Avoid window blink when handling OpenGL

Author: zyrkiel

src/DockAreaWidget.cpp

@@ -725,6 +725,8 @@ void CDockAreaWidget::setCurrentIndex(int index)
     Q_EMIT currentChanging(index);
     TabBar->setCurrentIndex(index);
 	d->ContentsLayout->setCurrentIndex(index);
+	// Force the widget to be native in order to avoid blinks with OpenGL widgets
+	d->ContentsLayout->currentWidget()->winId();
 	d->ContentsLayout->currentWidget()->show();
 	// Force the repaint of the current widget because mix of OpenGL widgets
 	// and Raster widgets could have not been entirely rendered