Fix flickering when resizing.

2 files changed, 6 insertions, 0 deletions

diff --git a/lib/backing_store_qt.cpp b/lib/backing_store_qt.cpp
index e5cc72016..ecaa2c50a 100644
--- a/lib/backing_store_qt.cpp
+++ b/lib/backing_store_qt.cpp
@@ -27,7 +27,12 @@ void BackingStoreQt::resize(const QSize& size)
 {
     m_isValid = false;
     if (size != m_pixelBuffer.size()) {
+        QPixmap oldBackingStore = m_pixelBuffer;
         m_pixelBuffer = QPixmap(size);
+
+        QPainter painter(&m_pixelBuffer);
+        painter.drawPixmap(oldBackingStore.rect(), oldBackingStore);
+
         m_host->WasResized();
     }
 }
diff --git a/lib/raster_window.cpp b/lib/raster_window.cpp
index cd5d038b0..75b927310 100644
--- a/lib/raster_window.cpp
+++ b/lib/raster_window.cpp
@@ -13,6 +13,7 @@ RasterWindow::RasterWindow(content::RenderWidgetHostViewQt* view, QWidget *paren
     , m_view(view)
 {
     setFocusPolicy(Qt::ClickFocus);
+    setAttribute(Qt::WA_OpaquePaintEvent);
 }
 
 void RasterWindow::setBackingStore(BackingStoreQt* backingStore)