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AWTEvent.javaAPI DocJava SE 5 API17021Fri Aug 26 14:56:42 BST 2005java.awt

AWTEvent

public abstract class AWTEvent extends EventObject
The root event class for all AWT events. This class and its subclasses supercede the original java.awt.Event class. Subclasses of this root AWTEvent class defined outside of the java.awt.event package should define event ID values greater than the value defined by RESERVED_ID_MAX.

The event masks defined in this class are needed by Component subclasses which are using Component.enableEvents() to select for event types not selected by registered listeners. If a listener is registered on a component, the appropriate event mask is already set internally by the component.

The masks are also used to specify to which types of events an AWTEventListener should listen. The masks are bitwise-ORed together and passed to Toolkit.addAWTEventListener.

see
Component#enableEvents
see
Toolkit#addAWTEventListener
see
java.awt.event.ActionEvent
see
java.awt.event.AdjustmentEvent
see
java.awt.event.ComponentEvent
see
java.awt.event.ContainerEvent
see
java.awt.event.FocusEvent
see
java.awt.event.InputMethodEvent
see
java.awt.event.InvocationEvent
see
java.awt.event.ItemEvent
see
java.awt.event.HierarchyEvent
see
java.awt.event.KeyEvent
see
java.awt.event.MouseEvent
see
java.awt.event.MouseWheelEvent
see
java.awt.event.PaintEvent
see
java.awt.event.TextEvent
see
java.awt.event.WindowEvent
author
Carl Quinn
author
Amy Fowler
version
1.55 06/02/04
since
1.1

Fields Summary
private byte[]
bdata
protected int
id
The event's id.
protected boolean
consumed
Controls whether or not the event is sent back down to the peer once the source has processed it - false means it's sent to the peer; true means it's not. Semantic events always have a 'true' value since they were generated by the peer in response to a low-level event.
transient boolean
focusManagerIsDispatching
transient boolean
isPosted
public static final long
COMPONENT_EVENT_MASK
The event mask for selecting component events.
public static final long
CONTAINER_EVENT_MASK
The event mask for selecting container events.
public static final long
FOCUS_EVENT_MASK
The event mask for selecting focus events.
public static final long
KEY_EVENT_MASK
The event mask for selecting key events.
public static final long
MOUSE_EVENT_MASK
The event mask for selecting mouse events.
public static final long
MOUSE_MOTION_EVENT_MASK
The event mask for selecting mouse motion events.
public static final long
WINDOW_EVENT_MASK
The event mask for selecting window events.
public static final long
ACTION_EVENT_MASK
The event mask for selecting action events.
public static final long
ADJUSTMENT_EVENT_MASK
The event mask for selecting adjustment events.
public static final long
ITEM_EVENT_MASK
The event mask for selecting item events.
public static final long
TEXT_EVENT_MASK
The event mask for selecting text events.
public static final long
INPUT_METHOD_EVENT_MASK
The event mask for selecting input method events.
static final long
INPUT_METHODS_ENABLED_MASK
The pseudo event mask for enabling input methods. We're using one bit in the eventMask so we don't need a separate field inputMethodsEnabled.
public static final long
PAINT_EVENT_MASK
The event mask for selecting paint events.
public static final long
INVOCATION_EVENT_MASK
The event mask for selecting invocation events.
public static final long
HIERARCHY_EVENT_MASK
The event mask for selecting hierarchy events.
public static final long
HIERARCHY_BOUNDS_EVENT_MASK
The event mask for selecting hierarchy bounds events.
public static final long
MOUSE_WHEEL_EVENT_MASK
The event mask for selecting mouse wheel events.
public static final long
WINDOW_STATE_EVENT_MASK
The event mask for selecting window state events.
public static final long
WINDOW_FOCUS_EVENT_MASK
The event mask for selecting window focus events.
public static final int
RESERVED_ID_MAX
The maximum value for reserved AWT event IDs. Programs defining their own event IDs should use IDs greater than this value.
private static Field
inputEvent_CanAccessSystemClipboard_Field
private static final long
serialVersionUID
Constructors Summary
public AWTEvent(Event event)
Constructs an AWTEvent object from the parameters of a 1.0-style event.

param
event the old-style event

        this(event.target, event.id);
public AWTEvent(Object source, int id)
Constructs an AWTEvent object with the specified source object and type.

