Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!hplabs!hpfcdc!stroyan
From: stroyan@hpfcdc.HP.COM (Mike Stroyan)
Newsgroups: comp.windows.x
Subject: Re: widget with colormap
Message-ID: <6910005@hpfcdc.HP.COM>
Date: 29 Mar 89 01:14:29 GMT
References: <8903281206.AA23640@faraday.ece.cmu.edu>
Organization: HP Ft. Collins, Co.
Lines: 22

> 	1) Did I miss the "right" way of doing this?  (ie: should
> 		my widget really be calling XInstallColormap?)

Don't call XInstallColormap.  It is antisocial.

The current ICCCM draft discusses telling the window manager by setting
the WM_COLORMAP_WINDOWS property of the top-level window.  The property
contains a list of window ids for which the window manager should
install the colormaps for when the application has colormap focus.  The
list is ordered in descending priority.  A subwindow's colormap can be
made more important by listing the top-level window after the subwindow.
Otherwise the top-level window will have highest priority.

Unfortunately, most window managers don't yet observe the
WM_COLORMAP_WINDOWS property.  For now you probably can get the effect
you want by changing the colormap attribute of the top-level window
whenever the widget is entered or exited.  You can either keep the
window id in a global variable or follow the widget parent entries to
the top widget.  If the parent window and widget window have different
visuals, then this method can't be used.

Mike Stroyan, stroyan@hpfcla.hp.com