Cocoa: Fix qmlscene flicker on startup.

The SG render thread was racing window creation in
the GUI thread, which would cause flicker if the
window won the race and was shown before the SG
thread had a frame ready.

Send a synchronous expose event before showing the
window - this will wait for the SG render thread.

In addition, don't defer NSwindow creation. The GL
context setup is done before the window is shown
and needs a fully created window.

New API: QWindowSystemInterface::handleSynchronousExposeEvent
Retire: QWindowSystemInterface::handleExposeEvent

Change-Id: I0bb46089d16ec4882aaac8db67b57d15e0f51531
Reviewed-on: http://codereview.qt.nokia.com/3399
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Gunnar Sletta <gunnar.sletta@nokia.com>
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@nokia.com>

diff --git a/src/gui/kernel/qwindowsysteminterface_qpa.cpp b/src/gui/kernel/qwindowsysteminterface_qpa.cpp
index d6f94b6..d862d05 100644 (file)
--- a/src/gui/kernel/qwindowsysteminterface_qpa.cpp
+++ b/src/gui/kernel/qwindowsysteminterface_qpa.cpp
@@ -276,10 +276,10 @@ void QWindowSystemInterface::handleUnmapEvent(QWindow *tlw)
     QWindowSystemInterfacePrivate::queueWindowSystemEvent(e);
 }
 
-void QWindowSystemInterface::handleExposeEvent(QWindow *tlw, const QRegion &region)
+void QWindowSystemInterface::handleSynchronousExposeEvent(QWindow *tlw, const QRegion &region)
 {
     QWindowSystemInterfacePrivate::ExposeEvent *e = new QWindowSystemInterfacePrivate::ExposeEvent(tlw, region);
-    QWindowSystemInterfacePrivate::queueWindowSystemEvent(e);
+    QGuiApplicationPrivate::processWindowSystemEvent(e); // send event immediately.
 }
 
 bool QWindowSystemInterface::sendWindowSystemEvents(QAbstractEventDispatcher *eventDispatcher, QEventLoop::ProcessEventsFlags flags)

diff --git a/src/gui/kernel/qwindowsysteminterface_qpa.h b/src/gui/kernel/qwindowsysteminterface_qpa.h
index 2f3f8a1..99db5f2 100644 (file)
--- a/src/gui/kernel/qwindowsysteminterface_qpa.h
+++ b/src/gui/kernel/qwindowsysteminterface_qpa.h
@@ -105,7 +105,7 @@ public:
     static void handleMapEvent(QWindow *w);
     static void handleUnmapEvent(QWindow *w);
 
-    static void handleExposeEvent(QWindow *w, const QRegion &region);
+    static void handleSynchronousExposeEvent(QWindow *tlw, const QRegion &region);
 
     // Drag and drop. These events are sent immediately.
     static Qt::DropAction handleDrag(QWindow *w, QMimeData *dropData, const QPoint &p);

diff --git a/src/plugins/platforms/cocoa/qcocoawindow.mm b/src/plugins/platforms/cocoa/qcocoawindow.mm
index 78785a8..ef04fc4 100644 (file)
--- a/src/plugins/platforms/cocoa/qcocoawindow.mm
+++ b/src/plugins/platforms/cocoa/qcocoawindow.mm
@@ -121,8 +121,10 @@ void QCocoaWindow::setVisible(bool visible)
         if (window()->transientParent())
             setGeometry(window()->geometry());
 
+        // Make sure the QWindow has a frame ready before we show the NSWindow.
+        QWindowSystemInterface::handleSynchronousExposeEvent(window(), QRect(QPoint(), geometry().size()));
+
         [m_nsWindow makeKeyAndOrderFront:nil];
-        QWindowSystemInterface::handleExposeEvent(window(), QRect(QPoint(), geometry().size()));
     } else {
         [m_nsWindow orderOut:nil];
     }
@@ -319,7 +321,7 @@ QNSWindow * QCocoaWindow::createWindow()
         panel = [[NSPanel alloc] initWithContentRect:frame
                                    styleMask:m_windowAttributes
                                    backing:NSBackingStoreBuffered
-                                   defer:YES];
+                                   defer:NO]; // see window case below
 //  ### crashes
 //        [panel setFloatingPanel:needFloating];
 //        [panel setWorksWhenModal:worksWhenModal];
@@ -330,7 +332,8 @@ QNSWindow * QCocoaWindow::createWindow()
         window  = [[QNSWindow alloc] initWithContentRect:frame
                                             styleMask:(NSResizableWindowMask | NSClosableWindowMask | NSMiniaturizableWindowMask | NSTitledWindowMask)
                                             backing:NSBackingStoreBuffered
-                                            defer:YES];
+                                            defer:NO]; // Deferring window creation breaks OpenGL (the GL context is set up
+                                                       // before the window is shown and needs a proper window.).
         break;
     }
 

