From 5e2f4be486140d694c0acccbfc7a55fc7c104c61 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Samuel=20R=C3=B8dal?= <samuel.rodal@nokia.com>
Date: Thu, 17 Mar 2011 12:03:06 +0100
Subject: Switch to raster also when last window is destroyed (on MeeGo).

This will save GPU resources for applications that are in the
background for most of the time and only show a window now and then.

Reviewed-by: Armin Berres
---
 .../graphicssystems/meego/qmeegographicssystem.cpp | 39 +++++++++++++++++++++-
 1 file changed, 38 insertions(+), 1 deletion(-)

diff --git a/src/plugins/graphicssystems/meego/qmeegographicssystem.cpp b/src/plugins/graphicssystems/meego/qmeegographicssystem.cpp
index 18a0944..cb66695 100644
--- a/src/plugins/graphicssystems/meego/qmeegographicssystem.cpp
+++ b/src/plugins/graphicssystems/meego/qmeegographicssystem.cpp
@@ -59,6 +59,8 @@
 #include "qmeegographicssystem.h"
 #include "qmeegoextensions.h"
 
+#include <QTimer>
+
 bool QMeeGoGraphicsSystem::surfaceWasCreated = false;
 
 QHash <Qt::HANDLE, QPixmap*> QMeeGoGraphicsSystem::liveTexturePixmaps;
@@ -85,8 +87,12 @@ public:
     void addWidget(QWidget *widget);
     bool eventFilter(QObject *, QEvent *);
 
+    void handleMapNotify();
+
 private slots:
     void removeWidget(QObject *object);
+    void switchToRaster();
+    void switchToMeeGo();
 
 private:
     int visibleWidgets() const;
@@ -95,22 +101,46 @@ private:
     QList<QWidget *> m_widgets;
 };
 
+typedef bool(*QX11FilterFunction)(XEvent *event);
+Q_GUI_EXPORT void qt_installX11EventFilter(QX11FilterFunction func);
+
+static bool x11EventFilter(XEvent *event);
+
 QMeeGoGraphicsSystemSwitchHandler::QMeeGoGraphicsSystemSwitchHandler()
 {
+    qt_installX11EventFilter(x11EventFilter);
 }
 
 void QMeeGoGraphicsSystemSwitchHandler::addWidget(QWidget *widget)
 {
-    if (!m_widgets.contains(widget)) {
+    if (widget != qt_gl_share_widget() && !m_widgets.contains(widget)) {
         widget->installEventFilter(this);
         connect(widget, SIGNAL(destroyed(QObject *)), this, SLOT(removeWidget(QObject *)));
         m_widgets << widget;
     }
 }
 
+void QMeeGoGraphicsSystemSwitchHandler::handleMapNotify()
+{
+    if (m_widgets.isEmpty())
+        QTimer::singleShot(0, this, SLOT(switchToMeeGo()));
+}
+
 void QMeeGoGraphicsSystemSwitchHandler::removeWidget(QObject *object)
 {
     m_widgets.removeOne(static_cast<QWidget *>(object));
+    if (m_widgets.isEmpty())
+        QTimer::singleShot(0, this, SLOT(switchToRaster()));
+}
+
+void QMeeGoGraphicsSystemSwitchHandler::switchToRaster()
+{
+    QMeeGoGraphicsSystem::switchToRaster();
+}
+
+void QMeeGoGraphicsSystemSwitchHandler::switchToMeeGo()
+{
+    QMeeGoGraphicsSystem::switchToMeeGo();
 }
 
 int QMeeGoGraphicsSystemSwitchHandler::visibleWidgets() const
@@ -148,6 +178,13 @@ bool QMeeGoGraphicsSystemSwitchHandler::eventFilter(QObject *object, QEvent *eve
 
 Q_GLOBAL_STATIC(QMeeGoGraphicsSystemSwitchHandler, switch_handler)
 
+bool x11EventFilter(XEvent *event)
+{
+    if (event->type == MapNotify)
+        switch_handler()->handleMapNotify();
+    return false;
+}
+
 QWindowSurface* QMeeGoGraphicsSystem::createWindowSurface(QWidget *widget) const
 {
     QGLWidget *shareWidget = qt_gl_share_widget();
-- 
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