Volume 6A: Motif Programming Manual

User interface of quitbox.uil

The Quit PushButton manages the dialog, which causes it to be displayed. Pressing the OK PushButton exits the

application. There is no need to use the unmanage() callback in this example, as the Cancel PushButton unmanages

the dialog by default. You can easily apply the manage() and unmanage() callbacks to other dialogs in an

interface.

27.5.2 Creating Widgets

In the source code the entire user interface is defined in a single widget hierarchy. This technique is fine for a small

application, but for performance reasons it is not practical in a larger application. Creating a separate hierarchy for

each window allows you to divide an interface into separate modules, as discussed earlier in this chapter. The only

drawback to distributing dialog creation is that it takes longer for a dialog to appear the first time it is displayed. Since

this delay is typically not noticeable, we still recommend this approach.

You can support the as−needed dialog creation policy in UIL by adding another callback that creates a widget

hierarchy. A new widget hierarchy is created by calling MrmFetchWidget(). As a reminder, this function takes the

following form:

Cardinal

MrmFetchWidget(hierarchy, widget_name, parent, widget_return,

class_return)

MrmHierarchy hierarchy;

String widget_name;

Widget parent;

Widget *widget_return;

MrmType *class_return;

A creation callback needs three values ...