libjava/java/awt/Component.java

/* Copyright (C) 1999, 2000, 2001  Free Software Foundation

   This file is part of libgcj.

This software is copyrighted work licensed under the terms of the
Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
details.  */

package java.awt;
import java.awt.event.*;
import java.awt.image.*;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.lang.reflect.*;
import java.util.EventListener;
import java.util.Locale;
import java.util.ResourceBundle;
import java.util.Vector;
import java.awt.peer.ComponentPeer;
import java.awt.peer.LightweightPeer;
import java.beans.PropertyChangeSupport;
import java.beans.PropertyChangeListener;
// import javax.accessibility.AccessibleContext;

/**
  * The root of all evil.
  *
  * Status: Incomplete. The event dispatch mechanism is implemented. All 
  * other methods defined in the J2SE 1.3 API javadoc exist, but are mostly 
  * incomplete or only stubs; except for methods relating to the Drag and Drop, 
  * Input Method, and Accessibility frameworks: These methods are present but 
  * commented out.
  */
public abstract class Component implements ImageObserver, MenuContainer, 
					   java.io.Serializable
{

  /* Constants for use with getAlignmentX()/getAlignmentY(). */
  public static final float BOTTOM_ALIGNMENT = 1.0f,
			    CENTER_ALIGNMENT = 0.5f,
			    LEFT_ALIGNMENT   = 0.0f,
			    RIGHT_ALIGNMENT  = 1.0f,
			    TOP_ALIGNMENT    = 0.0f;

  /* Make the treelock a String so that it can easily be identified
     in debug dumps. We clone the String in order to avoid a conflict in 
     the unlikely event that some other package uses exactly the same string
     as a lock object. */
  static Object treeLock = new String("AWT_TREE_LOCK");

  /* Serialized fields from the serialization spec. */
  // FIXME: Default values?
  int x;
  int y;
  int width;
  int height;
  Color foreground;
  Color background;
  Font font;
  Font peerFont;
  Cursor cursor;
  Locale locale;
  boolean visible = true; // default (except for Window)
  boolean enabled = true;
  boolean valid;
  boolean hasFocus;
  //DropTarget dropTarget;
  Vector popups;
  String name;
  boolean nameExplicitlySet;
  Dimension minSize;
  Dimension prefSize;
  boolean newEventsOnly;  
  long eventMask = AWTEvent.PAINT_EVENT_MASK;
  PropertyChangeSupport changeSupport;
  boolean isPacked;
  int componentSerializedDataVersion;
  /* AccessibleContext accessibleContext; */

  /* Anything else is non-serializable, and should be declared "transient". */
  transient Container parent;
  transient java.awt.peer.ComponentPeer peer;

  transient ComponentListener componentListener;
  transient FocusListener focusListener;
  transient KeyListener keyListener;
  transient MouseListener mouseListener;
  transient MouseMotionListener mouseMotionListener;
  transient InputMethodListener inputMethodListener;
  transient HierarchyListener hierarchyListener;
  transient HierarchyBoundsListener hierarchyBoundsListener;

  transient ComponentOrientation orientation = ComponentOrientation.UNKNOWN;

  protected Component()
  {
  }

  public String getName()
  {
    if (name == null && !nameExplicitlySet)
      name = generateName();
    return name;
  }
  
  public void setName(String name)
  {
    nameExplicitlySet = true;
    this.name = name;
  }
  
  /** Subclasses should override this to return unique component names like 
    * "menuitem0".
    */
  String generateName()
  {
    // Component is abstract.
    return null;
  }
  
  public Container getParent()
  {
    return parent;  
  }
  
  /** @deprecated */
  // However, Classpath's Gtk peers rely on it.
  public java.awt.peer.ComponentPeer getPeer()
  {
    return peer;
  }
  
  // FIXME: java.awt.dnd classes not yet implemented
  /*
  public void setDropTarget(DropTarget dt)
  {
    this.dropTarget = dt;
  }
  
  public DropTarget getDropTarget()
  {
    return dropTarget;
  }
  */
  
  /** @since 1.3 */
  public GraphicsConfiguration getGraphicsConfiguration()
  {
    return getGraphicsConfigurationImpl();
  }

  /** Implementation method that allows classes such as Canvas and
      Window to override the graphics configuration without violating
      the published API. */
  GraphicsConfiguration getGraphicsConfigurationImpl()
  {
    if (peer != null)
      {
	GraphicsConfiguration config = peer.getGraphicsConfiguration();
	if (config != null)
	  return config;
      }

    if (parent != null)
      return parent.getGraphicsConfiguration();

    return null;
  }

  public final Object getTreeLock()
  {
    return treeLock;
  }

  public Toolkit getToolkit()
  {
    if (peer != null)
      {
	Toolkit tk = peer.getToolkit();
	if (tk != null)
	  return tk;
      }
    if (parent != null)
      return parent.getToolkit ();
    return Toolkit.getDefaultToolkit ();
  }

  public boolean isValid()
  {
    return valid;
  }
  
  /** @since 1.2 */
  public boolean isDisplayable()
  {
    if (parent != null)
      return parent.isDisplayable();
    return false;
  }
  
  public boolean isVisible()
  {
    return visible;
  }
  
  public boolean isShowing()
  {
    if (! visible || peer == null)
      return false;

    return parent == null ? true : parent.isShowing ();
  }
  
  public boolean isEnabled()
  {
    return enabled;
  }
  
  public void setEnabled(boolean b)
  {
    this.enabled = b;
    if (peer != null)
      peer.setEnabled(b);
  }
  
