52ef51261a5be2ca2dea9e73642240cd46b6d865
lrnassar
  Tue Apr 28 15:16:24 2026 -0700
Extend chromAlias info icon mouseover with usage description and docs link, refs #29201

Per Max's feedback on the ticket, expand the tooltip to explain where
alternative chromosome names can be used (position box, custom tracks,
track hubs, bigBed/bigWig) and link to the assembly hub help docs page.
Bold the "Alternate sequence names" header.

diff --git src/hg/hgTracks/hgTracks.c src/hg/hgTracks/hgTracks.c
index 63927f10708..d236a9cb0dd 100644
--- src/hg/hgTracks/hgTracks.c
+++ src/hg/hgTracks/hgTracks.c
@@ -8864,31 +8864,35 @@
         continue;
     if (sameString(a->name, displayName) || sameString(a->name, nativeName))
         continue;
     if (dy->stringSize > 0)
         dyStringAppend(dy, ", ");
     dyStringAppend(dy, a->name);
     }
 
 if (dy->stringSize == 0)
     {
     dyStringFree(&dy);
     return;
     }
 
 char *encoded = htmlEncode(dy->string);
-printf("<span id='chromAliases' title='Alternate sequence names: %s'>"
+printf("<span id='chromAliases' title='<b>Alternate sequence names</b>: %s<br><br>"
+       "Alternative sequence names can be used in the position box, custom tracks, "
+       "track hubs, bigBed, bigWig, and similar files. "
+       "See the <a href=\"/goldenPath/help/assemblyHubHelp.html#chromAlias\">docs page</a> "
+       "for more information'>"
        "<a>&#9432;</a></span>", encoded);
 freeMem(encoded);
 dyStringFree(&dy);
 }
 
 
 unsigned getParaLoadTimeout()
 // get the parallel load timeout in seconds (defaults to 90)
 {
 char *paraLoadTimeoutStr = cartOptionalString(cart, "parallelFetch.timeout");
 if (paraLoadTimeoutStr == NULL)
     paraLoadTimeoutStr = cfgOptionDefault("parallelFetch.timeout", "90");  // wait up to default 90 seconds.
 
 unsigned paraLoadTimeout = sqlUnsigned(paraLoadTimeoutStr);