public class AWTEventMulticaster extends Object implements ComponentListener, ContainerListener, FocusListener, KeyListener, MouseListener, MouseMotionListener, WindowListener, WindowFocusListener, WindowStateListener, ActionListener, ItemListener, AdjustmentListener, TextListener, InputMethodListener, HierarchyListener, HierarchyBoundsListener, MouseWheelListener
AWTEventMulticaster implements efficient and thread-safe multi-cast event dispatching for the AWT events defined in the java.awt.event package.
The following example illustrates how to use this class:
public myComponent extends Component {
ActionListener actionListener = null;
public synchronized void addActionListener(ActionListener l) {
actionListener = AWTEventMulticaster.add(actionListener, l);
}
public synchronized void removeActionListener(ActionListener l) {
actionListener = AWTEventMulticaster.remove(actionListener, l);
}
public void processEvent(AWTEvent e) {
// when event occurs which causes "action" semantic
ActionListener listener = actionListener;
if (listener != null) {
listener.actionPerformed(new ActionEvent());
}
}
} The important point to note is the first argument to the add and remove methods is the field maintaining the listeners. In addition you must assign the result of the add and remove methods to the field maintaining the listeners. AWTEventMulticaster is implemented as a pair of EventListeners that are set at construction time. AWTEventMulticaster is immutable. The add and remove methods do not alter AWTEventMulticaster in anyway. If necessary, a new AWTEventMulticaster is created. In this way it is safe to add and remove listeners during the process of an event dispatching. However, event listeners added during the process of an event dispatch operation are not notified of the event currently being dispatched.
All of the add methods allow null arguments. If the first argument is null, the second argument is returned. If the first argument is not null and the second argument is null, the first argument is returned. If both arguments are non-null, a new AWTEventMulticaster is created using the two arguments and returned.
For the remove methods that take two arguments, the following is returned:
null, if the first argument is null, or the arguments are equal, by way of ==. AWTEventMulticaster. remove(EventListener) on the first argument, supplying the second argument to the remove(EventListener) method. Swing makes use of EventListenerList for similar logic. Refer to it for details.
EventListenerListprotected final EventListener a
protected final EventListener b
protected AWTEventMulticaster(EventListener a,
EventListener b) Creates an event multicaster instance which chains listener-a with listener-b. Input parameters a and b should not be null, though implementations may vary in choosing whether or not to throw NullPointerException in that case.
a - listener-ab - listener-bprotected EventListener remove(EventListener oldl)
Removes a listener from this multicaster.
The returned multicaster contains all the listeners in this multicaster with the exception of all occurrences of oldl. If the resulting multicaster contains only one regular listener the regular listener may be returned. If the resulting multicaster is empty, then null may be returned instead.
No exception is thrown if oldl is null.
oldl - the listener to be removedpublic void componentResized(ComponentEvent e)
Handles the componentResized event by invoking the componentResized methods on listener-a and listener-b.
componentResized in interface ComponentListener
e - the component eventpublic void componentMoved(ComponentEvent e)
Handles the componentMoved event by invoking the componentMoved methods on listener-a and listener-b.
componentMoved in interface ComponentListener
e - the component eventpublic void componentShown(ComponentEvent e)
Handles the componentShown event by invoking the componentShown methods on listener-a and listener-b.
componentShown in interface ComponentListener
e - the component eventpublic void componentHidden(ComponentEvent e)
Handles the componentHidden event by invoking the componentHidden methods on listener-a and listener-b.
componentHidden in interface ComponentListener
e - the component eventpublic void componentAdded(ContainerEvent e)
Handles the componentAdded container event by invoking the componentAdded methods on listener-a and listener-b.
componentAdded in interface ContainerListener
e - the component eventpublic void componentRemoved(ContainerEvent e)
Handles the componentRemoved container event by invoking the componentRemoved methods on listener-a and listener-b.
