Support accessible inline text boxes.

content/browser/accessibility/browser_accessibility_win.cc

 // Copyright (c) 2012 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 "content/browser/accessibility/browser_accessibility_win.h"
 
 #include <UIAutomationClient.h>
 #include <UIAutomationCoreApi.h>
 
 #include "base/strings/string_number_conversions.h"
@@ skipping 340 matching lines @@
   return S_OK;
 }
 
 STDMETHODIMP BrowserAccessibilityWin::get_accChildCount(LONG* child_count) {
   if (!instance_active_)
     return E_FAIL;
 
   if (!child_count)
     return E_INVALIDARG;
 
-  *child_count = children_.size();
+  if (IsLeaf())
+    *child_count = 0;
+  else
+    *child_count = children_.size();
+
   return S_OK;
 }
 
 STDMETHODIMP BrowserAccessibilityWin::get_accDefaultAction(VARIANT var_id,
                                                            BSTR* def_action) {
   if (!instance_active_)
     return E_FAIL;
 
   if (!def_action)
     return E_INVALIDARG;
@@ skipping 2239 matching lines @@
 
 STDMETHODIMP BrowserAccessibilityWin::get_childAt(
     unsigned int child_index,
     ISimpleDOMNode** node) {
   if (!instance_active_)
     return E_FAIL;
 
   if (!node)
     return E_INVALIDARG;
 
-  if (child_index < children_.size()) {
+  if (IsLeaf() || child_index < children_.size()) {

[David Tseng, 2013/10/23 16:42:46]

I'm confused by this indexing logic;  child_index < child_.size()? So, to index
into children_, child_index needs to be >= children_.size()?

[dmazzoni, 2013/10/30 16:45:26]

Ack! Yes, you found a longstanding bug. We never caught it because it only
affected ISimpleDOMNode. I think ISimpleDOMNode is used occasionally, but no
screen reader appears to ever use it to walk the DOM tree.

I replaced this with PlatformGetChild followed by a NULL check.

     *node = NULL;
     return S_FALSE;
   }
 
   *node = children_[child_index]->ToBrowserAccessibilityWin()->NewReference();
   return S_OK;
 }
 
 //
 // ISimpleDOMText methods.
@@ skipping 1029 matching lines @@
   // The role should always be set.
   DCHECK(!role_name_.empty() || ia_role_);
 
   // If we didn't explicitly set the IAccessible2 role, make it the same
   // as the MSAA role.
   if (!ia2_role_)
     ia2_role_ = ia_role_;
 }
 
 }  // namespace content