java.awt

Class KeyboardFocusManager

java.lang.Object

java.awt.KeyboardFocusManager

All Implemented Interfaces:

KeyEventDispatcher, KeyEventPostProcessor

public abstract class KeyboardFocusManager
extends Object
implements KeyEventDispatcher, KeyEventPostProcessor

The KeyboardFocusManager is responsible for managing the active and focused Windows, and the current focus owner. The focus owner is defined as the Component in an application that will typically receive all KeyEvents generated by the user. The focused Window is the Window that is, or contains, the focus owner. Only a Frame can be the active Window. The native windowing system may denote the active Window or its children with special decorations, such as a highlighted title bar. The active Window is always either the focused Window, or the first Frame that is an owner of the focused Window.

The KeyboardFocusManager is both a centralized location for client code to query for the focus owner and initiate focus changes, and an event dispatcher for all FocusEvents, WindowEvents related to focus, and KeyEvents.

Some browsers partition applets in different code bases into separate contexts, and establish walls between these contexts. In such a scenario, there will be one KeyboardFocusManager per context. Other browsers place all applets into the same context, implying that there will be only a single, global KeyboardFocusManager for all applets. This behavior is implementation-dependent. Consult your browser's documentation for more information. No matter how many contexts there may be, however, there can never be more than one focus owner, focused Window, or active Window, per ClassLoader.

Since:

1.4

Version:

1.40, 01/23/03

Author:

David Mendenhall

See Also:

Window, Frame, FocusEvent, WindowEvent, KeyEvent

Field Summary

Fields

Modifier and Type	Field and Description
static int	BACKWARD_TRAVERSAL_KEYS The identifier for the Backward focus traversal keys.
static int	DOWN_CYCLE_TRAVERSAL_KEYS The identifier for the Down Cycle focus traversal keys.
static int	FORWARD_TRAVERSAL_KEYS The identifier for the Forward focus traversal keys.
static int	UP_CYCLE_TRAVERSAL_KEYS The identifier for the Up Cycle focus traversal keys.