componentRemoved in interface ContainerListener
e - the component eventpublic void focusGained(FocusEvent e)
Handles the focusGained event by invoking the focusGained methods on listener-a and listener-b.
focusGained in interface FocusListener
e - the focus eventpublic void focusLost(FocusEvent e)
Handles the focusLost event by invoking the focusLost methods on listener-a and listener-b.
focusLost in interface FocusListener
e - the focus eventpublic void keyTyped(KeyEvent e)
Handles the keyTyped event by invoking the keyTyped methods on listener-a and listener-b.
keyTyped in interface KeyListener
e - the key eventpublic void keyPressed(KeyEvent e)
Handles the keyPressed event by invoking the keyPressed methods on listener-a and listener-b.
keyPressed in interface KeyListener
e - the key eventpublic void keyReleased(KeyEvent e)
Handles the keyReleased event by invoking the keyReleased methods on listener-a and listener-b.
keyReleased in interface KeyListener
e - the key eventpublic void mouseClicked(MouseEvent e)
Handles the mouseClicked event by invoking the mouseClicked methods on listener-a and listener-b.
mouseClicked in interface MouseListener
e - the mouse eventpublic void mousePressed(MouseEvent e)
Handles the mousePressed event by invoking the mousePressed methods on listener-a and listener-b.
mousePressed in interface MouseListener
e - the mouse eventpublic void mouseReleased(MouseEvent e)
Handles the mouseReleased event by invoking the mouseReleased methods on listener-a and listener-b.
mouseReleased in interface MouseListener
e - the mouse eventpublic void mouseEntered(MouseEvent e)
Handles the mouseEntered event by invoking the mouseEntered methods on listener-a and listener-b.
mouseEntered in interface MouseListener
e - the mouse eventpublic void mouseExited(MouseEvent e)
Handles the mouseExited event by invoking the mouseExited methods on listener-a and listener-b.
mouseExited in interface MouseListener
e - the mouse eventpublic void mouseDragged(MouseEvent e)
Handles the mouseDragged event by invoking the mouseDragged methods on listener-a and listener-b.
mouseDragged in interface MouseMotionListener
e - the mouse eventpublic void mouseMoved(MouseEvent e)
Handles the mouseMoved event by invoking the mouseMoved methods on listener-a and listener-b.
mouseMoved in interface MouseMotionListener
e - the mouse eventpublic void windowOpened(WindowEvent e)
Handles the windowOpened event by invoking the windowOpened methods on listener-a and listener-b.
windowOpened in interface WindowListener
e - the window eventpublic void windowClosing(WindowEvent e)
Handles the windowClosing event by invoking the windowClosing methods on listener-a and listener-b.
windowClosing in interface WindowListener
e - the window eventpublic void windowClosed(WindowEvent e)
Handles the windowClosed event by invoking the windowClosed methods on listener-a and listener-b.
windowClosed in interface WindowListener
e - the window eventpublic void windowIconified(WindowEvent e)
Handles the windowIconified event by invoking the windowIconified methods on listener-a and listener-b.
windowIconified in interface WindowListener
e - the window eventFrame.setIconImage(java.awt.Image)public void windowDeiconified(WindowEvent e)
Handles the windowDeiconfied event by invoking the windowDeiconified methods on listener-a and listener-b.
windowDeiconified in interface WindowListener
e - the window eventpublic void windowActivated(WindowEvent e)
Handles the windowActivated event by invoking the windowActivated methods on listener-a and listener-b.
windowActivated in interface WindowListener
e - the window eventpublic void windowDeactivated(WindowEvent e)
Handles the windowDeactivated event by invoking the windowDeactivated methods on listener-a and listener-b.
windowDeactivated in interface WindowListener
e - the window eventpublic void windowStateChanged(WindowEvent e)
Handles the windowStateChanged event by invoking the windowStateChanged methods on listener-a and listener-b.