  /** @deprecated */
  public void enable()
  {
    setEnabled(true);
  }
  
  /** @deprecated */
  public void enable(boolean b)
  {
    setEnabled(b);
  }
  
  /** @deprecated */
  public void disable()
  {
    setEnabled(false);
  }
  
  public boolean isDoubleBuffered()
  {
    return false;
  }
  
  /** @since 1.2 */
  public void enableInputMethods(boolean enable)
  {
    // FIXME
  }
  
  /** @specnote  Inspection by subclassing shows that Sun's implementation
                 calls show(boolean) which then calls show() or hide(). It is
		 the show() method that is overriden in subclasses like Window.
		 We do the same to preserve compatibility for subclasses. */
  public void setVisible(boolean b)
  {
    show (b);
  }
  
  /** @deprecated */
  public void show()
  {
    if (peer != null)
      peer.setVisible(true);
    this.visible = true;
  }
  
  /** @deprecated */
  public void show(boolean b)
  {
    if (b)
      show();
    else
      hide();
  }
  
  /** @deprecated */
  public void hide()
  {
    if (peer != null)
      peer.setVisible(false);
    this.visible = false;
  }
  
  public Color getForeground()
  {
    if (foreground != null)
      return foreground;
    if (parent != null)
      return parent.getForeground();
    return null;
  }
  
  public void setForeground(Color c)
  {
    if (peer != null)
      peer.setForeground(c);
    this.foreground = c;
  }

  /** @return the background color of the component. null may be
      returned instead of the actual background color, if this
      method is called before the component is added to the
      component hierarchy. */
  public Color getBackground()
  {
    if (background != null)
      return background;
    if (parent != null)
      return parent.getBackground();
    return null;
  }
  
  public void setBackground(Color c)
  {
    if (peer != null)
      peer.setBackground(c);
    this.background = c;
  }
  
  public Font getFont()
  {
    if (font != null)
      return font;
    if (parent != null)
      return parent.getFont();
    return null;
  }
  
  public void setFont(Font f)
  {
    if (peer != null)
      peer.setFont(f);
    this.font = f;
  }

  public Locale getLocale() throws IllegalComponentStateException
  {
    if (locale != null)
      return locale;
    if (parent == null)
      throw new IllegalComponentStateException
        ("Component has no parent: Can not determine Locale");
    return parent.getLocale();
  }
  
  public void setLocale(Locale l)  
  {
    this.locale = l;
    
    /* new writing/layout direction perhaps, or make more/less
       room for localized text labels */
    invalidate();
  }
  
  public ColorModel getColorModel()
  {
    GraphicsConfiguration config = getGraphicsConfiguration();

    if (config != null)
      return config.getColorModel();

    return getToolkit().getColorModel();    
  }

  public Point getLocation()
  {
    return new Point(x, y);
  }

  public Point getLocationOnScreen()
  {
    if (! isShowing ())
      throw new IllegalComponentStateException ("component not showing");

    // We know peer != null here.
    return peer.getLocationOnScreen ();
  }

  /** @deprecated Use getLocation() instead. */
  public Point location()
  {
    return getLocation();
  }

  public void setLocation (int x, int y)
  {
    if ((this.x == x) && (this.y == y))
      return;
    
    invalidate();
    
    this.x = x;
    this.y = y;
    if (peer != null)
      peer.setBounds(x, y, width, height);
  }

  /** @deprecated */
  public void move(int x, int y)
  {
    setLocation(x,y);
  }
  
  public void setLocation(Point p)
  {
    setLocation(p.x, p.y);
  }
  
  public Dimension getSize()
  {
    return new Dimension(width, height);
  }
  
  /** @deprecated */
  public Dimension size()
  {
    return getSize();
  }
  
  public void setSize(int width, int height)
  {
    if ((this.width == width) && (this.height == height))
      return;

    invalidate();

    this.width = width;
    this.height = height;
    if (peer != null)
      peer.setBounds(x, y, width, height);
  }
  
  /** @deprecated */
  public void resize(int width, int height)
  {
    setSize(width, height);
  }
  
  public void setSize(Dimension d)
  {
    setSize(d.width, d.height);
  }

  /** @deprecated */
  public void resize(Dimension d)
  {
    setSize(d.width, d.height);
  }

  public Rectangle getBounds()
  {
    return new Rectangle (x, y, width, height);
  }

