How do I create a Motif main window that doesn't have a system menu, minimize and maximize boxes? I just cannot find out how by googling and reading docs and tutorials. I believe that it should be possible with some additional parameters for XtVaCreateManagedWindow, but which?
I have tried several variants of XtVaSetValues (topWid, XmNmwmDecorations, ...) but none worked. Instead I get an error message that I need to use a vendor shell for this. Most widget types aren't derived from vendor shells however, and when I e.g. try to use a dialog shell and put a scrollable text widget inside of it, then then text widget seems to control the dialog.
Apparently it's not (easily) possible to get rid of the window (system) menu, but it seems to be possible to disable window menu items with some code like this:
int i;
XtVaGetValues (widget, XmNmwmFunctions, &i);
i &= ~(MWM_FUNC_ALL | MWM_FUNC_MINIMIZE | MWM_FUNC_MAXIMIZE | MWM_FUNC_CLOSE);
XtVaSetValues (widget, XmNmwmFunctions, i);
which removes the related window decoration too and apparently even works for non vendor shell widgets.