param
source the object where the event originated
id
the event type

        super(source);
	this.id = id;
        switch(id) {
          case ActionEvent.ACTION_PERFORMED:
          case ItemEvent.ITEM_STATE_CHANGED:
          case AdjustmentEvent.ADJUSTMENT_VALUE_CHANGED:
          case TextEvent.TEXT_VALUE_CHANGED:
            consumed = true;
            break;
          default:
        }
Methods Summary
protected voidconsume()
Consumes this event, if this event can be consumed. Only low-level, system events can be consumed

        switch(id) {
          case KeyEvent.KEY_PRESSED:
          case KeyEvent.KEY_RELEASED:
          case MouseEvent.MOUSE_PRESSED:
          case MouseEvent.MOUSE_RELEASED:
          case MouseEvent.MOUSE_MOVED:
          case MouseEvent.MOUSE_DRAGGED:
          case MouseEvent.MOUSE_ENTERED:
          case MouseEvent.MOUSE_EXITED:
          case MouseEvent.MOUSE_WHEEL:
          case InputMethodEvent.INPUT_METHOD_TEXT_CHANGED:
          case InputMethodEvent.CARET_POSITION_CHANGED:
              consumed = true;
              break;
          default:
              // event type cannot be consumed
        }
java.awt.EventconvertToOld()
Converts a new event to an old one (used for compatibility). If the new event cannot be converted (because no old equivalent exists) then this returns null. Note: this method is here instead of in each individual new event class in java.awt.event because we don't want to make it public and it needs to be called from java.awt.

        Object src = getSource();
        int newid = id;

        switch(id) {
          case KeyEvent.KEY_PRESSED:
          case KeyEvent.KEY_RELEASED:
              KeyEvent ke = (KeyEvent)this;
              if (ke.isActionKey()) {
                  newid = (id == KeyEvent.KEY_PRESSED?
                           Event.KEY_ACTION : Event.KEY_ACTION_RELEASE);
              }
              int keyCode = ke.getKeyCode();
              if (keyCode == KeyEvent.VK_SHIFT ||
                  keyCode == KeyEvent.VK_CONTROL ||
                  keyCode == KeyEvent.VK_ALT) {
                  return null;  // suppress modifier keys in old event model.
              }
              // no mask for button1 existed in old Event - strip it out
              return new Event(src, ke.getWhen(), newid, 0, 0,
                               Event.getOldEventKey(ke),
                               (ke.getModifiers() & ~InputEvent.BUTTON1_MASK));

          case MouseEvent.MOUSE_PRESSED:
          case MouseEvent.MOUSE_RELEASED:
          case MouseEvent.MOUSE_MOVED:
          case MouseEvent.MOUSE_DRAGGED:
          case MouseEvent.MOUSE_ENTERED:
          case MouseEvent.MOUSE_EXITED:
              MouseEvent me = (MouseEvent)this;
              // no mask for button1 existed in old Event - strip it out
              Event olde = new Event(src, me.getWhen(), newid,
                               me.getX(), me.getY(), 0,
                               (me.getModifiers() & ~InputEvent.BUTTON1_MASK));
              olde.clickCount = me.getClickCount();
              return olde;

          case FocusEvent.FOCUS_GAINED:
              return new Event(src, Event.GOT_FOCUS, null);

          case FocusEvent.FOCUS_LOST:
              return new Event(src, Event.LOST_FOCUS, null);

          case WindowEvent.WINDOW_CLOSING:
          case WindowEvent.WINDOW_ICONIFIED:
          case WindowEvent.WINDOW_DEICONIFIED:
              return new Event(src, newid, null);

          case ComponentEvent.COMPONENT_MOVED:
              if (src instanceof Frame || src instanceof Dialog) {
                  Point p = ((Component)src).getLocation();
                  return new Event(src, 0, Event.WINDOW_MOVED, p.x, p.y, 0, 0);
              }
              break;

          case ActionEvent.ACTION_PERFORMED:
              ActionEvent ae = (ActionEvent)this;
              String cmd;
              if (src instanceof Button) {
                  cmd = ((Button)src).getLabel();
              } else if (src instanceof MenuItem) {
                  cmd = ((MenuItem)src).getLabel();
              } else {
                  cmd = ae.getActionCommand();
              }
              return new Event(src, 0, newid, 0, 0, 0, ae.getModifiers(), cmd);

          case ItemEvent.ITEM_STATE_CHANGED:
              ItemEvent ie = (ItemEvent)this;
              Object arg;
              if (src instanceof List) {
                  newid = (ie.getStateChange() == ItemEvent.SELECTED?
                           Event.LIST_SELECT : Event.LIST_DESELECT);
                  arg = ie.getItem();
              } else {
                  newid = Event.ACTION_EVENT;
                  if (src instanceof Choice) {
                      arg = ie.getItem();

