Overlap scale on scrollbar but not correctly exposed?

["MD Tsai" <md tsai gmail com>]

Hi,

I'm writing a custom widget inherit from scrollbar (V/H), with a scale
overlap on scrollbar.

The custom widget overrides realize, which calls parent class' realize of
scrollbar.
In scale part, scale->window is parent window and scale->event_window assign
with correct size.

When expose, both scrollbar and scale calls parent class' expose but only
scrollbar draw correct. The rectangle of scale is gray and no slider. Mouse
click does not work.

Is there any one has experience about custom widget without container widget
and from scratch? Please kindly give me some hints about this.

Thanks a lot.

Eric