/*******************************************************************************
 * Copyright (c) 2000, 2008 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.widgets;


import org.eclipse.swt.internal.*;
import org.eclipse.swt.internal.wpf.*;
import org.eclipse.swt.internal.win32.*;
import org.eclipse.swt.*;
import org.eclipse.swt.events.*;

/**
 * This class is the abstract superclass of all user interface objects.  
 * Widgets are created, disposed and issue notification to listeners
 * when events occur which affect them.
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>(none)</dd>
 * <dt><b>Events:</b></dt>
 * <dd>Dispose</dd>
 * </dl>
 * <p>
 * IMPORTANT: This class is intended to be subclassed <em>only</em>
 * within the SWT implementation. However, it has not been marked
 * final to allow those outside of the SWT development team to implement
 * patched versions of the class in order to get around specific
 * limitations in advance of when those limitations can be addressed
 * by the team.  Any class built using subclassing to access the internals
 * of this class will likely fail to compile or run between releases and
 * may be strongly platform specific. Subclassing should not be attempted
 * without an intimate and detailed understanding of the workings of the
 * hierarchy. No support is provided for user-written classes which are
 * implemented as subclasses of this class.
 * </p>
 *
 * @see #checkSubclass
 * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
 */

public abstract class Widget {
	/**
	 * the handle to the OS resource 
	 * (Warning: This field is platform dependent)
	 * <p>
	 * <b>IMPORTANT:</b> This field is <em>not</em> part of the SWT
	 * public API. It is marked public only so that it can be shared
	 * within the packages provided by SWT. It is not available on all
	 * platforms and should never be accessed from application code.
	 * </p>
	 * 
	 * @noreference This field is not intended to be referenced by clients.
	 */
	public int handle;
	int jniRef;
	int style, state;
	Display display;
	EventTable eventTable;
	Object data;

	/* Global state flags */
	static final int DISPOSED		= 1<<0;
	static final int CANVAS			= 1<<1;
	static final int KEYED_DATA		= 1<<2;
	static final int DISABLED		= 1<<3;
	static final int HIDDEN			= 1<<4;
	
	/* A layout was requested on this widget */
	static final int LAYOUT_NEEDED	= 1<<5;
	
	/* The preferred size of a child has changed */
	static final int LAYOUT_CHANGED = 1<<6;
	
	/* A layout was requested in this widget hierachy */
	static final int LAYOUT_CHILD = 1<<7;

	/* Background flags */
	static final int THEME_BACKGROUND = 1<<8;
	static final int DRAW_BACKGROUND = 1<<9;
	static final int PARENT_BACKGROUND = 1<<10;
	
	/* Dispose and release flags */
	static final int RELEASED		= 1<<11;
	static final int DISPOSE_SENT	= 1<<12;
	
	static final int MOVED		= 1<<13;
	static final int RESIZED	= 1<<14;
	
	/* DragDetect */
	static final int DRAG_DETECT	= 1<<15;
	
	/* Notify of the opportunity to skin this widget */
	static final int SKIN_NEEDED = 1<<16;
	
	/* Default size for widgets */
	static final int DEFAULT_WIDTH	= 64;
	static final int DEFAULT_HEIGHT	= 64;


	static final int CLICK = 1;
	
/**
 * Prevents uninitialized instances from being created outside the package.
 */
Widget () {
}

/**
 * Constructs a new instance of this class given its parent
 * and a style value describing its behavior and appearance.
 * <p>
 * The style value is either one of the style constants defined in
 * class <code>SWT</code> which is applicable to instances of this
 * class, or must be built by <em>bitwise OR</em>'ing together 
 * (that is, using the <code>int</code> "|" operator) two or more
 * of those <code>SWT</code> style constants. The class description
 * lists the style constants that are applicable to the class.
 * Style bits are also inherited from superclasses.
 * </p>
 *
 * @param parent a widget which will be the parent of the new instance (cannot be null)
 * @param style the style of widget to construct
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the parent is disposed</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
 *    <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
 * </ul>
 *
 * @see SWT
 * @see #checkSubclass
 * @see #getStyle
 */
public Widget (Widget parent, int style) {
	checkSubclass ();
	checkParent (parent);
	this.style = style;
	display = parent.display;
	reskinWidget ();
}

void _addListener (int eventType, Listener listener) {
	if (eventTable == null) eventTable = new EventTable ();
	eventTable.hook (eventType, listener);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when an event of the given type occurs. When the
 * event does occur in the widget, the listener is notified by
 * sending it the <code>handleEvent()</code> message. The event
 * type is one of the event constants defined in class <code>SWT</code>.
 *
 * @param eventType the type of event to listen for
 * @param listener the listener which should be notified when the event occurs
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see Listener
 * @see SWT
 * @see #getListeners(int)
 * @see #removeListener(int, Listener)
 * @see #notifyListeners
 */
public void addListener (int eventType, Listener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	_addListener (eventType, listener);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when the widget is disposed. When the widget is
 * disposed, the listener is notified by sending it the
 * <code>widgetDisposed()</code> message.
 *
 * @param listener the listener which should be notified when the receiver is disposed
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see DisposeListener
 * @see #removeDisposeListener
 */
public void addDisposeListener (DisposeListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.Dispose, typedListener);
}

