCurrentTrackData.failedTrackDataRequest(this.responseText);
                     delete downloadCurrentTrackData.currentRequests[apiUrl];
                 }
             }
         };
         xmlhttp.open("GET", apiUrl, true);
         xmlhttp.send();  // sends request and exits this function
         // the onreadystatechange callback above will trigger
         // when the data has safely arrived
         // wait for the request to complete before making the download file
         downloadCurrentTrackData.intervalId = setInterval(downloadCurrentTrackData.makeDownloadFile, 200, apiUrl);
     },
 
 
     showDownloadUi: function() {
         // Populate the dialog with the current list of tracks
         // and allow the user to select which ones to download
         // Grey out tracks that are currently unsupported by the api
         // or are protected data
         var downloadDialog = $("#downloadDialog")[0];
         if (!downloadDialog) {
             downloadDialog = document.createElement("div");
             downloadDialog.id = "downloadDialog";
             downloadDialog.style = "display: none";
             document.body.append(downloadDialog);
             var popMaxHeight = ($(window).height() - 40);
             var popMaxWidth  = ($(window).width() - 40);
             var popWidth     = 700;
             if (popWidth > popMaxWidth)
                 popWidth = popMaxWidth;
             downloadTrackDataButtons = {};
             downloadTrackDataButtons.Download = downloadCurrentTrackData.startDownload;
             downloadTrackDataButtons.Cancel = function(){
                 $(this).dialog("close");
             };
             $(downloadDialog).dialog({
                 title: "Download track data in view",
                 resizable: false,
                 height: 'auto',
                 width: popWidth,
                 minHeight: 200,
                 minWidth: 400,
                 maxHeight: popMaxHeight,
                 maxWidth: popMaxWidth,
                 modal: true,
                 closeOnEscape: true,
                 autoOpen: false,
                 buttons: downloadTrackDataButtons
             });
         }
         htmlStr = "<p>Use this selection window to download track data" +
             " for the current region (" + genomePos.get() + "). Please note that large regions" +
             " may be slow to download.</p>";
         htmlStr  += "<div><button id='checkAllDownloadTracks'>Check All</button>" +
             "&nbsp;" +
             "<button id='uncheckAllDownloadTracks'>Clear All</button>" +
             "</div>";
         _.each(hgTracks.trackDb, function(track, trackName) {
             showDisabledMsg = false;
             if (!trackName.includes("Squish") && trackName !== "ruler" && track.visibility > 0) {
                 htmlStr += "<input type=checkbox class='downloadTrackName' id='" + trackName + "'";
                 if (trackName.startsWith("ct_") || trackName === "hgPcrResult" ||
                         track.type === "mathWig" || !tdbIsLeaf(track)) {
                     showDisabledMsg = true;
                     htmlStr += " disabled ";
                 } else {
                     htmlStr += " checked ";
                 }
                 htmlStr +=  ">";
                 htmlStr += "<label>" + track.shortLabel + "</label>";
                 htmlStr += "</input>";
                 if (showDisabledMsg) {
                     htmlStr += "&nbsp;<span id='" + trackName + "Tooltip'><a href='#'>(?)</a></span>";
                 }
                 htmlStr += "<br>";
             }
         });
         htmlStr += "<div ><label style='padding-right: 10px' for='downloadFileName'>Enter an output file name</label>";
         htmlStr += "<input type=text size=30 class='downloadFileName' id='downloadFileName'" +
             " value='" + getDb() + ".tracks'></input>";
         htmlStr += "<br>";
         htmlStr += "<label style='padding-right: 10px' for='outputFormat'>Choose an output format</label>";
         htmlStr += "<select name='outputFormat' id='outputFormat'>";
         htmlStr += "<option selected value='json'>JSON</option>";
         htmlStr += "<option value='csv'>CSV</option>";
         htmlStr += "<option value='tsv'>TSV</option>";
         htmlStr += "</select>";
         htmlStr += "<br>";
         htmlStr += "<label style='padding-right: 10px' for='downloadTrackHeaders'>Include track column headers</label>";
         htmlStr += "<input type='checkbox' checked id='downloadTrackHeaders'></input>";
         htmlStr += "</div>";
         downloadDialog.innerHTML = htmlStr;
         $("#checkAllDownloadTracks").on("click", function() {
             $(".downloadTrackName").each(function(i, elem) {
                 elem.checked = true;
             });
         });
         $("#uncheckAllDownloadTracks").on("click", function() {
             $(".downloadTrackName").each(function(i, elem) {
                 elem.checked = false;
             });
         });
         $(downloadDialog).dialog('open');
         $("[id$='Tooltip'").each(function(i, elem) {
             addMouseover(elem, "This track must be downloaded with the Table Browser");
         });
     }
 };
 
   ///////////////
  //// READY ////
 ///////////////
 $(document).ready(function()
 {
     imageV2.moveTiming();
 