  /** @deprecated */
  public Rectangle bounds()
  {
    return getBounds();
  }
  
  public void setBounds(int x, int y, int w, int h)
  {
    if (this.x == x
	&& this.y == y
	&& this.width == w
	&& this.height == h)
      return;

    invalidate();

    this.x = x;
    this.y = y;
    this.width = w;
    this.height = h;

    if (peer != null)
      peer.setBounds(x, y, w, h);
  }
  
  /** @deprecated */
  public void reshape(int x, int y, int width, int height)
  {
    setBounds(x, y, width, height);
  }
  
  public void setBounds(Rectangle r)
  { 
    setBounds(r.x, r.y, r.width, r.height);
  }
  
  /** @since 1.2 */
  public int getX()
  {
    return x;
  }
  
  /** @since 1.2 */
  public int getY()
  {
    return y;
  }
  
  /** @since 1.2 */
  public int getWidth()
  {
    return width;
  }
  
  /** @since 1.2 */
  public int getHeight()
  {
    return height;
  }
  
  public Rectangle getBounds(Rectangle r)
  {
    r.x = this.x;
    r.y = this.y;
    r.width = this.width;
    r.height = this.height;
    return r;
  }
  
  public Dimension getSize(Dimension d)
  {
    d.width = this.width;
    d.height = this.height;
    return d;
  }
  
  public Point getLocation(Point p)
  {
    p.x = x;
    p.y = y;
    return p;
  }
  
  /** @since 1.2 */
  public boolean isOpaque()
  {
    return !isLightweight();
  }
  
  /** 
   * Return whether the component is lightweight.
   *
   * @return true if component has a peer and and the peer is lightweight.
   *
   * @since 1.2
   */  
  public boolean isLightweight()
  {
    return (peer != null) && (peer instanceof LightweightPeer);
  }
  
  public Dimension getPreferredSize()
  {
    if (peer == null)
      return new Dimension(width, height);
    else
      return peer.getPreferredSize();
  }

  /** @deprecated */
  public Dimension preferredSize()
  {
    return getPreferredSize();
  }
  
  public Dimension getMinimumSize()
  {
    if (peer == null)
      return new Dimension(width, height);
    else
      return peer.getMinimumSize();
  }

  /** @deprecated */
  public Dimension minimumSize()
  {
    return getMinimumSize();
  }

  public Dimension getMaximumSize()
  {
    return new Dimension(Integer.MAX_VALUE, Integer.MAX_VALUE);
  }

  public float getAlignmentX()
  {
    return CENTER_ALIGNMENT;
  }

  public float getAlignmentY()
  {
    return CENTER_ALIGNMENT;
  }

  public void doLayout()
  {
    // nothing to do unless we're a container
  }
  
  /** @deprecated */
  public void layout()
  {
    doLayout();
  }
  
  public void validate()
  {
    // nothing to do unless we're a container
  }
  
  public void invalidate()
  {
    valid = false;

    if ((parent != null) && parent.valid)
      parent.invalidate ();
  }

  public Graphics getGraphics()
  {
    if (peer != null)
      {
	Graphics gfx = peer.getGraphics();
	if (gfx != null)
	  return gfx;
      
	// create graphics for lightweight:
	Container parent = getParent();
	if (parent != null)
	  {
	    gfx = parent.getGraphics();
	    Rectangle bounds = getBounds();
	    gfx.setClip(bounds);
	    gfx.translate(bounds.x, bounds.y);
	    return gfx;
	  }
      }
    return null;
  }
  
  public FontMetrics getFontMetrics(Font font)
  {
    if (peer == null)
      return getToolkit().getFontMetrics(font);
    return peer.getFontMetrics (font);
  }

  public void setCursor(Cursor cursor)
  {
    this.cursor = cursor;
    if (peer != null)
      peer.setCursor (cursor);
  }

  public Cursor getCursor()
  {
    return this.cursor;
  }
  
  public void paint(Graphics g)
  {  
  }
  
  public void update(Graphics g)
  {
    paint(g);
  }
  
  public void paintAll(Graphics g)
  {    
    if (!visible)
      return;
	
    if (peer != null)
      peer.paint(g);
    paint(g);
  }
  
  public void repaint()
  {
    repaint(0, 0, 0, getWidth(), getHeight());
  }
  
  public void repaint(long tm)
  {
    repaint(tm, 0, 0, getWidth(), getHeight());
  }
  
  public void repaint(int x, int y, int width, int height)
  {
    repaint(0, x, y, width, height);
  }
  
  public void repaint(long tm, int x, int y, int width, int height)
  {    
    // Handle lightweight repainting by forwarding to native parent
    if (isLightweight() && (parent != null))
      {
	if (parent != null)
	  parent.repaint(tm, x+getX(), y+getY(), width, height);
	return;
      }

    if (peer != null)
      peer.repaint(tm, x, y, width, height);
  }

  public void print(Graphics g)
  {
    paint(g);
  }

  public void printAll(Graphics g)
  {
    paintAll(g);
  }

  public boolean imageUpdate (Image img, int infoflags, int x, int y,
			      int w, int h)
  {
    // FIXME
    return false;
  }

