https://invisible-island.net/xterm/xtoolkit/
XtRealizeWidget, XtIsRealized, XtUnrealizeWidget - realize and unreal-
ize widgets
#include <X11/Intrinsic.h>
void XtRealizeWidget(Widget w);
Boolean XtIsRealized(Widget w);
void XtUnrealizeWidget(Widget w);
w Specifies the widget.
If the widget is already realized, XtRealizeWidget simply returns.
Otherwise, it performs the following:
o Binds all action names in the widget's translation table to proce-
dures (see Section 10.1.2).
o Makes a post-order traversal of the widget tree rooted at the
specified widget and calls the change_managed procedure of each
composite widget that has one or more managed children.
o Constructs an XSetWindowAttributes structure filled in with infor-
mation derived from the Core widget fields and calls the realize
procedure for the widget, which adds any widget-specific
attributes and creates the X window.
o If the widget is not a subclass of compositeWidgetClass,
XtRealizeWidget returns; otherwise, it continues and performs the
following:
- Descends recursively to each of the widget's managed children
and calls the realize procedures. Primitive widgets that
instantiate children are responsible for realizing those
children themselves.
- Maps all of the managed children windows that have
mapped_when_managed True. (If a widget is managed but
mapped_when_managed is False, the widget is allocated visual
space but is not displayed. Some people seem to like this to
indicate certain states.)
If the widget is a top-level shell widget (that is, it has no parent),
and mapped_when_managed is True, XtRealizeWidget maps the widget win-
dow.
The XtIsRealized function returns True if the widget has been realized,
that is, if the widget has a nonzero X window ID.
Some widget procedures (for example, set_values) might wish to operate
differently after the widget has been realized.
The XtUnrealizeWidget function destroys the windows of an existing wid-
get and all of its children (recursively down the widget tree). To
recreate the windows at a later time, call XtRealizeWidget again. If
the widget was managed, it will be unmanaged automatically before its
window is freed.
XtManageChildren(3)
X Toolkit Intrinsics – C Language Interface
Xlib - C Language X Interface
X Version 11 libXt 1.1.5.2 XtRealizeWidget(3)