AWTEventMulticaster

Name

Description

This class multicasts events to event listeners. Each multicaster has two listeners, cunningly named a and b. When an event source calls one of the listener methods of the multicaster, the multicaster calls the same listener method on both a and b. Multicasters are built into trees using the static add() and remove() methods. In this way a single event can be sent to many listeners.

Static methods make it easy to implement event multicasting in component subclasses. Each time an add<type>Listener() function is called in the component subclass, call the corresponding AWTEventMulticaster.add() method to chain together (or "tree up") listeners. Similarly, when a remove<type>Listener() function is called, AWTEventMulticaster.remove() can be called to remove a chained listener.

Class Definition

public class java.awt.AWTEventMulticaster extends java.lang.Object implements java.awt.event.ActionListener, java.awt.event.AdjustmentListener, java.awt.event.ComponentListener, java.awt.event.ContainerListener, java.awt.event.FocusListener, java.awt.event.ItemListener, java.awt.event.KeyListener, java.awt.event.MouseListener, java.awt.event.MouseMotionListener, java.awt.event.TextListener, java.awt.event.WindowListener {
 // Variables protected EventListener a; protected EventListener b; // Constructors protected AWTEventMulticaster(EventListener a, EventListener b); // Class Methods public static ActionListener add(ActionListener a, ActionListener b);
public static AdjustmentListener add(AdjustmentListener a, AdjustmentListener b);
public static ComponentListener add(ComponentListener a, ComponentListener b);
public static ContainerListener add(ContainerListener a, ContainerListener b);
public static FocusListener add(FocusListener a, FocusListener b);
public static ItemListener add(ItemListener a, ItemListener b);
public static KeyListener add(KeyListener a, KeyListener b);
public static MouseListener add(MouseListener a, MouseListener b);
public static MouseMotionListener add(MouseMotionListener a, MouseMotionListener b);
public static TextListener add(TextListener a, TextListener b);
public static WindowListener add(WindowListener a, WindowListener b); protected static EventListener addInternal(EventListener a, EventListener b);
public static ActionListener remove(ActionListener l, ActionListener oldl);
public static AdjustmentListener remove(AdjustmentListener l, AdjustmentListener oldl);
public static ComponentListener remove(ComponentListener l, ComponentListener oldl);
public static ContainerListener remove(ContainerListener l, ContainerListener oldl);
public static FocusListener remove(FocusListener l, FocusListener oldl);
public static ItemListener remove(ItemListener l, ItemListener oldl);
public static KeyListener remove(KeyListener l, KeyListener oldl);
public static MouseListener remove(MouseListener l, MouseListener oldl);
public static MouseMotionListener remove(MouseMotionListener l, MouseMotionListener oldl);
public static TextListener remove(TextListener l, TextListener oldl);
public static WindowListener remove(WindowListener l, WindowListener; protected static EventListener removeInternal(EventListener l, EventListener oldl); // Instance Methods public void actionPerformed(ActionEvent e);
public void adjustmentValueChanged(AdjustmentEvent e);
public void componentAdded(ContainerEvent e);
public void componentHidden(ComponentEvent e);
public void componentMoved(ComponentEvent e);
public void componentRemoved(ContainerEvent e);
public void componentResized(ComponentEvent e);
public void componentShown(ComponentEvent e);
public void focusGained(FocusEvent e);
public void focusLost(FocusEvent e);
public void itemStateChanged(ItemEvent e);
public void keyPressed(KeyEvent e);
public void keyReleased(KeyEvent e);
public void keyTyped(KeyEvent e);
public void mouseClicked(MouseEvent e);
public void mouseDragged(MouseEvent e);
public void mouseEntered(MouseEvent e);
public void mouseExited(MouseEvent e);
public void mouseMoved(MouseEvent e);
public void mousePressed(MouseEvent e);
public void mouseReleased(MouseEvent e);
public void textValueChanged(TextEvent e);
public void windowActivated(WindowEvent e);
public void windowClosed(WindowEvent e);
public void windowClosing(WindowEvent e);
public void windowDeactivated(WindowEvent e);
public void windowDeiconified(WindowEvent e);
public void windowIconified(WindowEvent e);
public void windowOpened(WindowEvent e); // Protected Instance Methods protected EventListener remove(EventListener oldl); protected void saveInternal(ObjectOutputStream s, String k) throws IOException;
}

Variables

a

protected EventListener a

One of the EventListeners this AWTEventMulticaster sends events to.

b

protected EventListener b

One of the EventListeners this AWTEventMulticaster sends events to.

