Accessibility Mac: Cache Accessible Elements and Notify about changes

The big change is that we now keep the id objects representing accessibles
around so that they are persistent for ATs.
This improves performance of Mac accessibility significantly.

This is required for notifications which are now sent so that many things work much better,
for example the VoiceOver focus follows the keyboard focus.

The parent element in QCocoaAccessibleElement was removed, we can
dynamically access it more reliably.

Change-Id: I686d212f40d28b392dcc22f16f3c3430f08bdc98
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>

1 files changed, 12 insertions, 1 deletions

diff --git a/src/gui/accessible/qaccessiblecache.cpp b/src/gui/accessible/qaccessiblecache.cpp
index fe66c6e19d..09c155515e 100644
--- a/src/gui/accessible/qaccessiblecache.cpp
+++ b/src/gui/accessible/qaccessiblecache.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
 ** Contact: http://www.qt-project.org/legal
 **
 ** This file is part of the QtGui module of the Qt Toolkit.
@@ -49,6 +49,13 @@ QT_BEGIN_NAMESPACE
     \brief Maintains a cache of accessible interfaces.
 */
 
+Q_GLOBAL_STATIC(QAccessibleCache, qAccessibleCache)
+
+QAccessibleCache *QAccessibleCache::instance()
+{
+    return qAccessibleCache;
+}
+
 /*
   The ID is always in the range [INT_MAX+1, UINT_MAX].
   This makes it easy on windows to reserve the positive integer range
@@ -113,6 +120,10 @@ void QAccessibleCache::deleteInterface(QAccessible::Id id, QObject *obj)
     if (obj)
         objectToId.remove(obj);
     delete iface;
+
+#ifdef Q_OS_MACX
+    removeCocoaElement(id);
+#endif
 }
 
 QT_END_NAMESPACE