Make ChromeVox use child-index based offsets again for selection.

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 144 matching lines @@
     return this.index_;
   },
 
 
   /**
    * A node appropriate for making selections.
    * @return {AutomationNode}
    * @private
    */
   get selectionNode_() {
-    if (!this.node)
+    var adjustedNode = this.node;
+    if (!adjustedNode)
       return null;
 
-    if (this.node.role == RoleType.inlineTextBox)
-      return this.node.parent;
+    // Selections over line break nodes are broken.
+    var parent = adjustedNode.parent;
+    var grandparent = parent && parent.parent;
+    if (parent.role == RoleType.lineBreak) {
+      adjustedNode = grandparent;
+    } else if (grandparent.role == RoleType.lineBreak) {
+      adjustedNode = grandparent.parent;
+    } else if (this.index_ == cursors.NODE_INDEX ||
+        adjustedNode.role == RoleType.inlineTextBox ||
+        chrome.automation.NameFromType[adjustedNode.nameFrom] != 'contents') {
+      // A node offset or unselectable character offset.
+      adjustedNode = parent;
+    } else {
+      // A character offset into content.
+      adjustedNode =
+          adjustedNode.find({role: RoleType.staticText}) || adjustedNode;
+    }
 
-    return this.node;
+    return adjustedNode;
   },
 
   /**
    * An index appropriate for making selections.  If this cursor has a
    * cursors.NODE_INDEX index, the selection index is a node offset e.g. the
    * index in parent. If not, the index is a character offset.
    * @return {number}
    * @private
    */
   get selectionIndex_() {
     var adjustedIndex = this.index_;
-    if (this.node.role == RoleType.inlineTextBox) {
+
+    // Selecting things under a line break is currently broken.
+    if (this.node.role == RoleType.inlineTextBox &&
+        this.node.parent && this.node.parent.role != RoleType.lineBreak) {
       if (adjustedIndex == cursors.NODE_INDEX)
         adjustedIndex = 0;
 
       var sibling = this.node.previousSibling;
       while (sibling) {
         adjustedIndex += sibling.name.length;
         sibling = sibling.previousSibling;
       }
-    } else if (this.index_ == cursors.NODE_INDEX) {
-      // Indicies of this kind are buggy. Set it to 0 (different than the DOM
-      // index in parent convention).
-      adjustedIndex = 0;
+    } else if (this.index_ == cursors.NODE_INDEX ||
+        chrome.automation.NameFromType[this.node.nameFrom] != 'contents') {
+      // A node offset or unselectable character offset.
+
+      // The selected node could have been adjusted upwards in the tree.
+      var childOfSelection = this.node;
+      do {
+        adjustedIndex = childOfSelection.indexInParent;
+        childOfSelection = childOfSelection.parent;
+      } while (childOfSelection && childOfSelection != this.selectionNode_);
     }
+    // A character offset into content is the remaining case. It requires no
+    // adjustment.
+
     return adjustedIndex;
   },
 
   /**
    * Gets the accessible text of the node associated with this cursor.
    *
    * @param {!AutomationNode=} opt_node Use this node rather than this cursor's
    * node.
    * @return {string}
    */
@@ skipping 403 matching lines @@
     if (!startNode || !endNode)
       return;
 
     // Only allow selections within the same web tree.
     if (startNode.root &&
         startNode.root.role == RoleType.rootWebArea &&
         startNode.root == endNode.root) {
       // We want to adjust to select the entire node for node offsets;
       // otherwise, use the plain character offset.
       var startIndex = this.start.selectionIndex_;
-      var endIndex = this.end.index == cursors.NODE_INDEX ?
+      var endIndex = this.end.index_ == cursors.NODE_INDEX ?
           this.end.selectionIndex_ + 1 : this.end.selectionIndex_;
 
       chrome.automation.setDocumentSelection(
           { anchorObject: startNode,
             anchorOffset: startIndex,
             focusObject: endNode,
             focusOffset: endIndex }
       );
     }
   },
@@ skipping 11 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