try catch

git-svn-id: svn://svn.open-ils.org/ILS/trunk@5694 dcc99617-32d9-48b4-a31d-7c20da2025e4

diff --git a/Open-ILS/xul/staff_client/chrome/content/util/list.js b/Open-ILS/xul/staff_client/chrome/content/util/list.js
index da8f313..5f8a1e0 100644 (file)
--- a/Open-ILS/xul/staff_client/chrome/content/util/list.js
+++ b/Open-ILS/xul/staff_client/chrome/content/util/list.js
@@ -453,14 +453,18 @@ util.list.prototype = {
                try {
                        //dump('detect_visible  obj.node = ' + obj.node + '\n');
                        /* FIXME - this is a hack.. if the implementation of tree changes, this could break */
-                       var scrollbar = document.getAnonymousNodes( document.getAnonymousNodes(obj.node)[1] )[1];
-                       var curpos = scrollbar.getAttribute('curpos');
-                       var maxpos = scrollbar.getAttribute('maxpos');
-                       //alert('curpos = ' + curpos + ' maxpos = ' + maxpos + ' obj.curpos = ' + obj.curpos + ' obj.maxpos = ' + obj.maxpos + '\n');
-                       if ((curpos != obj.curpos) || (maxpos != obj.maxpos)) {
-                               if ( obj.auto_retrieve() > 0 ) {
-                                       obj.curpos = curpos; obj.maxpos = maxpos;
+                       try {
+                               var scrollbar = document.getAnonymousNodes( document.getAnonymousNodes(obj.node)[1] )[1];
+                               var curpos = scrollbar.getAttribute('curpos');
+                               var maxpos = scrollbar.getAttribute('maxpos');
+                               //alert('curpos = ' + curpos + ' maxpos = ' + maxpos + ' obj.curpos = ' + obj.curpos + ' obj.maxpos = ' + obj.maxpos + '\n');
+                               if ((curpos != obj.curpos) || (maxpos != obj.maxpos)) {
+                                       if ( obj.auto_retrieve() > 0 ) {
+                                               obj.curpos = curpos; obj.maxpos = maxpos;
+                                       }
                                }
+                       } catch(E) {
+                               obj.error.sdump('D_ERROR', 'List implementation changed? ' + E);
                        }
                } catch(E) { obj.error.sdump('D_ERROR',E); }
        },