/*
 * @(#)Component.java	1.357 03/04/14
 *
 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
package java.awt;

import java.io.PrintStream;
import java.io.PrintWriter;
import java.util.Vector;
import java.util.Locale;
import java.util.EventListener;
import java.util.Iterator;
import java.util.HashSet;
import java.util.Set;
import java.util.Collections;
import java.awt.peer.ComponentPeer;
import java.awt.peer.ContainerPeer;
import java.awt.peer.LightweightPeer;
import java.awt.image.BufferStrategy;
import java.awt.image.ImageObserver;
import java.awt.image.ImageProducer;
import java.awt.image.ColorModel;
import java.awt.image.VolatileImage;
import java.awt.event.*;
import java.awt.datatransfer.Transferable;
import java.awt.dnd.DnDConstants;
import java.awt.dnd.DragSource;
import java.awt.dnd.DragSourceContext;
import java.awt.dnd.DragSourceListener;
import java.awt.dnd.InvalidDnDOperationException;
import java.io.Serializable;
import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.io.IOException;
import java.beans.PropertyChangeListener;
import java.awt.event.InputMethodListener;
import java.awt.event.InputMethodEvent;
import java.awt.im.InputContext;
import java.awt.im.InputMethodRequests;
import java.awt.dnd.DropTarget;
import javax.accessibility.*;
import java.awt.GraphicsConfiguration;
import javax.accessibility.*;

import sun.security.action.GetPropertyAction;
import sun.awt.AppContext;
import sun.awt.SunToolkit;
import sun.awt.ConstrainableGraphics;
import sun.awt.DebugHelper;
import sun.awt.WindowClosingListener;
import sun.awt.WindowClosingSupport;
import sun.awt.GlobalCursorManager;
import sun.awt.dnd.SunDropTargetEvent;
import sun.awt.im.CompositionArea;

/**
 * A <em>component</em> is an object having a graphical representation
 * that can be displayed on the screen and that can interact with the
 * user. Examples of components are the buttons, checkboxes, and scrollbars
 * of a typical graphical user interface. <p>
 * The <code>Component</code> class is the abstract superclass of
 * the nonmenu-related Abstract Window Toolkit components. Class
 * <code>Component</code> can also be extended directly to create a
 * lightweight component. A lightweight component is a component that is
 * not associated with a native opaque window.
 * <p>
 * <h3>Serialization</h3>
 * It is important to note that only AWT listeners which conform
 * to the <code>Serializable</code> protocol will be saved when
 * the object is stored.  If an AWT object has listeners that
 * aren't marked serializable, they will be dropped at
 * <code>writeObject</code> time.  Developers will need, as always,
 * to consider the implications of making an object serializable.
 * One situation to watch out for is this:
 * <pre>
 *    import java.awt.*;
 *    import java.awt.event.*;
 *    import java.io.Serializable;
 *    
 *    class MyApp implements ActionListener, Serializable
 *    {
 *        BigObjectThatShouldNotBeSerializedWithAButton bigOne;
 *        Button aButton = new Button();
 *      
 *        MyApp()
 *        {
 *            // Oops, now aButton has a listener with a reference
 *            // to bigOne!
 *            aButton.addActionListener(this);
 *        }
 *    
 *        public void actionPerformed(ActionEvent e)
 *        {
 *            System.out.println("Hello There");
 *        }
 *    }
 * </pre>
 * In this example, serializing <code>aButton</code> by itself
 * will cause <code>MyApp</code> and everything it refers to
 * to be serialized as well.  The problem is that the listener
 * is serializable by coincidence, not by design.  To separate
 * the decisions about <code>MyApp</code> and the 
 * <code>ActionListener</code> being serializable one can use a 
 * nested class, as in the following example:
 * <pre>
 *    import java.awt.*;
 *    import java.awt.event.*;
 *    import java.io.Serializable;
 *
 *    class MyApp java.io.Serializable
 *    {
 *         BigObjectThatShouldNotBeSerializedWithAButton bigOne;
 *         Button aButton = new Button();
 *
 *         class MyActionListener implements ActionListener
 *         {
 *             public void actionPerformed(ActionEvent e)
 *             {
 *                 System.out.println("Hello There");
 *             }
 *         }
 * 
 *         MyApp()
 *         {
 *             aButton.addActionListener(new MyActionListener());
 *         }
 *    }
 * </pre>
 * <p>
 * <b>Note</b>: For more information on the paint mechanisms utilitized
 * by AWT and Swing, including information on how to write the most
 * efficient painting code, see
 * <a href="http://java.sun.com/products/jfc/tsc/articles/painting/index.html">Painting in AWT and Swing</a>.
 *
 * @version 	1.357, 04/14/03
 * @author 	Arthur van Hoff
 * @author 	Sami Shaio
 */
public abstract class Component implements ImageObserver, MenuContainer,
    Serializable
{
    /**
     * The peer of the component. The peer implements the component's
     * behavior. The peer is set when the <code>Component</code> is 
     * added to a container that also is a peer.
     * @see #addNotify
     * @see #removeNotify
     */
    transient ComponentPeer peer;

    /**
     * The parent of the object. It may be <code>null</code>
     * for top-level components.
     * @see #getParent
     */
    transient Container parent;

    /**
     * The <code>AppContext</code> of the component.  This is set in
     * the constructor and never changes.
     */
    transient AppContext appContext;

    /**
     * The x position of the component in the parent's coordinate system.
     *
     * @serial
     * @see #getLocation
     */
    int x;

    /**
     * The y position of the component in the parent's coordinate system.
     *
     * @serial
     * @see #getLocation
     */
    int y;