Method Summary

Methods

Modifier and Type	Method and Description
void	addKeyEventDispatcher(KeyEventDispatcher dispatcher) Adds a KeyEventDispatcher to this KeyboardFocusManager's dispatcher chain.
void	addKeyEventPostProcessor(KeyEventPostProcessor processor) Adds a KeyEventPostProcessor to this KeyboardFocusManager's post- processor chain.
void	addPropertyChangeListener(PropertyChangeListener listener) Adds a PropertyChangeListener to the listener list.
void	addVetoableChangeListener(VetoableChangeListener listener) Adds a VetoableChangeListener to the listener list.
void	clearGlobalFocusOwner() Clears the global focus owner at both the Java and native levels.
abstract boolean	dispatchEvent(AWTEvent e) This method is called by the AWT event dispatcher requesting that the current KeyboardFocusManager dispatch the specified event on its behalf.
abstract boolean	dispatchKeyEvent(KeyEvent e) Typically this method will be called by dispatchEvent if no other KeyEventDispatcher in the dispatcher chain dispatched the KeyEvent, or if no other KeyEventDispatchers are registered.
void	downFocusCycle() Moves the focus down one focus traversal cycle from the current focus owner, if and only if the current focus owner is a Container that is a focus cycle root.
abstract void	downFocusCycle(Container aContainer) Moves the focus down one focus traversal cycle.
void	focusNextComponent() Focuses the Component after the current focus owner.
abstract void	focusNextComponent(Component aComponent) Focuses the Component after aComponent, typically based on a FocusTraversalPolicy.
void	focusPreviousComponent() Focuses the Component before the current focus owner.
abstract void	focusPreviousComponent(Component aComponent) Focuses the Component before aComponent, typically based on a FocusTraversalPolicy.
Window	getActiveWindow() Returns the active Window, if the active Window is in the same context as the calling thread.
Container	getCurrentFocusCycleRoot() Returns the current focus cycle root, if the current focus cycle root is in the same context as the calling thread.
static KeyboardFocusManager	getCurrentKeyboardFocusManager() Returns the current KeyboardFocusManager instance for the calling thread's context.
Set	getDefaultFocusTraversalKeys(int id) Returns a Set of default focus traversal keys for a given traversal operation.
FocusTraversalPolicy	getDefaultFocusTraversalPolicy() Returns the default FocusTraversalPolicy.
Window	getFocusedWindow() Returns the focused Window, if the focused Window is in the same context as the calling thread.
Component	getFocusOwner() Returns the focus owner, if the focus owner is in the same context as the calling thread.
Component	getPermanentFocusOwner() Returns the permanent focus owner, if the permanent focus owner is in the same context as the calling thread.
PropertyChangeListener[]	getPropertyChangeListeners() Returns an array of all the property change listeners registered on this keyboard focus manager.
VetoableChangeListener[]	getVetoableChangeListeners() Returns an array of all the vetoable change listeners registered on this keyboard focus manager.
abstract boolean	postProcessKeyEvent(KeyEvent e) This method will be called by dispatchKeyEvent.
abstract void	processKeyEvent(Component focusedComponent, KeyEvent e) This method initiates a focus traversal operation if and only if the KeyEvent represents a focus traversal key for the specified focusedComponent.
void	redispatchEvent(Component target, AWTEvent e) Redispatches an AWTEvent in such a way that the AWT event dispatcher will not recursively request that the KeyboardFocusManager, or any installed KeyEventDispatchers, dispatch the event again.
void	removeKeyEventDispatcher(KeyEventDispatcher dispatcher) Removes a KeyEventDispatcher which was previously added to this KeyboardFocusManager's dispatcher chain.
void	removeKeyEventPostProcessor(KeyEventPostProcessor processor) Removes a previously added KeyEventPostProcessor from this KeyboardFocusManager's post-processor chain.
void	removePropertyChangeListener(PropertyChangeListener listener) Removes a PropertyChangeListener from the listener list.
void	removeVetoableChangeListener(VetoableChangeListener listener) Removes a VetoableChangeListener from the listener list.
void	setDefaultFocusTraversalKeys(int id, Set keystrokes) Sets the default focus traversal keys for a given traversal operation.
void	setDefaultFocusTraversalPolicy(FocusTraversalPolicy defaultPolicy) Sets the default FocusTraversalPolicy.
void	upFocusCycle() Moves the focus up one focus traversal cycle from the current focus owner.
abstract void	upFocusCycle(Component aComponent) Moves the focus up one focus traversal cycle.

Methods inherited from class java.lang.Object

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

Field Detail

FORWARD_TRAVERSAL_KEYS

public static final int FORWARD_TRAVERSAL_KEYS

The identifier for the Forward focus traversal keys.

See Also:

setDefaultFocusTraversalKeys(int, java.util.Set), getDefaultFocusTraversalKeys(int), Component.setFocusTraversalKeys(int, java.util.Set), Component.getFocusTraversalKeys(int), Constant Field Values

BACKWARD_TRAVERSAL_KEYS

public static final int BACKWARD_TRAVERSAL_KEYS

The identifier for the Backward focus traversal keys.

See Also:

setDefaultFocusTraversalKeys(int, java.util.Set), getDefaultFocusTraversalKeys(int), Component.setFocusTraversalKeys(int, java.util.Set), Component.getFocusTraversalKeys(int), Constant Field Values

UP_CYCLE_TRAVERSAL_KEYS

public static final int UP_CYCLE_TRAVERSAL_KEYS

The identifier for the Up Cycle focus traversal keys.

See Also:

setDefaultFocusTraversalKeys(int, java.util.Set), getDefaultFocusTraversalKeys(int), Component.setFocusTraversalKeys(int, java.util.Set), Component.getFocusTraversalKeys(int), Constant Field Values

DOWN_CYCLE_TRAVERSAL_KEYS

public static final int DOWN_CYCLE_TRAVERSAL_KEYS

The identifier for the Down Cycle focus traversal keys.