windowStateChanged in interface WindowStateListener
e - the window eventpublic void windowGainedFocus(WindowEvent e)
Handles the windowGainedFocus event by invoking the windowGainedFocus methods on listener-a and listener-b.
windowGainedFocus in interface WindowFocusListener
e - the window eventpublic void windowLostFocus(WindowEvent e)
Handles the windowLostFocus event by invoking the windowLostFocus methods on listener-a and listener-b.
windowLostFocus in interface WindowFocusListener
e - the window eventpublic void actionPerformed(ActionEvent e)
Handles the actionPerformed event by invoking the actionPerformed methods on listener-a and listener-b.
actionPerformed in interface ActionListener
e - the action eventpublic void itemStateChanged(ItemEvent e)
Handles the itemStateChanged event by invoking the itemStateChanged methods on listener-a and listener-b.
itemStateChanged in interface ItemListener
e - the item eventpublic void adjustmentValueChanged(AdjustmentEvent e)
Handles the adjustmentValueChanged event by invoking the adjustmentValueChanged methods on listener-a and listener-b.
adjustmentValueChanged in interface AdjustmentListener
e - the adjustment eventpublic void textValueChanged(TextEvent e)
Description copied from interface: TextListener
Invoked when the value of the text has changed. The code written for this method performs the operations that need to occur when text changes.
textValueChanged in interface TextListener
public void inputMethodTextChanged(InputMethodEvent e)
Handles the inputMethodTextChanged event by invoking the inputMethodTextChanged methods on listener-a and listener-b.
inputMethodTextChanged in interface InputMethodListener
e - the item eventpublic void caretPositionChanged(InputMethodEvent e)
Handles the caretPositionChanged event by invoking the caretPositionChanged methods on listener-a and listener-b.
caretPositionChanged in interface InputMethodListener
e - the item eventpublic void hierarchyChanged(HierarchyEvent e)
Handles the hierarchyChanged event by invoking the hierarchyChanged methods on listener-a and listener-b.
hierarchyChanged in interface HierarchyListener
e - the item eventHierarchyEvent.getChangeFlags()public void ancestorMoved(HierarchyEvent e)
Handles the ancestorMoved event by invoking the ancestorMoved methods on listener-a and listener-b.
ancestorMoved in interface HierarchyBoundsListener
e - the item eventpublic void ancestorResized(HierarchyEvent e)
Handles the ancestorResized event by invoking the ancestorResized methods on listener-a and listener-b.
ancestorResized in interface HierarchyBoundsListener
e - the item eventpublic void mouseWheelMoved(MouseWheelEvent e)
Handles the mouseWheelMoved event by invoking the mouseWheelMoved methods on listener-a and listener-b.
mouseWheelMoved in interface MouseWheelListener
e - the mouse eventMouseWheelEventpublic static ComponentListener add(ComponentListener a,
ComponentListener b) Adds component-listener-a with component-listener-b and returns the resulting multicast listener.
a - component-listener-ab - component-listener-bpublic static ContainerListener add(ContainerListener a,
ContainerListener b) Adds container-listener-a with container-listener-b and returns the resulting multicast listener.
a - container-listener-ab - container-listener-bpublic static FocusListener add(FocusListener a,
FocusListener b) Adds focus-listener-a with focus-listener-b and returns the resulting multicast listener.
a - focus-listener-ab - focus-listener-bpublic static KeyListener add(KeyListener a,
KeyListener b) Adds key-listener-a with key-listener-b and returns the resulting multicast listener.
a - key-listener-ab - key-listener-bpublic static MouseListener add(MouseListener a,
MouseListener b) Adds mouse-listener-a with mouse-listener-b and returns the resulting multicast listener.
a - mouse-listener-ab - mouse-listener-bpublic static MouseMotionListener add(MouseMotionListener a,
MouseMotionListener b) Adds mouse-motion-listener-a with mouse-motion-listener-b and returns the resulting multicast listener.
