Fixed line start offsets.

ui/accessibility/ax_node.cc

 // Copyright 2013 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.
 
 #include "ui/accessibility/ax_node.h"
 
 #include <algorithm>
 
 #include "base/strings/string16.h"
 #include "ui/gfx/transform.h"
@@ skipping 42 matching lines @@
     return parent()->IsDescendantOf(ancestor);
 
   return false;
 }
 
 std::vector<int> AXNode::GetOrComputeLineStartOffsets() {
   std::vector<int> line_offsets;
   if (data().GetIntListAttribute(AX_ATTR_CACHED_LINE_STARTS, &line_offsets))
     return line_offsets;
 
-  int end_offset = 0;
-  ComputeLineStartOffsets(&line_offsets, &end_offset);
+  int start_offset = 0;
+  ComputeLineStartOffsets(&line_offsets, &start_offset);
   data_.AddIntListAttribute(AX_ATTR_CACHED_LINE_STARTS, line_offsets);
   return line_offsets;
 }
 
 void AXNode::ComputeLineStartOffsets(std::vector<int>* line_offsets,
-                                     int* end_offset) const {
+                                     int* start_offset) const {
   DCHECK(line_offsets);
-  DCHECK(end_offset);
+  DCHECK(start_offset);
   for (const AXNode* child : children()) {
     DCHECK(child);
     if (child->child_count()) {
-      child->ComputeLineStartOffsets(line_offsets, end_offset);
+      child->ComputeLineStartOffsets(line_offsets, start_offset);
       continue;
     }
 
+    if (!child->data().HasIntAttribute(ui::AX_ATTR_PREVIOUS_ON_LINE_ID))

[David Tseng, 2016/10/19 17:39:42]

This is still wrong...

- this would include 0; there's *never* a line break at the beginning of the
content (i.e. before the first character in a content editable)
- this would include leaf nodes that don't have any accessible text like a div
with an empty aria label.
- this would not handle the case where the last character is a hard line break

I think you really just want inline textbox nodes.

Also, the confusion over start and end and break: I would think of the line
index as the index in-between characters that involve a line break (either a
hard or soft line break). This would allow us to then talk about a line break
between two characters, before the first character, after the last character,
etc.

+      line_offsets->push_back(*start_offset);
     base::string16 text = child->data().GetString16Attribute(ui::AX_ATTR_NAME);
-    *end_offset += static_cast<int>(text.length());
-    if (!child->data().HasIntAttribute(ui::AX_ATTR_NEXT_ON_LINE_ID))
-      line_offsets->push_back(*end_offset);
+    *start_offset += static_cast<int>(text.length());
   }
 }
 
 }  // namespace ui