Added automatic graphicssystem switching on meego when app is minimized.

When all top-level widgets are minimized we switch to raster to reduce
GPU memory consumption. We switch back to graphicssystem meego when at
least one top-level widget is shown normally again. The switching only
applies when the runtime graphicssystem is being used. The switching
only applies when the runtime graphicssystem is being used.

Task-number: QTBUG-18013
Reviewed-by: Armin Berres

4 files changed, 71 insertions, 43 deletions

diff --git a/tools/qmeegographicssystemhelper/qmeegographicssystemhelper.cpp b/tools/qmeegographicssystemhelper/qmeegographicssystemhelper.cpp
index ac32995..3f39bda 100644
--- a/tools/qmeegographicssystemhelper/qmeegographicssystemhelper.cpp
+++ b/tools/qmeegographicssystemhelper/qmeegographicssystemhelper.cpp
@@ -47,7 +47,6 @@
 #include <private/qpixmap_raster_p.h>
 #include <private/qwindowsurface_gl_p.h>
 #include "qmeegoruntime.h"
-#include "qmeegoswitchevent.h"
 
 QString QMeeGoGraphicsSystemHelper::runningGraphicsSystemName()
 {
@@ -77,46 +76,12 @@ bool QMeeGoGraphicsSystemHelper::isRunningRuntime()
 
 void QMeeGoGraphicsSystemHelper::switchToMeeGo()
 {
-    if (isRunningMeeGo())
-        return;
-
-    if (QApplicationPrivate::instance()->graphics_system_name != QLatin1String("runtime"))
-        qWarning("Can't switch to meego - switching only supported with 'runtime' graphics system.");
-    else {
-        QMeeGoSwitchEvent willSwitchEvent(QLatin1String("meego"), QMeeGoSwitchEvent::WillSwitch);
-        foreach (QWidget *widget, QApplication::topLevelWidgets())
-            QCoreApplication::sendEvent(widget, &willSwitchEvent);
-
-        QApplication *app = static_cast<QApplication *>(QCoreApplication::instance());
-        app->setGraphicsSystem(QLatin1String("meego"));
-
-        QMeeGoSwitchEvent didSwitchEvent(QLatin1String("meego"), QMeeGoSwitchEvent::DidSwitch);
-        foreach (QWidget *widget, QApplication::topLevelWidgets())
-            QCoreApplication::sendEvent(widget, &didSwitchEvent);
-    }
+    QMeeGoRuntime::switchToMeeGo();
 }
 
 void QMeeGoGraphicsSystemHelper::switchToRaster()
 {
-    if (runningGraphicsSystemName() == QLatin1String("raster"))
-        return;
-
-    if (QApplicationPrivate::instance()->graphics_system_name != QLatin1String("runtime"))
-        qWarning("Can't switch to raster - switching only supported with 'runtime' graphics system.");
-    else {
-        QMeeGoSwitchEvent willSwitchEvent(QLatin1String("raster"), QMeeGoSwitchEvent::WillSwitch);
-        foreach (QWidget *widget, QApplication::topLevelWidgets())
-            QCoreApplication::sendEvent(widget, &willSwitchEvent);
-
-        QApplication *app = static_cast<QApplication *>(QCoreApplication::instance());
-        app->setGraphicsSystem(QLatin1String("raster"));
-
-	QMeeGoRuntime::invalidateLiveSurfaces();
-
-        QMeeGoSwitchEvent didSwitchEvent(QLatin1String("raster"), QMeeGoSwitchEvent::DidSwitch);
-        foreach (QWidget *widget, QApplication::topLevelWidgets())
-            QCoreApplication::sendEvent(widget, &didSwitchEvent);
-    }
+    QMeeGoRuntime::switchToRaster();
 }
 
 Qt::HANDLE QMeeGoGraphicsSystemHelper::imageToEGLSharedImage(const QImage &image)
@@ -170,3 +135,8 @@ void QMeeGoGraphicsSystemHelper::setSwapBehavior(SwapMode mode)
     else if (mode == KillSwap)
         QGLWindowSurface::swapBehavior = QGLWindowSurface::KillSwap;
 }
+
+void QMeeGoGraphicsSystemHelper::enableSwitchEvents()
+{
+    QMeeGoRuntime::enableSwitchEvents();
+}
diff --git a/tools/qmeegographicssystemhelper/qmeegographicssystemhelper.h b/tools/qmeegographicssystemhelper/qmeegographicssystemhelper.h
index 5a3b57e..9e50652 100644
--- a/tools/qmeegographicssystemhelper/qmeegographicssystemhelper.h
+++ b/tools/qmeegographicssystemhelper/qmeegographicssystemhelper.h
@@ -97,14 +97,21 @@ public:
     */
     static bool isRunningRuntime();
 