void addWidget () {
}

/**
 * Returns a style with exactly one style bit set out of
 * the specified set of exclusive style bits. All other
 * possible bits are cleared when the first matching bit
 * is found. Bits that are not part of the possible set
 * are untouched.
 *
 * @param style the original style bits
 * @param int0 the 0th possible style bit
 * @param int1 the 1st possible style bit
 * @param int2 the 2nd possible style bit
 * @param int3 the 3rd possible style bit
 * @param int4 the 4th possible style bit
 * @param int5 the 5th possible style bit
 *
 * @return the new style bits
 */
static int checkBits (int style, int int0, int int1, int int2, int int3, int int4, int int5) {
	int mask = int0 | int1 | int2 | int3 | int4 | int5;
	if ((style & mask) == 0) style |= int0;
	if ((style & int0) != 0) style = (style & ~mask) | int0;
	if ((style & int1) != 0) style = (style & ~mask) | int1;
	if ((style & int2) != 0) style = (style & ~mask) | int2;
	if ((style & int3) != 0) style = (style & ~mask) | int3;
	if ((style & int4) != 0) style = (style & ~mask) | int4;
	if ((style & int5) != 0) style = (style & ~mask) | int5;
	return style;
}

boolean checkEvent (int e) {
	if (isDisposed ()) return false;
	int routedEventType =  OS.RoutedEventArgs_typeid ();
	int source = 0;
	if (OS.Type_IsInstanceOfType (routedEventType, e)) {
		source = OS.RoutedEventArgs_OriginalSource (e);
	}
	OS.GCHandle_Free (routedEventType);
	if (source == 0) return true;
	if (OS.Object_Equals (source, handle)) {
		OS.GCHandle_Free (source);
		return true;
	}
	Widget widget = display.getWidget (source);
	OS.GCHandle_Free (source);
	if (widget == this) return true;
	if (hasItems ()) {
		if (this == widget.getWidgetControl ()) return true;
	} 
	return false;
}

void checkOrientation (Widget parent) {
	style &= ~SWT.MIRRORED;
	if ((style & (SWT.LEFT_TO_RIGHT | SWT.RIGHT_TO_LEFT)) == 0) {
		if (parent != null) {
			if ((parent.style & SWT.LEFT_TO_RIGHT) != 0) style |= SWT.LEFT_TO_RIGHT;
			if ((parent.style & SWT.RIGHT_TO_LEFT) != 0) style |= SWT.RIGHT_TO_LEFT;
		}
	}
	style = checkBits (style, SWT.LEFT_TO_RIGHT, SWT.RIGHT_TO_LEFT, 0, 0, 0, 0);
}

void checkOpened () {
	/* Do nothing */
}

/**
 * Throws an exception if the specified widget can not be
 * used as a parent for the receiver.
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the parent is disposed</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
 * </ul>
 */
void checkParent (Widget parent) {
	if (parent == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (parent.isDisposed ()) error (SWT.ERROR_INVALID_ARGUMENT);
	parent.checkWidget ();
	parent.checkOpened ();
}

/**
 * Checks that this class can be subclassed.
 * <p>
 * The SWT class library is intended to be subclassed 
 * only at specific, controlled points (most notably, 
 * <code>Composite</code> and <code>Canvas</code> when
 * implementing new widgets). This method enforces this
 * rule unless it is overridden.
 * </p><p>
 * <em>IMPORTANT:</em> By providing an implementation of this
 * method that allows a subclass of a class which does not 
 * normally allow subclassing to be created, the implementer
 * agrees to be fully responsible for the fact that any such
 * subclass will likely fail between SWT releases and will be
 * strongly platform specific. No support is provided for
 * user-written classes which are implemented in this fashion.
 * </p><p>
 * The ability to subclass outside of the allowed SWT classes
 * is intended purely to enable those not on the SWT development
 * team to implement patches in order to get around specific
 * limitations in advance of when those limitations can be
 * addressed by the team. Subclassing should not be attempted
 * without an intimate and detailed understanding of the hierarchy.
 * </p>
 *
 * @exception SWTException <ul>
 *    <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
 * </ul>
 */
protected void checkSubclass () {
	if (!isValidSubclass ()) error (SWT.ERROR_INVALID_SUBCLASS);
}

/**
 * Throws an <code>SWTException</code> if the receiver can not
 * be accessed by the caller. This may include both checks on
 * the state of the receiver and more generally on the entire
 * execution context. This method <em>should</em> be called by
 * widget implementors to enforce the standard SWT invariants.
 * <p>
 * Currently, it is an error to invoke any method (other than
 * <code>isDisposed()</code>) on a widget that has had its 
 * <code>dispose()</code> method called. It is also an error
 * to call widget methods from any thread that is different
 * from the thread that created the widget.
 * </p><p>
 * In future releases of SWT, there may be more or fewer error
 * checks and exceptions may be thrown for different reasons.
 * </p>
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
protected void checkWidget () {
	Display display = this.display;
	if (display == null) error (SWT.ERROR_WIDGET_DISPOSED);
	if (display.thread != Thread.currentThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
	if ((state & DISPOSED) != 0) error (SWT.ERROR_WIDGET_DISPOSED);
}

void createHandle () {
}

int createDotNetString (String string, boolean fixMnemonic) {
	if (string == null) return 0;
	char [] buffer;
	if (fixMnemonic) {
		buffer = fixMnemonic (string); 
	} else {
		int length = string.length ();
		buffer = new char [length + 1];
		string.getChars (0, length, buffer, 0);
	}
	int ptr = OS.gcnew_String (buffer);
	if (ptr == 0) error (SWT.ERROR_NO_HANDLES);
	return ptr;
}

static String createJavaString (int ptr) {
	int charArray = OS.String_ToCharArray (ptr);
	char[] chars = new char[OS.String_Length (ptr)];
	OS.memcpy (chars, charArray, chars.length * 2);
	OS.GCHandle_Free (charArray);
	return new String (chars);
}

void createWidget () {
	jniRef = OS.NewGlobalRef (this);
	if (jniRef == 0) error (SWT.ERROR_NO_HANDLES);
	createHandle ();
	addWidget ();
	register ();
	hookEvents ();
	setNameScope ();
}

void deregister () {
}

/**
 * Destroys the widget in the operating system and releases
 * the widget's handle.  If the widget does not have a handle,
 * this method may hide the widget, mark the widget as destroyed
 * or do nothing, depending on the widget.
 * <p>
 * When a widget is destroyed in the operating system, its
 * descendents are also destroyed by the operating system.
 * This means that it is only necessary to call <code>destroyWidget</code>
 * on the root of the widget tree.
 * </p><p>
 * This method is called after <code>releaseWidget()</code>.
 * </p><p>
 * See also <code>releaseChild()</code>, <code>releaseWidget()</code>
 * and <code>releaseHandle()</code>.
 * </p>
 * 
 * @see #dispose
 */
void destroyWidget () {
	releaseHandle ();
}

