Alien vs Native Windows - Flicker in Screen Transition

Hello Buddies,

I am developing an application with Qt 4.5 on Linux (Ubuntu 9.04). The widgets are created by default as aliens. But, my intent is that, in the application screen, there will be a portion on which video will be displayed, on X11 surface.

My problem is with passing the window handle to the player engine (Xine), which expects an X11 surface window handle.

I have used winId() to get the window handle of the widget on which the video should be displayed, and passed the co-prdinates of that widget, for the surface on which the video has to be rendered. This works perfect.

The problem is that, whn I move back and forth in the application, I observe a flicker. I guess it is for native windows forced by winId(). I tried clearing the idget attribute with WA_DontCreateNativeAncestors a true for the widget, after I use winId for it, and also set application attributes with AA_NativeWindows false. But the flicker remains.

Specifically, my question is how can I remove the flicker? Is thre any way to retain alien windows from native windows, after using winId() ?

Once a widget is "dealienated", you can't "alienate" it back.