b4bb3a8a5e38cc6f8f58adc19186469f379a64af
max
  Mon Apr 29 14:55:30 2013 -0700
adding mouseOverField to trackDb for bigBed and using it for the spMut track
diff --git src/hg/hgTracks/hgTracks.h src/hg/hgTracks/hgTracks.h
index 58d9233..bb86dbc 100644
--- src/hg/hgTracks/hgTracks.h
+++ src/hg/hgTracks/hgTracks.h
@@ -301,40 +301,41 @@
     highlightBackground=1,
     highlightOutline=2
     };
 
 struct linkedFeatures
 /* A linked set of features - drawn as a bunch of boxes (often exons)
  * connected by horizontal lines (often introns).  About 75% of
  * the browser tracks end up as linkedFeatures. */
     {
     struct linkedFeatures *next;
     int start, end;			/* Start/end in browser coordinates. */
     int tallStart, tallEnd;		/* Start/end of fat display. */
     int grayIx;				/* Average of components. */
     int filterColor;			/* Filter color (-1 for none) */
     float score;                        /* score for this feature */
-    char *name;				/* Accession of query seq. */
+    char *name;				/* Accession of query seq. Usually also the label. */
     int orientation;                    /* Orientation. */
     struct simpleFeature *components;   /* List of component simple features. */
     struct simpleFeature *codons;       /* If zoomed to CDS or codon level.*/
     void *extra;			/* Extra info that varies with type. */
     void *original;			/* The structure that was converted
 					   into this (when needed later).  */
     struct itemAttr *itemAttr;          /* itemAttr object for this lf, or NULL */
     unsigned highlightColor;            /* highlight color,0 if no highlight */
     enum highlightMode highlightMode;   /* highlight mode,0 if no highlight */
+    char* mouseOver;                    /* mouse over text */
     };
 
 struct linkedFeaturesSeries
 /* series of linked features that are comprised of multiple linked features */
 {
     struct linkedFeaturesSeries *next;
     char *name;                      /* name for series of linked features */
     int start, end;                     /* Start/end in browser coordinates. */
     int orientation;                    /* Orientation. */
     int grayIx;				/* Gray index (average of features) */
     boolean noLine;                     /* if true don't draw line connecting features */
     struct linkedFeatures *features;    /* linked features for a series */
 };
 
 struct knownGenesExtra