diff --git a/src/plugins/platforms/wayland/qwaylandwindow.cpp b/src/plugins/platforms/wayland/qwaylandwindow.cpp
index f685dae..48da7b5 100644 (file)
--- a/src/plugins/platforms/wayland/qwaylandwindow.cpp
+++ b/src/plugins/platforms/wayland/qwaylandwindow.cpp
@@ -125,7 +125,7 @@ void QWaylandWindow::attach(QWaylandBuffer *buffer)
     mBuffer = buffer;
     if (mSurface) {
         wl_surface_attach(mSurface, buffer->buffer(),0,0);
-        QWindowSystemInterface::handleExposeEvent(window(), QRect(QPoint(), geometry().size()));
+        QWindowSystemInterface::handleSynchronousExposeEvent(window(), QRect(QPoint(), geometry().size()));
     }
 }
 

diff --git a/src/plugins/platforms/windows/qwindowswindow.cpp b/src/plugins/platforms/windows/qwindowswindow.cpp
index 95b770f..8e10ae6 100644 (file)
--- a/src/plugins/platforms/windows/qwindowswindow.cpp
+++ b/src/plugins/platforms/windows/qwindowswindow.cpp
@@ -902,7 +902,7 @@ void QWindowsWindow::handleWmPaint(HWND hwnd, UINT,
         if (QWindowsContext::verboseIntegration)
             qDebug() << __FUNCTION__ << this << window() << updateRect;
 
-        QWindowSystemInterface::handleExposeEvent(window(), QRegion(updateRect));
+        QWindowSystemInterface::handleSynchronousExposeEvent(window(), QRegion(updateRect));
         clearFlag(WithinWmPaint);
         m_hdc = 0;
         EndPaint(hwnd, &ps);

diff --git a/src/plugins/platforms/xcb/qxcbconnection.cpp b/src/plugins/platforms/xcb/qxcbconnection.cpp
index a8ffc58..c60e066 100644 (file)
--- a/src/plugins/platforms/xcb/qxcbconnection.cpp
+++ b/src/plugins/platforms/xcb/qxcbconnection.cpp
@@ -472,7 +472,7 @@ void QXcbConnection::handleXcbEvent(xcb_generic_event_t *event)
 
     switch (response_type) {
     case XCB_EXPOSE:
-        HANDLE_PLATFORM_WINDOW_EVENT(xcb_expose_event_t, window, handleExposeEvent);
+        HANDLE_PLATFORM_WINDOW_EVENT(xcb_expose_event_t, window, handleSynchronousExposeEvent);
     case XCB_BUTTON_PRESS:
         HANDLE_PLATFORM_WINDOW_EVENT(xcb_button_press_event_t, event, handleButtonPressEvent);
     case XCB_BUTTON_RELEASE:

diff --git a/src/plugins/platforms/xcb/qxcbwindow.cpp b/src/plugins/platforms/xcb/qxcbwindow.cpp
index 0f3d1d5..db8d37e 100644 (file)
--- a/src/plugins/platforms/xcb/qxcbwindow.cpp
+++ b/src/plugins/platforms/xcb/qxcbwindow.cpp
@@ -1074,7 +1074,7 @@ QXcbEGLSurface *QXcbWindow::eglSurface() const
 void QXcbWindow::handleExposeEvent(const xcb_expose_event_t *event)
 {
     QRect rect(event->x, event->y, event->width, event->height);
-    QWindowSystemInterface::handleExposeEvent(window(), rect);
+    QWindowSystemInterface::handleSynchronousExposeEvent(window(), rect);
 }
 
 void QXcbWindow::handleClientMessageEvent(const xcb_client_message_event_t *event)