Re: How to get image of offscreen widget or window ?

[James Henstridge <james jamesh id au>]

On 16/06/2004 11:01 PM, Grim S wrote:

> I have a GTK window which is slightly offscreen - when
> i used gdk_drawable_get_image() the offscreen portions
> are black in color - is there an api/hack/anything
> which will allow me to get to the drawing of
> widget/window, or make the widget/window paint to a
> different context?
> Is there a defect for this problem ?
> Any help would be greatly appreciated.
>  
First of all, gtk-devel-list is a list for discussing the development of 
GTK.  For questions like this about developing with GTK, you should use 
gtk-list or gtk-app-devel-list.

In X11, windows (unlike pixmaps) have no backing store.  If they aren't 
on screen, or are obscured, then there is no contents to grab.

However, if you are using an X server that supports the composite 
extension (currently only the freedesktop.org X server), then it is 
possible to redirect a window hierarchy to render to a pixmap.  This 
would allow you to grab the contents of the window, even if it isn't 
visible on the screen.  It will take a while before you can rely on this 
sort of functionality though.

James.

--
Email: james daa com au
WWW:   http://www.daa.com.au/~james/