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.
EventListenerList
Modifier and Type | Field and Description |
---|---|
protected java.util.EventListener |
a
|
protected java.util.EventListener |
b
|
Modifier and Type | Static Method and Description |
---|---|
static ActionListener |
add(ActionListener a,
ActionListener b)
Adds action-listener-a with action-listener-b and
returns the resulting multicast listener.
|
static AdjustmentListener |
add(AdjustmentListener a,
AdjustmentListener b)
Adds adjustment-listener-a with adjustment-listener-b and
returns the resulting multicast listener.
|
static ComponentListener |
add(ComponentListener a,
ComponentListener b)
Adds component-listener-a with component-listener-b and
returns the resulting multicast listener.
|
static ContainerListener |
add(ContainerListener a,
ContainerListener b)
Adds container-listener-a with container-listener-b and
returns the resulting multicast listener.
|
static FocusListener |
add(FocusListener a,
FocusListener b)
Adds focus-listener-a with focus-listener-b and
returns the resulting multicast listener.
|
static HierarchyBoundsListener |
add(HierarchyBoundsListener a,
HierarchyBoundsListener b)
Adds hierarchy-bounds-listener-a with hierarchy-bounds-listener-b and
returns the resulting multicast listener.
|
static HierarchyListener |
add(HierarchyListener a,
HierarchyListener b)
Adds hierarchy-listener-a with hierarchy-listener-b and
returns the resulting multicast listener.
|
static InputMethodListener |
add(InputMethodListener a,
InputMethodListener b)
Adds input-method-listener-a with input-method-listener-b and
returns the resulting multicast listener.
|
static ItemListener |
add(ItemListener a,
ItemListener b)
Adds item-listener-a with item-listener-b and
returns the resulting multicast listener.
|
static KeyListener |
add(KeyListener a,
KeyListener b)
Adds key-listener-a with key-listener-b and
returns the resulting multicast listener.
|
static MouseListener |
add(MouseListener a,
MouseListener b)
Adds mouse-listener-a with mouse-listener-b and
returns the resulting multicast listener.
|
static MouseMotionListener |
add(MouseMotionListener a,
MouseMotionListener b)
Adds mouse-motion-listener-a with mouse-motion-listener-b and
returns the resulting multicast listener.
|
static MouseWheelListener |
add(MouseWheelListener a,
MouseWheelListener b)
Adds mouse-wheel-listener-a with mouse-wheel-listener-b and
returns the resulting multicast listener.
|
static TextListener |
add(TextListener a,
TextListener b)
|
static WindowFocusListener |
add(WindowFocusListener a,
WindowFocusListener b)
Adds window-focus-listener-a with window-focus-listener-b
and returns the resulting multicast listener.
|
static WindowListener |
add(WindowListener a,
WindowListener b)
Adds window-listener-a with window-listener-b and
returns the resulting multicast listener.
|
static WindowStateListener |
add(WindowStateListener a,
WindowStateListener b)
Adds window-state-listener-a with window-state-listener-b
and returns the resulting multicast listener.
|
protected static java.util.EventListener |
addInternal(java.util.EventListener a,
java.util.EventListener b)
Returns the resulting multicast listener from adding listener-a
and listener-b together.
|
static <T extends java.util.EventListener> |
getListeners(java.util.EventListener l,
java.lang.Class<T> listenerType)
Returns an array of all the objects chained as
FooListener s by the specified
java.util.EventListener . |
static ActionListener |
remove(ActionListener l,
ActionListener oldl)
Removes the old action-listener from action-listener-l and
returns the resulting multicast listener.
|
static AdjustmentListener |
remove(AdjustmentListener l,
AdjustmentListener oldl)
Removes the old adjustment-listener from adjustment-listener-l and
returns the resulting multicast listener.
|
static ComponentListener |
remove(ComponentListener l,
ComponentListener oldl)
Removes the old component-listener from component-listener-l and
returns the resulting multicast listener.
|
static ContainerListener |
remove(ContainerListener l,
ContainerListener oldl)
Removes the old container-listener from container-listener-l and
returns the resulting multicast listener.
|
static FocusListener |
remove(FocusListener l,
FocusListener oldl)
Removes the old focus-listener from focus-listener-l and
returns the resulting multicast listener.
|
static HierarchyBoundsListener |
remove(HierarchyBoundsListener l,
HierarchyBoundsListener oldl)
Removes the old hierarchy-bounds-listener from
hierarchy-bounds-listener-l and returns the resulting multicast
listener.