     // hg.conf will turn this on 2020-10 - Hiram
     if (window.mouseOverEnabled) { mouseOver.addListener(); }
 
     // custom tracks get little trash icons
     $("div.trackDeleteIcon").on("click", onTrackDelIconClick );
 
     // quickLift tracks get a little 'x' icon
     $("div.quickLiftDelIcon").on("click", onQuickLiftDelIconClick );
 
     // on Safari the back button doesn't call the ready function.  Reload the page if
     // the back button was pressed.
     $(window).on("pageshow", function(event) {
         if (event.originalEvent.persisted) {
                 window.location.reload() ;
         }
     });
 
     // The page may be reached via browser history (back button)
     // If so, then this code should detect if the image has been changed via js/ajax
     // and will reload the image if necessary.
     // NOTE: this is needed for IE but other browsers can detect the dirty page much earlier
     if (!imageV2.backSupport) {
         if (imageV2.isDirtyPage()) {
             // mark as non dirty to avoid infinite loop in chrome.
             imageV2.markAsCleanPage();
             jQuery('body').css('cursor', 'wait');
             window.location = "../cgi-bin/hgTracks?hgsid=" + getHgsid();
             return false;
         }
     }
 
     initVars();
     imageV2.loadSuggestBox();
     if ($('#pdfLink').length === 1) {
         $('#pdfLink').on("click", function(i) {
             var thisForm = normed($('#TrackForm'));
             if (thisForm) {
                 //alert("posting form:"+$(thisForm).attr('name'));
                 updateOrMakeNamedVariable($(thisForm),'hgt.psOutput','on');
                 return postTheForm($(thisForm).attr('name'),this.href);
             }
             return true;
         });
     }
 
     if (imageV2.enabled) {
 
         // Make imgTbl allow drag reorder of imgTrack rows
         dragReorder.init();
         var imgTable = $(".tableWithDragAndDrop");
         if ($(imgTable).length > 0) {
             $(imgTable).tableDnD({
                 onDragClass: "trDrag",
                 dragHandle: "dragHandle",
                 scrollAmount: 40,
                 onDragStart: function(ev, table, row) {
                     mouse.saveOffset(ev);
                     $(document).on('mousemove',posting.blockTheMapOnMouseMove);
 
                     // Can drag a contiguous set of rows if dragging blue button
                     table.tableDnDConfig.dragObjects = [ row ]; // defaults to just the one
                     var btn = $( row ).find('p.btnBlue');  // btnBlue means cursor over left button
                     if (btn.length === 1) {
                         table.tableDnDConfig.dragObjects = dragReorder.getContiguousRowSet(row);
                         var compositeSet = dragReorder.getCompositeSet(row);
                         if (compositeSet && compositeSet.length > 0)
                             $( compositeSet ).find('p.btn').addClass('blueButtons');// blue persists
                     }
                 },
                 onDrop: function(table, row, dragStartIndex) {
                     var compositeSet = dragReorder.getCompositeSet(row);
                     if (compositeSet && compositeSet.length > 0)
                         $( compositeSet ).find('p.btn').removeClass('blueButtons');// blue persists
                      // NOTE: As of jquery 1.6, attr() can no longer be used to get/set values
                      // that are not explicitly attributes, instead prop() should be used instead.
                      // However this can cause problems in our legacy code because prop() returns
                      // undefined if the property was not set! rowIndex is a property set by
                      // tableDnd so we must use prop() to check for it's value, not attr()
                     let rowIndex = $(row).prop('rowIndex');
                     if (typeof rowIndex !== "undefined" && rowIndex !== dragStartIndex) {
                         // NOTE Even if dragging a contiguous set of rows,
                         // still only need to check the one under the cursor.
                         if (dragReorder.setOrder) {
                             dragReorder.setOrder(table);
                         }
                         dragReorder.zipButtons( table );
                     }
                     $(document).off('mousemove',posting.blockTheMapOnMouseMove);
                     // Timeout necessary incase the onDrop over map item. onDrop takes precedence.
                     setTimeout(posting.allowMapClicks,100);
                 }
             });
         }
 
         // Drag scroll init
         if (hgTracks.imgBoxPortal) {
             // Turn on drag scrolling.
             $("div.scroller").panImages();
         }
 