/**
 * Disposes of the operating system resources associated with
 * the receiver and all its descendants. After this method has
 * been invoked, the receiver and all descendants will answer
 * <code>true</code> when sent the message <code>isDisposed()</code>.
 * Any internal connections between the widgets in the tree will
 * have been removed to facilitate garbage collection.
 * This method does nothing if the widget is already disposed.
 * <p>
 * NOTE: This method is not called recursively on the descendants
 * of the receiver. This means that, widget implementers can not
 * detect when a widget is being disposed of by re-implementing
 * this method, but should instead listen for the <code>Dispose</code>
 * event.
 * </p>
 *
 * @exception SWTException <ul>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see #addDisposeListener
 * @see #removeDisposeListener
 * @see #checkWidget
 */
public void dispose () {
	/*
	* Note:  It is valid to attempt to dispose a widget
	* more than once.  If this happens, fail silently.
	*/
	if (isDisposed ()) return;
	if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
	release (true);
}

boolean dragOverride () {
	return false;
}

static void dumpObjectType (int object) {
	int objectType = OS.Object_GetType(object);
	int type = OS.Type_FullName(objectType);
	String typeName = createJavaString(type);
	OS.GCHandle_Free(objectType);
	OS.GCHandle_Free(type);
	System.out.println(typeName);
}

void dumpVisualTree (int visual, int depth) {
	for (int i = 0; i < depth; i++) System.out.print ("\t");
	int type = OS.Object_GetType (visual);
	int typeNamePtr = OS.Type_FullName (type);
	OS.GCHandle_Free (type);
	String typeName = createJavaString (typeNamePtr);
	OS.GCHandle_Free(typeNamePtr);
	int name = OS.FrameworkElement_Name (visual);
	double width = OS.FrameworkElement_Width (visual);
	double actualWidth = OS.FrameworkElement_ActualWidth (visual);
	double height = OS.FrameworkElement_Height (visual);
	double actualHeight = OS.FrameworkElement_ActualHeight (visual);
	String widgetName = createJavaString (name);
	OS.GCHandle_Free (name);
	System.out.println(typeName + " ["+widgetName+ " width=" + width + " actualWidth=" + actualWidth + " height=" + height + " actualHeight=" + actualHeight+"]");
	int count = OS.VisualTreeHelper_GetChildrenCount(visual);
	for (int i = 0; i < count; i++) {
		int child = OS.VisualTreeHelper_GetChild (visual, i);
		dumpVisualTree(child, depth+1);
		OS.GCHandle_Free(child);
	}	
}
/**
 * Does whatever widget specific cleanup is required, and then
 * uses the code in <code>SWTError.error</code> to handle the error.
 *
 * @param code the descriptive error code
 *
 * @see SWT#error(int)
 */
void error (int code) {
	SWT.error(code);
}

boolean filters (int eventType) {
	return display.filters (eventType);
}

char [] fixMnemonic (String string) {
	int length = string.length ();
	char [] text = new char [length];
	string.getChars (0, length, text, 0);
	int i = 0, j = 0;
	char [] result = new char [length * 2 + 1];
	while (i < length) {
		switch (text [i]) {
			case '&':
				if (i + 1 < length && text [i + 1] == '&') {
					i++; 
				} else {
					text [i] = '_';
				}
				break;
			case '_':
				result [j++] = '_';
				break;
		}
		result [j++] = text [i++];
	}
	return result;
}

/**
 * Returns the application defined widget data associated
 * with the receiver, or null if it has not been set. The
 * <em>widget data</em> is a single, unnamed field that is
 * stored with every widget. 
 * <p>
 * Applications may put arbitrary objects in this field. If
 * the object stored in the widget data needs to be notified
 * when the widget is disposed of, it is the application's
 * responsibility to hook the Dispose event on the widget and
 * do so.
 * </p>
 *
 * @return the widget data
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - when the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - when called from the wrong thread</li>
 * </ul>
 *
 * @see #setData(Object)
 */
public Object getData () {
	checkWidget();
	return (state & KEYED_DATA) != 0 ? ((Object []) data) [0] : data;
}

/**
 * Returns the application defined property of the receiver
 * with the specified name, or null if it has not been set.
 * <p>
 * Applications may have associated arbitrary objects with the
 * receiver in this fashion. If the objects stored in the
 * properties need to be notified when the widget is disposed
 * of, it is the application's responsibility to hook the
 * Dispose event on the widget and do so.
 * </p>
 *
 * @param	key the name of the property
 * @return the value of the property or null if it has not been set
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the key is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see #setData(String, Object)
 */
public Object getData (String key) {
	checkWidget();
	if (key == null) error (SWT.ERROR_NULL_ARGUMENT);
	if ((state & KEYED_DATA) != 0) {
		Object [] table = (Object []) data;
		for (int i=1; i<table.length; i+=2) {
			if (key.equals (table [i])) return table [i+1];
		}
	}
	return null;
}