  public Image createImage(ImageProducer producer)
  {
    // FIXME
    return null;
  }

  public Image createImage(int width, int height)
  {
    return getGraphicsConfiguration().createCompatibleImage(width, height);
  }

  public boolean prepareImage(Image image, ImageObserver observer)
  {
    // FIXME
    return false;
  }

  public boolean prepareImage(Image image, int width, int height, ImageObserver observer)
  {
    // FIXME
    return false;
  }

  public int checkImage(Image image, ImageObserver observer)
  {
    // FIXME
    return 0;
  }

  public int checkImage (Image image, int width, int height, ImageObserver observer)
  {
    if (peer != null)
      return peer.checkImage (image, width, height, observer);
    return getToolkit ().checkImage (image, width, height, observer);
  }

  public boolean contains (int x, int y)
  {
    return (x >= 0) && (y >= 0) && (x < width) && (y < height);
  }

  /** @deprecated */
  public boolean inside(int x, int y)
  {
    return contains(x,y);
  }

  public boolean contains(Point p)
  {
    return contains(p.x, p.y);
  }

  public Component getComponentAt(int x, int y)
  {
    if (contains(x,y))
      return this;
    return null;
  }

  /** @deprecated */
  public Component locate(int x, int y)
  {
    return getComponentAt(x, y);
  }

  public Component getComponentAt(Point p)
  {
    return getComponentAt(p.x, p.y);
  }

  /** @deprecated */
  public void deliverEvent(Event e)
  {
    
  }

  /** Forward AWT events to processEvent() if:
    *     - Events have been enabled for this type of event via enableEvents(),
    *   OR:
    *	 - There is at least one registered listener for this type of event
    * 
    * @specnote This method is final, but we need to be able to 
    *           override it in order to handle other event types in our 
    *	        subclasses. The solution is to define a second, non-final
    *           method - dispatchEventImpl() - to actually do the work. 
    *           Investigations with Thread.dumpStack() on the dispatch thread 
    *           in JDK 1.3 show Sun's implementation is doing the same 
    *           thing.
    */
  public final void dispatchEvent(AWTEvent e)
  {
    dispatchEventImpl(e);

    /* Give the peer a chance to handle the event. */
    if (peer != null)
      peer.handleEvent(e);
  }

  void dispatchEventImpl(AWTEvent e)
  {
    // Make use of event id's in order to avoid multiple instanceof tests.
    if (e.id <= ComponentEvent.COMPONENT_LAST 
        && e.id >= ComponentEvent.COMPONENT_FIRST
        && (componentListener != null 
	    || (eventMask & AWTEvent.COMPONENT_EVENT_MASK) != 0))
      processEvent(e);
    else if (e.id <= KeyEvent.KEY_LAST
             && e.id >= KeyEvent.KEY_FIRST
	     && (keyListener != null
		 || (eventMask & AWTEvent.KEY_EVENT_MASK) != 0))
      processEvent(e);
    else if (e.id <= MouseEvent.MOUSE_LAST
             && e.id >= MouseEvent.MOUSE_FIRST
	     && (mouseListener != null
		 || mouseMotionListener != null
		 || (eventMask & AWTEvent.MOUSE_EVENT_MASK) != 0))
      processEvent(e);
    else if (e.id <= FocusEvent.FOCUS_LAST
             && e.id >= FocusEvent.FOCUS_FIRST
	     && (focusListener != null
		 || (eventMask & AWTEvent.FOCUS_EVENT_MASK) != 0))
      processEvent(e);
    else if (e.id <= InputMethodEvent.INPUT_METHOD_LAST
             && e.id >= InputMethodEvent.INPUT_METHOD_FIRST
	     && (inputMethodListener != null
		 || (eventMask & AWTEvent.INPUT_METHOD_EVENT_MASK) != 0))
      processEvent(e);
    else if (e.id <= HierarchyEvent.HIERARCHY_LAST
             && e.id >= HierarchyEvent.HIERARCHY_FIRST
	     && (hierarchyListener != null
		 || hierarchyBoundsListener != null
		 || (eventMask & AWTEvent.HIERARCHY_EVENT_MASK) != 0))
      processEvent(e);
    else if (e.id <= PaintEvent.PAINT_LAST
	     && e.id >= PaintEvent.PAINT_FIRST
	     && (eventMask & AWTEvent.PAINT_EVENT_MASK) != 0)      
      processEvent(e);
  }
  