    /**
     * The width of the component.
     *
     * @serial
     * @see #getSize
     */
    int width;

    /**
     * The height of the component.
     *
     * @serial
     * @see #getSize
     */
    int height;

    /**
     * The foreground color for this component.
     * <code>foreground</code> can be <code>null</code>.
     *
     * @serial
     * @see #getForeground
     * @see #setForeground
     */
    Color	foreground;

    /**
     * The background color for this component.
     * <code>background</code> can be <code>null</code>.
     *
     * @serial
     * @see #getBackground
     * @see #setBackground
     */
    Color	background;

    /**
     * The font used by this component.
     * The <code>font</code> can be <code>null</code>.
     *
     * @serial
     * @see #getFont
     * @see #setFont
     */
    Font	font;

    /**
     * The font which the peer is currently using. 
     * (<code>null</code> if no peer exists.)
     */
    Font        peerFont;

    /**
     * The cursor displayed when pointer is over this component.
     * This value can be <code>null</code>.
     *
     * @serial
     * @see #getCursor
     * @see #setCursor
     */
    Cursor	cursor;

    /**
     * The locale for the component.
     *
     * @serial
     * @see #getLocale
     * @see #setLocale
     */
    Locale      locale;

    /**
     * A reference to a <code>GraphicsConfiguration</code> object
     * used to describe the characteristics of a graphics
     * destination.
     * This value can be <code>null</code>.
     *
     * @since 1.3
     * @serial
     * @see GraphicsConfiguration
     * @see #getGraphicsConfiguration
     */
    transient GraphicsConfiguration graphicsConfig = null;
	
    /**
     * A reference to a <code>BufferStrategy</code> object
     * used to manipulate the buffers on this component.
     *
     * @since 1.4
     * @see java.awt.image.BufferStrategy
     * @see #getBufferStrategy()
     */
    transient BufferStrategy bufferStrategy = null;
	
    /**
     * True when the object should ignore all repaint events.
     *
     * @since 1.4
     * @serial
     * @see #setIgnoreRepaint
     * @see #getIgnoreRepaint
     */
    boolean ignoreRepaint = false;

    /**
     * True when the object is visible. An object that is not
     * visible is not drawn on the screen.
     *
     * @serial
     * @see #isVisible
     * @see #setVisible
     */
    boolean visible = true;

    /**
     * True when the object is enabled. An object that is not
     * enabled does not interact with the user.
     *
     * @serial
     * @see #isEnabled
     * @see #setEnabled
     */
    boolean enabled = true;

    /**
     * True when the object is valid. An invalid object needs to
     * be layed out. This flag is set to false when the object
     * size is changed.
     *
     * @serial
     * @see #isValid
     * @see #validate
     * @see #invalidate
     */
    boolean valid = false;

    /**
     * The <code>DropTarget</code> associated with this component.
     *
     * @since 1.2
     * @serial 
     * @see #setDropTarget
     * @see #getDropTarget
     */
    DropTarget dropTarget;

    /**
     * @serial
     * @see #add
     */
    Vector popups;

    /**
     * A component's name.
     * This field can be <code>null</code>.
     *
     * @serial
     * @see #getName
     * @see #setName(String)
     */
    private String name;
  
    /**
     * A bool to determine whether the name has
     * been set explicitly. <code>nameExplicitlySet</code> will
     * be false if the name has not been set and
     * true if it has.
     *
     * @serial
     * @see #getName
     * @see #setName(String)
     */
    private boolean nameExplicitlySet = false;

      /**
     * Indicates whether this Component can be focused.
     *
     * @serial
     * @see #setFocusable
     * @see #isFocusable
     * @since 1.4
     */
    private boolean focusable = true;

    private static final int FOCUS_TRAVERSABLE_UNKNOWN = 0;
    private static final int FOCUS_TRAVERSABLE_DEFAULT = 1;
    private static final int FOCUS_TRAVERSABLE_SET = 2;

    /**
     * Tracks whether this Component is relying on default focus travesability.
     *
     * @serial
     * @since 1.4
     */
    private int isFocusTraversableOverridden = FOCUS_TRAVERSABLE_UNKNOWN;

    /**
     * The focus traversal keys. These keys will generate focus traversal
     * behavior for Components for which focus traversal keys are enabled. If a
     * value of null is specified for a traversal key, this Component inherits
     * that traversal key from its parent. If all ancestors of this Component
     * have null specified for that traversal key, then the current
     * KeyboardFocusManager's default traversal key is used.
     *
     * @serial
     * @see #setFocusTraversalKeys
     * @see #getFocusTraversalKeys
     * @since 1.4
     */
    Set[] focusTraversalKeys;

    private static final String[] focusTraversalKeyPropertyNames = {
        "forwardFocusTraversalKeys",
        "backwardFocusTraversalKeys",
        "upCycleFocusTraversalKeys",
        "downCycleFocusTraversalKeys"
    };

    /**
     * Indicates whether focus traversal keys are enabled for this Component.
     * Components for which focus traversal keys are disabled receive key
     * events for focus traversal keys. Components for which focus traversal
     * keys are enabled do not see these events; instead, the events are
     * automatically converted to traversal operations.
     *
     * @serial
     * @see #setFocusTraversalKeysEnabled
     * @see #getFocusTraversalKeysEnabled
     * @since 1.4
     */
    private boolean focusTraversalKeysEnabled = true;

    /**
     * The locking object for AWT component-tree and layout operations.
     *
     * @see #getTreeLock
     */
    static final Object LOCK = new AWTTreeLock();
    static class AWTTreeLock {}