a - mouse-motion-listener-ab - mouse-motion-listener-bpublic static WindowListener add(WindowListener a,
WindowListener b) Adds window-listener-a with window-listener-b and returns the resulting multicast listener.
a - window-listener-ab - window-listener-bpublic static WindowStateListener add(WindowStateListener a,
WindowStateListener b) Adds window-state-listener-a with window-state-listener-b and returns the resulting multicast listener.
a - window-state-listener-ab - window-state-listener-bpublic static WindowFocusListener add(WindowFocusListener a,
WindowFocusListener b) Adds window-focus-listener-a with window-focus-listener-b and returns the resulting multicast listener.
a - window-focus-listener-ab - window-focus-listener-bpublic static ActionListener add(ActionListener a,
ActionListener b) Adds action-listener-a with action-listener-b and returns the resulting multicast listener.
a - action-listener-ab - action-listener-bpublic static ItemListener add(ItemListener a,
ItemListener b) Adds item-listener-a with item-listener-b and returns the resulting multicast listener.
a - item-listener-ab - item-listener-bpublic static AdjustmentListener add(AdjustmentListener a,
AdjustmentListener b) Adds adjustment-listener-a with adjustment-listener-b and returns the resulting multicast listener.
a - adjustment-listener-ab - adjustment-listener-bpublic static TextListener add(TextListener a,
TextListener b) public static InputMethodListener add(InputMethodListener a,
InputMethodListener b) Adds input-method-listener-a with input-method-listener-b and returns the resulting multicast listener.
a - input-method-listener-ab - input-method-listener-bpublic static HierarchyListener add(HierarchyListener a,
HierarchyListener b) Adds hierarchy-listener-a with hierarchy-listener-b and returns the resulting multicast listener.
a - hierarchy-listener-ab - hierarchy-listener-bpublic static HierarchyBoundsListener add(HierarchyBoundsListener a,
HierarchyBoundsListener b) Adds hierarchy-bounds-listener-a with hierarchy-bounds-listener-b and returns the resulting multicast listener.
a - hierarchy-bounds-listener-ab - hierarchy-bounds-listener-bpublic static MouseWheelListener add(MouseWheelListener a,
MouseWheelListener b) Adds mouse-wheel-listener-a with mouse-wheel-listener-b and returns the resulting multicast listener.
a - mouse-wheel-listener-ab - mouse-wheel-listener-bpublic static ComponentListener remove(ComponentListener l,
ComponentListener oldl) Removes the old component-listener from component-listener-l and returns the resulting multicast listener.
l - component-listener-loldl - the component-listener being removedpublic static ContainerListener remove(ContainerListener l,
ContainerListener oldl) Removes the old container-listener from container-listener-l and returns the resulting multicast listener.
l - container-listener-loldl - the container-listener being removedpublic static FocusListener remove(FocusListener l,
FocusListener oldl) Removes the old focus-listener from focus-listener-l and returns the resulting multicast listener.
l - focus-listener-loldl - the focus-listener being removedpublic static KeyListener remove(KeyListener l,
KeyListener oldl) Removes the old key-listener from key-listener-l and returns the resulting multicast listener.
l - key-listener-loldl - the key-listener being removedpublic static MouseListener remove(MouseListener l,
MouseListener oldl) Removes the old mouse-listener from mouse-listener-l and returns the resulting multicast listener.
l - mouse-listener-loldl - the mouse-listener being removedpublic static MouseMotionListener remove(MouseMotionListener l,
MouseMotionListener oldl) Removes the old mouse-motion-listener from mouse-motion-listener-l and returns the resulting multicast listener.
l - mouse-motion-listener-loldl - the mouse-motion-listener being removedpublic static WindowListener remove(WindowListener l,
WindowListener oldl) Removes the old window-listener from window-listener-l and returns the resulting multicast listener.
l - window-listener-loldl - the window-listener being removedpublic static WindowStateListener remove(WindowStateListener l,
WindowStateListener oldl) Removes the old window-state-listener from window-state-listener-l and returns the resulting multicast listener.
