Re: How to make my own widget semi-transparent?

[John Stebbins <stebbins jetheaddev com>]

The documentation for GdkWindow has a good example of how to do 
translucent widgets.
http://library.gnome.org/devel/gdk/unstable/gdk-Windows.html#composited-window-example
Your attachments didn't go through, so I can't say what your doing 
wrong. But if I had to guess, I would say you're probably not correctly 
setting up the expose event.  Also, I wrote a custom widget to 
generalize multiple overlapping translucent layers.  You might want to 
have a look at it.  http://www.stebbins.biz/home/node/5

On 04/08/2009 09:25 PM, Zhe Su wrote:
> Hi,
>    I'm writing a program which uses cairo to paint some customized
> semi-transparent widgets.These widgets might overlap with each other.
> However I didn't find a way to make the widgets truely semi-transparent. If
> a widget is covered by another widget, then the covered area will always be
> erased by the upper widget.
>    A test program and its screenshot is attached. The program draws a window
> with two fixed widgets, both are painted with cairo. One is semi-transparent
> green another is blue. No matter if composite extension is enabled or not,
> the result is not what I expect.
>    Anyone know how to implement real semi-transparent widgets with current
> gtk?
>
> Regards
> James Su
>