GtkProgressBar ignoring gtk_widget_queue_draw()

[Richard Stellingwerff <remenic gmail com>]

Hi,

I am new to this list, so please bear with me :)

Currently I'm working on a gtk engine called Clearlooks. Based on a
nice idea from jimmac, I tried to implement an animated progressbar.

Unfortunately, it seems that no matter how often I call
gtk_widget_queue_draw() on a GtkProgressBar, it will not get redrawn.
Apparently there's some double-double buffering going on or something.
I added printf() to the draw_box method, but it never gets drawn on a
GtkProgressBar's expose event. It only gets called after a resize
event. So somewhere the contents are kept offscreen and then just
blitted onto the screen. This is not the case for other widgets like
buttons. An expose event will cause a redraw event.

I am not sure why GtkProgressBar is different in this regard. Can a
redraw somehow be forced? I need to do this, because a timeout will
periodically call a repaint to all visible progressbars.

Jimmac's animated scrollbar mockup can be found here:
http://jimmac.musichall.cz/weblog.php/Design/Progress.php

It appears that a GtkButton has a NO_WINDOW and MAPPED widget flag,
while GtkProgressBar has not. I'm not sure if either one has something
to do with it, since I can't really find any straight answers in the
documentation.

Hopefully someone can help me out on this one.

Kind regards,
Richard Stellingwerff.