    /**
     * Internal, cached size information.
     * (This field perhaps should have been transient).
     *
     * @serial
     */
    Dimension minSize;

    /**
     * Internal, cached size information
     * (This field perhaps should have been transient).
     *
     * @serial
     */
    Dimension prefSize;

    /**
     * The orientation for this component.
     * @see #getComponentOrientation
     * @see #setComponentOrientation
     */
    transient ComponentOrientation componentOrientation
                = ComponentOrientation.UNKNOWN;

    /**
     * <code>newEventsOnly</code> will be true if the event is
     * one of the event types enabled for the component.
     * It will then allow for normal processing to
     * continue.  If it is false the event is passed
     * to the component's parent and up the ancestor
     * tree until the event has been consumed.
     *
     * @serial
     * @see #dispatchEvent
     */
    boolean newEventsOnly = false;
    transient ComponentListener componentListener;
    transient FocusListener focusListener;
    transient HierarchyListener hierarchyListener;
    transient HierarchyBoundsListener hierarchyBoundsListener;
    transient KeyListener keyListener;
    transient MouseListener mouseListener;
    transient MouseMotionListener mouseMotionListener;
    transient MouseWheelListener mouseWheelListener;
    transient InputMethodListener inputMethodListener;
    
    transient RuntimeException windowClosingException = null;

    /** Internal, constants for serialization */
    final static String actionListenerK = "actionL";
    final static String adjustmentListenerK = "adjustmentL";
    final static String componentListenerK = "componentL";
    final static String containerListenerK = "containerL";
    final static String focusListenerK = "focusL";
    final static String itemListenerK = "itemL";
    final static String keyListenerK = "keyL";
    final static String mouseListenerK = "mouseL";
    final static String mouseMotionListenerK = "mouseMotionL";
    final static String mouseWheelListenerK = "mouseWheelL";
    final static String textListenerK = "textL";
    final static String ownedWindowK = "ownedL";
    final static String windowListenerK = "windowL";
    final static String inputMethodListenerK = "inputMethodL";
    final static String hierarchyListenerK = "hierarchyL";
    final static String hierarchyBoundsListenerK = "hierarchyBoundsL";
    final static String windowStateListenerK = "windowStateL";
    final static String windowFocusListenerK = "windowFocusL";

    /**
     * The <code>eventMask</code> is ONLY set by subclasses via 
     * <code>enableEvents</code>.
     * The mask should NOT be set when listeners are registered
     * so that we can distinguish the difference between when
     * listeners request events and subclasses request them.
     * One bit is used to indicate whether input methods are
     * enabled; this bit is set by <code>enableInputMethods</code> and is
     * on by default.
     *
     * @serial
     * @see #enableInputMethods
     * @see AWTEvent
     */
    long eventMask = AWTEvent.INPUT_METHODS_ENABLED_MASK;

    private static final DebugHelper dbg = DebugHelper.create(Component.class);

    /**
     * Static properties for incremental drawing.
     * @see #imageUpdate
     */
    static boolean isInc;
    static int incRate;
    static {
        /* ensure that the necessary native libraries are loaded */
	Toolkit.loadLibraries();
	/* initialize JNI field and method ids */
        if (!GraphicsEnvironment.isHeadless()) {
            initIDs();
        }

	String s = (String) java.security.AccessController.doPrivileged(
               new GetPropertyAction("awt.image.incrementaldraw"));
	isInc = (s == null || s.equals("true"));

	s = (String) java.security.AccessController.doPrivileged(
               new GetPropertyAction("awt.image.redrawrate"));
	incRate = (s != null) ? Integer.parseInt(s) : 100;
    }

    /**
     * Ease-of-use constant for <code>getAlignmentY()</code>.  
     * Specifies an alignment to the top of the component.
     * @see     #getAlignmentY
     */
    public static final float TOP_ALIGNMENT = 0.0f;

    /**
     * Ease-of-use constant for <code>getAlignmentY</code> and
     * <code>getAlignmentX</code>. Specifies an alignment to
     * the center of the component
     * @see     #getAlignmentX
     * @see     #getAlignmentY
     */
    public static final float CENTER_ALIGNMENT = 0.5f;

    /**
     * Ease-of-use constant for <code>getAlignmentY</code>.  
     * Specifies an alignment to the bottom of the component.
     * @see     #getAlignmentY
     */
    public static final float BOTTOM_ALIGNMENT = 1.0f;

    /**
     * Ease-of-use constant for <code>getAlignmentX</code>. 
     * Specifies an alignment to the left side of the component.
     * @see     #getAlignmentX
     */
    public static final float LEFT_ALIGNMENT = 0.0f;

    /**
     * Ease-of-use constant for <code>getAlignmentX</code>.
     * Specifies an alignment to the right side of the component.
     * @see     #getAlignmentX
     */
    public static final float RIGHT_ALIGNMENT = 1.0f;

    /*
     * JDK 1.1 serialVersionUID
     */
    private static final long serialVersionUID = -7644114512714619750L;

    /**
     * If any <code>PropertyChangeListeners</code> have been registered,
     * the <code>changeSupport</code> field describes them.
     *
     * @serial
     * @since 1.2
     * @see #addPropertyChangeListener
     * @see #removePropertyChangeListener
     * @see #firePropertyChange
     */
    private java.beans.PropertyChangeSupport changeSupport;

    boolean isPacked = false;

    /**
     * This object is used as a key for internal hashtables.
     */
    transient private Object privateKey = new Object();