/**
 * Returns the <code>Display</code> that is associated with
 * the receiver.
 * <p>
 * A widget's display is either provided when it is created
 * (for example, top level <code>Shell</code>s) or is the
 * same as its parent's display.
 * </p>
 *
 * @return the receiver's display
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public Display getDisplay () {
	Display display = this.display;
	if (display == null) error (SWT.ERROR_WIDGET_DISPOSED);
	return display;
}

/**
 * Returns an array of listeners who will be notified when an event 
 * of the given type occurs. The event type is one of the event constants 
 * defined in class <code>SWT</code>.
 *
 * @param eventType the type of event to listen for
 * @return an array of listeners that will be notified when the event occurs
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see Listener
 * @see SWT
 * @see #addListener(int, Listener)
 * @see #removeListener(int, Listener)
 * @see #notifyListeners
 * 
 * @since 3.4
 */
public Listener[] getListeners (int eventType) {
	checkWidget();
	if (eventTable == null) return new Listener[0];
	return eventTable.getListeners(eventType);
}

Menu getMenu () {
	return null;
}

/**
 * Returns the name of the widget. This is the name of
 * the class without the package name.
 *
 * @return the name of the widget
 */
String getName () {
	String string = getClass ().getName ();
	int index = string.lastIndexOf ('.');
	if (index == -1) return string;
	return string.substring (index + 1, string.length ());
}

/*
 * Returns a short printable representation for the contents
 * of a widget. For example, a button may answer the label
 * text. This is used by <code>toString</code> to provide a
 * more meaningful description of the widget.
 *
 * @return the contents string for the widget
 *
 * @see #toString
 */
String getNameText () {
	return ""; //$NON-NLS-1$
}

/**
 * Returns the receiver's style information.
 * <p>
 * Note that the value which is returned by this method <em>may
 * not match</em> the value which was provided to the constructor
 * when the receiver was created. This can occur when the underlying
 * operating system does not support a particular combination of
 * requested styles. For example, if the platform widget used to
 * implement a particular SWT widget always has scroll bars, the
 * result of calling this method would always have the
 * <code>SWT.H_SCROLL</code> and <code>SWT.V_SCROLL</code> bits set.
 * </p>
 *
 * @return the style bits
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public int getStyle () {
	checkWidget();
	return style;
}

Control getWidgetControl () {
	return null;
}

boolean hasItems () {
	return false;
}

void hookEvents () {
}

/*
 * Returns <code>true</code> if the specified eventType is
 * hooked, and <code>false</code> otherwise. Implementations
 * of SWT can avoid creating objects and sending events
 * when an event happens in the operating system but
 * there are no listeners hooked for the event.
 *
 * @param eventType the event to be checked
 *
 * @return <code>true</code> when the eventType is hooked and <code>false</code> otherwise
 *
 * @see #isListening
 */
boolean hooks (int eventType) {
	if (eventTable == null) return false;
	return eventTable.hooks (eventType);
}

/**
 * Returns <code>true</code> if the widget has been disposed,
 * and <code>false</code> otherwise.
 * <p>
 * This method gets the dispose state for the widget.
 * When a widget has been disposed, it is an error to
 * invoke any other method (except {@link #dispose()}) using the widget.
 * </p>
 *
 * @return <code>true</code> when the widget is disposed and <code>false</code> otherwise
 */
public boolean isDisposed () {
	return (state & DISPOSED) != 0;
}

/**
 * Returns <code>true</code> if there are any listeners
 * for the specified event type associated with the receiver,
 * and <code>false</code> otherwise. The event type is one of
 * the event constants defined in class <code>SWT</code>.
 *
 * @param eventType the type of event
 * @return true if the event is hooked
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see SWT
 */
public boolean isListening (int eventType) {
	checkWidget();
	return hooks (eventType);
}

/*
 * Returns <code>true</code> when subclassing is
 * allowed and <code>false</code> otherwise
 *
 * @return <code>true</code> when subclassing is allowed and <code>false</code> otherwise
 */
boolean isValidSubclass () {
	return Display.isValidClass (getClass ());
}

/*
 * Returns <code>true</code> when the current thread is
 * the thread that created the widget and <code>false</code>
 * otherwise.
 *
 * @return <code>true</code> when the current thread is the thread that created the widget and <code>false</code> otherwise
 */
boolean isValidThread () {
	return getDisplay ().isValidThread ();
}

void mapEvent (int hwnd, Event event) {
}

boolean mnemonicMatch (int accessText, char key) {
	if (accessText == 0) return false;
	char mnemonic = OS.AccessText_AccessKey (accessText);
	return Character.toLowerCase (key) == Character.toLowerCase (mnemonic);
}

/**
 * Notifies all of the receiver's listeners for events
 * of the given type that one such event has occurred by
 * invoking their <code>handleEvent()</code> method.  The
 * event type is one of the event constants defined in class
 * <code>SWT</code>.
 *
 * @param eventType the type of event which has occurred
 * @param event the event data
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @see SWT
 * @see #addListener
 * @see #getListeners(int)
 * @see #removeListener(int, Listener)
 */
public void notifyListeners (int eventType, Event event) {
	checkWidget();
	if (event == null) event = new Event ();
	sendEvent (eventType, event);
}

void postEvent (int eventType) {
	sendEvent (eventType, null, false);
}

void postEvent (int eventType, Event event) {
	sendEvent (eventType, event, false);
}

