Re: How to redraw the blanked section of a widget after a expose-event?

[Paul Davis <paul linuxaudiosystems com>]

On Thu, 2007-09-27 at 10:42 +0800, krist misra wrote:
> Hi experts,
> 
> I am using GTK+ and gstreamer to capture and show the video frames, I
> created a drawable widget using gtk_drawing_area_new() and using
> xvimage element of gstreamer to render the video, I also connected
> them by a gstreamer function gst_x_overlay_set_xwindow_id(), so the
> video frames rendered  by xvimage can show in the widget, now it works
> well.

> But I encounter a problem that if part of the drawable widget being
> covered by a menu or something, when the menu disappears, the covered
> section keeps blank, even other part of the widget still show the
> video.

an expose event handler is required to *redraw* the area specified in
the expose event. receipt of this event means (generally speaking) that
whatever the contents of the window in that area used to be, they are
lost and needed to be recomputed/redrawn.