    /**
     * Constructs a new component. Class <code>Component</code> can be
     * extended directly to create a lightweight component that does not
     * utilize an opaque native window. A lightweight component must be
     * hosted by a native container somewhere higher up in the component
     * tree (for example, by a <code>Frame</code> object).
     */
    protected Component() {
	appContext = AppContext.getAppContext();
	SunToolkit.insertTargetMapping(this, appContext);
    }

    void initializeFocusTraversalKeys() {
	focusTraversalKeys = new Set[3];
    }

    /**
     * Constructs a name for this component.  Called by <code>getName</code>
     * when the name is <code>null</code>.
     */
    String constructComponentName() {
        return null; // For strict compliance with prior platform versions, a Component
                     // that doesn't set its name should return null from
                     // getName()
    }

    /**
     * Gets the name of the component.
     * @return this component's name
     * @see    #setName
     * @since JDK1.1
     */
    public String getName() {
        if (name == null && !nameExplicitlySet) {
            synchronized(this) {
                if (name == null && !nameExplicitlySet)
                    name = constructComponentName();
            }
        }
        return name;
    }

    /**
     * Sets the name of the component to the specified string.
     * @param name  the string that is to be this 
     *		 component's name
     * @see #getName
     * @since JDK1.1
     */
    public void setName(String name) {
        synchronized(this) {
            this.name = name;
            nameExplicitlySet = true;
        }
    }

    /**
     * Gets the parent of this component.
     * @return the parent container of this component
     * @since JDK1.0
     */
    public Container getParent() {
	return getParent_NoClientCode();
    }

    // NOTE: This method may be called by privileged threads.
    //       This functionality is implemented in a package-private method 
    //       to insure that it cannot be overridden by client subclasses. 
    //       DO NOT INVOKE CLIENT CODE ON THIS THREAD!
    final Container getParent_NoClientCode() {
	return parent;
    }

    /**
     * @deprecated As of JDK version 1.1,
     * programs should not directly manipulate peers;
     * replaced by <code>boolean isDisplayable()</code>.
     */
    public ComponentPeer getPeer() {
	return peer;
    }

    /**
     * Associate a <code>DropTarget</code> with this component.
     * The <code>Component</code> will receive drops only if it
     * is enabled.
     *
     * @see #isEnabled
     * @param dt The DropTarget
     */

    public synchronized void setDropTarget(DropTarget dt) {
	if (dt == dropTarget || (dropTarget != null && dropTarget.equals(dt)))
	    return;

	DropTarget old;

	if ((old = dropTarget) != null) {
	    if (peer != null) dropTarget.removeNotify(peer);

	    DropTarget t = dropTarget;

	    dropTarget = null;

	    try {
	        t.setComponent(null);
	    } catch (IllegalArgumentException iae) {
		// ignore it.
	    }
	}

	// if we have a new one, and we have a peer, add it!

	if ((dropTarget = dt) != null) {
	    try {
	        dropTarget.setComponent(this);
	        if (peer != null) dropTarget.addNotify(peer);
	    } catch (IllegalArgumentException iae) {
		if (old != null) {
		    try {
	        	old.setComponent(this);
	        	if (peer != null) dropTarget.addNotify(peer);
		    } catch (IllegalArgumentException iae1) {
			// ignore it!
		    }
		}
	    }
	}
    }

    /**
     * Gets the <code>DropTarget</code> associated with this 
     * <code>Component</code>.
     */

    public synchronized DropTarget getDropTarget() { return dropTarget; }

    /**
     * Gets the <code>GraphicsConfiguration</code> associated with this
     * <code>Component</code>.
     * If the <code>Component</code> has not been assigned a specific
     * <code>GraphicsConfiguration</code>,
     * the <code>GraphicsConfiguration</code> of the 
     * <code>Component</code> object's top-level container is
     * returned.
     * If the <code>Component</code> has been created, but not yet added
     * to a <code>Container</code>, this method returns <code>null</code>.
     *
     * @return the <code>GraphicsConfiguration</code> used by this
     * 		<code>Component</code> or <code>null</code>
     * @since 1.3
     */
    public GraphicsConfiguration getGraphicsConfiguration() {
        synchronized(getTreeLock()) {
            if (graphicsConfig != null) {
                return graphicsConfig;
            } else if (getParent() != null) {
                return getParent().getGraphicsConfiguration();
            } else {
                return null;
            }
        }
    }

    /**
     * Resets this <code>Component</code>'s
     * <code>GraphicsConfiguration</code> back to a default
     * value.  For most componenets, this is <code>null</code>.
     * Called from the Toolkit thread, so NO CLIENT CODE.
     */
	void resetGC() {
		synchronized(getTreeLock()) {
			graphicsConfig = null;
		}
	}

    /*
     * Not called on Component, but needed for Canvas and Window
     */
    void setGCFromPeer() {
        synchronized(getTreeLock()) {
            if (peer != null) { // can't imagine how this will be false, 
                                // but just in case
                graphicsConfig = peer.getGraphicsConfiguration();
            } else {
                graphicsConfig = null;
            }
        }
    }

    /**
     * Checks that this component's <code>GraphicsDevice</code>
     * <code>idString</code> matches the string argument.
     */
	void checkGD(String stringID) {
		if (graphicsConfig != null) {
			if (!graphicsConfig.getDevice().getIDstring().equals(stringID)) {
				throw new IllegalArgumentException(
	   			"adding a container to a container on a different GraphicsDevice");
			}
		}
	}
	
    /**
     * Gets this component's locking object (the object that owns the thread
     * sychronization monitor) for AWT component-tree and layout
     * operations.
     * @return this component's locking object
     */
    public final Object getTreeLock() {
	return LOCK;
    }

