Improve raster graphics system performance on Mac.

This fixes the qmlviewer "sluggish animations and lost
mouse events" issue by making sure we don't block and
wait for for the screen refresh when flushing the
backing store to the screen.

Review: Richard Moe Gustavsen

Details:

- Don't force repaints, flush the backingstore in response
  to a Cocoa paint/display events only.
- Flush once per window.
- Get the CGContext from the window (don't create a new one)
- Don't call CGContextiFlush on the context.

6 files changed, 60 insertions, 9 deletions

diff --git a/src/gui/kernel/qcocoasharedwindowmethods_mac_p.h b/src/gui/kernel/qcocoasharedwindowmethods_mac_p.h
index 1a265d0..7829a4e 100644
--- a/src/gui/kernel/qcocoasharedwindowmethods_mac_p.h
+++ b/src/gui/kernel/qcocoasharedwindowmethods_mac_p.h
@@ -51,6 +51,9 @@
  NSPanel, while QCocoaWindow needs to inherit NSWindow rather than NSPanel).
 ****************************************************************************/
 
+#include <private/qapplication_p.h>
+#include <private/qbackingstore_p.h>
+
 QT_BEGIN_NAMESPACE
 extern Qt::MouseButton cocoaButton2QtButton(NSInteger buttonNum); // qcocoaview.mm
 extern QPointer<QWidget> qt_button_down; //qapplication_mac.cpp
@@ -185,3 +188,20 @@ QT_END_NAMESPACE
     return [super frameViewClassForStyleMask:styleMask];
 }
 
+- (void)displayIfNeeded
+{
+
+    QWidget *qwidget = [[QT_MANGLE_NAMESPACE(QCocoaWindowDelegate) sharedDelegate] qt_qwidgetForWindow:self];
+    if (qwidget == 0) {
+        [super displayIfNeeded];
+        return;
+    }
+
+    if (QApplicationPrivate::graphicsSystem() != 0) {
+        if (QWidgetBackingStore *bs = qt_widget_private(qwidget)->maybeBackingStore())
+            bs->sync(qwidget, qwidget->rect());
+    }
+    [super displayIfNeeded];
+}
+
+
diff --git a/src/gui/kernel/qcocoaview_mac.mm b/src/gui/kernel/qcocoaview_mac.mm
index d255604..2c35be2 100644
--- a/src/gui/kernel/qcocoaview_mac.mm
+++ b/src/gui/kernel/qcocoaview_mac.mm
@@ -520,10 +520,11 @@ extern "C" {
 - (void)drawRect:(NSRect)aRect
 {
     if (QApplicationPrivate::graphicsSystem() != 0) {
-        if (QWidgetBackingStore *bs = qwidgetprivate->maybeBackingStore())
-            bs->markDirty(qwidget->rect(), qwidget);
-        qwidgetprivate->syncBackingStore(qwidget->rect());
-        return;
+        if (QWidgetBackingStore *bs = qwidgetprivate->maybeBackingStore()) {
+            // Drawing is handled on the window level
+            // See qcocoasharedwindowmethods_mac_p.
+            return;
+        }
     }
     CGContextRef cg = (CGContextRef)[[NSGraphicsContext currentContext] graphicsPort];
     qwidgetprivate->hd = cg;
diff --git a/src/gui/kernel/qt_cocoa_helpers_mac.mm b/src/gui/kernel/qt_cocoa_helpers_mac.mm
index e06a810..65c04e5 100644
--- a/src/gui/kernel/qt_cocoa_helpers_mac.mm
+++ b/src/gui/kernel/qt_cocoa_helpers_mac.mm
@@ -1162,7 +1162,7 @@ CGContextRef qt_mac_graphicsContextFor(QWidget *widget)
     CGrafPtr port = GetWindowPort(qt_mac_window_for(widget));
     QDBeginCGContext(port, &context);
 #else
-    CGContextRef context = (CGContextRef)[[NSGraphicsContext graphicsContextWithWindow:qt_mac_window_for(widget)] graphicsPort];
+    CGContextRef context = reinterpret_cast<CGContextRef>([[qt_mac_window_for(widget) graphicsContext] graphicsPort]);
 #endif
     return context;
 }
diff --git a/src/gui/kernel/qwidget.cpp b/src/gui/kernel/qwidget.cpp
index ffad38b..78a25ac 100644
--- a/src/gui/kernel/qwidget.cpp
+++ b/src/gui/kernel/qwidget.cpp
@@ -1660,7 +1660,13 @@ void QWidgetPrivate::syncBackingStore()
         repaint_sys(dirty);
         dirty = QRegion();
     } else if (QWidgetBackingStore *bs = maybeBackingStore()) {
+#ifdef QT_MAC_USE_COCOA
+        Q_UNUSED(bs);
+        void qt_mac_set_needs_display(QWidget *, QRegion);
+        qt_mac_set_needs_display(q_func(), QRegion());
+#else
         bs->sync();
+#endif
     }
 }
 
@@ -1668,8 +1674,15 @@ void QWidgetPrivate::syncBackingStore(const QRegion &region)
 {
     if (paintOnScreen())
         repaint_sys(region);
-    else if (QWidgetBackingStore *bs = maybeBackingStore())
+    else if (QWidgetBackingStore *bs = maybeBackingStore()) {
+#ifdef QT_MAC_USE_COCOA
+        Q_UNUSED(bs);
+        void qt_mac_set_needs_display(QWidget *, QRegion);
+        qt_mac_set_needs_display(q_func(), region);
+#else
         bs->sync(q_func(), region);
+#endif
+    }
 }
 
 void QWidgetPrivate::setUpdatesEnabled_helper(bool enable)
diff --git a/src/gui/kernel/qwidget_mac.mm b/src/gui/kernel/qwidget_mac.mm
index 78c1562..b5888b4 100644
--- a/src/gui/kernel/qwidget_mac.mm
+++ b/src/gui/kernel/qwidget_mac.mm
@@ -565,6 +565,25 @@ inline static void qt_mac_set_window_group_to_popup(OSWindowRef window)
 }
 #endif
 
+#ifdef QT_MAC_USE_COCOA
+void qt_mac_set_needs_display(QWidget *widget, QRegion region)
+{
+    NSView *theNSView = qt_mac_nativeview_for(widget);
+    if (region.isNull()) {
+        [theNSView setNeedsDisplay:YES];
+        return;
+    }
+
+    QVector<QRect> rects = region.rects();
+    for (int i = 0; i<rects.count(); ++i) {
+        const QRect &rect = rects.at(i);
+        NSRect nsrect = NSMakeRect(rect.x(), rect.y(), rect.width(), rect.height());
+        [theNSView setNeedsDisplayInRect:nsrect];
+    }
+
+}
+#endif
+
 inline static bool updateRedirectedToGraphicsProxyWidget(QWidget *widget, const QRect &rect)
 {
     if (!widget)
diff --git a/src/gui/painting/qwindowsurface_raster.cpp b/src/gui/painting/qwindowsurface_raster.cpp
index a0d2b9b..eee6bef 100644
--- a/src/gui/painting/qwindowsurface_raster.cpp
+++ b/src/gui/painting/qwindowsurface_raster.cpp
@@ -295,10 +295,8 @@ void QRasterWindowSurface::flush(QWidget *widget, const QRegion &rgn, const QPoi
     CGContextRestoreGState(context);
 #ifndef QT_MAC_USE_COCOA
     QDEndCGContext(port, &context);
-#else
-    CGContextFlush(context);
-#endif
 #endif
+#endif // Q_WS_MAC
 
 #ifdef Q_OS_SYMBIAN
     Q_UNUSED(widget);