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From: keith@EXPO.LCS.MIT.EDU (Keith Packard)
Newsgroups: comp.windows.x
Subject: Re: Colormap problems with R3
Message-ID: <8811081928.AA05258@EXPO.LCS.MIT.EDU>
Date: 8 Nov 88 19:28:36 GMT
References: <835@nic.MR.NET>
Sender: daemon@bloom-beacon.MIT.EDU
Organization: The Internet
Lines: 39


> Hello, I'm having some problems with changing the colormap in my program.
> Here is what I'm doing:
>
>	XCreateColormap()
>	XAllocColorCells()
>	XStoreColors()
>	XSetWindowColormap()
>	XInstallColormap()
>	XPutImage()


The window manager is responsible for managing shared resources
in the server (like screen real-estate, colormaps and the keyboard).

To support this, some support was put into uwm to manage colormaps.  It's
pretty primitive as the ICCCM isn't ready yet.  All that it does
is notice colormap change events on top-level windows and track the
keyboard focus, installing the colormap for the current window.

If you simply remove the XInstallColormap call from your application,
uwm will automatically notice the colormap change for the window and
act accordingly.

Problems arise when the colormap you created is not associated
with the top-level window.  Simply make the top-level window
*also* use the new colormap and uwm will play ball.  The ICCCM will
address this issue directly, and propose mechanisms for managing
different colormaps for sub-windows.

Unfortunately, no other window managers track colormaps, so you
might want to add code which optionally installs the new
colormap (bleah).  Eventually, you should expect all window managers
to conform to the ICCCM proposal, in which case you would never
call XInstallColormap in an application.

						Keith Packard
						MIT X Consortium
						(617) 253-1428
						keith@EXPO.LCS.MIT.EDU