Fire AX text inserted event when embedded obj char changes.

content/browser/accessibility/browser_accessibility_manager_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_manager_win.h"
 
 #include "base/command_line.h"
 #include "base/win/scoped_comptr.h"
 #include "base/win/windows_version.h"
 #include "content/browser/accessibility/browser_accessibility_state_impl.h"
@@ skipping 279 matching lines @@
     bool root_changed,
     const std::vector<ui::AXTreeDelegate::Change>& changes) {
   BrowserAccessibilityManager::OnAtomicUpdateFinished(root_changed, changes);
 
   if (root_changed) {
     // In order to make screen readers aware of the new accessibility root,
     // we need to fire a focus event on it.
     OnWindowFocused();
   }
 
-  // BrowserAccessibilityManager::OnAtomicUpdateFinished calls
-  // OnUpdateFinished() on each node in |changes|. However, the
-  // IAccessibleText text for a node is a concatenatenation of all of its child
-  // text nodes, so we can't compute a node's IAccessibleText in
-  // OnUpdateFinished because its children may not have been updated yet.
-  //
-  // So we make a second pass here to update IAccessibleText.
+  // Do a sequence of Windows-specific updates on each node. Each one is
+  // done in a single pass that must complete before the next step starts.
+  // The first step moves win_attributes_ to old_win_attributes_ and then
+  // recomputes all of win_attributes_ other than IAccessibleText.
   for (size_t i = 0; i < changes.size(); ++i) {
     BrowserAccessibility* obj = GetFromAXNode(changes[i].node);
-    if (obj && obj->IsNative())
-      obj->ToBrowserAccessibilityWin()->UpdateIAccessibleText();
+    if (obj && obj->IsNative() && !obj->PlatformIsChildOfLeaf())
+      obj->ToBrowserAccessibilityWin()->UpdateStep1ComputeWinAttributes();
+  }
+
+  // The next step updates the hypertext of each node, which is a
+  // concatenatenation of all of its child text nodes, so it can't run until

[David Tseng, 2015/01/30 23:57:25]

nit: contatenation

[dmazzoni, 2015/01/31 07:45:21]

Done.

+  // the text of all of the nodes was computed in the previous step.
+  for (size_t i = 0; i < changes.size(); ++i) {
+    BrowserAccessibility* obj = GetFromAXNode(changes[i].node);
+    if (obj && obj->IsNative() && !obj->PlatformIsChildOfLeaf())
+      obj->ToBrowserAccessibilityWin()->UpdateStep2ComputeHypertext();
+  }
+
+  // The third step fires events on nodes based on what's changed - like
+  // if the name, value, or description changed, or if the hypertext had
+  // text inserted or removed. It's able to figure out exactly what changed
+  // because we still have old_win_attributes_ populated.
+  // This step has to run after the previous two steps complete because the
+  // client may walk the tree when it receives any of these events.
+  for (size_t i = 0; i < changes.size(); ++i) {
+    BrowserAccessibility* obj = GetFromAXNode(changes[i].node);
+    if (obj && obj->IsNative() && !obj->PlatformIsChildOfLeaf()) {
+      obj->ToBrowserAccessibilityWin()->UpdateStep3FireEvents(
+          changes[i].type == AXTreeDelegate::SUBTREE_CREATED);
+    }
+  }
+
+  // The final step is to delete old_win_attributes_ since they're not
+  // needed anymore.
+  for (size_t i = 0; i < changes.size(); ++i) {
+    BrowserAccessibility* obj = GetFromAXNode(changes[i].node);
+    if (obj && obj->IsNative() && !obj->PlatformIsChildOfLeaf())
+      obj->ToBrowserAccessibilityWin()->UpdateStep4DeleteOldWinAttributes();

[David Tseng, 2015/01/30 23:57:25]

Could you combine this last step with the above one?

[dmazzoni, 2015/01/31 07:45:21]

Sure. It doesn't really need its own step.

   }
 }
 
 void BrowserAccessibilityManagerWin::TrackScrollingObject(
     BrowserAccessibilityWin* node) {
   if (tracked_scroll_object_)
     tracked_scroll_object_->Release();
   tracked_scroll_object_ = node;
   tracked_scroll_object_->AddRef();
 }
@@ skipping 20 matching lines @@
           child_manager->GetFromUniqueIdWin(unique_id_win);
       if (result)
         return result;
     }
   }
 
   return NULL;
 }
 
 }  // namespace content