Index: jquery.treeTable.css
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/token/jquery.treeTable.css,v
retrieving revision 1.2
diff -u -p -r1.2 jquery.treeTable.css
--- jquery.treeTable.css	10 Jul 2010 13:57:47 -0000	1.2
+++ jquery.treeTable.css	30 Jan 2011 12:03:06 -0000
@@ -9,7 +9,7 @@
 /* jquery.treeTable.collapsible
  * ------------------------------------------------------------------------- */
 .treeTable tr td .expander {
-  background-position: left center;
+  background-position: -100px 0; /* move the image outside the visible part of the element */
   background-repeat: no-repeat;
   cursor: pointer;
   padding: 0;
@@ -24,6 +24,10 @@
   background-image: url(arrow-down.png);
 }
 
+.treeTable tr td a.expander:focus {
+  font-weight: bold;
+}
+
 /* jquery.treeTable.sortable
  * ------------------------------------------------------------------------- */
 .treeTable tr.selected, .treeTable tr.accept {
Index: jquery.treeTable.js
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/token/jquery.treeTable.js,v
retrieving revision 1.1
diff -u -p -r1.1 jquery.treeTable.js
--- jquery.treeTable.js	16 Mar 2010 23:48:58 -0000	1.1
+++ jquery.treeTable.js	30 Jan 2011 12:03:06 -0000
@@ -42,7 +42,9 @@
     expandable: true,
     indent: 19,
     initialState: "collapsed",
-    treeColumn: 0
+    treeColumn: 0,
+    stringExpand: "Expand",
+    stringCollapse: "Collapse"
   };
   
   // Recursively hide all node's children in a tree
@@ -124,8 +126,20 @@
   $.fn.toggleBranch = function() {
     if($(this).hasClass("collapsed")) {
       $(this).expand();
+      // Replace the image src, alt, and title.
+      $(this).children('td:first-child').children('a:first-child').children('img:first-child').attr({
+        src:   getBackgroundImageSrc($(this).children('td:first-child').children('a:first-child')),
+        title: options.stringCollapse,
+        alt:   options.stringCollapse
+      });
     } else {
       $(this).removeClass("expanded").collapse();
+      // Replace the image src, alt, and title.
+      $(this).children('td:first-child').children('a:first-child').children('img:first-child').attr({
+        src:   getBackgroundImageSrc($(this).children('td:first-child').children('a:first-child')),
+        title: options.stringExpand,
+        alt:   options.stringExpand
+      });
     }
     
     return this;
@@ -178,8 +192,9 @@
         });
         
         if(options.expandable) {
-          cell.prepend('<span style="margin-left: -' + options.indent + 'px; padding-left: ' + options.indent + 'px" class="expander"></span>');
-          $(cell[0].firstChild).click(function() { node.toggleBranch(); });
+          cell.wrapInner('<a href="#" title="' + options.stringExpand + '" style="margin-left: -' + options.indent + 'px; padding-left: ' + options.indent + 'px" class="expander"></a>');
+          $(cell[0].firstChild).click(function() { node.toggleBranch(); return false; });
+          $(cell[0].firstChild).keydown(function(e) { if(e.keyCode == 13) {node.toggleBranch(); return false; }});
           
           if(options.clickableNodeNames) {
             cell[0].style.cursor = "pointer";
@@ -190,7 +205,7 @@
               }
             });
           }
-          
+
           // Check for a class set explicitly by the user, otherwise set the default class
           if(!(node.hasClass("expanded") || node.hasClass("collapsed"))) {
             node.addClass(options.initialState);
@@ -199,6 +214,10 @@
           if(node.hasClass("expanded")) {
             node.expand();
           }
+
+          // Change the background css image to a foreground image, to provide an accessible UI.
+          backgroundImage = getBackgroundImageSrc($(cell[0].firstChild)); 
+          $(cell[0].firstChild).prepend('<img src="' + backgroundImage + '" alt="' + options.stringExpand + '" title="' + options.stringExpand + '" />');
         }
       }
     }
@@ -218,4 +237,9 @@
       }
     }
   };
+
+  function getBackgroundImageSrc(element) {
+    // Take the background-image css attribute, and remove the url("") text.
+    return element.css('background-image').replace(/^url\(\"/, '').replace(/\"\)$/, '');
+  }
 })(jQuery);
Index: token.js
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/token/token.js,v
retrieving revision 1.3
diff -u -p -r1.3 token.js
--- token.js	20 Mar 2010 19:48:25 -0000	1.3
+++ token.js	30 Jan 2011 12:03:06 -0000
@@ -5,7 +5,11 @@
 Drupal.behaviors.tokenTree = {
   attach: function (context, settings) {
     $('table.token-tree', context).once('token-tree', function () {
-      $(this).treeTable();
+      opts = {
+        stringCollapse: Drupal.t('Collapse'),
+        stringExpand:   Drupal.t('Expand')
+      };
+      $(this).treeTable(opts);
     });
   }
 };