  /** @deprecated */
  public boolean postEvent(Event e)
  {
    return false;
  }
  
  public synchronized void addComponentListener(ComponentListener l)
  {
    componentListener = AWTEventMulticaster.add(componentListener, l);
    if (componentListener != null)
      enableEvents(AWTEvent.COMPONENT_EVENT_MASK);
  }
  
  public synchronized void removeComponentListener(ComponentListener l)
  {
    componentListener = AWTEventMulticaster.remove(componentListener, l);
  }
  
  public synchronized void addFocusListener(FocusListener l)
  {
    focusListener = AWTEventMulticaster.add(focusListener, l);
    if (focusListener != null)
      enableEvents(AWTEvent.FOCUS_EVENT_MASK);    
  }
  
  public synchronized void removeFocusListener(FocusListener l)
  {
    focusListener = AWTEventMulticaster.remove(focusListener, l);
  }
  
  /** @since 1.3 */
  public synchronized void addHierarchyListener(HierarchyListener l)
  {
    hierarchyListener = AWTEventMulticaster.add(hierarchyListener, l);
    if (hierarchyListener != null)
      enableEvents(AWTEvent.HIERARCHY_EVENT_MASK);    
  }
  
  /** @since 1.3 */
  public synchronized void removeHierarchyListener(HierarchyListener l)
  {
    hierarchyListener = AWTEventMulticaster.remove(hierarchyListener, l);
  }

  /** @since 1.3 */
  public synchronized void addHierarchyBoundsListener(HierarchyBoundsListener l)
  {
    hierarchyBoundsListener = 
      AWTEventMulticaster.add(hierarchyBoundsListener, l);
    if (hierarchyBoundsListener != null)
      enableEvents(AWTEvent.HIERARCHY_EVENT_MASK);    
  }

  /** @since 1.3 */
  public synchronized void 
    removeHierarchyBoundsListener(HierarchyBoundsListener l)
  {
    hierarchyBoundsListener = 
      AWTEventMulticaster.remove(hierarchyBoundsListener, l);
  }

  public synchronized void addKeyListener(KeyListener l)
  {
    keyListener = AWTEventMulticaster.add(keyListener, l);
    if (keyListener != null)
      enableEvents(AWTEvent.KEY_EVENT_MASK);    
  }

  public synchronized void removeKeyListener(KeyListener l)
  {
    keyListener = AWTEventMulticaster.remove(keyListener, l);
  }

  public synchronized void addMouseListener(MouseListener l)
  {
    mouseListener = AWTEventMulticaster.add(mouseListener, l);
    if (mouseListener != null)
      enableEvents(AWTEvent.MOUSE_EVENT_MASK);    
  }

  public synchronized void removeMouseListener(MouseListener l)
  {
    mouseListener = AWTEventMulticaster.remove(mouseListener, l);    
  }

  public synchronized void addMouseMotionListener(MouseMotionListener l)
  {
    mouseMotionListener = AWTEventMulticaster.add(mouseMotionListener, l);
    if (mouseMotionListener != null)
      enableEvents(AWTEvent.MOUSE_EVENT_MASK);    
  }

  public synchronized void removeMouseMotionListener(MouseMotionListener l)
  {
    mouseMotionListener = AWTEventMulticaster.remove(mouseMotionListener, l);
  }

  /** @since 1.2 */
  public synchronized void addInputMethodListener(InputMethodListener l)
  {
    inputMethodListener = AWTEventMulticaster.add(inputMethodListener, l);
    if (inputMethodListener != null)
      enableEvents(AWTEvent.INPUT_METHOD_EVENT_MASK);    
  }

  /** @since 1.2 */
  public synchronized void removeInputMethodListener(InputMethodListener l)
  {
    inputMethodListener = AWTEventMulticaster.remove(inputMethodListener, l);
  }

  /** Returns all registered EventListers of the given listenerType. 
    * listenerType must be a subclass of EventListener, or a 
    * ClassClassException is thrown.
    * @since 1.3 
    */
  public EventListener[] getListeners(Class listenerType)
  {
    if (listenerType == ComponentListener.class)
      return getListenersImpl(listenerType, componentListener);
    else if (listenerType == FocusListener.class)
      return getListenersImpl(listenerType, focusListener);
    else if (listenerType == KeyListener.class)
      return getListenersImpl(listenerType, keyListener);
    else if (listenerType == MouseListener.class)
      return getListenersImpl(listenerType, mouseListener);
    else if (listenerType == MouseMotionListener.class)
      return getListenersImpl(listenerType, mouseMotionListener);
    else if (listenerType == InputMethodListener.class)
      return getListenersImpl(listenerType, inputMethodListener);
    else if (listenerType == HierarchyListener.class)
      return getListenersImpl(listenerType, hierarchyListener);
    else if (listenerType == HierarchyBoundsListener.class)
      return getListenersImpl(listenerType, hierarchyBoundsListener);
    else
      return getListenersImpl(listenerType, null);
  }
  
  static EventListener[] getListenersImpl(Class listenerType, EventListener el)
  {
    if (! EventListener.class.isAssignableFrom(listenerType))
      throw new ClassCastException();
    