Constructors

AWTEventMulticaster

protected AWTEventMulticaster (EventListener a, EventListener b)

• Parameters
• • a
  • A listener that receives events.
  • b
  • A listener that receives events.
• Description
• Constructs an AWTEventMulticaster that sends events it receives to the supplied listeners. The constructor is protected because it is only the class methods of AWTEventMulticaster that ever instantiate this class.

Class Methods

add

public static ActionListener add (ActionListener a, ActionListener b)

• Parameters
• • a
  • An event listener.
  • b
  • An event listener.
• Returns
• A listener object that passes events to a and b.

public static AdjustmentListener add (AdjustmentListener a, AdjustmentListener b)

• Parameters
• • a
  • An event listener.
  • b
  • An event listener.
• Returns
• A listener object that passes events to a and b.

public static ComponentListener add (ComponentListener a, ComponentListener b)

• Parameters
• • a
  • An event listener.
  • b
  • An event listener.
• Returns
• A listener object that passes events to a and b.

public static ContainerListener add (ContainerListener a, ContainerListener b)

• Parameters
• • a
  • An event listener.
  • b
  • An event listener.
• Returns
• A listener object that passes events to a and b.

public static FocusListener add (FocusListener a, FocusListener b)

• Parameters
• • a
  • An event listener.
  • b
  • An event listener.
• Returns
• A listener object that passes events to a and b.

public static ItemListener add (ItemListener a, ItemListener b)

• Parameters
• • a
  • An event listener.
  • b
  • An event listener.
• Returns
• A listener object that passes events to a and b.

public static KeyListener add (KeyListener a, KeyListener b)

• Parameters
• • a
  • An event listener.
  • b
  • An event listener.
• Returns
• A listener object that passes events to a and b.

public static MouseListener add (MouseListener a, MouseListener b)

• Parameters
• • a
  • An event listener.
  • b
  • An event listener.
• Returns
• A listener object that passes events to a and b.

public static MouseMotionListener add (MouseMotionListener a, MouseMotionListener b)

• Parameters
• • a
  • An event listener.
  • b
  • An event listener.
• Returns
• A listener object that passes events to a and b.

public static TextListener add (TextListener a, TextListener b)

• Parameters
• • a
  • An event listener.
  • b
  • An event listener.
• Returns
• A listener object that passes events to a and b.

public static WindowListener add (WindowListener a, WindowListener b)

• Parameters
• • a
  • An event listener.
  • b
  • An event listener.
• Returns
• A listener object that passes events to a and b.

addInternal

public static EventListener addInternal (EventListener a, EventListener b)

• Parameters
• • a
  • An event listener.
  • b
  • An event listener.
• Returns
• A listener object that passes events to a and b.
• Description
• This method is a helper for the add() methods.

remove

public static ActionListener remove (ActionListener l, ActionListener oldl)

• Parameters
• • l
  • An event listener.
  • oldl
  • An event listener.
• Returns
• A listener object that multicasts to l but not oldl.

public static AdjustmentListener remove (AdjustmentListener l, AdjustmentListener oldl)

• Parameters
• • l
  • An event listener.
  • oldl
  • An event listener.
• Returns
• A listener object that multicasts to l but not oldl.

public static ComponentListener remove (ComponentListener l, ComponentListener oldl)

• Parameters
• • l
  • An event listener.
  • oldl
  • An event listener.
• Returns
• A listener object that multicasts to l but not oldl.

public static ContainerListener remove (ContainerListener l, ContainerListener oldl)

• Parameters
• • l
  • An event listener.
  • oldl
  • An event listener.
• Returns
• A listener object that multicasts to l but not oldl.

public static FocusListener remove (FocusListener l, FocusListener oldl)

• Parameters
• • l
  • An event listener.
  • oldl
  • An event listener.
• Returns
• A listener object that multicasts to l but not oldl.

public static ItemListener remove (ItemListener l, ItemListener oldl)

• Parameters
• • l
  • An event listener.
  • oldl
  • An event listener.
• Returns
• A listener object that multicasts to l but not oldl.

public static KeyListener remove (KeyListener l, KeyListener oldl)

• Parameters
• • l
  • An event listener.
  • oldl
  • An event listener.
• Returns
• A listener object that multicasts to l but not oldl.

public static MouseListener remove (MouseListener l, MouseListener oldl)

• Parameters
• • l
  • An event listener.
  • oldl
  • An event listener.
• Returns
• A listener object that multicasts to l but not oldl.

public static MouseMotionListener remove (MouseMotionListener l, MouseMotionListener oldl)

