Better work around for Blink selection issues.

chrome/browser/resources/chromeos/chromevox/cvox2/background/cursors.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @fileoverview Classes related to cursors that point to and select parts of
  * the automation tree.
  */
 
 goog.provide('cursors.Cursor');
@@ skipping 147 matching lines @@
     var adjustedIndex = this.index_;
     if (this.node.role == RoleType.inlineTextBox) {
       if (adjustedIndex == cursors.NODE_INDEX)
         adjustedIndex = 0;
 
       var sibling = this.node.previousSibling;
       while (sibling) {
         adjustedIndex += sibling.name.length;
         sibling = sibling.previousSibling;
       }
+    }
 
+    if (this.selectionNode_ && AutomationPredicate.text(this.selectionNode_)) {
       // Work around Blink's somewhat unexpected offset calculation which
-      // requires us to consider all previous siblings of the parenting static
-      // text.
-      var parent = this.node.parent;
-      if (parent.role == RoleType.staticText) {
-        sibling = parent.previousSibling;
-        while (sibling) {
-          if (sibling.name)
-            adjustedIndex += sibling.name.length;
-          sibling = sibling.previousSibling;
+      // requires us to consider all previous siblings of the parenting node of
+      // the static text.
+
+      var parent = this.selectionNode_.parent;
+      if (parent) {
+        // Grab all of the text nodes and accumulate their lengths up to
+        // but not including the current static text node.
+        var texts = [];
+        AutomationUtil.findNodePre(parent, Dir.FORWARD, function(node) {
+          if (AutomationPredicate.text(node))
+            texts.push(node);
+          return false;
+        });
+
+        for (var i = 0; i < texts.length; i++) {
+          if (texts[i] == this.selectionNode_)
+            break;
+
+          adjustedIndex += texts[i].name.length;
         }
       }
     } else if (this.index_ == cursors.NODE_INDEX) {
       if (this.index_ == cursors.NODE_INDEX) {
         // Translate the index into a selection on the parent.
         if (this.node.parent)
           adjustedIndex = this.node.indexInParent;
       }
     }
     return adjustedIndex;
@@ skipping 392 matching lines @@
   /**
    * Select the text contained within this range.
    */
   select: function() {
     var startNode = this.start.selectionNode_;
     var endNode = this.end.selectionNode_;
 
     if (!startNode || !endNode)
       return;
 
-    // Find the most common root.
-    var uniqueAncestors = AutomationUtil.getUniqueAncestors(startNode, endNode);
-    var mcr = startNode.root;
-    if (uniqueAncestors) {
-      var common = uniqueAncestors.pop().parent;
-      if (common)
-        mcr = common.root;
-    }
-
-    if (!mcr || mcr.role == RoleType.desktop)
-      return;
-
-    if (mcr === startNode.root && mcr === endNode.root) {
+    // Only allow selections inside of the same web tree.
+    if (startNode.root &&
+        startNode.root.role == RoleType.rootWebArea &&
+        startNode.root === endNode.root) {
       var startIndex = this.start.selectionIndex_;
 
       // We want to adjust to select the entire node for node offsets;
       // otherwise, use the plain character offset.
       var endIndex = this.end.index == cursors.NODE_INDEX ?
           this.end.selectionIndex_ + 1 : this.end.selectionIndex_;
 
       chrome.automation.setDocumentSelection(
           { anchorObject: startNode,
             anchorOffset: startIndex,
@@ skipping 16 matching lines @@
   /**
    * Returns whether this range has valid start and end cursors.
    * @return {boolean}
    */
   isValid: function() {
     return this.start.isValid() && this.end.isValid();
   }
 };
 
 });  // goog.scope