|
static HierarchyListener |
remove(HierarchyListener l,
HierarchyListener oldl)
Removes the old hierarchy-listener from hierarchy-listener-l and
returns the resulting multicast listener.
|
static InputMethodListener |
remove(InputMethodListener l,
InputMethodListener oldl)
Removes the old input-method-listener from input-method-listener-l and
returns the resulting multicast listener.
|
static ItemListener |
remove(ItemListener l,
ItemListener oldl)
Removes the old item-listener from item-listener-l and
returns the resulting multicast listener.
|
static KeyListener |
remove(KeyListener l,
KeyListener oldl)
Removes the old key-listener from key-listener-l and
returns the resulting multicast listener.
|
static MouseListener |
remove(MouseListener l,
MouseListener oldl)
Removes the old mouse-listener from mouse-listener-l and
returns the resulting multicast listener.
|
static MouseMotionListener |
remove(MouseMotionListener l,
MouseMotionListener oldl)
Removes the old mouse-motion-listener from mouse-motion-listener-l
and returns the resulting multicast listener.
|
static MouseWheelListener |
remove(MouseWheelListener l,
MouseWheelListener oldl)
Removes the old mouse-wheel-listener from mouse-wheel-listener-l
and returns the resulting multicast listener.
|
static TextListener |
remove(TextListener l,
TextListener oldl)
|
static WindowFocusListener |
remove(WindowFocusListener l,
WindowFocusListener oldl)
Removes the old window-focus-listener from window-focus-listener-l
and returns the resulting multicast listener.
|
static WindowListener |
remove(WindowListener l,
WindowListener oldl)
Removes the old window-listener from window-listener-l and
returns the resulting multicast listener.
|
static WindowStateListener |
remove(WindowStateListener l,
WindowStateListener oldl)
Removes the old window-state-listener from window-state-listener-l
and returns the resulting multicast listener.
|
protected static java.util.EventListener |
removeInternal(java.util.EventListener l,
java.util.EventListener oldl)
Returns the resulting multicast listener after removing the
old listener from listener-l.
|
protected static void |
save(java.io.ObjectOutputStream s,
java.lang.String k,
java.util.EventListener l)
|
Modifier | Constructor and Description |
---|---|
protected |
AWTEventMulticaster(java.util.EventListener a,
java.util.EventListener b)
Creates an event multicaster instance which chains listener-a
with listener-b.
|
Modifier and Type | Method and Description |
---|---|
void |
actionPerformed(ActionEvent e)
Handles the actionPerformed event by invoking the
actionPerformed methods on listener-a and listener-b.
|
void |
adjustmentValueChanged(AdjustmentEvent e)
Handles the adjustmentValueChanged event by invoking the
adjustmentValueChanged methods on listener-a and listener-b.
|
void |
ancestorMoved(HierarchyEvent e)
Handles the ancestorMoved event by invoking the
ancestorMoved methods on listener-a and listener-b.
|
void |
ancestorResized(HierarchyEvent e)
Handles the ancestorResized event by invoking the
ancestorResized methods on listener-a and listener-b.
|
void |
caretPositionChanged(InputMethodEvent e)
Handles the caretPositionChanged event by invoking the
caretPositionChanged methods on listener-a and listener-b.
|
void |
componentAdded(ContainerEvent e)
Handles the componentAdded container event by invoking the
componentAdded methods on listener-a and listener-b.
|
void |
componentHidden(ComponentEvent e)
Handles the componentHidden event by invoking the
componentHidden methods on listener-a and listener-b.
|
void |
componentMoved(ComponentEvent e)
Handles the componentMoved event by invoking the
componentMoved methods on listener-a and listener-b.
|
void |
componentRemoved(ContainerEvent e)
Handles the componentRemoved container event by invoking the
componentRemoved methods on listener-a and listener-b.
|
void |
componentResized(ComponentEvent e)
Handles the componentResized event by invoking the
componentResized methods on listener-a and listener-b.
|
void |
componentShown(ComponentEvent e)
Handles the componentShown event by invoking the
componentShown methods on listener-a and listener-b.
|
void |
focusGained(FocusEvent e)
Handles the focusGained event by invoking the
focusGained methods on listener-a and listener-b.
|
void |
focusLost(FocusEvent e)
Handles the focusLost event by invoking the
focusLost methods on listener-a and listener-b.
