Window resize problem

[Richard Zhao]

Hi,

I'm drawing a window directly in frame buffer. But when the window
resize, the background window cannot draw correct. The top window
still draws on background window.
It seems:
When a top window resize from big to small, it re-draw bottom window
first, and then update the width/height got from XGetWindowAttributes.

Is there some method to solve this problem?

Thanks
Richard