Re: How to implement transparency in GtkWidget?

[Paul Pogonyshev <pogonyshev gmx net>]

I accidentally CC'ed it to `gtk-devel-list' instead of here.
Moderators of that list can just delete the message.  Sorry.

Gaurav Jain wrote:
> Hi All,
>
> I had sent this mail to the list a few days ago, but got no reply.
> Could somebody please reply to it, or let me know where I can find the
> answer to my question?)
>
> I wish to know if it is possible to draw a GtkWidget directly to an
> offscreen bitmap (without drawing it on the screen).  I need this so
> that I can implement transparency in the widget (over it's background
> on screen), by first creating a pixmap of the widget, and then
> rendering that pixmap on the screen with a set level of transparency.
> (By the way, is there any direct way to implement transparency?).

Basically, this gonna be difficult and slow, if at all possible.  The
main problem is that X Window System doesn't really support transparency.

You could try to use

        gdk_window_set_back_pixmap (widget->window, NULL, FALSE);

to turn background off and then use GdkPibuf as off-screen widget
representation and on expose draw this pixbuf onto the widget.

Paul