|
void |
hierarchyChanged(HierarchyEvent e)
Handles the hierarchyChanged event by invoking the
hierarchyChanged methods on listener-a and listener-b.
|
void |
inputMethodTextChanged(InputMethodEvent e)
Handles the inputMethodTextChanged event by invoking the
inputMethodTextChanged methods on listener-a and listener-b.
|
void |
itemStateChanged(ItemEvent e)
Handles the itemStateChanged event by invoking the
itemStateChanged methods on listener-a and listener-b.
|
void |
keyPressed(KeyEvent e)
Handles the keyPressed event by invoking the
keyPressed methods on listener-a and listener-b.
|
void |
keyReleased(KeyEvent e)
Handles the keyReleased event by invoking the
keyReleased methods on listener-a and listener-b.
|
void |
keyTyped(KeyEvent e)
Handles the keyTyped event by invoking the
keyTyped methods on listener-a and listener-b.
|
void |
mouseClicked(MouseEvent e)
Handles the mouseClicked event by invoking the
mouseClicked methods on listener-a and listener-b.
|
void |
mouseDragged(MouseEvent e)
Handles the mouseDragged event by invoking the
mouseDragged methods on listener-a and listener-b.
|
void |
mouseEntered(MouseEvent e)
Handles the mouseEntered event by invoking the
mouseEntered methods on listener-a and listener-b.
|
void |
mouseExited(MouseEvent e)
Handles the mouseExited event by invoking the
mouseExited methods on listener-a and listener-b.
|
void |
mouseMoved(MouseEvent e)
Handles the mouseMoved event by invoking the
mouseMoved methods on listener-a and listener-b.
|
void |
mousePressed(MouseEvent e)
Handles the mousePressed event by invoking the
mousePressed methods on listener-a and listener-b.
|
void |
mouseReleased(MouseEvent e)
Handles the mouseReleased event by invoking the
mouseReleased methods on listener-a and listener-b.
|
void |
mouseWheelMoved(MouseWheelEvent e)
Handles the mouseWheelMoved event by invoking the
mouseWheelMoved methods on listener-a and listener-b.
|
protected java.util.EventListener |
remove(java.util.EventListener oldl)
Removes a listener from this multicaster.
|
protected void |
saveInternal(java.io.ObjectOutputStream s,
java.lang.String k)
|
void |
textValueChanged(TextEvent e)
Invoked when the value of the text has changed.
|
void |
windowActivated(WindowEvent e)
Handles the windowActivated event by invoking the
windowActivated methods on listener-a and listener-b.
|
void |
windowClosed(WindowEvent e)
Handles the windowClosed event by invoking the
windowClosed methods on listener-a and listener-b.
|
void |
windowClosing(WindowEvent e)
Handles the windowClosing event by invoking the
windowClosing methods on listener-a and listener-b.
|
void |
windowDeactivated(WindowEvent e)
Handles the windowDeactivated event by invoking the
windowDeactivated methods on listener-a and listener-b.
|
void |
windowDeiconified(WindowEvent e)
Handles the windowDeiconfied event by invoking the
windowDeiconified methods on listener-a and listener-b.
|
void |
windowGainedFocus(WindowEvent e)
Handles the windowGainedFocus event by invoking the windowGainedFocus
methods on listener-a and listener-b.
|
void |
windowIconified(WindowEvent e)
Handles the windowIconified event by invoking the
windowIconified methods on listener-a and listener-b.
|
void |
windowLostFocus(WindowEvent e)
Handles the windowLostFocus event by invoking the windowLostFocus
methods on listener-a and listener-b.
|
void |
windowOpened(WindowEvent e)
Handles the windowOpened event by invoking the
windowOpened methods on listener-a and listener-b.
|
void |
windowStateChanged(WindowEvent e)
Handles the windowStateChanged event by invoking the
windowStateChanged methods on listener-a and listener-b.
