command line to change wallpaper

[Matthew Weier OPhinney]

-- Biju Chacko <biju_chacko at vsnl.net> wrote
(on Saturday, 25 October 2003, 02:05 PM +0530):
> On Sat, 25 Oct 2003 10:16:16 +0200, Jasper Huijsmans wrote:
> > Op za 25-10-2003, om 09:36 schreef Biju Chacko:
> > 
> > > Wouldn't life be much simpler if xfdesktop's pseudo-root-window was
> > > transparent? Then everybody's favourite root pixmap changer would work. Is
> > > this practical?
> > > 
> > 
> > I don't think it's that simple, unfortunately. It would indeed be a very
> > nice solution. Luca can perhaps comment on this as well.
> > 
> > A gtk toplevel window can not be transparent, I think. For that you need
> > an input-only window, which is fine as long as you don't want to add
> > other widgets (icons) to it. Also, instead of an input-only window,
> > luca's solution of using the root window directly is just as easy,
> > either through gdk or using xlib directly.
> 
> Hmmm ... 
> 
> Excuse me if my ideas are kinda daft, but I don't know as much about the issues
> as you do.
> 
> Would it be possible to simulate transparency by monitoring the root window
> using gdk or xlib? As the background pixmaps changes, change the
> pseudo-root-window pixmap? AFAIK, that's how transparent xterms work don't they?

You might want to check out how ROX and, in particular, the ROX
application WallPaper, handles this. Thomas Leonard has written a
tutorial on how to create background applications for ROX, and I recall
seeing some information on how he got xearth to work with the ROX
backdrop. IIRC, his backdrop application would update the backdrop every
specified interval with the results of the program that was running. So,
as xearth updated, the application would rewrite the ROX backdrop.

This could probably be cannibalized for use with xfdesktop. The examples
Thomas used were in python -- so writing a C implementation would take
some effort. If a standard wrapper could be written, then any third
party application could be used as the backdrop setter, as well as a
simple image.

-- 
Matthew Weier O'Phinney
http://weierophinney.net/matthew/