+    //! Enables the sending of QMeeGoSwitchEvent's when the graphicssystem switches.
+    /*!
+      An application that wishes to start receive QMeegoSwitchEvents must call this function.
+    */
+    static void enableSwitchEvents();
+
     //! Switches to meego graphics system. 
     /*!
      When running with the 'runtime' graphics system, sets the currently active 
      system to 'meego'. The window surface and all the resources are automatically
      migrated to OpenGL. Will fail if the active graphics system is not 'runtime'.
      Calling this function will emit QMeeGoSwitchEvent to the top level widgets.
-     Two events will be emitted for each switch -- one before the switch (QMeeGoSwitchEvent::WillSwitch)
-     and one after the switch (QMeeGoSwitchEvent::DidSwitch).
+     If switch events are enabled, two events will be emitted for each switch --
+     one before the switch (QMeeGoSwitchEvent::WillSwitch) and one after the
+     switch (QMeeGoSwitchEvent::DidSwitch).
     */
     static void switchToMeeGo();
 
@@ -114,9 +121,9 @@ public:
      system to 'raster'. The window surface and the graphics resources (including the 
      EGL shared image resources) are automatically migrated back to the CPU. All OpenGL 
      resources (surface, context, cache, font cache) are automaticall anihilated.
-     Calling this function will emit QMeeGoSwitchEvent to the top level widgets.
-     Two events will be emitted for each switch -- one before the switch (QMeeGoSwitchEvent::WillSwitch)
-     and one after the switch (QMeeGoSwitchEvent::DidSwitch).
+     Calling this function will emit QMeeGoSwitchEvent to the top level widgets. If switch
+     events are enabled, two events will be emitted for each switch -- one before the
+     switch (QMeeGoSwitchEvent::WillSwitch) and one after the switch (QMeeGoSwitchEvent::DidSwitch).
     */
     static void switchToRaster();
 
diff --git a/tools/qmeegographicssystemhelper/qmeegoruntime.cpp b/tools/qmeegographicssystemhelper/qmeegoruntime.cpp
index 7c81d51..15f9cdf 100644
--- a/tools/qmeegographicssystemhelper/qmeegoruntime.cpp
+++ b/tools/qmeegographicssystemhelper/qmeegoruntime.cpp
@@ -41,6 +41,11 @@
 
 #include "qmeegoruntime.h"
 
+#include "qmeegoswitchevent.h"
+
+#include <QtGui/QApplication>
+#include <QtGui/QWidget>
+
 #include <private/qlibrary_p.h>
 #include <private/qfactoryloader_p.h>
 #include <private/qgraphicssystemplugin_p.h>
@@ -49,6 +54,7 @@
 #define ENSURE_INITIALIZED {if (!initialized) initialize();}
 
 bool QMeeGoRuntime::initialized = false;
+bool QMeeGoRuntime::switchEventsEnabled = false;
 
 typedef int (*QMeeGoImageToEglSharedImageFunc) (const QImage&);
 typedef QPixmapData* (*QMeeGoPixmapDataFromEglSharedImageFunc) (Qt::HANDLE handle, const QImage&);
@@ -66,6 +72,9 @@ typedef Qt::HANDLE (*QMeeGoLiveTextureGetHandleFunc) (QPixmap*);
 typedef void* (*QMeeGoCreateFenceSyncFunc) (void);
 typedef void (*QMeeGoDestroyFenceSyncFunc) (void *fs);
 typedef void (*QMeeGoInvalidateLiveSurfacesFunc) (void);
+typedef void (*QMeeGoSwitchToRasterFunc) (void);
+typedef void (*QMeeGoSwitchToMeeGoFunc) (void);
+typedef void (*QMeeGoRegisterSwitchCallbackFunc) (void (*callback)(int type, const char *name));
 
 static QMeeGoImageToEglSharedImageFunc qt_meego_image_to_egl_shared_image = NULL;
 static QMeeGoPixmapDataFromEglSharedImageFunc qt_meego_pixmapdata_from_egl_shared_image = NULL;
@@ -83,6 +92,16 @@ static QMeeGoLiveTextureGetHandleFunc qt_meego_live_texture_get_handle = NULL;
 static QMeeGoCreateFenceSyncFunc qt_meego_create_fence_sync = NULL;
 static QMeeGoDestroyFenceSyncFunc qt_meego_destroy_fence_sync = NULL;
 static QMeeGoInvalidateLiveSurfacesFunc qt_meego_invalidate_live_surfaces = NULL;
+static QMeeGoSwitchToRasterFunc qt_meego_switch_to_raster = NULL;
+static QMeeGoSwitchToMeeGoFunc qt_meego_switch_to_meego = NULL;
+static QMeeGoRegisterSwitchCallbackFunc qt_meego_register_switch_callback = NULL;
+
+extern "C" void handleSwitch(int type, const char *name)
+{
+    QMeeGoSwitchEvent switchEvent((QLatin1String(name)), QMeeGoSwitchEvent::State(type));
+    foreach (QWidget *widget, QApplication::topLevelWidgets())
+        QCoreApplication::sendEvent(widget, &switchEvent);
+}
 
