how to tell a window is completely redrawn?
ijs at txcorp.com
Wed Mar 9 13:16:21 PST 2005
Thanks for your e-mail, Vladimir.
Could you please elaborate on what you mean by "blocking input"?
On Wed, 9 Mar 2005, Vladimir Dergachev wrote:
> Date: Wed, 9 Mar 2005 15:20:01 -0500 (EST)
> From: Vladimir Dergachev <volodya at mindspring.com>
> To: Jonathan Lennox <lennox at cs.columbia.edu>
> Cc: Irek Szczesniak <ijs at txcorp.com>, xorg at lists.freedesktop.org
> Subject: Re: how to tell a window is completely redrawn?
> On Wed, 9 Mar 2005, Jonathan Lennox wrote:
> > On Tuesday, March 8 2005, "Irek Szczesniak" wrote to "xorg at lists.freedesktop.org" saying:
> >>>> I need to wait for a window to be completely redrawn, and then take a
> >>>> picture of it with XGetImage. This window is not mine, and the only
> >>>> thing I know about it is its ID.
> >>>> How can I tell that the X server has compeletly redrawn the window?
> > If you're using a current Xorg server, you could use the Xdamage extension.
> > There could be some issues with over-estimation of damage, though.
> > You could also use Xrecord to actually peek at the requests the window's
> > client is sending.
> > In general, "completely redrawn" is an application-specific concept, so I'd
> > imagine you'd need to know some details of how your target application draws
> > things.
> Just to emphasize this point - the application might be a video player in
> which case it never stops drawing as long as the playback is going on.
> One way to do what Irek wants would be to wait until application blocks on
> input - if you know it is sleeping you know it is done doing whatever it
> was doing for the moment.
> This would also work with some video playback apps as I would expect that
> frame synchronization might work by waiting for vsync to arrive.
> Practical implementation of this is another matter..
> Vladimir Dergachev
> > --
> > Jonathan Lennox
> > lennox at cs dot columbia dot edu
> > _______________________________________________
> > xorg mailing list
> > xorg at lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/xorg
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