Improve omnibox accessibility on Windows.

views/widget/native_widget_win.h

Index: views/widget/native_widget_win.h
===================================================================
--- views/widget/native_widget_win.h	(revision 107097)
+++ views/widget/native_widget_win.h	(working copy)
@@ -14,6 +14,7 @@
 #include <string>
 #include <vector>
 
+#include "base/hash_tables.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
@@ -102,22 +103,12 @@
     can_update_layered_window_ = can_update_layered_window;
   }
 
-  // Obtain the view event with the given MSAA child id.  Used in
+  // Obtain the view corresponding to a MSAA child id. Used in
   // NativeViewAccessibilityWin::get_accChild to support requests for
   // children of windowless controls.  May return NULL
   // (see ViewHierarchyChanged).
-  View* GetAccessibilityViewEventAt(int id);
+  View* GetAccessibilityViewFromChildId(long id);

[sky, 2011/10/25 20:08:45]

How about naming this GetViewByAccessibleId().
I don't like having to keep the map up to date. Is it possible to have this walk
the tree each time it's invoked?

[dmazzoni, 2011/10/26 16:46:13]

Sure - since the view hierarchy is pretty small, I don't see a problem with
this. I added a helper function to search recursively.

 
-  // Add a view that has recently fired an accessibility event.  Returns a MSAA
-  // child id which is generated by: -(index of view in vector + 1) which
-  // guarantees a negative child id.  This distinguishes the view from
-  // positive MSAA child id's which are direct leaf children of views that have
-  // associated hWnd's (e.g. NativeWidgetWin).
-  int AddAccessibilityViewEvent(View* view);
-
-  // Clear a view that has recently been removed on a hierarchy change.
-  void ClearAccessibilityViewEvent(View* view);
-
   // Hides the window if it hasn't already been force-hidden. The force hidden
   // count is tracked, so calling multiple times is allowed, you just have to
   // be sure to call PopForceHidden the same number of times.
@@ -595,17 +586,9 @@
   // Value determines whether the Widget is customized for accessibility.
   static bool screen_reader_active_;
 
-  // The maximum number of view events in our vector below.
-  static const int kMaxAccessibilityViewEvents = 20;
+  // A map from a unique ID to a descendant view, for accessibility.
+  base::hash_map<long, View*> accessibility_id_view_map_;
 
-  // A vector used to access views for which we have sent notifications to
-  // accessibility clients.  It is used as a circular queue.
-  std::vector<View*> accessibility_view_events_;
-
-  // The current position of the view events vector.  When incrementing,
-  // we always mod this value with the max view events above .
-  int accessibility_view_events_index_;
-
   // The last cursor that was active before the current one was selected. Saved
   // so that we can restore it.
   gfx::NativeCursor previous_cursor_;