https://invisible-island.net/xterm/xtoolkit/
XtMapWidget, XtSetMappedWhenManaged, XtUnmapWidget - map and unmap wid-
gets
#include <X11/Intrinsic.h>
void XtMapWidget(Widget w);
void XtSetMappedWhenManaged(Widget w, Boolean map_when_managed);
void XtUnmapWidget(Widget w);
map_when_managed
Specifies a Boolean value that indicates the new value of the
map_when_managed field.
w Specifies the widget.
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. XtSetMappedWhen-
Managed is a convenience function that is equivalent to (but slightly
faster than) calling XtSetValues and setting the new value for the
mappedWhenManaged resource. As an alternative to using XtSetMapped-
WhenManaged to control mapping, a client may set mapped_when_managed to
False and use XtMapWidget and XtUnmapWidget explicitly.
XtManageChildren(3)
X Toolkit Intrinsics – C Language Interface
Xlib - C Language X Interface
X Version 11 libXt 1.1.5.2 XtMapWidget(3)