Class DefaultKeyboardFocusManager
java.lang.Object
java.awt.KeyboardFocusManager
java.awt.DefaultKeyboardFocusManager
- All Implemented Interfaces:
KeyEventDispatcher
,KeyEventPostProcessor
- Direct Known Subclasses:
FocusManager
The default KeyboardFocusManager for AWT applications. Focus traversal is
done in response to a Component's focus traversal keys, and using a
Container's FocusTraversalPolicy.
Please see How to Use the Focus Subsystem, a section in The Java Tutorial, and the Focus Specification for more information.
- Since:
- 1.4
- See Also:
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Field Summary
Fields declared in class java.awt.KeyboardFocusManager
BACKWARD_TRAVERSAL_KEYS, DOWN_CYCLE_TRAVERSAL_KEYS, FORWARD_TRAVERSAL_KEYS, UP_CYCLE_TRAVERSAL_KEYS
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionprotected void
dequeueKeyEvents
(long after, Component untilFocused) Releases for normal dispatching to the current focus owner all KeyEvents which were enqueued because of a call toenqueueKeyEvents
with the same timestamp and Component.protected void
discardKeyEvents
(Component comp) Discards all KeyEvents which were enqueued because of one or more calls toenqueueKeyEvents
with the specified Component, or one of its descendants.boolean
This method is called by the AWT event dispatcher requesting that the current KeyboardFocusManager dispatch the specified event on its behalf.boolean
Called bydispatchEvent
if no other KeyEventDispatcher in the dispatcher chain dispatched the KeyEvent, or if no other KeyEventDispatchers are registered.void
downFocusCycle
(Container aContainer) Moves the focus down one focus traversal cycle.protected void
enqueueKeyEvents
(long after, Component untilFocused) Delays dispatching of KeyEvents until the specified Component becomes the focus owner.void
focusNextComponent
(Component aComponent) Focuses the Component after aComponent, typically based on a FocusTraversalPolicy.void
focusPreviousComponent
(Component aComponent) Focuses the Component before aComponent, typically based on a FocusTraversalPolicy.boolean
This method will be called bydispatchKeyEvent
.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
upFocusCycle
(Component aComponent) Moves the focus up one focus traversal cycle.Methods declared in class java.awt.KeyboardFocusManager
addKeyEventDispatcher, addKeyEventPostProcessor, addPropertyChangeListener, addPropertyChangeListener, addVetoableChangeListener, addVetoableChangeListener, clearFocusOwner, clearGlobalFocusOwner, downFocusCycle, firePropertyChange, fireVetoableChange, focusNextComponent, focusPreviousComponent, getActiveWindow, getCurrentFocusCycleRoot, getCurrentKeyboardFocusManager, getDefaultFocusTraversalKeys, getDefaultFocusTraversalPolicy, getFocusedWindow, getFocusOwner, getGlobalActiveWindow, getGlobalCurrentFocusCycleRoot, getGlobalFocusedWindow, getGlobalFocusOwner, getGlobalPermanentFocusOwner, getKeyEventDispatchers, getKeyEventPostProcessors, getPermanentFocusOwner, getPropertyChangeListeners, getPropertyChangeListeners, getVetoableChangeListeners, getVetoableChangeListeners, redispatchEvent, removeKeyEventDispatcher, removeKeyEventPostProcessor, removePropertyChangeListener, removePropertyChangeListener, removeVetoableChangeListener, removeVetoableChangeListener, setCurrentKeyboardFocusManager, setDefaultFocusTraversalKeys, setDefaultFocusTraversalPolicy, setGlobalActiveWindow, setGlobalCurrentFocusCycleRoot, setGlobalFocusedWindow, setGlobalFocusOwner, setGlobalPermanentFocusOwner, upFocusCycle
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Constructor Details
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DefaultKeyboardFocusManager
public DefaultKeyboardFocusManager()Constructs aDefaultKeyboardFocusManager
.
