Re: Accessing the Root Window in Perl

I don't believe X11 provides any means for Clients to ask the server for any information about any window -- including the root window. That's why "Eterm" requires that your either use Enlightenment as your windows manager, or set the background with "Esetroot" if you want any level of transparency. This gives Eterm something to query to find out what pixels are where in the root window.

I can't seem to find any docs mentioning an API to allow arbitrary programs to query Enlightenment/Esetroot for the background info, but i didn't look too hard so that doesn't mean it doesn't exist.

You could allways write your own wrapper script for setting the background image (using xv, or what have you) and making a symlink to the last file used to set the background that your other scritps can allways refrence when they want to know what the background is.

Comment on Re: Accessing the Root Window in Perl

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Re: Accessing the Root Window in Perl by Abigail-II (Bishop) on May 24, 2003 at 11:44 UTC
I don't believe X11 provides any means for Clients to ask the server for any information about any window Sure it does. Ever used `xmag`? Or a graphics editor like `xpaint` that allows you to pick the colour of any pixel on the screen? `xli` or `xloadimage`, that can inspect or share colour palettes already in use (important in the time X-servers often used 256 colour palettes)? `fvwm2` has no problem using partially transparent icons; and if I view a partially transparent gif with `display` (which comes with ImageMagick), I get to see what's underneath (and even the focus goes to the underlaying application). And you may be familiar with `xscreensaver` which has a few screensavers that use the current display. You can say a lot of bad things about X, that it's slow, that it uses a lot of memory, that it's insecure, and that it's hard to program with. But the one reason that it's still going strong is that anything is possible. And that includes transparency, and inspecting the pixels of other applications. But I'm not an X-windows programmer (it's been more than 10 years since I last wrote an X-windows program (in C, pure, raw X-windows, no widget sets used)), so how it's done, I do not know. Abigail	[reply] [d/l] [select]
Re: Re: Accessing the Root Window in Perl by arthas (Hermit) on May 24, 2003 at 09:04 UTC
Multi Gnome Terminal allows transparent background with any (gnome-compliant?) window manager (I use it with sawfish). So, even though I have no further information, I think that at least under GNOME there's a standard API to query for backgorund information. Michele.	[reply]