https://invisible-island.net/xterm/xtoolkit/
XtCreateApplicationContext, XtDestroyApplicationContext, XtWidgetTo-
ApplicationContext, XtToolkitInitialize - create, destroy, and obtain
an application context
#include <X11/Intrinsic.h>
XtAppContext XtCreateApplicationContext(void);
void XtDestroyApplicationContext(XtAppContext app_context);
XtAppContext XtWidgetToApplicationContext(Widget w);
void XtToolkitInitialize(void);
app_context
Specifies the application context.
w Specifies the widget that you want the application context
for.
The XtCreateApplicationContext function returns an application context,
which is an opaque type. Every application must have at least one ap-
plication context.
The XtDestroyApplicationContext function destroys the specified appli-
cation context as soon as it is safe to do so. If called from with an
event dispatch (for example, a callback procedure), XtDestroy-
ApplicationContext does not destroy the application context until the
dispatch is complete.
The XtWidgetToApplicationContext function returns the application con-
text for the specified widget.
The XtToolkitInitialize function initializes the Intrinsics internals.
If XtToolkitInitialize was previously called it returns immediately.
XtDisplayInitialize(3)
X Toolkit Intrinsics - C Language Interface
Xlib - C Language X Interface
X Version 11 libXt 1.3.1 XtCreateApplicationContext(3)