XWindows - how capture window ?

[Valery Reznic]

--- On Sat, 2/20/10, Ori Berger <linux-il at orib.net> wrote:

> From: Ori Berger <linux-il at orib.net>
> Subject: Re: XWindows - how capture window ?
> To: "linux-il." <linux-il at cs.huji.ac.il>
> Cc: "Valery Reznic" <valery_reznic at yahoo.com>
> Date: Saturday, February 20, 2010, 11:53 PM
> Valery Reznic wrote:
> > Do you have any ideas, how can I render this window
> off screen and capture it's content ?
> >   
> You can probably run an Xvnc server (X server that sends
> updates out through the vnc protocol, rather than actually
> updating screen). As far as any software is concerned, this
> is a real screen, so you can run anything on it. However, it
> does not need to be visible on any physical display; Also,
> if the whole reason is to let this app work through the
> network, then xvnc is a complete solution all by itself

I probably don't explain myself.

Application should run on the usual display and be visible.
But when certain button is pressed mentioned before window's content should be captured.

I through about using Xvnc (and Xvbf) and even tried it.
The trouble is I need initialize connection to the new display and display's colormap and who now what else. This application do a lot of
strange and complicate things in a rather messy way.
Make the same to the other display is not an easy task.

Is it a way to do it at the same display ?

Valery
>