— A function that identifies whether a widget can
determines whether the specified widget is eligible to
receive focus through keyboard traversal. In general, a widget is eligible to
receive focus when all of the following conditions are true:
- The widget and its ancestors are not being destroyed, are sensitive, and
have a value of True for XmNtraversalOn.
- The widget and its ancestors are realized, managed, and (except for
gadgets) mapped. If an application unmaps a widget that has its
XmNmappedWhenManaged resource set to True, the return value is
- Some part of the widget's rectangular area is unobscured by the widget's
ancestors, or some part of the widget's rectangular area is inside the
work window (but possibly outside the clip window) of a ScrolledWindow
whose XmNscrollingPolicy is XmAUTOMATIC and whose
XmNtraverseObscuredCallback is not NULL.
Some widgets may not be eligible to receive focus even if they meet all these
conditions. For example, most managers cannot receive focus through keyboard
traversal. Some widgets may be eligible to receive focus under particular
conditions. For example, a DrawingArea is eligible to receive focus if it
meets the conditions above and has no child whose XmNtraversalOn
resource is True.
Note that when all widgets in a shell hierarchy have been made untraversable,
they are considered to have lost focus. When a widget in this hierarchy is
made traversable again, it regains focus.
may return unexpected results when widget
ancestors are overlapped by their siblings.
- Specifies the ID of the widget
Returns True if the widget is eligible to receive focus through keyboard
traversal; otherwise, returns False.
(3) and XmProcessTraversal