See Also:

setDefaultFocusTraversalKeys(int, java.util.Set), getDefaultFocusTraversalKeys(int), Component.setFocusTraversalKeys(int, java.util.Set), Component.getFocusTraversalKeys(int), Constant Field Values

Method Detail

getCurrentKeyboardFocusManager

public static KeyboardFocusManager getCurrentKeyboardFocusManager()

Returns the current KeyboardFocusManager instance for the calling thread's context.

Returns:

this thread's context's KeyboardFocusManager

getFocusOwner

public Component getFocusOwner()

Returns the focus owner, if the focus owner is in the same context as the calling thread. The focus owner is defined as the Component in an application that will typically receive all KeyEvents generated by the user. KeyEvents which map to the focus owner's focus traversal keys will not be delivered if focus traversal keys are enabled for the focus owner. In addition, KeyEventDispatchers may retarget or consume KeyEvents before they reach the focus owner.

Returns:

the focus owner, or null if the focus owner is not a member of the calling thread's context

clearGlobalFocusOwner

public void clearGlobalFocusOwner()

Clears the global focus owner at both the Java and native levels. If there exists a focus owner, that Component will receive a permanent FOCUS_LOST event. After this operation completes, the native windowing system will discard all user-generated KeyEvents until the user selects a new Component to receive focus, or a Component is given focus explicitly via a call to requestFocus(). This operation does not change the focused or active Windows.

See Also:

Component.requestFocus(), FocusEvent.FOCUS_LOST

getPermanentFocusOwner

public Component getPermanentFocusOwner()

Returns the permanent focus owner, if the permanent focus owner is in the same context as the calling thread. The permanent focus owner is defined as the last Component in an application to receive a permanent FOCUS_GAINED event. The focus owner and permanent focus owner are equivalent unless a temporary focus change is currently in effect. In such a situation, the permanent focus owner will again be the focus owner when the temporary focus change ends.

Returns:

the permanent focus owner, or null if the permanent focus owner is not a member of the calling thread's context

getFocusedWindow

public Window getFocusedWindow()

Returns the focused Window, if the focused Window is in the same context as the calling thread. The focused Window is the Window that is or contains the focus owner.

Returns:

the focused Window, or null if the focused Window is not a member of the calling thread's context

getActiveWindow

public Window getActiveWindow()

Returns the active Window, if the active Window is in the same context as the calling thread. Only a Frame can be the active Window. The native windowing system may denote the active Window or its children with special decorations, such as a highlighted title bar. The active Window is always either the focused Window, or the first Frame that is an owner of the focused Window.

Returns:

the active Window, or null if the active Window is not a member of the calling thread's context

getDefaultFocusTraversalPolicy

public FocusTraversalPolicy getDefaultFocusTraversalPolicy()

Returns the default FocusTraversalPolicy. Top-level components use this value on their creation to initialize their own focus traversal policy by explicit call to Container.setFocusTraversalPolicy.

Returns:

the default FocusTraversalPolicy. null will never be returned.

See Also:

setDefaultFocusTraversalPolicy(java.awt.FocusTraversalPolicy), Container.setFocusTraversalPolicy(java.awt.FocusTraversalPolicy), Container.getFocusTraversalPolicy()

setDefaultFocusTraversalPolicy

public void setDefaultFocusTraversalPolicy(FocusTraversalPolicy defaultPolicy)

Sets the default FocusTraversalPolicy. Top-level components use this value on their creation to initialize their own focus traversal policy by explicit call to Container.setFocusTraversalPolicy. Note: this call doesn't affect already created components as they have their policy initialized. Only new components will use this policy as their default policy.

Parameters:

defaultPolicy - the new, default FocusTraversalPolicy

Throws:

IllegalArgumentException - if defaultPolicy is null

See Also:

getDefaultFocusTraversalPolicy(), Container.setFocusTraversalPolicy(java.awt.FocusTraversalPolicy), Container.getFocusTraversalPolicy()

setDefaultFocusTraversalKeys

public void setDefaultFocusTraversalKeys(int id,
                                Set keystrokes)

Sets the default focus traversal keys for a given traversal operation. This traversal key Set will be in effect on all Windows that have no such Set of their own explicitly defined. This Set will also be inherited, recursively, by any child Component of those Windows that has no such Set of its own explicitly defined.

