75) How can I send an expose event to a Drawing Area widget? (or

any other, come to that). I want to send an expose event so that it will
redraw itself.

Answer: Use the Xlib call

        XClearArea(XtDisplay(w), XtWindow(w), 0, 0, 0, 0, True)

This clears the widget's window and generates an expose event in doing so.
The widgets expose action will then redraw it.  This uses a round trip
request.  An alternative, without the round trip is

from orca!mesa!rthomson@uunet.uu.net  (Rich Thomson):

    Widget da;
    XmDrawingAreaCallbackStruct da_struct;

    da_struct.reason = XmCR_EXPOSE;
    da_struct.event = (XEvent *) NULL;
    da_struct.window = XtWindow(da);

    XtCallCallbacks(da, XmNexposeCallback, (XtPointer) da_struct);