|
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-b
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 removedcomponentResized
in interface ComponentListener
e
- the component eventcomponentMoved
in interface ComponentListener
e
- the component eventcomponentShown
in interface ComponentListener
e
- the component eventcomponentHidden
in interface ComponentListener
e
- the component eventcomponentAdded
in interface ContainerListener
e
- the component eventcomponentRemoved
in interface ContainerListener
e
- the component eventfocusGained
in interface FocusListener
e
- the focus eventfocusLost
in interface FocusListener
e
- the focus eventkeyTyped
in interface KeyListener
e
- the key eventkeyPressed
in interface KeyListener
e
- the key eventkeyReleased
in interface KeyListener
e
- the key eventmouseClicked
in interface MouseListener
e
- the mouse eventmousePressed
in interface MouseListener
e
- the mouse eventmouseReleased
in interface MouseListener
e
- the mouse eventmouseEntered
in interface MouseListener
e
- the mouse eventmouseExited
in interface MouseListener
e
- the mouse eventmouseDragged
in interface MouseMotionListener
e
- the mouse eventmouseMoved
in interface MouseMotionListener
e
- the mouse eventwindowOpened
in interface WindowListener
e
- the window eventwindowClosing
in interface WindowListener
e
- the window eventwindowClosed
in interface WindowListener
e
- the window eventwindowIconified
in interface WindowListener
e
- the window eventFrame.setIconImage(java.awt.Image)
windowDeiconified
in interface WindowListener
e
- the window eventwindowActivated
in interface WindowListener
e
- the window eventwindowDeactivated
in interface WindowListener
e
- the window eventwindowStateChanged
in interface WindowStateListener
e
- the window eventwindowGainedFocus
in interface WindowFocusListener
e
- the window eventwindowLostFocus
in interface WindowFocusListener
e
- the window eventactionPerformed
in interface ActionListener
e
- the action eventitemStateChanged
in interface ItemListener
e
- the item eventadjustmentValueChanged
in interface AdjustmentListener
e
- the adjustment eventTextListener
textValueChanged
in interface TextListener
inputMethodTextChanged
in interface InputMethodListener
e
- the item eventcaretPositionChanged
in interface InputMethodListener
e
- the item eventhierarchyChanged
in interface HierarchyListener
e
- the item eventHierarchyEvent.getChangeFlags()
ancestorMoved
in interface HierarchyBoundsListener
e
- the item eventancestorResized
in interface HierarchyBoundsListener
e
- the item eventmouseWheelMoved
in interface MouseWheelListener
e
- the mouse eventMouseWheelEvent
java.io.IOException
a
- component-listener-ab
- component-listener-ba
- container-listener-ab
- container-listener-ba
- focus-listener-ab
- focus-listener-ba
- key-listener-ab
- key-listener-ba
- mouse-listener-ab
- mouse-listener-ba
- mouse-motion-listener-ab
- mouse-motion-listener-ba
- window-listener-ab
- window-listener-ba
- window-state-listener-ab
- window-state-listener-ba
- window-focus-listener-ab
- window-focus-listener-ba
- action-listener-ab
- action-listener-ba
- item-listener-ab
- item-listener-ba
- adjustment-listener-ab
- adjustment-listener-ba
- input-method-listener-ab
- input-method-listener-ba
- hierarchy-listener-ab
- hierarchy-listener-ba
- hierarchy-bounds-listener-ab
- hierarchy-bounds-listener-ba
- mouse-wheel-listener-ab
- mouse-wheel-listener-bl
- component-listener-loldl
- the component-listener being removedl
- container-listener-loldl
- the container-listener being removedl
- focus-listener-loldl
- the focus-listener being removedl
- key-listener-loldl
- the key-listener being removedl
- mouse-listener-loldl
- the mouse-listener being removedl
- mouse-motion-listener-loldl
- the mouse-motion-listener being removedl
- window-listener-loldl
- the window-listener being removedl
- window-state-listener-loldl
- the window-state-listener being removedl
- window-focus-listener-loldl
- the window-focus-listener being removedl
- action-listener-loldl
- the action-listener being removedl
- item-listener-loldl
- the item-listener being removedl
- adjustment-listener-loldl
- the adjustment-listener being removedl
- input-method-listener-loldl
- the input-method-listener being removedl
- hierarchy-listener-loldl
- the hierarchy-listener being removedl
- hierarchy-bounds-listener-loldl
- the hierarchy-bounds-listener being removedl
- mouse-wheel-listener-loldl
- the mouse-wheel-listener being removeda
- event listener-ab
- event listener-bl
- the listener being removed fromoldl
- the listener being removedjava.io.IOException
FooListener
s by the specified
java.util.EventListener
.
FooListener
s 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 chanined,
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
FooListener
s by the specified multicast
listener, or an empty array if no such listeners have been
chained by the specified multicast listenerjava.lang.NullPointerException
- if the specified
listenertype
parameter is null
java.lang.ClassCastException
- if listenerType
doesn't specify a class or interface that implements
java.util.EventListener