Volume 6A: Motif Programming Manual

new behavior. If you need to change the default behavior, you should use XmNONE and XmTAB_GROUP to control

whether or not a widget is a tab group or a member of one. To control whether the widget is part of the whole

keyboard traversal mechanism, use the XmNtraversalOn resource.

9.8.3 Handling Event Translations

In order for manager widgets to implement keyboard traversal, they have their own event translation tables that

specify what happens when certain events occur. As discussed in Chapter 2, The Motif Programming Model, a

translation table specifies a series of one or more events and an action that is invoked if the event occurs. The X

Toolkit Intrinsics handles event translations automatically; when the user presses the TAB key, Xt looks up the event

<Key>Tab in the table and invokes the corresponding action procedure. In this case, the procedure changes the input

focus from the current tab group to the next one on the list.

This mechanism is dependent on the window hierarchy of the widget tree. Events are first delivered to the widget

associated with the window where the event took place. If that widget (or its window) does not handle the type of

event delivered, it passes the event up the window tree to its parent, which then has the option of dealing with the

event. Assuming that the parent is a manager widget of some kind, it now has the option to process the event. If the

event is a keyboard traversal event, the appropriate action routine moves the input focus. The default event ...