         // Retrieve tracks via AJAX that may take too long to draw initialliy (i.e. a remote bigWig)
         var retrievables = $('#imgTbl').find("tr.mustRetrieve");
         if ($(retrievables).length > 0) {
             $(retrievables).each( function (i) {
                 var trackName = $(this).attr('id').substring(3);
                 imageV2.requestImgUpdate(trackName,"","");
             });
         }
         imageV2.loadRemoteTracks();
 
         if (typeof clinicalTour !== 'undefined') {
             if (typeof startClinicalOnLoad !== 'undefined' && startClinicalOnLoad){
                 clinicalTour.start();
             }
         }
         // show a tutorial page if this is a new user
         if (typeof basicTour !== 'undefined') {
             if (typeof startTutorialOnLoad !== 'undefined' && startTutorialOnLoad) {
                 basicTour.start();
             }
             let lsKey = "hgTracks_hideTutorial";
             let isUserLoggedIn = (typeof userLoggedIn !== 'undefined' && userLoggedIn === true);
             let hideTutorial = localStorage.getItem(lsKey);
             let tutMsgKey = "hgTracks_tutMsgCount";
             let tmp = localStorage.getItem(tutMsgKey), tutMsgCount = 0;
             if (tmp !== null) {tutMsgCount = parseInt(tmp);}
             // if the user is not logged in and they have not already gone through the
             // tutorial
             if (!isUserLoggedIn && !hideTutorial && tutMsgCount < 5) {
                 let msg = "New to the Genome Browser? See our short (2-3 minute) guided tutorial. " +
                     "All tutorials can be found in the top blue bar menu under <b>Help</b> > <b>Interactive Tutorial</b>.<br>" +
                     "<button id='showTutorialLink' href=\"#showTutorial\">Start tutorial</button>";
                 notifBoxSetup("hgTracks", "hideTutorial", msg, true);
                 notifBoxShow("hgTracks", "hideTutorial");
                 localStorage.setItem("hgTracks_tutMsgCount", ++tutMsgCount);
                 $("#showTutorialLink").on("click", function() {
                     $("#hgTracks_hideTutorialnotifyHideForever").trigger("click");
                     basicTour.start();
                 });
             }
         }
         // allow the user to bring the tutorials popup via a new help menu button
         let tutorialLinks = document.createElement("li");
         tutorialLinks.id = "hgTracksHelpTutorialLinks";
         tutorialLinks.innerHTML = "<a id='hgTracksHelpTutorialLinks' href='#showTutorialPopup'>" +
             "Interactive Tutorials</a>";
         $("#help > ul")[0].appendChild(tutorialLinks);
         $("#hgTracksHelpTutorialLinks").on("click", function () {
             // Check to see if the tutorial popup has been generated already
             let tutorialPopupExists = document.getElementById ("tutorialContainer");
             if (!tutorialPopupExists) {
                 // Create the tutorial popup if it doesn't exist
                 createTutorialPopup();
             } else {
                 //otherwise use jquery-ui to open the popup
                 $("#tutorialContainer").dialog("open");
             }
         });
         
         // Any highlighted region must be shown and warnBox must play nice with it.
         imageV2.drawHighlights();
         // When warnBox is dismissed, any image highlight needs to be redrawn.
         $('#warnOK').on("click", function (e) { imageV2.drawHighlights();});
         // Also extend the function that shows the warn box so that it too redraws the highlight.
         showWarnBox = (function (oldShowWarnBox) {
             function newShowWarnBox() {
                 oldShowWarnBox.apply();
                 imageV2.drawHighlights();
             }
             return newShowWarnBox;
         })(showWarnBox);
         // redraw highlights if the notification box is closed
         $("[id$=notifyHide],[id$=notifyHideForever]").on("click", function(e) {
             imageV2.drawHighlights();
         });
         notifBoxShow = (function(oldNotifBoxShow) {
             function newNotifBoxShow() {
                 oldNotifBoxShow.apply(null, arguments);
                 imageV2.drawHighlights();
             }
             return newNotifBoxShow;
         })(notifBoxShow);
     }
 
     // Drag select in chromIdeogram
     if ($('img#chrom').length === 1) {
         if ($('area.cytoBand').length >= 1) {
             $('img#chrom').chromDrag();
         }
     }
 
     // Track search uses tabs
     trackSearch.init();
 
     // Drag select initialize
     if (imageV2.enabled) {   // moved from window.load().
         dragSelect.load(true);
 
         if ($('#hgTrackUiDialog'))
             $('#hgTrackUiDialog').hide();
 
         // Don't load contextMenu if jquery.contextmenu.js hasn't been loaded
         if (jQuery.fn.contextMenu) {
             rightClick.load(imageV2.imgTbl);
         }
     }
 
     // jquery.history.js Back-button support
     if (imageV2.enabled && imageV2.backSupport) {
         imageV2.setupHistory();
     }
 
     // ensure clicks into hgTrackUi save the cart state
     $("td a").each( function (tda) {
         if (this.href && this.href.indexOf("hgTrackUi") !== -1) {
             this.onclick = posting.saveSettings;
         }
     });
 