    /**
     * Gets the toolkit of this component. Note that
     * the frame that contains a component controls which
     * toolkit is used by that component. Therefore if the component
     * is moved from one frame to another, the toolkit it uses may change.
     * @return  the toolkit of this component
     * @since JDK1.0
     */
    public Toolkit getToolkit() {
	return getToolkitImpl();
    }

    /*
     * This is called by the native code, so client code can't
     * be called on the toolkit thread.
     */
    final Toolkit getToolkitImpl() {
      	ComponentPeer peer = this.peer;
 	if ((peer != null) && ! (peer instanceof LightweightPeer)){
	    return peer.getToolkit();
	}
	Container parent = this.parent;
	if (parent != null) {
	    return parent.getToolkitImpl();
	}
	return Toolkit.getDefaultToolkit();
    }

    /**
     * Determines whether this component is valid. A component is valid
     * when it is correctly sized and positioned within its parent
     * container and all its children are also valid. Components are
     * invalidated when they are first shown on the screen.
     * @return <code>true</code> if the component is valid, <code>false</code>
     * otherwise
     * @see #validate
     * @see #invalidate
     * @since JDK1.0
     */
    public boolean isValid() {
	return (peer != null) && valid;
    }

    /**
     * Determines whether this component is displayable. A component is 
     * displayable when it is connected to a native screen resource.
     * <p>
     * A component is made displayable either when it is added to
     * a displayable containment hierarchy or when its containment
     * hierarchy is made displayable.
     * A containment hierarchy is made displayable when its ancestor 
     * window is either packed or made visible.
     * <p>
     * A component is made undisplayable either when it is removed from
     * a displayable containment hierarchy or when its containment hierarchy
     * is made undisplayable.  A containment hierarchy is made 
     * undisplayable when its ancestor window is disposed.
     *
     * @return <code>true</code> if the component is displayable, 
     * <code>false</code> otherwise
     * @see Container#add(Component)
     * @see Window#pack
     * @see Window#show
     * @see Container#remove(Component)
     * @see Window#dispose
     * @since 1.2
     */
    public boolean isDisplayable() {
	return getPeer() != null;
    }

    /**
     * Determines whether this component should be visible when its
     * parent is visible. Components are 
     * initially visible, with the exception of top level components such 
     * as <code>Frame</code> objects.
     * @return <code>true</code> if the component is visible,
     * <code>false</code> otherwise
     * @see #setVisible
     * @since JDK1.0
     */
    public boolean isVisible() {
	return visible;
    }

    /**
     * Determines whether this component will be displayed on the screen
     * if it's displayable.
     * @return <code>true</code> if the component and all of its ancestors
     * 		are visible, <code>false</code> otherwise
     */
    boolean isRecursivelyVisible() {
        return visible && (parent == null || parent.isRecursivelyVisible());
    }

    /**
     * Determines whether this component is showing on screen. This means
     * that the component must be visible, and it must be in a container
     * that is visible and showing.
     * @return <code>true</code> if the component is showing,
     * 		<code>false</code> otherwise
     * @see #setVisible
     * @since JDK1.0
     */
    public boolean isShowing() {
	if (visible && (peer != null)) {
    	    Container parent = this.parent;
	    return (parent == null) || parent.isShowing();
	}
	return false;
    }

    /**
     * Determines whether this component is enabled. An enabled component
     * can respond to user input and generate events. Components are
     * enabled initially by default. A component may be enabled or disabled by
     * calling its <code>setEnabled</code> method.
     * @return <code>true</code> if the component is enabled,
     * 		<code>false</code> otherwise
     * @see #setEnabled
     * @since JDK1.0
     */
    public boolean isEnabled() {
	return isEnabledImpl();
    }

    /*
     * This is called by the native code, so client code can't
     * be called on the toolkit thread.
     */
    final boolean isEnabledImpl() {
	return enabled;
    }

    /**
     * Enables or disables this component, depending on the value of the
     * parameter <code>b</code>. An enabled component can respond to user
     * input and generate events. Components are enabled initially by default.
     *
     * <p>Note: Disabling a lightweight component does not prevent it from
     * receiving MouseEvents.
     *
     * @param     b   If <code>true</code>, this component is 
     *            enabled; otherwise this component is disabled
     * @see #isEnabled
     * @see #isLightweight
     * @since JDK1.1
     */
    public void setEnabled(boolean b) {
    	enable(b);
    }

    /**
     * @deprecated As of JDK version 1.1,
     * replaced by <code>setEnabled(boolean)</code>.
     */
    public void enable() {
    	if (!enabled) {
	    synchronized (getTreeLock()) {
		enabled = true;
		ComponentPeer peer = this.peer;
		if (peer != null) {
		    peer.enable();
		    if (visible) {
        		updateCursorImmediately();
		    }
		}
	    }  
            if (accessibleContext != null) {
                accessibleContext.firePropertyChange(
                    AccessibleContext.ACCESSIBLE_STATE_PROPERTY, 
                    null, AccessibleState.ENABLED);
            }
	}
    }

    /**
     * @deprecated As of JDK version 1.1,
     * replaced by <code>setEnabled(boolean)</code>.
     */
    public void enable(boolean b) {
	if (b) {
	    enable();
	} else {
	    disable();
	}
    }