    Vector v = new Vector();
    if (el != null)
      getListenerList (el, v);    
    EventListener[] el_a = (EventListener[]) Array.newInstance(listenerType, 
							       v.size());
    v.copyInto(el_a);
    return el_a;
  }

  static void getListenerList(EventListener el, Vector v)
  {
    if (el instanceof AWTEventMulticaster)
      {
        AWTEventMulticaster mc = (AWTEventMulticaster) el;
        getListenerList(mc.a, v);
	getListenerList(mc.b, v);
      }
    else
      v.addElement(el);      
  }

  // The input method framework is currently unimplemented.  
  // /** @since 1.2 */
  //
  //public InputMethodRequests getInputMethodRequests()
  //
  // /** @since 1.2 */
  //
  // public InputContext getInputContext()

  protected final void enableEvents(long eventsToEnable)
  {
    eventMask |= eventsToEnable;
    // TODO: Unlike Sun's implementation, I think we should try and 
    // enable/disable events at the peer (gtk/X) level. This will avoid 
    // clogging the event pipeline with useless mousemove events that 
    // we arn't interested in, etc. This will involve extending the peer 
    // interface, but thats okay because the peer interfaces have been
    // deprecated for a long time, and no longer feature in the 
    // API specification at all.

    if (isLightweight() && (parent != null))
      parent.enableEvents(eventsToEnable);
    else if (peer != null)
      peer.setEventMask (eventMask);
  }

  protected final void disableEvents(long eventsToDisable)
  {
    eventMask &= ~eventsToDisable;
    // forward new event mask to peer?
  }

  /** coalesceEvents is called by the EventQueue if two events with the same 
    * event id are queued. Returns a new combined event, or null if no 
    * combining is done. 
    */
  protected AWTEvent coalesceEvents(AWTEvent existingEvent, AWTEvent newEvent)
  {
    switch (existingEvent.id)
      {
      case MouseEvent.MOUSE_MOVED:
      case MouseEvent.MOUSE_DRAGGED:
	// Just drop the old (intermediate) event and return the new one.
	return newEvent;
      case PaintEvent.PAINT:
      case PaintEvent.UPDATE:
	return coalescePaintEvents((PaintEvent) existingEvent,
				   (PaintEvent) newEvent);
      }
    return null;
  }
  
  /**
   * Coalesce paint events. Current heuristic is: Merge if the union of
   * areas is less than twice that of the sum of the areas. The X server
   * tend to create a lot of paint events that are adjacent but not
   * overlapping.
   *
   * <pre>
   * +------+
   * |      +-----+  ...will be merged
   * |      |     |
   * |      |     |
   * +------+     |
   *        +-----+
   * 
   * +---------------+--+
   * |               |  |  ...will not be merged
   * +---------------+  |
   *                 |  |
   *                 |  |
   *                 |  |
   *                 |  |
   *                 |  |
   *                 +--+
   * </pre>
   */

  private PaintEvent coalescePaintEvents(PaintEvent queuedEvent,
					 PaintEvent newEvent)
  {
    Rectangle r1 = queuedEvent.getUpdateRect();
    Rectangle r2 = newEvent.getUpdateRect();
    Rectangle union = r1.union(r2);
    
    int r1a = r1.width * r1.height;
    int r2a = r2.width * r2.height;
    int ua  = union.width * union.height;
    
    if (ua > (r1a+r2a)*2)
      return null;
    /* The 2 factor should maybe be reconsidered. Perhaps 3/2
       would be better? */

    newEvent.setUpdateRect(union);
    return newEvent;
  }




  /** Forward event to the appropriate processXXXEvent method based on the
    * event type.
    */
  protected void processEvent(AWTEvent e)
  {

    /* Note: the order of these if statements are
       important. Subclasses must be checked first. Eg. MouseEvent
       must be checked before ComponentEvent, since a MouseEvent
       object is also an instance of a ComponentEvent. */

    if (e instanceof FocusEvent)
      processFocusEvent((FocusEvent) e);
    else if (e instanceof PaintEvent)
      processPaintEvent((PaintEvent) e);
    else if (e instanceof MouseEvent)
      {
        if (e.id == MouseEvent.MOUSE_MOVED 
	    || e.id == MouseEvent.MOUSE_DRAGGED)
	  processMouseMotionEvent((MouseEvent) e);
	else
	  processMouseEvent((MouseEvent) e);
      }
    else if (e instanceof ComponentEvent)
      processComponentEvent((ComponentEvent) e);
    else if (e instanceof KeyEvent)
      processKeyEvent((KeyEvent) e);
    else if (e instanceof InputMethodEvent)
      processInputMethodEvent((InputMethodEvent) e);
    else if (e instanceof HierarchyEvent)
      {
        if (e.id == HierarchyEvent.HIERARCHY_CHANGED)
	  processHierarchyEvent((HierarchyEvent) e);
	else
	  processHierarchyBoundsEvent((HierarchyEvent) e);
      }
  }
  
  protected void processComponentEvent(ComponentEvent e)
  {
    if (componentListener == null)
      return;
    switch (e.id)
      {
        case ComponentEvent.COMPONENT_HIDDEN:
	  componentListener.componentHidden(e);
	break;
		
