Make EGL surface transparency working on Symbian.

When the hardware is capable enough, setting WA_TranslucentBackground
will not lead to falling back to raster, but will continue using
OpenVG or OpenGL based rendering. However this needs an alpha channel
which was not requested previously. This patch corrects it.

Task-number: QT-4729
Reviewed-by: Jani Hautakangas

1 files changed, 8 insertions, 3 deletions

diff --git a/src/gui/egl/qegl_symbian.cpp b/src/gui/egl/qegl_symbian.cpp
index 6533d112ed..fabf9d16ee 100644
--- a/src/gui/egl/qegl_symbian.cpp
+++ b/src/gui/egl/qegl_symbian.cpp
@@ -42,6 +42,7 @@
 #include <QtGui/qpaintdevice.h>
 #include <QtGui/qpixmap.h>
 #include <QtGui/qwidget.h>
+#include <QtGui/private/qapplication_p.h>
 
 #include "qegl_p.h"
 #include "qeglcontext_p.h"
@@ -73,10 +74,14 @@ void QEglProperties::setPaintDeviceFormat(QPaintDevice *dev)
         return;
 
     int devType = dev->devType();
-    if (devType == QInternal::Image)
+    if (devType == QInternal::Image) {
         setPixelFormat(static_cast<QImage *>(dev)->format());
-    else
-        setPixelFormat(QImage::Format_RGB32);
+    } else {
+        QImage::Format format = QImage::Format_RGB32;
+        if (QApplicationPrivate::instance() && QApplicationPrivate::instance()->useTranslucentEGLSurfaces)
+            format = QImage::Format_ARGB32_Premultiplied;
+        setPixelFormat(format);
+    }
 }