5 files changed, 43 insertions, 8 deletions
diff --git a/src/gui/kernel/qwidget.cpp b/src/gui/kernel/qwidget.cpp
index 5705214762..758cccefdc 100644
--- a/src/gui/kernel/qwidget.cpp
+++ b/src/gui/kernel/qwidget.cpp
@@ -1588,6 +1588,7 @@ QWidget::~QWidget()
 
     // delete layout while we still are a valid widget
     delete d->layout;
+    d->layout = 0;
     // Remove myself from focus list
 
     Q_ASSERT(d->focus_next->d_func()->focus_prev == this);
diff --git a/src/gui/kernel/qwidget_mac.mm b/src/gui/kernel/qwidget_mac.mm
index 354f05ba10..27a1bb6940 100644
--- a/src/gui/kernel/qwidget_mac.mm
+++ b/src/gui/kernel/qwidget_mac.mm
@@ -2733,7 +2733,7 @@ QWidget::macCGHandle() const
     return handle();
 }
 
-void qt_mac_repaintParentUnderAlienWidget(QWidget *alienWidget)
+void qt_mac_updateParentUnderAlienWidget(QWidget *alienWidget)
 {
     QWidget *nativeParent = alienWidget->nativeParentWidget();
     if (!nativeParent)
@@ -2741,7 +2741,7 @@ void qt_mac_repaintParentUnderAlienWidget(QWidget *alienWidget)
 
     QPoint globalPos = alienWidget->mapToGlobal(QPoint(0, 0));
     QRect dirtyRect = QRect(nativeParent->mapFromGlobal(globalPos), alienWidget->size());
-    nativeParent->repaint(dirtyRect);
+    nativeParent->update(dirtyRect);
 }
 
 void QWidget::destroy(bool destroyWindow, bool destroySubWindows)
@@ -2752,7 +2752,7 @@ void QWidget::destroy(bool destroyWindow, bool destroySubWindows)
     if (!isWindow() && parentWidget())
         parentWidget()->d_func()->invalidateBuffer(d->effectiveRectFor(geometry()));
     if (!internalWinId())
-        qt_mac_repaintParentUnderAlienWidget(this);
+        qt_mac_updateParentUnderAlienWidget(this);
     d->deactivateWidgetCleanup();
     qt_mac_event_release(this);
     if(testAttribute(Qt::WA_WState_Created)) {
@@ -3526,8 +3526,8 @@ void QWidgetPrivate::show_sys()
             // INVARIANT: q is native. Just show the view:
             [view setHidden:NO];
         } else {
-            // INVARIANT: q is alien. Repaint q instead:
-            q->repaint();
+            // INVARIANT: q is alien. Update q instead:
+            q->update();
         }
 #endif
     }
@@ -3683,7 +3683,7 @@ void QWidgetPrivate::hide_sys()
             [view setHidden:YES];
         } else {
             // INVARIANT: q is alien. Repaint where q is placed instead:
-            qt_mac_repaintParentUnderAlienWidget(q);
+            qt_mac_updateParentUnderAlienWidget(q);
         }
 #endif
     }
diff --git a/src/gui/painting/qgraphicssystemfactory.cpp b/src/gui/painting/qgraphicssystemfactory.cpp
index 62a60d77c0..6212674c77 100644
--- a/src/gui/painting/qgraphicssystemfactory.cpp
+++ b/src/gui/painting/qgraphicssystemfactory.cpp
@@ -74,7 +74,7 @@ QGraphicsSystem *QGraphicsSystemFactory::create(const QString& key)
     if (system.isEmpty()) {
         system = QLatin1String("runtime");
     }
-#elif defined (QT_GRAPHICSSYSTEM_RASTER) && !defined(Q_WS_WIN) && !defined(Q_OS_SYMBIAN) || defined(Q_WS_X11)
+#elif defined (QT_GRAPHICSSYSTEM_RASTER) && !defined(Q_WS_WIN) && !defined(Q_OS_SYMBIAN) || defined(Q_WS_X11) || (defined (Q_WS_MAC) && defined(QT_MAC_USE_COCOA))
     if (system.isEmpty()) {
         system = QLatin1String("raster");
     }
diff --git a/src/gui/painting/qunifiedtoolbarsurface_mac.cpp b/src/gui/painting/qunifiedtoolbarsurface_mac.cpp
index 3876c3d1a2..2fda6b9555 100644
--- a/src/gui/painting/qunifiedtoolbarsurface_mac.cpp
+++ b/src/gui/painting/qunifiedtoolbarsurface_mac.cpp
@@ -152,7 +152,8 @@ void QUnifiedToolbarSurface::beginPaint(const QRegion &rgn)
 void QUnifiedToolbarSurface::updateToolbarOffset(QWidget *widget)
 {
     QMainWindowLayout *mlayout = qobject_cast<QMainWindowLayout*> (widget->window()->layout());
-    mlayout->updateUnifiedToolbarOffset();
+    if (mlayout)
+        mlayout->updateUnifiedToolbarOffset();
 }
 
 void QUnifiedToolbarSurface::flush(QWidget *widget, const QRegion &region, const QPoint &offset)
diff --git a/src/gui/painting/qunifiedtoolbarsurface_mac_p.h b/src/gui/painting/qunifiedtoolbarsurface_mac_p.h
index 0a7ebf1759..6b1243e790 100644
--- a/src/gui/painting/qunifiedtoolbarsurface_mac_p.h
+++ b/src/gui/painting/qunifiedtoolbarsurface_mac_p.h
@@ -65,6 +65,39 @@ QT_BEGIN_NAMESPACE
 
 class QNativeImage;
 
+//
+// This is the implementation of the unified toolbar on Mac OS X
+// with the graphics system raster.
+//
+// General idea:
+// -------------
+// We redirect the painting of widgets inside the unified toolbar
+// to a special window surface, the QUnifiedToolbarSurface.
+// We need a separate window surface because the unified toolbar
+// is out of the content view.
+// The input system is the same as for the unified toolbar with the
+// native (CoreGraphics) engine.
+//
+// Execution flow:
+// ---------------
+// The unified toolbar is triggered by QMainWindow::setUnifiedTitleAndToolBarOnMac().
+// It calls QMainWindowLayout::insertIntoMacToolbar() which will
+// set all the appropriate variables (offsets, redirection, ...).
+// When Qt tells a widget to repaint, QWidgetPrivate::drawWidget()
+// checks if the widget is inside the unified toolbar and exits without
+// painting is that is the case.
+// We trigger the rendering of the unified toolbar in QWidget::repaint()
+// and QWidget::update().
+// We keep track of flush requests via "flushRequested" variable. That
+// allow flush() to be a no-op if no repaint occured for a widget.
+// We rely on the needsDisplay: and drawRect: mecanism for drawing our
+// content into the graphics context.
+//
+// Notes:
+// ------
+// The painting of items inside the unified toolbar is expensive.
+// Too many repaints will drastically slow down the whole application.
+//
 
 class QUnifiedToolbarSurfacePrivate
 {