void register () {
}

/*
 * Releases the widget hiearchy and optionally destroys
 * the receiver.
 * <p>
 * Typically, a widget with children will broadcast this
 * message to all children so that they too can release their
 * resources.  The <code>releaseHandle</code> method is used
 * as part of this broadcast to zero the handle fields of the
 * children without calling <code>destroyWidget</code>.  In
 * this scenario, the children are actually destroyed later,
 * when the operating system destroys the widget tree.
 * </p>
 * 
 * @param destroy indicates that the receiver should be destroyed
 * 
 * @see #dispose
 * @see #releaseHandle
 * @see #releaseParent
 * @see #releaseWidget
*/
void release (boolean destroy) {
	if ((state & DISPOSE_SENT) == 0) {
		state |= DISPOSE_SENT;
		sendEvent (SWT.Dispose);
	}
	if ((state & DISPOSED) == 0) {
		releaseChildren (destroy);
	}
	if ((state & RELEASED) == 0) {
		state |= RELEASED;
		if (destroy) {
			releaseParent ();
			releaseWidget ();
			destroyWidget ();
		} else {
			releaseWidget ();
			releaseHandle ();
		}
	}
}

void releaseChildren (boolean destroy) {
}

/*
 * Releases the widget's handle by zero'ing it out.
 * Does not destroy or release any operating system
 * resources.
 * <p>
 * This method is called after <code>releaseWidget</code>
 * or from <code>destroyWidget</code> when a widget is being
 * destroyed to ensure that the widget is marked as destroyed
 * in case the act of destroying the widget in the operating
 * system causes application code to run in callback that
 * could access the widget.
 * </p>
 *
 * @see #dispose
 * @see #releaseChildren
 * @see #releaseParent
 * @see #releaseWidget
 */
void releaseHandle () {
	state |= DISPOSED;
	display = null;
	if (jniRef != 0) OS.DeleteGlobalRef (jniRef);
	jniRef = 0;
}

/*
 * Releases the receiver, a child in a widget hierarchy,
 * from its parent.
 * <p>
 * When a widget is destroyed, it may be necessary to remove
 * it from an internal data structure of the parent. When
 * a widget has no handle, it may also be necessary for the
 * parent to hide the widget or otherwise indicate that the
 * widget has been disposed. For example, disposing a menu
 * bar requires that the menu bar first be released from the
 * shell when the menu bar is active.
 * </p>
 * 
 * @see #dispose
 * @see #releaseChildren
 * @see #releaseWidget
 * @see #releaseHandle
 */
void releaseParent () {
}

/*
 * Releases any internal resources back to the operating
 * system and clears all fields except the widget handle.
 * <p>
 * When a widget is destroyed, resources that were acquired
 * on behalf of the programmer need to be returned to the
 * operating system.  For example, if the widget made a
 * copy of an icon, supplied by the programmer, this copy
 * would be freed in <code>releaseWidget</code>.  Also,
 * to assist the garbage collector and minimize the amount
 * of memory that is not reclaimed when the programmer keeps
 * a reference to a disposed widget, all fields except the
 * handle are zero'd.  The handle is needed by <code>destroyWidget</code>.
 * </p>
 * 
 * @see #dispose
 * @see #releaseChildren
 * @see #releaseHandle
 * @see #releaseParent
 */
void releaseWidget () {
	deregister ();
	eventTable = null;
	data = null;
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when an event of the given type occurs. The event
 * type is one of the event constants defined in class <code>SWT</code>.
 *
 * @param eventType the type of event to listen for
 * @param listener the listener which should no longer be notified
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see Listener
 * @see SWT
 * @see #addListener
 * @see #getListeners(int)
 * @see #notifyListeners
 */
public void removeListener (int eventType, Listener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (eventType, listener);
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when an event of the given type occurs.
 * <p>
 * <b>IMPORTANT:</b> This method is <em>not</em> part of the SWT
 * public API. It is marked public only so that it can be shared
 * within the packages provided by SWT. It should never be
 * referenced from application code.
 * </p>
 *
 * @param eventType the type of event to listen for
 * @param listener the listener which should no longer be notified
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see Listener
 * @see #addListener
 * 
 * @noreference This method is not intended to be referenced by clients.
 */
protected void removeListener (int eventType, SWTEventListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (eventType, listener);
}

/**
 * Marks the widget to be skinned. 
 * <p>
 * The skin event is sent to the receiver's display when appropriate (usually before the next event
 * is handled). Widgets are automatically marked for skinning upon creation as well as when its skin
 * id or class changes. The skin id and/or class can be changed by calling <code>Display.setData(String, Object)</code> 
 * with the keys SWT.SKIN_ID and/or SWT.SKIN_CLASS. Once the skin event is sent to a widget, it 
 * will not be sent again unless <code>reskin(int)</code> is called on the widget or on an ancestor 
 * while specifying the <code>SWT.ALL</code> flag.  
 * </p>
 * <p>
 * The parameter <code>flags</code> may be either:
 * <dl>
 * <dt><b>SWT.ALL</b></dt>
 * <dd>all children in the receiver's widget tree should be skinned</dd>
 * <dt><b>SWT.NONE</b></dt>
 * <dd>only the receiver should be skinned</dd>
 * </dl>
 * </p>
 * @param flags the flags specifying how to reskin
 * 
 * @exception SWTException 
 * <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * @since 3.6
 */
public void reskin (int flags) {
	checkWidget ();
	reskinWidget ();
	if ((flags & SWT.ALL) != 0) reskinChildren (flags);
}

void reskinChildren (int flags) {	
}

void reskinWidget() {
	if ((state & SKIN_NEEDED) != SKIN_NEEDED) {
		this.state |= SKIN_NEEDED;
		display.addSkinnableWidget(this);
	}
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when the widget is disposed.
 *
 * @param listener the listener which should no longer be notified
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see DisposeListener
 * @see #addDisposeListener
 */
public void removeDisposeListener (DisposeListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.Dispose, listener);
}

