Recreate Symbian raster backing store when WA_TranslucentBackground set

Task-number: QTBUG-17288
Reviewed-by: Jani Hautakangas
(cherry picked from commit ca663a7252637f8066a0e7368650e72094220b69)

1 files changed, 13 insertions, 4 deletions

diff --git a/src/gui/painting/qwindowsurface_s60.cpp b/src/gui/painting/qwindowsurface_s60.cpp
index 7dc5cb7..9f371a8 100644
--- a/src/gui/painting/qwindowsurface_s60.cpp
+++ b/src/gui/painting/qwindowsurface_s60.cpp
@@ -61,13 +61,11 @@ struct QS60WindowSurfacePrivate
     QList<QImage*> bufferImages;
 };
 
-QS60WindowSurface::QS60WindowSurface(QWidget* widget)
-    : QWindowSurface(widget), d_ptr(new QS60WindowSurfacePrivate)
+TDisplayMode displayMode(bool opaque)
 {
 
     TDisplayMode mode = S60->screenDevice()->DisplayMode();
-    bool isOpaque = qt_widget_private(widget)->isOpaque;
-    if (isOpaque) {
+    if (opaque) {
         mode = EColor16MU;
     } else  {
         if (QSysInfo::symbianVersion() >= QSysInfo::SV_SF_3)
@@ -75,7 +73,13 @@ QS60WindowSurface::QS60WindowSurface(QWidget* widget)
         else
             mode = EColor16MA; // Symbian prior to Symbian^3 sw accelerates EColor16MA
     }
+    return mode;
+}
 
+QS60WindowSurface::QS60WindowSurface(QWidget* widget)
+    : QWindowSurface(widget), d_ptr(new QS60WindowSurfacePrivate)
+{
+    TDisplayMode mode = displayMode(qt_widget_private(widget)->isOpaque);
     // We create empty CFbsBitmap here -> it will be resized in setGeometry
     CFbsBitmap *bitmap = q_check_ptr(new CFbsBitmap);	// CBase derived object needs check on new
     qt_symbian_throwIfError( bitmap->Create( TSize(0, 0), mode ) );
@@ -121,6 +125,11 @@ void QS60WindowSurface::beginPaint(const QRegion &rgn)
 
     if (!qt_widget_private(window())->isOpaque) {
         QS60PixmapData *pixmapData = static_cast<QS60PixmapData *>(d_ptr->device.data_ptr().data());
+
+        TDisplayMode mode = displayMode(false);
+        if (pixmapData->cfbsBitmap->DisplayMode() != mode)
+            pixmapData->convertToDisplayMode(mode);
+
         pixmapData->beginDataAccess();
 
         QPainter p(&pixmapData->image);