Volume 6A: Motif Programming Manual

The layout of a dialog box

The widget hierarchy of a dialog box

4.3.1 The Manager Widget Class

As with the Primitive widget class and the Gadget class, the Manager widget class is a superclass for all of the Motif

manager widgets. The Manager class is another metaclass. You never create an instance of a Manager widget; you

create an instance of one of its subclasses. The actual widget classes that you use are shown in the figure.

Manager is subclassed from the Xt Constraint class, which in turn is subclassed from the Xt Composite class. The

Composite widget class defines the basic characteristics of widgets that are able to manage the size and position of

other widgets. Xt uses the general term -composite widget for any widget with this capability. The Constraint class

adds the capability to provide additional resources for the widgets that are being managed. These resources constrain

the position of the widgets. They can be thought of as hints about how the widgets should be laid out.

4 Overview of the Motif Toolkit 4.3.1 The Manager Widget Class

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The Manager widget class hierarchy

Motif provides a number of general−purpose manager widgets that allow the programmer to manage the size and

arrangement of an arbitrary number of children. In some ways, the art of Motif programming is the design ...