boolean sendDragEvent (int e) {
	return sendMouseEvent (SWT.DragDetect, e, false);
}

boolean sendDragEvent (int button, int stateMask, int x, int y) {
	Event event = new Event ();
	event.button = button;
	event.x = x;
	event.y = y;
	event.stateMask = stateMask;
	postEvent (SWT.DragDetect, event);
	return event.doit;
}

void sendEvent (Event event) {
	Display display = event.display;
	if (!display.filterEvent (event)) {
		if (eventTable != null) eventTable.sendEvent (event);
	}
}

void sendEvent (int eventType) {
	sendEvent (eventType, null, true);
}

void sendEvent (int eventType, Event event) {
	sendEvent (eventType, event, true);
}

void sendEvent (int eventType, Event event, boolean send) {
	if (eventTable == null && !display.filters (eventType)) {
		return;
	}
	if (event == null) event = new Event ();
	event.type = eventType;
	event.display = display;
	event.widget = this;
	if (event.time == 0) {
		event.time = display.getLastEventTime ();
	}
	if (send) {
		sendEvent (event);
	} else {
		display.postEvent (event);
	}
}

boolean sendKeyEvent (int type, int e, boolean textInput) {
	if (textInput) {
		int text = OS.TextCompositionEventArgs_Text(e);
		if (OS.String_Length(text) == 0) {
			OS.GCHandle_Free(text);
			text = OS.TextCompositionEventArgs_SystemText(e);
			if (OS.String_Length(text) == 0) {
				OS.GCHandle_Free(text);
				text = OS.TextCompositionEventArgs_ControlText(e);
				if (OS.String_Length(text) == 0) {
					return false;
				}
			}
		}
		int chars = OS.String_ToCharArray(text);
		char[] buffer = new char[OS.String_Length(text)]; 
		OS.memcpy(buffer, chars, buffer.length * 2);
		OS.GCHandle_Free(chars);
		OS.GCHandle_Free(text);
		for (int i = 0; i < buffer.length; i++) {
			Event event = new Event ();
			if (buffer.length == 1) {
				event.keyCode = Display.translateKey(display.lastKey);
			}
			event.character = buffer[i];
			//hack for dead key
			if (display.deadChar) {
				event.character = display.lastChar;
				display.deadChar = false;
			}
			setInputState(event, type, 0, 0);
			sendEvent (type, event);
			if (isDisposed ()) return false;
		}
		return true;
	} else {
		Event event = new Event ();
		if (!setKeyState (event, type, e)) return true;
		sendEvent (type, event);
		if (isDisposed ()) return false;
		return event.doit;
	}
}

boolean sendMouseEvent (int type, int e, boolean send) {
	boolean hooksType = hooks (type) || filters (type);
	boolean hooksDoubleClick = type == SWT.MouseDown && (hooks (SWT.MouseDoubleClick) || filters (SWT.MouseDoubleClick));
	if (!hooksType && !hooksDoubleClick) return true;
	Event event = new Event ();
	if (type == SWT.MouseDown || type == SWT.MouseUp || type == SWT.DragDetect) {
		event.button = OS.MouseButtonEventArgs_ChangedButton (e) + 1;
		event.count = OS.MouseButtonEventArgs_ClickCount (e);
	}
	if (type == SWT.MouseWheel) {
		int lines = OS.SystemParameters_WheelScrollLines ();
		int delta = OS.MouseWheelEventArgs_Delta (e);
		if (lines == -1) {
			event.detail = SWT.SCROLL_PAGE;
			event.count = delta / 120;
		} else {
			event.detail = SWT.SCROLL_LINE;
			event.count = delta * lines / 120;
		}
	}
	int point = OS.MouseEventArgs_GetPosition (e, handle);
	event.x = (int) OS.Point_X (point);
	event.y = (int) OS.Point_Y (point);
	OS.GCHandle_Free (point);
	setInputState (event, type, e, 0);
	Event doubleClick = null; 
	if (hooksDoubleClick && (event.count & 1) == 0) {
		doubleClick = new Event();
		doubleClick.button = event.button;
		doubleClick.x = event.x;
		doubleClick.y = event.y;
		doubleClick.count = event.count;
		doubleClick.stateMask = event.stateMask;
	}
	if (send) {
		sendEvent (type, event);
		if (isDisposed ()) return false;
	} else {
		postEvent (type, event);
	}
	if (doubleClick != null) {
		if (send) {
			sendEvent (SWT.MouseDoubleClick, doubleClick);
			if (isDisposed ()) return false;
		} else {
			postEvent (SWT.MouseDoubleClick, doubleClick);
		}
	}
	return event.doit;
}
void sendSelectionEvent (int eventType) {
	sendSelectionEvent (eventType, null, false);
}

void sendSelectionEvent (int eventType, Event event, boolean send) {
	if (eventTable == null && !display.filters (eventType)) {
		return;
	}
	if (event == null) event = new Event ();
//	setInputState (event, state);
	sendEvent (eventType, event, send);
}

//TEMPORARY CODE
void setClipping (int widget, boolean clip) {
	//TODO - should be is-kind-of UIElement rather than not DrawingVisual
	int type = OS.Object_GetType(widget);
	int drawingVisualType = OS.DrawingVisual_typeid();
	if (!OS.Object_Equals(type, drawingVisualType)) {	
		OS.UIElement_ClipToBounds (widget, clip);
	}
	OS.GCHandle_Free(drawingVisualType);
	OS.GCHandle_Free(type);
	int count = OS.VisualTreeHelper_GetChildrenCount(widget);
	for (int i = 0; i < count; i++) {
		int child = OS.VisualTreeHelper_GetChild (widget, i);
		setClipping(child, clip);
		OS.GCHandle_Free(child);
	}		
}

