| A FocusTraversalPolicy that determines traversal order based on the order
of child Components in a Container. From a particular focus cycle root, the
policy makes a pre-order traversal of the Component hierarchy, and traverses
a Container's children according to the ordering of the array returned by
Container.getComponents(). Portions of the hierarchy that are
not visible and displayable will not be searched.
If client code has explicitly set the focusability of a Component by either
overriding Component.isFocusTraversable() or
Component.isFocusable(), or by calling
Component.setFocusable(), then a DefaultFocusTraversalPolicy
behaves exactly like a ContainerOrderFocusTraversalPolicy. If, however, the
Component is relying on default focusability, then a
DefaultFocusTraversalPolicy will reject all Components with non-focusable
peers. This is the default FocusTraversalPolicy for all AWT Containers.
The focusability of a peer is implementation-dependent. Sun recommends that
all implementations for a particular native platform construct peers with
the same focusability. The recommendations for Windows and Unix are that
Canvases, Labels, Panels, Scrollbars, ScrollPanes, Windows, and lightweight
Components have non-focusable peers, and all other Components have focusable
peers. These recommendations are used in the Sun AWT implementations. Note
that the focusability of a Component's peer is different from, and does not
impact, the focusability of the Component itself.
Please see
How to Use the Focus Subsystem,
a section in The Java Tutorial, and the
Focus Specification
for more information.
author:
David Mendenhall
version:
1.13, 05/05/07
See Also: Container.getComponents
See Also: Component.isFocusable
See Also: Component.setFocusable
since:
1.4 |