    /**
     * @deprecated As of JDK version 1.1,
     * replaced by <code>setEnabled(boolean)</code>.
     */
    public void disable() {
        if (enabled) {
            KeyboardFocusManager.clearMostRecentFocusOwner(this);
            synchronized (getTreeLock()) {
                enabled = false;
                if (isFocusOwner()) {
                    // Don't clear the global focus owner. If transferFocus
                    // fails, we want the focus to stay on the disabled
                    // Component so that keyboard traversal, et. al. still
                    // makes sense to the user.
                    autoTransferFocus(false);
                }
                ComponentPeer peer = this.peer;
                if (peer != null) {
                    peer.disable();
                    if (visible) {
                        updateCursorImmediately();
                    }
                }
            }
            if (accessibleContext != null) {
                accessibleContext.firePropertyChange(
                    AccessibleContext.ACCESSIBLE_STATE_PROPERTY,
                    null, AccessibleState.ENABLED);
            }
        }
    }

    /**
     * Returns true if this component is painted to an offscreen image
     * ("buffer") that's copied to the screen later.  Component
     * subclasses that support double buffering should override this
     * method to return true if double buffering is enabled.
     * 
     * @return false by default
     */
    public boolean isDoubleBuffered() {
        return false;
    }

    /**
     * Enables or disables input method support for this component. If input
     * method support is enabled and the component also processes key events,
     * incoming events are offered to
     * the current input method and will only be processed by the component or
     * dispatched to its listeners if the input method does not consume them.
     * By default, input method support is enabled.
     *
     * @param enable true to enable, false to disable
     * @see #processKeyEvent
     * @since 1.2
     */
    public void enableInputMethods(boolean enable) {
        if (enable) {
	    if ((eventMask & AWTEvent.INPUT_METHODS_ENABLED_MASK) != 0)
		return;

	    // If this component already has focus, then activate the
	    // input method by dispatching a synthesized focus gained
	    // event.
	    if (isFocusOwner()) {
		InputContext inputContext = getInputContext();
		if (inputContext != null) {
		    FocusEvent focusGainedEvent =
			new FocusEvent(this, FocusEvent.FOCUS_GAINED);
		    inputContext.dispatchEvent(focusGainedEvent);
		}
	    }

            eventMask |= AWTEvent.INPUT_METHODS_ENABLED_MASK;
        } else {
	    if (areInputMethodsEnabled()) {
		InputContext inputContext = getInputContext();
		if (inputContext != null) {
		    inputContext.endComposition();
		    inputContext.removeNotify(this);
		}
	    }
            eventMask &= ~AWTEvent.INPUT_METHODS_ENABLED_MASK;
        }
    }

    /**
     * Shows or hides this component depending on the value of parameter
     * <code>b</code>.
     * @param b  if <code>true</code>, shows this component;
     * otherwise, hides this component
     * @see #isVisible
     * @since JDK1.1
     */
    public void setVisible(boolean b) {
    	show(b);
    }

    /**
     * @deprecated As of JDK version 1.1,
     * replaced by <code>setVisible(boolean)</code>.
     */
    public void show() {
	if (!visible) {
	    synchronized (getTreeLock()) {
		visible = true;
    	    	ComponentPeer peer = this.peer;
		if (peer != null) {
		    peer.show();
		    createHierarchyEvents(HierarchyEvent.HIERARCHY_CHANGED,
					  this, parent,
					  HierarchyEvent.SHOWING_CHANGED,
                                          Toolkit.enabledOnToolkit(AWTEvent.HIERARCHY_EVENT_MASK));
		    if (peer instanceof LightweightPeer) {
			repaint();
		    }
        	    updateCursorImmediately();
		}

                if (componentListener != null ||
                    (eventMask & AWTEvent.COMPONENT_EVENT_MASK) != 0 ||
                    Toolkit.enabledOnToolkit(AWTEvent.COMPONENT_EVENT_MASK)) {
                    ComponentEvent e = new ComponentEvent(this,
                                     ComponentEvent.COMPONENT_SHOWN);
                    Toolkit.getEventQueue().postEvent(e);
                }
	    }
    	    Container parent = this.parent;
	    if (parent != null) {
		parent.invalidate();
	    }
	}
    }

    /**
     * @deprecated As of JDK version 1.1,
     * replaced by <code>setVisible(boolean)</code>.
     */
    public void show(boolean b) {
	if (b) {
	    show();
	} else {
            isPacked = false;
	    hide();
	}
    }

    boolean containsFocus() {
        return isFocusOwner();
    }

    void clearMostRecentFocusOwnerOnHide() {
        KeyboardFocusManager.clearMostRecentFocusOwner(this);
    }

    void clearCurrentFocusCycleRootOnHide() {
        /* do nothing */
    }

    /**
     * @deprecated As of JDK version 1.1,
     * replaced by <code>setVisible(boolean)</code>.
     */
    public void hide() {
        if (visible) {
            clearCurrentFocusCycleRootOnHide();
            clearMostRecentFocusOwnerOnHide();
            synchronized (getTreeLock()) {
                visible = false;
                if (containsFocus()) {
                    autoTransferFocus(true);
                }
                ComponentPeer peer = this.peer;
                if (peer != null) {
                    peer.hide();
                    createHierarchyEvents(HierarchyEvent.HIERARCHY_CHANGED,
                                          this, parent,
                                          HierarchyEvent.SHOWING_CHANGED,
                                          Toolkit.enabledOnToolkit(AWTEvent.HIERARCHY_EVENT_MASK));
                    if (peer instanceof LightweightPeer) {
                        repaint();
                    }
                    updateCursorImmediately();
                }
                if (componentListener != null ||
                    (eventMask & AWTEvent.COMPONENT_EVENT_MASK) != 0 ||
                    Toolkit.enabledOnToolkit(AWTEvent.COMPONENT_EVENT_MASK)) {
                    ComponentEvent e = new ComponentEvent(this,
                                     ComponentEvent.COMPONENT_HIDDEN);
                    Toolkit.getEventQueue().postEvent(e);
                }
            }
            Container parent = this.parent;
            if (parent != null) {
                parent.invalidate();
            }
        }
    }

