🚀 go-pugleaf

> 7.  Calls XtSetWMColormapWindows(toplevel, &canvas, 1).
> 8.  Calls XtAppMainLoop().

> If I use xprop to print out the window properties, it says
> "WM_COLORMAP_WINDOWS(WINDOW): window id #  0x800002", and that is indeed
> the correct window ID for my canvas widget.
> 
> I have found that I can get the desired behavior by replacing step 6 with an
> XSetWindowColormap on my toplevel window, and eliminating step 7 entirely.
> But I don't really *want* my toplevel window to use the RGB_GREEN_MAP.

According to the ICCCM the top level window's colormap will be given
priority over the windows in the WM_COLORMAP_WINDOWS property unless
the top level window also appears in the property.  Use something like
the following code to list your canvas window ahead of the toplevel window.

{
	Widget list[2];
	list[0] = canvas;
	list[1] = toplevel;
	XtSetWMColormapWindows(toplevel, list, 2);
}

Unless the server can actually support multiple simultaneous colormaps,
this will make the server always use RGB_GREEN_MAP when colormap focus
is on your application window.  You might want to consider swapping the
order of the WM_COLORMAP_WINDOWS list based on Enter and Leave events
on the canvas widget.

Mike Stroyan, stroyan@hpfcla.hp.com