l - window-state-listener-loldl - the window-state-listener being removedpublic static WindowFocusListener remove(WindowFocusListener l,
WindowFocusListener oldl) Removes the old window-focus-listener from window-focus-listener-l and returns the resulting multicast listener.
l - window-focus-listener-loldl - the window-focus-listener being removedpublic static ActionListener remove(ActionListener l,
ActionListener oldl) Removes the old action-listener from action-listener-l and returns the resulting multicast listener.
l - action-listener-loldl - the action-listener being removedpublic static ItemListener remove(ItemListener l,
ItemListener oldl) Removes the old item-listener from item-listener-l and returns the resulting multicast listener.
l - item-listener-loldl - the item-listener being removedpublic static AdjustmentListener remove(AdjustmentListener l,
AdjustmentListener oldl) Removes the old adjustment-listener from adjustment-listener-l and returns the resulting multicast listener.
l - adjustment-listener-loldl - the adjustment-listener being removedpublic static TextListener remove(TextListener l,
TextListener oldl) public static InputMethodListener remove(InputMethodListener l,
InputMethodListener oldl) Removes the old input-method-listener from input-method-listener-l and returns the resulting multicast listener.
l - input-method-listener-loldl - the input-method-listener being removedpublic static HierarchyListener remove(HierarchyListener l,
HierarchyListener oldl) Removes the old hierarchy-listener from hierarchy-listener-l and returns the resulting multicast listener.
l - hierarchy-listener-loldl - the hierarchy-listener being removedpublic static HierarchyBoundsListener remove(HierarchyBoundsListener l,
HierarchyBoundsListener oldl) Removes the old hierarchy-bounds-listener from hierarchy-bounds-listener-l and returns the resulting multicast listener.
l - hierarchy-bounds-listener-loldl - the hierarchy-bounds-listener being removedpublic static MouseWheelListener remove(MouseWheelListener l,
MouseWheelListener oldl) Removes the old mouse-wheel-listener from mouse-wheel-listener-l and returns the resulting multicast listener.
l - mouse-wheel-listener-loldl - the mouse-wheel-listener being removedprotected static EventListener addInternal(EventListener a,
EventListener b) Returns the resulting multicast listener from adding listener-a and listener-b together. If listener-a is null, it returns listener-b; If listener-b is null, it returns listener-a If neither are null, then it creates and returns a new AWTEventMulticaster instance which chains a with b.
a - event listener-ab - event listener-bprotected static EventListener removeInternal(EventListener l,
EventListener oldl) Returns the resulting multicast listener after removing the old listener from listener-l. If listener-l equals the old listener OR listener-l is null, returns null. Else if listener-l is an instance of AWTEventMulticaster, then it removes the old listener from it. Else, returns listener l.
l - the listener being removed fromoldl - the listener being removedprotected void saveInternal(ObjectOutputStream s,
String k)
throws IOException IOExceptionprotected static void save(ObjectOutputStream s,
String k,
EventListener l)
throws IOException IOExceptionpublic static <T extends EventListener> T[] getListeners(EventListener l,
Class<T> listenerType) Returns an array of all the objects chained as FooListeners by the specified java.util.EventListener. FooListeners are chained by the AWTEventMulticaster using the addFooListener method. If a null listener is specified, this method returns an empty array. If the specified listener is not an instance of AWTEventMulticaster, this method returns an array which contains only the specified listener. If no such listeners are chained, this method returns an empty array.
l - the specified java.util.EventListener
listenerType - the type of listeners requested; this parameter should specify an interface that descends from java.util.EventListener
FooListeners by the specified multicast listener, or an empty array if no such listeners have been chained by the specified multicast listenerNullPointerException - if the specified listenertype parameter is null
ClassCastException - if listenerType doesn't specify a class or interface that implements java.util.EventListener
© 1993–2017, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.