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From: dsr@mir.mitre.org (Douglas S. Rand)
Newsgroups: comp.windows.x
Subject: Re: Colormap with widgets
Keywords: Xt,widgets,colormaps
Message-ID: <1991Jan18.160846.16581@linus.mitre.org>
Date: 18 Jan 91 16:08:46 GMT
References: <1991Jan17.173335.2260@uokmax.ecn.uoknor.edu>
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Reply-To: dsr@mir.mitre.org (Douglas S. Rand)
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In article <1991Jan17.173335.2260@uokmax.ecn.uoknor.edu>, jigang@alliant.backbone.uoknor.edu (Jigang Yang) writes:
> 
> I got problem about using colormaps with widgets.
> 
> I first use :  XCreateColormap() to create a new colormap and read all colors
> from default colormap and save them into new colormap.
> 
> Then XInstallColormap();
> 
> Then create some widgets and attach them with some callbacks;
> 
> Then the mainloop.
> 
> 
> In some callbacks, I change the RGB values of the new colormap(since it is
> installed, it should be the current colormap), and install it again. 
> 
> But I only see the widgets using the newly changed color when they are focused.
> For example, if you focus / click the button, the colormap is changed,
> and then it seems to use the original colormap again! Why!!! 
> 
Because when you install a colormap in a Window (remember all your Widgets are
X Windows) the colormap only becomes visible when that window is in focus.  How
else could it work on a display with only one active colormap? (I am presuming a
PseudoColor visual and one active colormap at a time)  This is what colormaps
are for.  If you want the button, or whatever, to always be colored a certain
way you must use the default colormap.


-- 
Douglas S. Rand 
Internet:   <dsrand@mitre.org>
Snail:	    MITRE, Burlington Road, Bedford, MA 
Disclaimer: MITRE might agree with me - then again...
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