        case ComponentEvent.COMPONENT_MOVED:
	  componentListener.componentMoved(e);
	break;
	
	case ComponentEvent.COMPONENT_RESIZED:
	  componentListener.componentResized(e);
	break;
	
	case ComponentEvent.COMPONENT_SHOWN:
	  componentListener.componentShown(e);
	break;
      }
  }
  
  protected void processFocusEvent(FocusEvent e)
  {
    if (focusListener == null)
      return;
    switch (e.id)
      {
        case FocusEvent.FOCUS_GAINED:
	  focusListener.focusGained(e);
	break;
        case FocusEvent.FOCUS_LOST:
	  focusListener.focusLost(e);
	break;
      }    
  }
  
  protected void processKeyEvent(KeyEvent e)
  {
    if (keyListener == null)
      return;
    switch (e.id)
      {
	case KeyEvent.KEY_PRESSED:
	  keyListener.keyPressed(e);
	break;
	case KeyEvent.KEY_RELEASED:
	  keyListener.keyReleased(e);
	break;
	case KeyEvent.KEY_TYPED:
	  keyListener.keyTyped(e);
	break;
      }
  }
  
  protected void processMouseEvent(MouseEvent e)
  {
    if (mouseListener == null)
      return;
    switch (e.id)
      {
	case MouseEvent.MOUSE_CLICKED:
	  mouseListener.mouseClicked(e);
	break;
        case MouseEvent.MOUSE_ENTERED:
	  mouseListener.mouseEntered(e);
	break;
	case MouseEvent.MOUSE_EXITED:
	  mouseListener.mouseExited(e);
	break;
	case MouseEvent.MOUSE_PRESSED:
	  mouseListener.mousePressed(e);
	break;
	case MouseEvent.MOUSE_RELEASED:
	  mouseListener.mouseReleased(e);
	break;
      }
  }

  protected void processMouseMotionEvent(MouseEvent e)
  {
    if (mouseMotionListener == null)
      return;
    switch (e.id)
      {
	case MouseEvent.MOUSE_DRAGGED:
	  mouseMotionListener.mouseDragged(e);
	break;
        case MouseEvent.MOUSE_MOVED:
	  mouseMotionListener.mouseMoved(e);
	break;
      }	
  }
  
  /** @since 1.2 */
  protected void processInputMethodEvent(InputMethodEvent e)
  {
    if (inputMethodListener == null)
      return;
    switch (e.id)
      {
	case InputMethodEvent.CARET_POSITION_CHANGED:
          inputMethodListener.caretPositionChanged(e);
	break;
	case InputMethodEvent.INPUT_METHOD_TEXT_CHANGED:
          inputMethodListener.inputMethodTextChanged(e);
	break;
      }	
  }
  
  /** @since 1.3 */
  protected void processHierarchyEvent(HierarchyEvent e)
  {
    if (hierarchyListener == null)
      return;
    if (e.id == HierarchyEvent.HIERARCHY_CHANGED)
      hierarchyListener.hierarchyChanged(e);
  }
  
  /** @since 1.3 */
  protected void processHierarchyBoundsEvent(HierarchyEvent e)
  {
    if (hierarchyBoundsListener == null)
      return;
    switch (e.id)
      {
        case HierarchyEvent.ANCESTOR_MOVED:
	  hierarchyBoundsListener.ancestorMoved(e);
	break;
	case HierarchyEvent.ANCESTOR_RESIZED:
	  hierarchyBoundsListener.ancestorResized(e);
	break;
      }
  }

  private void processPaintEvent(PaintEvent event)
  {
    // Can't do graphics without peer
    if (peer == null)
      return;

    Graphics gfx = getGraphics();
    Shape clip = event.getUpdateRect();
    gfx.setClip(clip);

    switch (event.id)
      {
      case PaintEvent.PAINT:
	paint(gfx);
	break;
      case PaintEvent.UPDATE:
	update(gfx);
	break;
      default:
	throw new IllegalArgumentException("unknown paint event");
      }
  }
  
  /** @deprecated */
  public boolean handleEvent(Event evt)
  {
    return false;
  }
  
  /** @deprecated */
  public boolean mouseDown(Event evt, int x, int y)
  {
    return false;
  }
  
  /** @deprecated */
  public boolean mouseDrag(Event evt, int x, int y)
  {
    return false;
  }

  /** @deprecated */
  public boolean mouseUp(Event evt, int x, int y)
  {
    return false;
  }

  /** @deprecated */
  public boolean mouseMove(Event evt, int x, int y)
  {
    return false;
  }

  /** @deprecated */
  public boolean mouseEnter(Event evt, int x, int y)
  {
    return false;
  }

  /** @deprecated */
  public boolean mouseExit(Event evt, int x, int y)
  {
    return false;
  }

  /** @deprecated */
  public boolean keyDown(Event evt, int key)
  {
    return false;
  }