The default values for the default focus traversal keys are implementation-dependent. Sun recommends that all implementations for a particular native platform use the same default values. The recommendations for Windows and Unix are listed below. These recommendations are used in the Sun AWT implementations.

Identifier	Meaning	Default
KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS	Normal forward keyboard traversal	TAB on KEY_PRESSED, CTRL-TAB on KEY_PRESSED
KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS	Normal reverse keyboard traversal	SHIFT-TAB on KEY_PRESSED, CTRL-SHIFT-TAB on KEY_PRESSED
KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS	Go up one focus traversal cycle	none
KeyboardFocusManager.DOWN_CYCLE_TRAVERSAL_KEYS	Go down one focus traversal cycle	none

To disable a traversal key, use an empty Set; Collections.EMPTY_SET is recommended.

Using the AWTKeyStroke API, client code can specify on which of two specific KeyEvents, KEY_PRESSED or KEY_RELEASED, the focus traversal operation will occur. Regardless of which KeyEvent is specified, however, all KeyEvents related to the focus traversal key, including the associated KEY_TYPED event, will be consumed, and will not be dispatched to any Component. It is a runtime error to specify a KEY_TYPED event as mapping to a focus traversal operation, or to map the same event to multiple default focus traversal operations.

Parameters:

id - one of KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS, KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS, or KeyboardFocusManager.DOWN_CYCLE_TRAVERSAL_KEYS

keystrokes - the Set of AWTKeyStrokes for the specified operation

Throws:

IllegalArgumentException - if id is not one of KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS, KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS, or KeyboardFocusManager.DOWN_CYCLE_TRAVERSAL_KEYS, or if keystrokes is null, or if keystrokes contains null, or if any Object in keystrokes is not an AWTKeyStroke, or if any keystroke represents a KEY_TYPED event, or if any keystroke already maps to another default focus traversal operation

See Also:

getDefaultFocusTraversalKeys(int), Component.setFocusTraversalKeys(int, java.util.Set), Component.getFocusTraversalKeys(int)

getDefaultFocusTraversalKeys

public Set getDefaultFocusTraversalKeys(int id)

Returns a Set of default focus traversal keys for a given traversal operation. This traversal key Set will be in effect on all Windows that have no such Set of their own explicitly defined. This Set will also be inherited, recursively, by any child Component of those Windows that has no such Set of its own explicitly defined. (See setDefaultFocusTraversalKeys for a full description of each operation.)

Parameters:

id - one of KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS, KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS, or KeyboardFocusManager.DOWN_CYCLE_TRAVERSAL_KEYS

Returns:

the Set of AWTKeyStrokes for the specified operation; the Set will be unmodifiable, and may be empty; null will never be returned

Throws:

IllegalArgumentException - if id is not one of KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS, KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS, or KeyboardFocusManager.DOWN_CYCLE_TRAVERSAL_KEYS

See Also:

setDefaultFocusTraversalKeys(int, java.util.Set), Component.setFocusTraversalKeys(int, java.util.Set), Component.getFocusTraversalKeys(int)

getCurrentFocusCycleRoot

public Container getCurrentFocusCycleRoot()

Returns the current focus cycle root, if the current focus cycle root is in the same context as the calling thread. If the focus owner is itself a focus cycle root, then it may be ambiguous as to which Components represent the next and previous Components to focus during normal focus traversal. In that case, the current focus cycle root is used to differentiate among the possibilities.

Returns:

the current focus cycle root, or null if the current focus cycle root is not a member of the calling thread's context

addPropertyChangeListener

public void addPropertyChangeListener(PropertyChangeListener listener)

Adds a PropertyChangeListener to the listener list. The listener is registered for all bound properties of this class, including the following:

• the focus owner ("focusOwner")
• the permanent focus owner ("permanentFocusOwner")
• the focused Window ("focusedWindow")
• the active Window ("activeWindow")
• the default focus traversal policy ("defaultFocusTraversalPolicy")
• the Set of default FORWARD_TRAVERSAL_KEYS ("forwardDefaultFocusTraversalKeys")
• the Set of default BACKWARD_TRAVERSAL_KEYS ("backwardDefaultFocusTraversalKeys")
• the Set of default UP_CYCLE_TRAVERSAL_KEYS ("upCycleDefaultFocusTraversalKeys")
• the Set of default DOWN_CYCLE_TRAVERSAL_KEYS ("downCycleDefaultFocusTraversalKeys")
• the current focus cycle root ("currentFocusCycleRoot")

If listener is null, no exception is thrown and no action is performed.