                  } else { // Checkbox
                      arg = new Boolean(ie.getStateChange() == ItemEvent.SELECTED);
                  }
              }
              return new Event(src, newid, arg);

          case AdjustmentEvent.ADJUSTMENT_VALUE_CHANGED:
              AdjustmentEvent aje = (AdjustmentEvent)this;
              switch(aje.getAdjustmentType()) {
                case AdjustmentEvent.UNIT_INCREMENT:
                  newid = Event.SCROLL_LINE_DOWN;
                  break;
                case AdjustmentEvent.UNIT_DECREMENT:
                  newid = Event.SCROLL_LINE_UP;
                  break;
                case AdjustmentEvent.BLOCK_INCREMENT:
                  newid = Event.SCROLL_PAGE_DOWN;
                  break;
                case AdjustmentEvent.BLOCK_DECREMENT:
                  newid = Event.SCROLL_PAGE_UP;
                  break;
                case AdjustmentEvent.TRACK:
		  if (aje.getValueIsAdjusting()) {
		      newid = Event.SCROLL_ABSOLUTE;
		  }
		  else {
		      newid = Event.SCROLL_END;
		  }
                  break;
                default:
                  return null;
              }
              return new Event(src, newid, new Integer(aje.getValue()));

          default:
        }
        return null;
voidcopyPrivateDataInto(java.awt.AWTEvent that)
Copies all private data from this event into that. Space is allocated for the copied data that will be freed when the that is finalized. Upon completion, this event is not changed.

	that.bdata = this.bdata;
        // Copy canAccessSystemClipboard value from this into that.
        if (this instanceof InputEvent && that instanceof InputEvent) {
            Field field = get_InputEvent_CanAccessSystemClipboard();
            if (field != null) { 
                try {
                    boolean b = field.getBoolean(this);
                    field.setBoolean(that, b);
                } catch(IllegalAccessException e) {
                } 
            }
        }
voiddispatched()

        if (this instanceof InputEvent) {
            Field field = get_InputEvent_CanAccessSystemClipboard();
            if (field != null) { 
                try {
                    field.setBoolean(this, false);
                } catch(IllegalAccessException e) {
                } 
            }
        }
public intgetID()
Returns the event type.

        return id;
private static synchronized java.lang.reflect.Fieldget_InputEvent_CanAccessSystemClipboard()


     
        /* ensure that the necessary native libraries are loaded */
	Toolkit.loadLibraries();
        if (!GraphicsEnvironment.isHeadless()) {
            initIDs();
        }
     
        if (inputEvent_CanAccessSystemClipboard_Field == null) { 
            inputEvent_CanAccessSystemClipboard_Field =
                (Field)java.security.AccessController.doPrivileged(
                    new java.security.PrivilegedAction() {
                            public Object run() {
                                Field field = null;
                                try {
                                    field = InputEvent.class.
                                        getDeclaredField("canAccessSystemClipboard");
                                    field.setAccessible(true);
                                    return field;
                                } catch (SecurityException e) {
                                } catch (NoSuchFieldException e) {
                                }
                                return null;
                            }
                        });
        }

        return inputEvent_CanAccessSystemClipboard_Field;
private static native voidinitIDs()
Initialize JNI field and method IDs for fields that may be accessed from C.

protected booleanisConsumed()
Returns whether this event has been consumed.
        return consumed;
    
private native voidnativeSetSource(java.awt.peer.ComponentPeer peer)
public java.lang.StringparamString()
Returns a string representing the state of this Event.
This method is intended to be used only for debugging purposes, and the
content and format of the returned string may vary between
implementations. The returned string may be empty but may not be
null.
return
a string representation of this event
        return "";
    
public voidsetSource(java.lang.Object newSource)
Retargets an event to a new source. This method is typically used to
retarget an event to a lightweight child Component of the original
heavyweight source.


This method is intended to be used only by event targeting subsystems,
such as client-defined KeyboardFocusManagers. It is not for general
client use.
param
newSource the new Object to which the event should be dispatched
	if (source == newSource) {
	    return;
	}
 
	Component comp = null;
	if (newSource instanceof Component) {
	    comp = (Component)newSource;
	    while (comp != null && comp.peer != null &&
		   (comp.peer instanceof LightweightPeer)) {
		comp = comp.parent;
	    }
	}
 
	synchronized (this) {
	    source = newSource;
	    if (comp != null) {
		ComponentPeer peer = comp.peer;
		if (peer != null) {
		    nativeSetSource(peer);
		}
	    }
	}
    
public java.lang.StringtoString()
Returns a String representation of this object.
        String srcName = null;
        if (source instanceof Component) {
            srcName = ((Component)source).getName();
        } else if (source instanceof MenuComponent) {
            srcName = ((MenuComponent)source).getName();
        }
	return getClass().getName() + "[" + paramString() + "] on " +
            (srcName != null? srcName : source);