java.awt

Class ContainerOrderFocusTraversalPolicy

java.lang.Object

java.awt.FocusTraversalPolicy

java.awt.ContainerOrderFocusTraversalPolicy

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

DefaultFocusTraversalPolicy

public class ContainerOrderFocusTraversalPolicy
extends FocusTraversalPolicy
implements Serializable

ContainerOrderFocusTraversalPolicy defines a focus traversal order based on the order in which Components were packed in a Container. This policy performs a pre-order traversal of the Component hierarchy starting from a given focus cycle root. Portions of the hierarchy that are not visible and displayable are skipped. By default, this policy transfers focus down-cycle implicitly. That is, if a forward traversal is requested on a focus cycle root and the focus cycle root has focusable children, the focus will automatically be transfered down to the lower focus cycle. The default implementation of accept accepts only Components that are visible, displayable, enabled and focusable. Derived classes can override these acceptance criteria by overriding accept.

Since:

1.4

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
ContainerOrderFocusTraversalPolicy() Creates the ContainerOrderFocusTraversalPolicy object.

Method Summary

Methods

Modifier and Type	Method and Description
protected boolean	accept(Component current) Check whether the given Component is an acceptable target for the keyboard input focus.
Component	getComponentAfter(Container root, Component current) Returns the Component that should receive the focus after current.
Component	getComponentBefore(Container root, Component current) Returns the Component that should receive the focus before current.
Component	getDefaultComponent(Container root) Returns the default Component of root that should receive the focus.
Component	getFirstComponent(Container root) Returns the first Component of root that should receive the focus.
boolean	getImplicitDownCycleTraversal() Check whether or not implicit down cycling is enabled.
Component	getLastComponent(Container root) Returns the last Component of root that should receive the focus.
void	setImplicitDownCycleTraversal(boolean value) Set whether or not implicit down cycling is enabled.

Methods inherited from class java.awt.FocusTraversalPolicy

getInitialComponent

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ContainerOrderFocusTraversalPolicy

public ContainerOrderFocusTraversalPolicy()

Creates the ContainerOrderFocusTraversalPolicy object.

Method Detail

getComponentAfter

public Component getComponentAfter(Container root,
                          Component current)

Returns the Component that should receive the focus after current. root must be a focus cycle root of current.

Specified by:

getComponentAfter in class FocusTraversalPolicy

Parameters:

root - a focus cycle root of current

current - a (possibly indirect) child of root, or root itself

Returns:

the next Component in the focus traversal order for root, or null if no acceptable Component exists.

Throws:

IllegalArgumentException - If root is not a focus cycle root of current, or if either root or current is null.

getComponentBefore

public Component getComponentBefore(Container root,
                           Component current)

Returns the Component that should receive the focus before current. root must be a focus cycle root of current.

Specified by:

getComponentBefore in class FocusTraversalPolicy

Parameters:

root - a focus cycle root of current

current - a (possibly indirect) child of root, or root itself

Returns:

the previous Component in the focus traversal order for root, or null if no acceptable Component exists.

Throws:

IllegalArgumentException - If root is not a focus cycle root of current, or if either root or current is null.

getFirstComponent

public Component getFirstComponent(Container root)

Returns the first Component of root that should receive the focus.

Specified by:

getFirstComponent in class FocusTraversalPolicy

Parameters:

root - a focus cycle root

Returns:

the first Component in the focus traversal order for root, or null if no acceptable Component exists.

Throws:

IllegalArgumentException - If root is null.

getLastComponent

public Component getLastComponent(Container root)

Returns the last Component of root that should receive the focus.

Specified by:

getLastComponent in class FocusTraversalPolicy

Parameters:

root - a focus cycle root

Returns:

the last Component in the focus traversal order for root, or null if no acceptable Component exists.

Throws:

IllegalArgumentException - If root is null.

getDefaultComponent

public Component getDefaultComponent(Container root)

Returns the default Component of root that should receive the focus.

Specified by:

getDefaultComponent in class FocusTraversalPolicy

Parameters:

root - a focus cycle root

Returns:

the default Component in the focus traversal order for root, or null if no acceptable Component exists.

Throws:

IllegalArgumentException - If root is null.

setImplicitDownCycleTraversal

public void setImplicitDownCycleTraversal(boolean value)

Set whether or not implicit down cycling is enabled. If it is, then initiating a forward focus traversal operation onto a focus cycle root, the focus will be implicitly transferred into the root container's focus cycle.

Parameters:

value - the setting for implicit down cycling

getImplicitDownCycleTraversal

public boolean getImplicitDownCycleTraversal()

Check whether or not implicit down cycling is enabled. If it is, then initiating a forward focus traversal operation onto a focus cycle root, the focus will be implicitly transferred into the root container's focus cycle.

Returns:

true if the focus will be transferred down-cycle implicitly

accept

protected boolean accept(Component current)

Check whether the given Component is an acceptable target for the keyboard input focus.

Parameters:

current - the Component to check

Returns:

true if current is acceptable, false otherwise