Parameters:

listener - the PropertyChangeListener to be added

See Also:

removePropertyChangeListener(java.beans.PropertyChangeListener), getPropertyChangeListeners()

removePropertyChangeListener

public void removePropertyChangeListener(PropertyChangeListener listener)

Removes a PropertyChangeListener from the listener list. This method should be used to remove the PropertyChangeListeners that were registered for all bound properties of this class.

If listener is null, no exception is thrown and no action is performed.

Parameters:

listener - the PropertyChangeListener to be removed

See Also:

addPropertyChangeListener(java.beans.PropertyChangeListener), getPropertyChangeListeners()

getPropertyChangeListeners

public PropertyChangeListener[] getPropertyChangeListeners()

Returns an array of all the property change listeners registered on this keyboard focus manager.

Returns:

all of this keyboard focus manager's PropertyChangeListeners or an empty array if no property change listeners are currently registered

Since:

1.4

See Also:

addPropertyChangeListener(java.beans.PropertyChangeListener), removePropertyChangeListener(java.beans.PropertyChangeListener)

addVetoableChangeListener

public void addVetoableChangeListener(VetoableChangeListener listener)

Adds a VetoableChangeListener to the listener list. The listener is registered for all vetoable properties of this class, including the following:

• the focus owner ("focusOwner")
• the permanent focus owner ("permanentFocusOwner")
• the focused Window ("focusedWindow")
• the active Window ("activeWindow")

If listener is null, no exception is thrown and no action is performed.

Parameters:

listener - the VetoableChangeListener to be added

See Also:

removeVetoableChangeListener(java.beans.VetoableChangeListener), getVetoableChangeListeners()

removeVetoableChangeListener

public void removeVetoableChangeListener(VetoableChangeListener listener)

Removes a VetoableChangeListener from the listener list. This method should be used to remove the VetoableChangeListeners that were registered for all vetoable properties of this class.

If listener is null, no exception is thrown and no action is performed.

Parameters:

listener - the VetoableChangeListener to be removed

See Also:

addVetoableChangeListener(java.beans.VetoableChangeListener), getVetoableChangeListeners()

getVetoableChangeListeners

public VetoableChangeListener[] getVetoableChangeListeners()

Returns an array of all the vetoable change listeners registered on this keyboard focus manager.

Returns:

all of this keyboard focus manager's VetoableChangeListeners or an empty array if no vetoable change listeners are currently registered

Since:

1.4

See Also:

addVetoableChangeListener(java.beans.VetoableChangeListener), removeVetoableChangeListener(java.beans.VetoableChangeListener)

addKeyEventDispatcher

public void addKeyEventDispatcher(KeyEventDispatcher dispatcher)

Adds a KeyEventDispatcher to this KeyboardFocusManager's dispatcher chain. This KeyboardFocusManager will request that each KeyEventDispatcher dispatch KeyEvents generated by the user before finally dispatching the KeyEvent itself. KeyEventDispatchers will be notified in the order in which they were added. Notifications will halt as soon as one KeyEventDispatcher returns true from its dispatchKeyEvent method. There is no limit to the total number of KeyEventDispatchers which can be added, nor to the number of times which a particular KeyEventDispatcher instance can be added.

If a null dispatcher is specified, no action is taken and no exception is thrown.