    /**
     * Gets the foreground color of this component.
     * @return this component's foreground color; if this component does
     * not have a foreground color, the foreground color of its parent
     * is returned
     * @see #setForeground
     * @since JDK1.0
     * @beaninfo
     *       bound: true
     */
    public Color getForeground() {
      	Color foreground = this.foreground;
	if (foreground != null) {
	    return foreground;
	}
    	Container parent = this.parent;
	return (parent != null) ? parent.getForeground() : null;
    }

    /**
     * Sets the foreground color of this component.
     * @param c the color to become this component's 
     * 		foreground color; if this parameter is <code>null</code>
     *		then this component will inherit
     * 		the foreground color of its parent
     * @see #getForeground
     * @since JDK1.0
     */
    public void setForeground(Color c) {
	Color oldColor = foreground;
	ComponentPeer peer = this.peer;
	foreground = c;
	if (peer != null) {
	    c = getForeground();
	    if (c != null) {
		peer.setForeground(c);
	    }
	}
	// This is a bound property, so report the change to
	// any registered listeners.  (Cheap if there are none.)
	firePropertyChange("foreground", oldColor, c);
    }

    /**
     * Returns whether the foreground color has been explicitly set for this
     * Component. If this method returns <code>false</code>, this Component is
     * inheriting its foreground color from an ancestor.
     *
     * @return <code>true</code> if the foreground color has been explicitly
     *         set for this Component; <code>false</code> otherwise.
     * @since 1.4
     */
    public boolean isForegroundSet() {
        return (foreground != null);
    }

    /**
     * Gets the background color of this component.
     * @return this component's background color; if this component does
     * 		not have a background color,
     *		the background color of its parent is returned
     * @see #setBackground
     * @since JDK1.0
     */
    public Color getBackground() {
        Color background = this.background;
	if (background != null) {
	    return background;
	}
    	Container parent = this.parent;
	return (parent != null) ? parent.getBackground() : null;
    }

    /**
     * Sets the background color of this component.
     * <p>
     * The background color affects each component differently and the
     * parts of the component that are affected by the background color 
     * may differ between operating systems.
     *
     * @param c the color to become this component's color;
     * 		if this parameter is <code>null</code>, then this
     *		component will inherit the background color of its parent
     * @see #getBackground
     * @since JDK1.0
     * @beaninfo
     *       bound: true
     */
    public void setBackground(Color c) {
	Color oldColor = background;
	ComponentPeer peer = this.peer;
	background = c;
	if (peer != null) {
	    c = getBackground();
	    if (c != null) {
		peer.setBackground(c);
	    }
	}
	// This is a bound property, so report the change to
	// any registered listeners.  (Cheap if there are none.)
	firePropertyChange("background", oldColor, c);
    }

    /**
     * Returns whether the background color has been explicitly set for this
     * Component. If this method returns <code>false</code>, this Component is
     * inheriting its background color from an ancestor.
     *
     * @return <code>true</code> if the background color has been explicitly
     *         set for this Component; <code>false</code> otherwise.
     * @since 1.4
     */
    public boolean isBackgroundSet() {
        return (background != null);
    }

    /**
     * Gets the font of this component.
     * @return this component's font; if a font has not been set
     * for this component, the font of its parent is returned
     * @see #setFont
     * @since JDK1.0
     */
    public Font getFont() {
	return getFont_NoClientCode();
    }

    // NOTE: This method may be called by privileged threads.
    //       This functionality is implemented in a package-private method 
    //       to insure that it cannot be overridden by client subclasses. 
    //       DO NOT INVOKE CLIENT CODE ON THIS THREAD!
    final Font getFont_NoClientCode() {
        Font font = this.font;
	if (font != null) {
	    return font;
	}
    	Container parent = this.parent;
	return (parent != null) ? parent.getFont_NoClientCode() : null;
    }

    /**
     * Sets the font of this component.
     * @param f the font to become this component's font;
     * 		if this parameter is <code>null</code> then this
     *		component will inherit the font of its parent
     * @see #getFont
     * @since JDK1.0
     * @beaninfo
     *       bound: true
    */
    public void setFont(Font f) {
        Font oldFont, newFont;
        synchronized (this) {
            oldFont = font;
            ComponentPeer peer = this.peer;
            newFont = font = f;
            if (peer != null) {
                f = getFont();
                if (f != null) {
                    peer.setFont(f);
                    peerFont = f;
                }
            }
        }
        // This is a bound property, so report the change to
        // any registered listeners.  (Cheap if there are none.)
        firePropertyChange("font", oldFont, newFont);

        // This could change the preferred size of the Component.
        if (valid) {
            invalidate();
        }
    }

    /**
     * Returns whether the font has been explicitly set for this Component. If
     * this method returns <code>false</code>, this Component is inheriting its
     * font from an ancestor.
     *
     * @return <code>true</code> if the font has been explicitly set for this
     *         Component; <code>false</code> otherwise.
     * @since 1.4
     */
    public boolean isFontSet() {
        return (font != null);
    }

    /**
     * Gets the locale of this component.
     * @return this component's locale; if this component does not
     * 		have a locale, the locale of its parent is returned
     * @see #setLocale
     * @exception IllegalComponentStateException if the <code>Component</code>
     * 		does not have its own locale and has not yet been added to
     * 		a containment hierarchy such that the locale can be determined
     * 		from the containing parent
     * @since  JDK1.1
     */
    public Locale getLocale() {
        Locale locale = this.locale;
	if (locale != null) {
	  return locale;
	}
    	Container parent = this.parent;

	if (parent == null) {
	    throw new IllegalComponentStateException("This component must have a parent in order to determine its locale");
	} else {
	    return parent.getLocale();
	}
    }