/**
 * Sets the application defined widget data associated
 * with the receiver to be the argument. The <em>widget
 * data</em> is a single, unnamed field that is stored
 * with every widget. 
 * <p>
 * Applications may put arbitrary objects in this field. If
 * the object stored in the widget data needs to be notified
 * when the widget is disposed of, it is the application's
 * responsibility to hook the Dispose event on the widget and
 * do so.
 * </p>
 *
 * @param data the widget data
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - when the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - when called from the wrong thread</li>
 * </ul>
 * 
 * @see #getData()
 */
public void setData (Object data) {
	checkWidget();
	if ((state & KEYED_DATA) != 0) {
		((Object []) this.data) [0] = data;
	} else {
		this.data = data;
	}
}

/**
 * Sets the application defined property of the receiver
 * with the specified name to the given value.
 * <p>
 * Applications may associate arbitrary objects with the
 * receiver in this fashion. If the objects stored in the
 * properties need to be notified when the widget is disposed
 * of, it is the application's responsibility to hook the
 * Dispose event on the widget and do so.
 * </p>
 *
 * @param key the name of the property
 * @param value the new value for the property
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the key is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see #getData(String)
 */
public void setData (String key, Object value) {
	checkWidget();
	if (key == null) error (SWT.ERROR_NULL_ARGUMENT);
	int index = 1;
	Object [] table = null;
	if ((state & KEYED_DATA) != 0) {
		table = (Object []) data;
		while (index < table.length) {
			if (key.equals (table [index])) break;
			index += 2;
		}
	}
	if (value != null) {
		if ((state & KEYED_DATA) != 0) {
			if (index == table.length) {
				Object [] newTable = new Object [table.length + 2];
				System.arraycopy (table, 0, newTable, 0, table.length);
				data = table = newTable;
			}
		} else {
			table = new Object [3];
			table [0] = data;
			data = table;
			state |= KEYED_DATA;
		}
		table [index] = key;
		table [index + 1] = value;
	} else {
		if ((state & KEYED_DATA) != 0) {
			if (index != table.length) {
				int length = table.length - 2;
				if (length == 1) {
					data = table [0];
					state &= ~KEYED_DATA;
				} else {
					Object [] newTable = new Object [length];
					System.arraycopy (table, 0, newTable, 0, index);
					System.arraycopy (table, index + 2, newTable, index, length - index);
					data = newTable;
				}
			}
		}
	}
	
	// Demo 
	if ("XAML".equals(key) && value instanceof String) {
		setClipping (topHandle (), false);
		String string = (String) value;
		int ptr = createDotNetString(string, false);
		int stringReader = OS.gcnew_StringReader (ptr);
		int xmlReader = OS.XmlReader_Create (stringReader);
		int resource = OS.XamlReader_Load (xmlReader);
		if (resource != 0) {
			OS.FrameworkElement_Resources (handle, resource);
			OS.GCHandle_Free(resource);
		}
		OS.GCHandle_Free(xmlReader);
		OS.GCHandle_Free(stringReader);
		OS.GCHandle_Free(ptr);
	}
	if ("ResourceDictionary".equals(key) && value instanceof String) {
		String string = (String) value;
		int ptr = createDotNetString(string, false);
		int uri = OS.gcnew_Uri(ptr, OS.UriKind_RelativeOrAbsolute);
		int resources = OS.gcnew_ResourceDictionary();
		OS.ResourceDictionary_Source(resources, uri);
		OS.FrameworkElement_Resources(handle, resources);
		OS.GCHandle_Free(resources);
		OS.GCHandle_Free(uri);
		OS.GCHandle_Free(ptr);
	}
	if (key.equals(SWT.SKIN_CLASS) || key.equals(SWT.SKIN_ID)) this.reskin(SWT.ALL);
}

boolean sendFocusEvent (int type) {
	sendEvent (type);
	// widget could be disposed at this point
	return true;
}