 
     // add a 'link' to download the current track data (under hg.conf control)
     if (typeof showDownloadButton !== 'undefined' && showDownloadButton) {
         newListEl = document.createElement("li");
         newLink = document.createElement("a");
         newLink.setAttribute("id", "hgTracksDownload");
         newLink.setAttribute("name", "downloadTracks");
         newLink.textContent = "Download Current Track Data";
         newLink.href = "#";
         newListEl.appendChild(newLink);
         let opt = document.querySelector("#downloads > ul");
         if (opt) {
             opt.appendChild(newListEl);
             $("#hgTracksDownload").on("click", downloadCurrentTrackData.showDownloadUi);
         }
     }
 
     if (typeof doMyVariants !== 'undefined' && doMyVariants) {
         myVariants.init();
         document.getElementById("myVariantsButton").addEventListener("click", (e) => {
             e.preventDefault();
             e.stopPropagation();
             myVariants.showDialog();
         });
         // Add a "My Annotations" link to the My Data menu that opens the same
         // dialog as the Add Annotation button below the image.
         let myDataList = document.querySelector("#myData > ul");
         if (myDataList) {
             newListEl = document.createElement("li");
             newLink = document.createElement("a");
             newLink.setAttribute("id", "myAnnotationsMenuLink");
             newLink.setAttribute("title", "Add an item to the My Annotations track");
             newLink.textContent = "My Annotations";
             newLink.href = "#";
             newListEl.appendChild(newLink);
             // Place it right after Custom Tracks; fall back to the top of the menu.
             let customTracksItem = document.getElementById("customTracksMenuLink");
             if (customTracksItem && customTracksItem.parentNode.parentNode === myDataList)
                 myDataList.insertBefore(newListEl, customTracksItem.parentNode.nextSibling);
             else
                 myDataList.insertBefore(newListEl, myDataList.firstElementChild);
             newLink.addEventListener("click", (e) => {
                 e.preventDefault();
                 e.stopPropagation();
                 myVariants.showDialog();
             });
         }
     }
 
     if (typeof showMouseovers !== 'undefined' && showMouseovers) {
         convertTitleTagsToMouseovers();
     }
 
 });
 
 function hgtWarnTiming(maxSeconds) {
     /* show a dialog box if the page load time was slower than x seconds. Has buttons to hide or never show this again. */
     var loadTime = window.performance.timing.domContentLoadedEventStart-window.performance.timing.navigationStart; /// in msecs
     var loadSeconds = loadTime/1000;
     if (loadSeconds < maxSeconds)
         return;
 
     var skipNotification = localStorage.getItem("hgTracks.hideSpeedNotification");
     dumpCart(loadSeconds, skipNotification);
         
     if (skipNotification)
         return;
 
     msg = "This page took "+loadSeconds+" seconds to load, more than "+maxSeconds+" seconds. We strive to keep "+
         "the UCSC Genome Browser quick and responsive. See our "+
         "<b><a href='../FAQ/FAQtracks.html#speed' target='_blank'>display speed FAQ</a></b> for "+
         "common causes and solutions to slow performance. If this problem continues, you can create a  "+
         "session link via <b>My Data</b> &gt; <b>My Sessions</b> and send the link to <b>genome-www@soe.ucsc.edu</b>.";
     notifBoxSetup("hgTracks", "hideSpeedNotification", msg);
     notifBoxShow("hgTracks", "hideSpeedNotification");
 }
 
 //////////////////////////
 // Attempt to support panning by dragging IGV track.  The dragging works, but its not clear to do on drag end.
 
 document.addEventListener('DOMContentLoaded', function () {
     if (typeof igv !== 'undefined') {
 
         // TODO -- probably should use genomePos.get() and set() here, but I (JTR) don't fully understand that
         // object and calling set() seems to have side effects.  So this variable is a placeholder.
 
         const pos = {};
 
         igv.ucscTrackpan = (newPosition) => {
 
             const positionOffset = (newPosition - hgTracks.imgBoxPortalStart);
             const pixelOffset = Math.round(positionOffset / hgTracks.imgBoxBasesPerPixel);
             const newX = -(pixelOffset + hgTracks.imgBoxLeftLabel);
             var nowPos = newX.toString() + "px";
             $(".panImg").css({'left': nowPos});
             $('.tdData').css({'backgroundPosition': nowPos});
 
             pos.chrom = hgTracks.chromName;
             pos.start = Math.round(newPosition + 1);
             pos.end = pos.start + (hgTracks.winEnd - hgTracks.winStart);  // Dragging will not change the bp width
 
             $('#positionDisplay').text(pos.chrom + ":" + commify(pos.start) + "-" + commify(pos.end));
         };
 
         igv.ucscTrackpanEnd = () => {
             if (imageV2.inPlaceUpdate) {
                 imageV2.navigateInPlace("db=" + getDb() + "&position=" +
                     encodeURIComponent(pos.chrom + ":" + pos.start + "-" + pos.end),
                     null, false);
             } else {
                 document.TrackHeaderForm.submit();
             }
         };
     }
 });