  /** @deprecated */
  public boolean keyUp(Event evt, int key)
  {
    return false;
  }

  /** @deprecated */
  public boolean action(Event evt, Object what)
  {
    return false;
  }

  public void addNotify()
  {
    if (peer == null)
      peer = getToolkit().createComponent(this);

    /* Add notify children using a template method, so that it is
       possible to ensure that the new event mask delivered to the
       peer. */
    addNotifyContainerChildren();

    /* Now that all the children has gotten their peers, we should
       have the event mask needed for this component and its
       lightweight subcomponents. */

    peer.setEventMask(eventMask);

    /* We do not invalidate here, but rather leave that job up to
       the peer. For efficiency, the peer can choose not to
       invalidate if it is happy with the current dimensions,
       etc. */
  }

  void addNotifyContainerChildren() 
  {
    // nothing to do unless we're a container
  }

  public void removeNotify()
  {    
    if (peer != null)
      peer.dispose();
    peer = null;
  }
  
  /** @deprecated */
  public boolean gotFocus(Event evt, Object what)
  {
    return false;
  }
  
  /** @deprecated */
  public boolean lostFocus(Event evt, Object what)
  {
    return false;
  }

  public boolean isFocusTraversable()
  {
    return enabled && visible && (peer == null || peer.isFocusTraversable ());
  }

  public void requestFocus()
  {
    // If there's no peer then this component can't get the focus.  We
    // treat it as a silent rejection of the request.
    if (peer != null)
      peer.requestFocus ();
  }

  // This method is used to implement transferFocus().
  // CHILD is the child making the request.
  // This is overridden by Container; when called for an ordinary
  // component there is no child and so we always return null.
  Component findNextFocusComponent (Component child)
  {
    return null;
  }

  public void transferFocus()
  {
    Component next;
    if (parent == null)
      next = findNextFocusComponent (null);
    else
      next = parent.findNextFocusComponent (this);
    if (next != null && next != this)
      next.requestFocus ();
  }

  /** @deprecated */
  public void nextFocus()
  {
    transferFocus();
  }

  /** @since 1.2 */
  public boolean hasFocus()
  {
    return hasFocus;
  }

  public synchronized void add(PopupMenu popup)
  {
    if (popups == null)
      popups = new Vector();
    popups.addElement(popup);    
  }

  public synchronized void remove(MenuComponent popup)
  {
    popups.removeElement(popup);
  }

  protected String paramString()
  {
    StringBuffer param = new StringBuffer();
    String name = getName();
    if (name != null)
      {
	param.append(name);
	param.append(",");
      }
    param.append(width);
    param.append("x");
    param.append(height);
    param.append("+");
    param.append(x);
    param.append("+");
    param.append(y);
    
    if (!isValid())
      param.append(",invalid");
    if (!isVisible())
      param.append(",invisible");
    if (!isEnabled())
      param.append(",disabled");
    if (!isOpaque())
      param.append(",translucent");
    if (isDoubleBuffered())
      param.append(",doublebuffered");
    
    return param.toString();
  }

  public String toString()
  {
    return this.getClass().getName() + "[" + paramString() + "]";
  }

  public void list ()
  {
    list (System.out, 0);
  }

  public void list (PrintStream out)
  {
    list (out, 0);
  }

  public void list (PrintStream out, int indent)
  {
    for (int i = 0; i < indent; ++i)
      out.print (' ');
    out.println (toString ());
  }

  public void list (PrintWriter out)
  {
    list (out, 0);
  }

  public void list (PrintWriter out, int indent)
  {
    for (int i = 0; i < indent; ++i)
      out.print (' ');
    out.println (toString ());
  }

  public void addPropertyChangeListener(PropertyChangeListener listener)
  {
    if (changeSupport == null)
      changeSupport = new PropertyChangeSupport(this);
    changeSupport.addPropertyChangeListener(listener);
  }

  public void removePropertyChangeListener(PropertyChangeListener listener)
  {
    if (changeSupport != null)
      changeSupport.removePropertyChangeListener(listener);         
  }

  public void addPropertyChangeListener(String propertyName,
                                	PropertyChangeListener listener)
  {
    if (changeSupport == null)
      changeSupport = new PropertyChangeSupport(this);
    changeSupport.addPropertyChangeListener(propertyName, listener);  
  }

  public void removePropertyChangeListener(String propertyName,
                                           PropertyChangeListener listener)
  {
    if (changeSupport != null)
      changeSupport.removePropertyChangeListener(propertyName, listener);
  }

  protected void firePropertyChange(String propertyName, Object oldValue, 
                                    Object newValue)
  {
    if (changeSupport != null)
      changeSupport.firePropertyChange(propertyName, oldValue, newValue);    
  }

  public void setComponentOrientation(ComponentOrientation o)
  {
    orientation = o;
  }

  public ComponentOrientation getComponentOrientation()
  {
    return orientation;
  }

  /*
  public AccessibleContext getAccessibleContext()
  {
    return accessibleContext;
  }
  */
}