Path: utzoo!attcan!uunet!ginosko!gem.mps.ohio-state.edu!tut.cis.ohio-state.edu!ucbvax!bloom-beacon!SRC.DEC.COM!msm
From: msm@SRC.DEC.COM (Mark S. Manasse)
Newsgroups: comp.windows.x
Subject: Re: Virtual colormaps & DECwindows
Message-ID: <8907240118.AA18657@jumbo.pa.dec.com>
Date: 24 Jul 89 01:18:00 GMT
References: <223@nap1.cds.wpafb.af.mil>
Sender: daemon@bloom-beacon.MIT.EDU
Organization: The Internet
Lines: 29


Vern Staats writes:

> I just translated the coloredit example in Doug Young's book from 
> HP to Athena widgets.  My goals were to learn about using scroll 
> bars and the wonderful new virtual colormap capabilities of X11r3.  
> Unfortunately, it appears that virtual colormaps are uh, virtually 
> useless (sorry, couldn't resist :-) under the DECwindows window 
> manager.  Whenever I use XInstallColormap(...,my_map) somebody (and 
> I think its dxwm) goes and reinstalls the default colormap.
>  
> Is there some way to tell dxwm to leave my map installed, or at least 
> reinstall it when my application has focus?

As you can see from reading the Inter-Client Communications Conventions 
Manual, obedient applications are enjoined from ever calling 
InstallColormap.  Instead, applications that wish to install a single 
colormap are encouraged to use ChangeWindowAttributes to set that 
colomap as the colormap of their top-level window.  It would have 
been nicer to allow applications to install colormaps freely, but 
the protocol does not provide the necessary support to avoid race 
conditions to allow it.  The currently-shipped version of dxwm keeps 
track of what it believes to be the focus window for colormap, and 
keeps that window's colormap installed.  Since the current release 
of dxwm predates the ICCCM's adoption of COLORMAP_WINDOWS, it does 
not implement that feature of the ICCCM.

Mark