XtMapWidget(), XtSetMappedWhenManaged(), XtUnmapWidget() - map and unmap widgets
XtMapWidget (Widget w)
void XtSetMappedWhenManaged (Widget w, Boolean map_when_managed)
XtUnmapWidget (Widget w)
If the widget is realized and managed and if the new value of map_when_managed is True, XtSetMappedWhenManaged maps the window. If the widget is realized and managed and if the new value of map_when_managed is False, it unmaps the window. XtSetMappedWhenManaged(3) is a convenience function that is equivalent to (but slightly faster than) calling XtSetValues(3) and setting the new value for the mappedWhenManaged resource. As an alternative to using XtSetMappedWhenManaged(3) to control mapping, a client can set mapped_when_managed to False and use XtMapWidget(3) and XtUnmapWidget(3) explicitly.
X Toolkit Intrinsics - C Language Interface
Xlib - C Language X Interface