Parameters:

dispatcher - the KeyEventDispatcher to add to the dispatcher chain

See Also:

removeKeyEventDispatcher(java.awt.KeyEventDispatcher)

removeKeyEventDispatcher

public void removeKeyEventDispatcher(KeyEventDispatcher dispatcher)

Removes a KeyEventDispatcher which was previously added to this KeyboardFocusManager's dispatcher chain. This KeyboardFocusManager cannot itself be removed, unless it was explicitly re-registered via a call to addKeyEventDispatcher.

If a null dispatcher is specified, if the specified dispatcher is not in the dispatcher chain, or if this KeyboardFocusManager is specified without having been explicitly re-registered, no action is taken and no exception is thrown.

Parameters:

dispatcher - the KeyEventDispatcher to remove from the dispatcher chain

See Also:

addKeyEventDispatcher(java.awt.KeyEventDispatcher)

addKeyEventPostProcessor

public void addKeyEventPostProcessor(KeyEventPostProcessor processor)

Adds a KeyEventPostProcessor to this KeyboardFocusManager's post- processor chain. After a KeyEvent has been dispatched to and handled by its target, KeyboardFocusManager will request that each KeyEventPostProcessor perform any necessary post-processing as part of the KeyEvent's final resolution. KeyEventPostProcessors will be notified in the order in which they were added; the current KeyboardFocusManager will be notified last. Notifications will halt as soon as one KeyEventPostProcessor returns true from its postProcessKeyEvent method. There is no limit to the the total number of KeyEventPostProcessors that can be added, nor to the number of times that a particular KeyEventPostProcessor instance can be added.

If a null post-processor is specified, no action is taken and no exception is thrown.

Parameters:

processor - the KeyEventPostProcessor to add to the post-processor chain

See Also:

removeKeyEventPostProcessor(java.awt.KeyEventPostProcessor)

removeKeyEventPostProcessor

public void removeKeyEventPostProcessor(KeyEventPostProcessor processor)

Removes a previously added KeyEventPostProcessor from this KeyboardFocusManager's post-processor chain. This KeyboardFocusManager cannot itself be entirely removed from the chain. Only additional references added via addKeyEventPostProcessor can be removed.

If a null post-processor is specified, if the specified post-processor is not in the post-processor chain, or if this KeyboardFocusManager is specified without having been explicitly added, no action is taken and no exception is thrown.

Parameters:

processor - the KeyEventPostProcessor to remove from the post- processor chain

See Also:

addKeyEventPostProcessor(java.awt.KeyEventPostProcessor)

dispatchEvent

public abstract boolean dispatchEvent(AWTEvent e)

This method is called by the AWT event dispatcher requesting that the current KeyboardFocusManager dispatch the specified event on its behalf. It is expected that all KeyboardFocusManagers will dispatch all FocusEvents, all WindowEvents related to focus, and all KeyEvents. These events should be dispatched based on the KeyboardFocusManager's notion of the focus owner and the focused and active Windows, sometimes overriding the source of the specified AWTEvent. Dispatching must be done using redispatchEvent to prevent the AWT event dispatcher from recursively requesting that the KeyboardFocusManager dispatch the event again. If this method returns false, then the AWT event dispatcher will attempt to dispatch the event itself.

Parameters:

e - the AWTEvent to be dispatched

Returns:

true if this method dispatched the event; false otherwise

See Also:

redispatchEvent(java.awt.Component, java.awt.AWTEvent), dispatchKeyEvent(java.awt.event.KeyEvent)

redispatchEvent

public final void redispatchEvent(Component target,
                   AWTEvent e)

Redispatches an AWTEvent in such a way that the AWT event dispatcher will not recursively request that the KeyboardFocusManager, or any installed KeyEventDispatchers, dispatch the event again. Client implementations of dispatchEvent and client-defined KeyEventDispatchers must call redispatchEvent(target, e) instead of target.dispatchEvent(e) to dispatch an event.

This method is intended to be used only by KeyboardFocusManagers and KeyEventDispatchers. It is not for general client use.