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Method Details
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dispatchEvent
This method is called by the AWT event dispatcher requesting that the current KeyboardFocusManager dispatch the specified event on its behalf. DefaultKeyboardFocusManagers dispatch all FocusEvents, all WindowEvents related to focus, and all KeyEvents. These events are 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. If this method returnsfalse
, then the AWT event dispatcher will attempt to dispatch the event itself.- Specified by:
dispatchEvent
in classKeyboardFocusManager
- Parameters:
e
- the AWTEvent to be dispatched- Returns:
true
if this method dispatched the event;false
otherwise- See Also:
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dispatchKeyEvent
Called bydispatchEvent
if no other KeyEventDispatcher in the dispatcher chain dispatched the KeyEvent, or if no other KeyEventDispatchers are registered. If the event has not been consumed, its target is enabled, and the focus owner is not null, this method dispatches the event to its target. This method will also subsequently dispatch the event to all registered KeyEventPostProcessors. After all this operations are finished, the event is passed to peers for processing.In all cases, this method returns
true
, since DefaultKeyboardFocusManager is designed so that neitherdispatchEvent
, nor the AWT event dispatcher, should take further action on the event in any situation.- Specified by:
dispatchKeyEvent
in interfaceKeyEventDispatcher
- Specified by:
dispatchKeyEvent
in classKeyboardFocusManager
- Parameters:
e
- the KeyEvent to be dispatched- Returns:
true
- See Also:
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postProcessKeyEvent
This method will be called bydispatchKeyEvent
. It will handle any unconsumed KeyEvents that map to an AWTMenuShortcut
by consuming the event and activating the shortcut.- Specified by:
postProcessKeyEvent
in interfaceKeyEventPostProcessor
- Specified by:
postProcessKeyEvent
in classKeyboardFocusManager
- Parameters:
e
- the KeyEvent to post-process- Returns:
true
- See Also:
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processKeyEvent
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 focus owner.- Specified by:
processKeyEvent
in classKeyboardFocusManager
- Parameters:
focusedComponent
- the Component that is the basis for a focus traversal operation if the specified event represents a focus traversal key for the Componente
- the event that may represent a focus traversal key
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enqueueKeyEvents
Delays dispatching of KeyEvents until the specified Component becomes the focus owner. KeyEvents with timestamps later than the specified timestamp will be enqueued until the specified Component receives a FOCUS_GAINED event, or the AWT cancels the delay request by invokingdequeueKeyEvents
ordiscardKeyEvents
.- Specified by:
enqueueKeyEvents
in classKeyboardFocusManager
- Parameters:
after
- timestamp of current event, or the current, system time if the current event has no timestamp, or the AWT cannot determine which event is currently being handleduntilFocused
- Component which will receive a FOCUS_GAINED event before any pending KeyEvents- See Also:
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dequeueKeyEvents
Releases for normal dispatching to the current focus owner all KeyEvents which were enqueued because of a call toenqueueKeyEvents
with the same timestamp and Component. If the given timestamp is less than zero, the outstanding enqueue request for the given Component with the oldest timestamp (if any) should be cancelled.- Specified by:
dequeueKeyEvents
in classKeyboardFocusManager
- Parameters:
after
- the timestamp specified in the call toenqueueKeyEvents
, or any value < 0untilFocused
- the Component specified in the call toenqueueKeyEvents
- See Also:
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discardKeyEvents
Discards all KeyEvents which were enqueued because of one or more calls toenqueueKeyEvents
with the specified Component, or one of its descendants.- Specified by:
discardKeyEvents
in classKeyboardFocusManager
- Parameters:
comp
- the Component specified in one or more calls toenqueueKeyEvents
, or a parent of such a Component- See Also:
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focusPreviousComponent
Focuses the Component before aComponent, typically based on a FocusTraversalPolicy.- Specified by:
focusPreviousComponent
in classKeyboardFocusManager
- Parameters:
aComponent
- the Component that is the basis for the focus traversal operation- See Also:
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focusNextComponent
Focuses the Component after aComponent, typically based on a FocusTraversalPolicy.- Specified by:
focusNextComponent
in classKeyboardFocusManager
- Parameters:
aComponent
- the Component that is the basis for the focus traversal operation- See Also:
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upFocusCycle
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 the focus owner is set to the focus cycle root's default Component to focus, and the current focus cycle root is unchanged.- Specified by:
upFocusCycle
in classKeyboardFocusManager
- Parameters:
aComponent
- the Component that is the basis for the focus traversal operation- See Also:
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downFocusCycle
Moves the focus down one focus traversal cycle. 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.- Specified by:
downFocusCycle
in classKeyboardFocusManager
- Parameters:
aContainer
- the Container that is the basis for the focus traversal operation- See Also:
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