    /**
     * Sets the locale of this component.  This is a bound property.
     * @param l the locale to become this component's locale
     * @see #getLocale
     * @since JDK1.1
     */
    public void setLocale(Locale l) {
        Locale oldValue = locale;
	locale = l;

	// This is a bound property, so report the change to
	// any registered listeners.  (Cheap if there are none.)
	firePropertyChange("locale", oldValue, l);

	// This could change the preferred size of the Component.
	if (valid) {
	    invalidate();
	}
    }

    /**
     * Gets the instance of <code>ColorModel</code> used to display
     * the component on the output device.
     * @return the color model used by this component
     * @see java.awt.image.ColorModel
     * @see java.awt.peer.ComponentPeer#getColorModel()
     * @see Toolkit#getColorModel()
     * @since JDK1.0
     */
    public ColorModel getColorModel() {
    	ComponentPeer peer = this.peer;
	if ((peer != null) && ! (peer instanceof LightweightPeer)) {
	    return peer.getColorModel();
	} else if (GraphicsEnvironment.isHeadless()) {
            return ColorModel.getRGBdefault();
	} // else
	return getToolkit().getColorModel();
    }

    /**
     * Gets the location of this component in the form of a
     * point specifying the component's top-left corner.
     * The location will be relative to the parent's coordinate space.
     * <p>
     * Due to the asynchronous nature of native event handling, this
     * method can return outdated values (for instance, after several calls
     * of <code>setLocation()</code> in rapid succession).  For this
     * reason, the recommended method of obtaining a component's position is 
     * within <code>java.awt.event.ComponentListener.componentMoved()</code>,
     * which is called after the operating system has finished moving the 
     * component.
     * </p>
     * @return an instance of <code>Point</code> representing
     * 		the top-left corner of the component's bounds in
     *		the coordinate space of the component's parent
     * @see #setLocation
     * @see #getLocationOnScreen
     * @since JDK1.1
     */
    public Point getLocation() {
	return location();
    }

    /**
     * Gets the location of this component in the form of a point
     * specifying the component's top-left corner in the screen's
     * coordinate space.
     * @return an instance of <code>Point</code> representing
     * 		the top-left corner of the component's bounds in the
     * 		coordinate space of the screen
     * @throws <code>IllegalComponentStateException</code> if the
     * 		component is not showing on the screen
     * @see #setLocation
     * @see #getLocation
     */
    public Point getLocationOnScreen() {
	synchronized (getTreeLock()) {
	    return getLocationOnScreen_NoTreeLock();
	}
    }

    /* 
     * a package private version of getLocationOnScreen
     * used by GlobalCursormanager to update cursor
     */
    final Point getLocationOnScreen_NoTreeLock() {
	
	if (peer != null && isShowing()) {
	    if (peer instanceof LightweightPeer) {
		// lightweight component location needs to be translated
		// relative to a native component.
		Container host = getNativeContainer();
		Point pt = host.peer.getLocationOnScreen();
		for(Component c = this; c != host; c = c.getParent()) {
		    pt.x += c.x;
		    pt.y += c.y;
		}
		return pt;
	    } else {
		Point pt = peer.getLocationOnScreen();
		return pt;
	    }
	} else {
	    throw new IllegalComponentStateException("component must be showing on the screen to determine its location");
	}
    }
    
    
    /**
     * @deprecated As of JDK version 1.1,
     * replaced by <code>getLocation()</code>.
     */
    public Point location() {
	return new Point(x, y);
    }
    
    /**
     * Moves this component to a new location. The top-left corner of
     * the new location is specified by the <code>x</code> and <code>y</code>
     * parameters in the coordinate space of this component's parent.
     * @param x the <i>x</i>-coordinate of the new location's 
     * 		top-left corner in the parent's coordinate space
     * @param y the <i>y</i>-coordinate of the new location's 
     * 		top-left corner in the parent's coordinate space
     * @see #getLocation
     * @see #setBounds
     * @since JDK1.1
     */
    public void setLocation(int x, int y) {
	move(x, y);
    }
    
    /**
     * @deprecated As of JDK version 1.1,
     * replaced by <code>setLocation(int, int)</code>.
     */
    public void move(int x, int y) {
	setBounds(x, y, width, height);
    }

    /**
     * Moves this component to a new location. The top-left corner of
     * the new location is specified by point <code>p</code>. Point
     * <code>p</code> is given in the parent's coordinate space.
     * @param p the point defining the top-left corner 
     * 		of the new location, given in the coordinate space of this 
     * 		component's parent
     * @see #getLocation
     * @see #setBounds
     * @since JDK1.1
     */
    public void setLocation(Point p) {
    	setLocation(p.x, p.y);
    }

    /**
     * Returns the size of this component in the form of a
     * <code>Dimension</code> object. The <code>height</code>
     * field of the <code>Dimension</code> object contains
     * this component's height, and the <code>width</code>
     * field of the <code>Dimension</code> object contains
     * this component's width.
     * @return a <code>Dimension</code> object that indicates the
     * 		size of this component
     * @see #setSize
     * @since JDK1.1
     */
    public Dimension getSize() {
	return size();
    }

    /**
     * @deprecated As of JDK version 1.1,
     * replaced by <code>getSize()</code>.
     */
    public Dimension size() {
	return new Dimension(width, height);
    }

    /**
     * Resizes this component so that it has width <code>width</code>
     * and height <code>height</code>.
     * @param width the new width of this component in pixels