Parameters:

target - the Component to which the event should be dispatched

e - the event to dispatch

See Also:

dispatchEvent(java.awt.AWTEvent), KeyEventDispatcher

dispatchKeyEvent

public abstract boolean dispatchKeyEvent(KeyEvent e)

Typically this method will be called by dispatchEvent if no other KeyEventDispatcher in the dispatcher chain dispatched the KeyEvent, or if no other KeyEventDispatchers are registered. If an implementation of this method returns false, dispatchEvent may try to dispatch the KeyEvent itself, or may simply return false. If true is returned, dispatchEvent should return true as well.

Specified by:

dispatchKeyEvent in interface KeyEventDispatcher

Parameters:

e - the KeyEvent which the current KeyboardFocusManager has requested that this KeyEventDispatcher dispatch

Returns:

true if the KeyEvent was dispatched; false otherwise

See Also:

dispatchEvent(java.awt.AWTEvent)

postProcessKeyEvent

public abstract boolean postProcessKeyEvent(KeyEvent e)

This method will be called by dispatchKeyEvent. By default, this method will handle any unconsumed KeyEvents by consuming the event .

Specified by:

postProcessKeyEvent in interface KeyEventPostProcessor

Parameters:

e - the KeyEvent to post-process

Returns:

true to indicate that no other KeyEventPostProcessor will be notified of the KeyEvent.

See Also:

dispatchKeyEvent(java.awt.event.KeyEvent)

processKeyEvent

public abstract void processKeyEvent(Component focusedComponent,
                   KeyEvent e)

This method initiates a focus traversal operation if and only if the KeyEvent represents a focus traversal key for the specified focusedComponent. It is expected that focusedComponent is the current focus owner, although this need not be the case. If it is not, focus traversal will nevertheless proceed as if focusedComponent were the current focus owner.

Parameters:

focusedComponent - the Component that will be the basis for a focus traversal operation if the specified event represents a focus traversal key for the Component

e - the event that may represent a focus traversal key

focusNextComponent

public abstract void focusNextComponent(Component aComponent)

Focuses the Component after aComponent, typically based on a FocusTraversalPolicy.

Parameters:

aComponent - the Component that is the basis for the focus traversal operation

See Also:

FocusTraversalPolicy

focusPreviousComponent

public abstract void focusPreviousComponent(Component aComponent)

Focuses the Component before aComponent, typically based on a FocusTraversalPolicy.

Parameters:

aComponent - the Component that is the basis for the focus traversal operation

See Also:

FocusTraversalPolicy

upFocusCycle

public abstract void upFocusCycle(Component aComponent)

Moves the focus up one focus traversal cycle. Typically, the focus owner is set to aComponent's focus cycle root, and the current focus cycle root is set to the new focus owner's focus cycle root. If, however, aComponent's focus cycle root is a Window, then typically the focus owner is set to the Window's default Component to focus, and the current focus cycle root is unchanged.

Parameters:

aComponent - the Component that is the basis for the focus traversal operation

downFocusCycle

public abstract void downFocusCycle(Container aContainer)

Moves the focus down one focus traversal cycle. Typically, if aContainer is a focus cycle root, then the focus owner is set to aContainer's default Component to focus, and the current focus cycle root is set to aContainer. If aContainer is not a focus cycle root, then no focus traversal operation occurs.

Parameters:

aContainer - the Container that is the basis for the focus traversal operation

focusNextComponent

public final void focusNextComponent()

Focuses the Component after the current focus owner.

focusPreviousComponent

public final void focusPreviousComponent()

Focuses the Component before the current focus owner.

upFocusCycle

public final void upFocusCycle()

Moves the focus up one focus traversal cycle from the current focus owner. Typically, the new focus owner is set to the current focus owner's focus cycle root, and the current focus cycle root is set to the new focus owner's focus cycle root. If, however, the current focus owner's focus cycle root is a Window, then typically the focus owner is set to the focus cycle root's default Component to focus, and the current focus cycle root is unchanged.

downFocusCycle

public final void downFocusCycle()

Moves the focus down one focus traversal cycle from the current focus owner, if and only if the current focus owner is a Container that is a focus cycle root. Typically, the focus owner is set to the current focus owner's default Component to focus, and the current focus cycle root is set to the current focus owner. If the current focus owner is not a Container that is a focus cycle root, then no focus traversal operation occurs.