6de82671728ebf25c3edff3c677fc291d72a96c5
hiram
  Tue Jan 26 15:39:25 2021 -0800
turn off popUp when track scrolls off top refs #21980

diff --git src/hg/js/hgTracks.js src/hg/js/hgTracks.js
index 98b32bd..5addd5d 100644
--- src/hg/js/hgTracks.js
+++ src/hg/js/hgTracks.js
@@ -4620,31 +4620,31 @@
     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
+    if (tdTop < 0) { return; }  // track is scrolled off top of screen
     var tdWidth = Math.floor(tdRect.width);
     var tdHeight = Math.floor(tdRect.height);
     var rightSide = tdLeft + tdWidth;
     // clientX is the X coordinate of the mouse hot spot
     var clientX = Math.floor(evt.clientX);
     // 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, rightSide - clientX);
     }
 
     var windowUp = false;     // see if window is supposed to become visible