java.awt
Class ContainerOrderFocusTraversalPolicy

java.lang.Object
  extended by java.awt.FocusTraversalPolicy
      extended by 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
ContainerOrderFocusTraversalPolicy()
          Creates the ContainerOrderFocusTraversalPolicy object.
 
Method Summary
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