[Last modified: Feb 00]

Answer: You must specify the colormap, visual type, and depth for the shell
before it is realized.  If you don't specify all three resources (or specify
them incorrectly), you will probably get BadMatch protocol errors from your X
server.

Ken Lee, http://www.rahul.net/kenton/


Mike Stroyan, mike_stroyan@fc.hp.com, adds:
  It is convenient to use XrmPutResource to cause all widgets to pick up a
consistent set of visual, depth, and colormap.  It is just very difficult to
get at each and every shell including menushells created by functions like
XmVaCreateSimpleMenuBar and XmVaCreateSimpleOptionMenu.

This example uses the default visual for menus, but a non-default for the top
level shell:

if (!non_default_dialogs) {
    /* Set default depth and colormap of shell widgets, especially menus */
    Screen *default_screen;
    int default_depth;
    Colormap default_colormap;
    XrmDatabase db = XtDatabase(display);
    XrmValue v;

    default_screen = DefaultScreenOfDisplay(display);
    default_depth = DefaultDepthOfScreen(default_screen);
    default_colormap = DefaultColormapOfScreen(default_screen);
    v.size = sizeof(default_depth);
    v.addr = (XtPointer) &default_depth;
    XrmPutResource(&db,"*XmMenuShell.depth", XmRInt, &v);
    XrmPutResource(&db,"*XmDialogShell.depth", XmRInt, &v);
    v.size = sizeof(default_colormap);
    v.addr = (XtPointer) &default_colormap;
    XrmPutResource(&db,"*XmMenuShell.colormap", XmRColormap, &v);
    XrmPutResource(&db,"*XmDialogShell.colormap", XmRColormap, &v);
}

/* Get visual information. */
template.screen = DefaultScreen(display);
template.class = TrueColor;
template.depth = 24;
mask = VisualScreenMask | VisualDepthMask | VisualClassMask;
vilist = XGetVisualInfo(display, mask, &template, &nvisual);
if (nvisual == 0) {
    fprintf(stderr, "Cannot find an acceptable visual!0);
    exit(1);
}
visual = vilist[0].visual;
depth = vilist[0].depth;
XFree((char *) vilist);

private_colormap = XCreateColormap(display, DefaultRootWindow(display),
    visual, AllocNone);
{
    XColor real, exact;
    XAllocNamedColor(display, private_colormap, "Green", &real, &exact);
    green = real.pixel;
}

XtVaSetValues(toplevel,
    XmNdepth, depth,
    XmNvisual, visual,
    XmNcolormap, private_colormap,
    NULL);

if (non_default_dialogs) {
    /* Set non-default visual for all widgets. */
    XrmDatabase db = XtDatabase(display);
    XrmValue v;
    v.size = sizeof(visual);
    v.addr = (XtPointer) &visual;
    XrmPutResource(&db,"*visual", XmRVisual, &v);
}

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