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, 13 insertions, 15 deletions

diff --git a/src/gui/accessible/qaccessible.cpp b/src/gui/accessible/qaccessible.cpp
index dffdfa889a..776320a517 100644
--- a/src/gui/accessible/qaccessible.cpp
+++ b/src/gui/accessible/qaccessible.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.
@@ -591,8 +591,6 @@ QAccessible::RootObjectHandler QAccessible::installRootObjectHandler(RootObjectH
     return old;
 }
 
-Q_GLOBAL_STATIC(QAccessibleCache, qAccessibleCache)
-
 /*!
     If a QAccessibleInterface implementation exists for the given \a object,
     this function returns a pointer to the implementation; otherwise it
@@ -616,8 +614,8 @@ QAccessibleInterface *QAccessible::queryAccessibleInterface(QObject *object)
     if (!object)
         return 0;
 
-    if (Id id = qAccessibleCache->objectToId.value(object))
-        return qAccessibleCache->interfaceForId(id);
+    if (Id id = QAccessibleCache::instance()->objectToId.value(object))
+        return QAccessibleCache::instance()->interfaceForId(id);
 
     // Create a QAccessibleInterface for the object class. Start by the most
     // derived class and walk up the class hierarchy.
@@ -629,8 +627,8 @@ QAccessibleInterface *QAccessible::queryAccessibleInterface(QObject *object)
         for (int i = qAccessibleFactories()->count(); i > 0; --i) {
             InterfaceFactory factory = qAccessibleFactories()->at(i - 1);
             if (QAccessibleInterface *iface = factory(cn, object)) {
-                qAccessibleCache->insert(object, iface);
-                Q_ASSERT(qAccessibleCache->objectToId.contains(object));
+                QAccessibleCache::instance()->insert(object, iface);
+                Q_ASSERT(QAccessibleCache::instance()->objectToId.contains(object));
                 return iface;
             }
         }
@@ -652,8 +650,8 @@ QAccessibleInterface *QAccessible::queryAccessibleInterface(QObject *object)
         if (factory) {
             QAccessibleInterface *result = factory->create(cn, object);
             if (result) {   // Need this condition because of QDesktopScreenWidget
-                qAccessibleCache->insert(object, result);
-                Q_ASSERT(qAccessibleCache->objectToId.contains(object));
+                QAccessibleCache::instance()->insert(object, result);
+                Q_ASSERT(QAccessibleCache::instance()->objectToId.contains(object));
             }
             return result;
         }
@@ -665,8 +663,8 @@ QAccessibleInterface *QAccessible::queryAccessibleInterface(QObject *object)
 #ifndef QT_NO_ACCESSIBILITY
     if (object == qApp) {
         QAccessibleInterface *appInterface = new QAccessibleApplication;
-        qAccessibleCache->insert(object, appInterface);
-        Q_ASSERT(qAccessibleCache->objectToId.contains(qApp));
+        QAccessibleCache::instance()->insert(object, appInterface);
+        Q_ASSERT(QAccessibleCache::instance()->objectToId.contains(qApp));
         return appInterface;
     }
 #endif
@@ -691,7 +689,7 @@ QAccessibleInterface *QAccessible::queryAccessibleInterface(QObject *object)
 QAccessible::Id QAccessible::registerAccessibleInterface(QAccessibleInterface *iface)
 {
     Q_ASSERT(iface);
-    return qAccessibleCache->insert(iface->object(), iface);
+    return QAccessibleCache::instance()->insert(iface->object(), iface);
 }
 
 /*!
@@ -701,7 +699,7 @@ QAccessible::Id QAccessible::registerAccessibleInterface(QAccessibleInterface *i
 */
 void QAccessible::deleteAccessibleInterface(Id id)
 {
-    qAccessibleCache->deleteInterface(id);
+    QAccessibleCache::instance()->deleteInterface(id);
 }
 
 /*!
@@ -709,7 +707,7 @@ void QAccessible::deleteAccessibleInterface(Id id)
 */
 QAccessible::Id QAccessible::uniqueId(QAccessibleInterface *iface)
 {
-    Id id = qAccessibleCache->idToInterface.key(iface);
+    Id id = QAccessibleCache::instance()->idToInterface.key(iface);
     if (!id)
         id = registerAccessibleInterface(iface);
     return id;
@@ -722,7 +720,7 @@ QAccessible::Id QAccessible::uniqueId(QAccessibleInterface *iface)
 */
 QAccessibleInterface *QAccessible::accessibleInterface(Id id)
 {
-    return qAccessibleCache->idToInterface.value(id);
+    return QAccessibleCache::instance()->idToInterface.value(id);
 }