• Parameters
• • l
  • An event listener.
  • oldl
  • An event listener.
• Returns
• A listener object that multicasts to l but not oldl.

public static TextListener remove (TextListener l, TextListener oldl)

• Parameters
• • l
  • An event listener.
  • oldl
  • An event listener.
• Returns
• A listener object that multicasts to l but not oldl.

public static WindowListener remove (WindowListener l, WindowListener oldl)

• Parameters
• • l
  • An event listener.
  • oldl
  • An event listener.
• Returns
• A listener object that multicasts to l but not oldl.

public static WindowListener remove (WindowListener l, WindowListener oldl)

• Parameters
• • l
  • An event listener.
  • oldl
  • An event listener.
• Returns
• A listener object that multicasts to l but not oldl.

removeInternal

public static EventListener removeInternal (EventListener l, EventListener oldl)

• Parameters
• • l
  • An event listener.
  • oldl
  • An event listener.
• Returns
• A listener object that multicasts to l but not oldl.
• Description
• This method is a helper for the remove() methods.

Instance Methods

actionPerformed

public void actionPerformed (ActionEvent e)

• Parameters
• • e
  • The action event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

adjustmentValueChanged

public void adjustmentValueChanged (AdjustmentEvent e)

• Parameters
• • e
  • The adjustment event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

componentAdded

public void componentAdded (ContainerEvent e)

• Parameters
• • e
  • The container event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

componentHidden

public void componentHidden (ComponentEvent e)

• Parameters
• • e
  • The component event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

componentMoved

public void componentMoved (ComponentEvent e)

• Parameters
• • e
  • The component event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

componentRemoved

public void componentRemoved (ContainerEvent e)

• Parameters
• • e
  • The container event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

componentResized

public void componentResized (ComponentEvent e)

• Parameters
• • e
  • The component event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

componentShown

public void componentShown (ComponentEvent e)

• Parameters
• • e
  • The component event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

focusGained

public void focusGained (FocusEvent e)

• Parameters
• • e
  • The focus event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

focusLost

public void focusLost (FocusEvent e)

• Parameters
• • e
  • The focus event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

itemStateChanged

public void itemStateChanged (ItemEvent e)

• Parameters
• • e
  • The item event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

keyPressed

public void keyPressed (KeyEvent e)

• Parameters
• • e
  • The key event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

keyReleased

public void keyReleased (KeyEvent e)

• Parameters
• • e
  • The key event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

keyTyped

public void keyTyped (KeyEvent e)

• Parameters
• • e
  • The key event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

mouseClicked

public void mouseClicked (MouseEvent e)

• Parameters
• • e
  • The mouse event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

mouseDragged

public void mouseDragged (MouseEvent e)

• Parameters
• • e
  • The mouse event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

mouseEntered

public void mouseEntered (MouseEvent e)

• Parameters
• • e
  • The mouse event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

mouseExited

public void mouseExited (MouseEvent e)

• Parameters
• • e
  • The mouse event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

mouseMoved

public void mouseMoved (MouseEvent e)

• Parameters
• • e
  • The mouse event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

mousePressed

public void mousePressed (MouseEvent e)

• Parameters
• • e
  • The mouse event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

mouseReleased

public void mouseReleased (MouseEvent e)

• Parameters
• • e
  • The mouse event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

textValueChanged

public void textValueChanged (TextEvent e)

• Parameters
• • e
  • The text event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

windowActivated

public void windowActivated (WindowEvent e)

• Parameters
• • e
  • The window event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

windowClosed

public void windowClosed (WindowEvent e)

• Parameters
• • e
  • The window event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

windowClosing

public void windowClosing (WindowEvent e)

• Parameters
• • e
  • The window event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

windowDeactivated

public void windowDeactivated (WindowEvent e)

• Parameters
• • e
  • The window event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

windowDeiconified

public void windowDeiconified (WindowEvent e)

• Parameters
• • e
  • The window event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

windowIconified

public void windowIconified (WindowEvent e)

• Parameters
• • e
  • The window event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

windowOpened

public void windowOpened (WindowEvent e)

• Parameters
• • e
  • The window event that occurred.
• Description
• Handles the event by passing it on to listeners a and b.

Protected Instance Methods

remove

protected EventListener remove(EventListener oldl)

• Parameters
• • oldl
  • The listener to remove.
• Returns
• The resulting EventListener.
• Description
• This method removes oldl from the AWTEventMulticaster and returns the resulting listener.

See Also

ActionEvent, AdjustmentEvent, ComponentEvent, Event, EventListener, EventObject, FocusEvent, ItemEvent, KeyEvent, MouseEvent, WindowEvent