boolean setInputState (Event event, int type, int mouseEvent, int keyEvent) {
	int modifiers;
	if (keyEvent != 0) {
		int keyboardDevice = OS.KeyboardEventArgs_KeyboardDevice(keyEvent);
		modifiers = OS.KeyboardDevice_Modifiers(keyboardDevice);
		OS.GCHandle_Free(keyboardDevice);
	} else {
		modifiers = OS.Keyboard_Modifiers();
	}
	if ((modifiers & OS.ModifierKeys_Alt) != 0) event.stateMask |= SWT.ALT;
	if ((modifiers & OS.ModifierKeys_Shift) != 0) event.stateMask |= SWT.SHIFT;
	if ((modifiers & OS.ModifierKeys_Control) != 0) event.stateMask |= SWT.CONTROL;	
	if (mouseEvent != 0) {
		if (OS.MouseEventArgs_LeftButton(mouseEvent) == OS.MouseButtonState_Pressed) event.stateMask |= SWT.BUTTON1;
		if (OS.MouseEventArgs_MiddleButton(mouseEvent) == OS.MouseButtonState_Pressed) event.stateMask |= SWT.BUTTON2;
		if (OS.MouseEventArgs_RightButton(mouseEvent) == OS.MouseButtonState_Pressed) event.stateMask |= SWT.BUTTON3;
		if (OS.MouseEventArgs_XButton1(mouseEvent) == OS.MouseButtonState_Pressed) event.stateMask |= SWT.BUTTON4;
		if (OS.MouseEventArgs_XButton2(mouseEvent) == OS.MouseButtonState_Pressed) event.stateMask |= SWT.BUTTON5;
	} else {
		if (OS.Mouse_LeftButton() == OS.MouseButtonState_Pressed) event.stateMask |= SWT.BUTTON1;
		if (OS.Mouse_MiddleButton() == OS.MouseButtonState_Pressed) event.stateMask |= SWT.BUTTON2;
		if (OS.Mouse_RightButton() == OS.MouseButtonState_Pressed) event.stateMask |= SWT.BUTTON3;
		if (OS.Mouse_XButton1() == OS.MouseButtonState_Pressed) event.stateMask |= SWT.BUTTON4;
		if (OS.Mouse_XButton2() == OS.MouseButtonState_Pressed) event.stateMask |= SWT.BUTTON5;
	}
	switch (type) {
		case SWT.MouseDown:
		case SWT.MouseDoubleClick:
			if (event.button == 1) event.stateMask &= ~SWT.BUTTON1;
			if (event.button == 2) event.stateMask &= ~SWT.BUTTON2;
			if (event.button == 3) event.stateMask &= ~SWT.BUTTON3;
			if (event.button == 4) event.stateMask &= ~SWT.BUTTON4;
			if (event.button == 5) event.stateMask &= ~SWT.BUTTON5;
			break;
		case SWT.MouseUp:
			if (event.button == 1) event.stateMask |= SWT.BUTTON1;
			if (event.button == 2) event.stateMask |= SWT.BUTTON2;
			if (event.button == 3) event.stateMask |= SWT.BUTTON3;
			if (event.button == 4) event.stateMask |= SWT.BUTTON4;
			if (event.button == 5) event.stateMask |= SWT.BUTTON5;
			break;
		case SWT.KeyDown:
		case SWT.Traverse:
			if (event.keyCode == SWT.ALT) event.stateMask &= ~SWT.ALT;
			if (event.keyCode == SWT.SHIFT) event.stateMask &= ~SWT.SHIFT;
			if (event.keyCode == SWT.CONTROL) event.stateMask &= ~SWT.CONTROL;
			break;
		case SWT.KeyUp:
			if (event.keyCode == SWT.ALT) event.stateMask |= SWT.ALT;
			if (event.keyCode == SWT.SHIFT) event.stateMask |= SWT.SHIFT;
			if (event.keyCode == SWT.CONTROL) event.stateMask |= SWT.CONTROL;
			break;
	}		
	return true;
}

boolean setKeyState (Event event, int type, int e) {
	int key = display.lastKey = OS.KeyEventArgs_Key(e);
	boolean repeat = OS.KeyEventArgs_IsRepeat(e);
	switch (key) {
		case OS.Key_ImeProcessed:
			return false;
		case OS.Key_LeftAlt:
		case OS.Key_RightAlt:
		case OS.Key_LeftCtrl:
		case OS.Key_LeftShift:
		case OS.Key_RightCtrl:
		case OS.Key_RightShift:
			if (repeat) return false;
			break;
		case OS.Key_System:
			key = OS.KeyEventArgs_SystemKey(e);
			switch (key) {
				case OS.Key_LeftAlt:
				case OS.Key_RightAlt:
					if (repeat) return false;
			}
	}
	boolean textual = false;
	int vKey = OS.KeyInterop_VirtualKeyFromKey (key);
	int mapKey = Win32.MapVirtualKeyW (vKey, 2);
	if ((mapKey & 0x80000000) != 0) {
		display.deadChar = true;
		return false;
	}
	char [] result = new char [1];
	byte [] keyboard = new byte [256];
	Win32.GetKeyboardState (keyboard);
	textual = Win32.ToUnicode (vKey, 0, keyboard, result, 1, 0) == 1;
	if (textual && type == SWT.KeyDown) {
		if (display.deadChar) display.lastChar = result [0];
		//TODO  problem: in german, dead key + non-combing key
		// example: '^' + 'p' fails. 
		return false;
	}
	event.keyCode = Display.translateKey (key);
	switch (key) {
		case OS.Key_Back:		event.character = SWT.BS; break;
		case OS.Key_LineFeed:	event.character = SWT.LF; break;
		case OS.Key_Return: 	event.character = SWT.CR; break;
		case OS.Key_Delete:		event.character = SWT.DEL; break;
		case OS.Key_Escape:		event.character = SWT.ESC; break;
		case OS.Key_Tab: 		event.character = SWT.TAB; break;
	}
	if (type == SWT.KeyUp) event.character = result [0];
	return setInputState (event, type, 0, e);
}

void setNameScope() {
//	Name Scope should most likely be on topHandle, but animation
//	is using handle right now because topHandle isn't visible
//	OS.NameScope_SetNameScope(topHandle(), display.nameScope);
	OS.NameScope_SetNameScope(handle, display.nameScope);
}

boolean showMenu (int x, int y) {
	Event event = new Event ();
	event.x = x;
	event.y = y;
	sendEvent (SWT.MenuDetect, event);
	if (!event.doit) return true;
	Menu menu = getMenu ();
	if (menu != null && !menu.isDisposed ()) {
		if (x != event.x || y != event.y) {
			menu.setLocation (event.x, event.y);
		}
		menu.setVisible (true);
		return true;
	}
	return false;
}

int topHandle () {
	return handle;
}

/**
 * Returns a string containing a concise, human-readable
 * description of the receiver.
 *
 * @return a string representation of the receiver
 */
public String toString () {
	String string = "*Disposed*"; //$NON-NLS-1$
	if (!isDisposed ()) {
		string = "*Wrong Thread*"; //$NON-NLS-1$
		if (isValidThread ()) string = getNameText ();
	}
	return getName () + " {" + string + "}"; //$NON-NLS-1$ //$NON-NLS-2$
}

void updateLayout (int updateHandle) {
	boolean ignore = display.ignoreRender;
	display.ignoreRender = true;
	OS.UIElement_UpdateLayout (updateHandle);
	display.ignoreRender = ignore;
}

}