Volume 6A: Motif Programming Manual

XtManageChild (hello_main);

The widget management process in an Mrm application is different from the one used in a C code interface, where

you must use the widget creation convenience routines that create and manage the widgets, or explicitly call

XtManageChild() on each widget. However, Mrm makes one exception−−it does not manage shell widgets in

order to prevent menus and dialogs from popping up unexpectedly.

After managing the top−level widget, all that's left to do is realize the widgets and hand off control to Xt's event

processing loop. The following two calls make these steps happen:

XtRealizeWidget (toplevel);

XtAppMainLoop (app_context);

Again, these calls are part of any Xt application, whether or not you use UIL and Mrm to create the interface. The call

to XtRealizeWidget() creates windows for the widgets, initiates geometry management, and maps the windows.

The call to XtAppMainLoop() causes the application to begin processing events from the X server.

23.6 Summary

The basic purpose of UIL and Mrm is to provide a way to describe and create a Motif user interface. UIL is a static

user interface description language that allows you to define widget hierarchies and specify the resource and callback

settings of those widgets. Mrm is a run−time library that provides the application interface for creating the widgets

described in a UIL module. We considered some of the advantages and disadvantages of programming with UIL and

Mrm. Understanding these tradeoffs can help you decide when ...