 void QMeeGoRuntime::initialize()
 {
@@ -112,13 +131,17 @@ void QMeeGoRuntime::initialize()
         qt_meego_create_fence_sync = (QMeeGoCreateFenceSyncFunc) library.resolve("qt_meego_create_fence_sync");
         qt_meego_destroy_fence_sync = (QMeeGoDestroyFenceSyncFunc) library.resolve("qt_meego_destroy_fence_sync");
         qt_meego_invalidate_live_surfaces = (QMeeGoInvalidateLiveSurfacesFunc) library.resolve("qt_meego_invalidate_live_surfaces");
+        qt_meego_switch_to_raster = (QMeeGoSwitchToRasterFunc) library.resolve("qt_meego_switch_to_raster");
+        qt_meego_switch_to_meego = (QMeeGoSwitchToMeeGoFunc) library.resolve("qt_meego_switch_to_meego");
+        qt_meego_register_switch_callback = (QMeeGoRegisterSwitchCallbackFunc) library.resolve("qt_meego_register_switch_callback");
 
         if (qt_meego_image_to_egl_shared_image && qt_meego_pixmapdata_from_egl_shared_image && 
             qt_meego_pixmapdata_with_gl_texture && qt_meego_destroy_egl_shared_image && qt_meego_update_egl_shared_image_pixmap && 
             qt_meego_set_surface_fixed_size && qt_meego_set_surface_scaling && qt_meego_set_translucent && 
             qt_meego_pixmapdata_with_new_live_texture && qt_meego_pixmapdata_from_live_texture_handle &&
             qt_meego_live_texture_lock && qt_meego_live_texture_release && qt_meego_live_texture_get_handle &&
-            qt_meego_create_fence_sync && qt_meego_destroy_fence_sync && qt_meego_invalidate_live_surfaces)
+            qt_meego_create_fence_sync && qt_meego_destroy_fence_sync && qt_meego_invalidate_live_surfaces &&
+            qt_meego_switch_to_raster && qt_meego_switch_to_meego && qt_meego_register_switch_callback)
         {
             qDebug("Successfully resolved MeeGo graphics system: %s %s\n", qPrintable(libraryPrivate->fileName), qPrintable(libraryPrivate->fullVersion));
         } else {
@@ -242,3 +265,27 @@ void QMeeGoRuntime::invalidateLiveSurfaces()
     Q_ASSERT(qt_meego_invalidate_live_surfaces);
     qt_meego_invalidate_live_surfaces();
 }
+
+void QMeeGoRuntime::switchToRaster()
+{
+    ENSURE_INITIALIZED;
+    Q_ASSERT(qt_meego_switch_to_raster);
+    qt_meego_switch_to_raster();
+}
+
+void QMeeGoRuntime::switchToMeeGo()
+{
+    ENSURE_INITIALIZED;
+    Q_ASSERT(qt_meego_switch_to_meego);
+    qt_meego_switch_to_meego();
+}
+
+void QMeeGoRuntime::enableSwitchEvents()
+{
+    ENSURE_INITIALIZED;
+    if (!switchEventsEnabled) {
+        Q_ASSERT(qt_meego_register_switch_callback);
+        qt_meego_register_switch_callback(handleSwitch);
+        switchEventsEnabled = true;
+    }
+}
diff --git a/tools/qmeegographicssystemhelper/qmeegoruntime.h b/tools/qmeegographicssystemhelper/qmeegoruntime.h
index b91efae..6279b4c 100644
--- a/tools/qmeegographicssystemhelper/qmeegoruntime.h
+++ b/tools/qmeegographicssystemhelper/qmeegoruntime.h
@@ -63,7 +63,11 @@ public:
     static void* createFenceSync();
     static void destroyFenceSync(void *fs);
     static void invalidateLiveSurfaces();
+    static void switchToRaster();
+    static void switchToMeeGo();
+    static void enableSwitchEvents();
 
 private:
     static bool initialized;
+    static bool switchEventsEnabled;
 };