/*******************************************************************************
 * Copyright (c) 2000, 2013 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.photon.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.events.*;
import org.eclipse.swt.*;
import org.eclipse.swt.accessibility.*;

/**
 * Control is the abstract superclass of all windowed user interface classes.
 * <p>
 * <dl>
 * <dt><b>Styles:</b>
 * <dd>BORDER</dd>
 * <dd>LEFT_TO_RIGHT, RIGHT_TO_LEFT</dd>
 * <dt><b>Events:</b>
 * <dd>DragDetect, FocusIn, FocusOut, Help, KeyDown, KeyUp, MenuDetect, MouseDoubleClick, MouseDown, MouseEnter,
 *     MouseExit, MouseHover, MouseUp, MouseMove, MouseWheel, MouseHorizontalWheel, MouseVerticalWheel, Move,
 *     Paint, Resize, Traverse</dd>
 * </dl>
 * </p><p>
 * Only one of LEFT_TO_RIGHT or RIGHT_TO_LEFT may be specified.
 * </p><p>
 * IMPORTANT: This class is intended to be subclassed <em>only</em>
 * within the SWT implementation.
 * </p>
 * 
 * @see <a href="http://www.eclipse.org/swt/snippets/#control">Control snippets</a>
 * @see <a href="http://www.eclipse.org/swt/examples.php">SWT Example: ControlExample</a>
 * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
 * @noextend This class is not intended to be subclassed by clients.
 */
public abstract class Control extends Widget implements Drawable {
	Composite parent;
	Cursor cursor;
	Font font;
	Menu menu;
	Object layoutData;
	String toolTipText;
	Image backgroundImage;
	Region region;
	int toolTipHandle;
	Accessible accessible;
	
Control () {
	/* Do nothing */
}

/**
 * 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 composite control which will be the parent of the new instance (cannot be null)
 * @param style the style of control to construct
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the parent is null</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#BORDER
 * @see SWT#LEFT_TO_RIGHT
 * @see SWT#RIGHT_TO_LEFT
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public Control (Composite parent, int style) {
	super (parent, style);
	this.parent = parent;
	createWidget (0);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when the control is moved or resized, by sending
 * it one of the messages defined in the <code>ControlListener</code>
 * interface.
 *
 * @param listener the listener which should 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 ControlListener
 * @see #removeControlListener
 */
public void addControlListener(ControlListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.Resize,typedListener);
	addListener (SWT.Move,typedListener);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when a drag gesture occurs, by sending it
 * one of the messages defined in the <code>DragDetectListener</code>
 * interface.
 *
 * @param listener the listener which should 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 DragDetectListener
 * @see #removeDragDetectListener
 * 
 * @since 3.3
 */
public void addDragDetectListener (DragDetectListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.DragDetect,typedListener);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when the control gains or loses focus, by sending
 * it one of the messages defined in the <code>FocusListener</code>
 * interface.
 *
 * @param listener the listener which should 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 FocusListener
 * @see #removeFocusListener
 */
public void addFocusListener (FocusListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.FocusIn,typedListener);
	addListener (SWT.FocusOut,typedListener);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when gesture events are generated for the control,
 * by sending it one of the messages defined in the
 * <code>GestureListener</code> interface.
 * <p>
 * NOTE: If <code>setTouchEnabled(true)</code> has previously been
 * invoked on the receiver then <code>setTouchEnabled(false)</code>
 * must be invoked on it to specify that gesture events should be
 * sent instead of touch events.
 * </p>
 * 
 * @param listener the listener which should 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 GestureListener
 * @see #removeGestureListener
 * @see #setTouchEnabled
 * 
 * @since 3.7
 */
public void addGestureListener (GestureListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.Gesture, typedListener);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when help events are generated for the control,
 * by sending it one of the messages defined in the
 * <code>HelpListener</code> interface.
 *
 * @param listener the listener which should 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 HelpListener
 * @see #removeHelpListener
 */
public void addHelpListener (HelpListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.Help, typedListener);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when keys are pressed and released on the system keyboard, by sending
 * it one of the messages defined in the <code>KeyListener</code>
 * interface.
 * <p>
 * When a key listener is added to a control, the control
 * will take part in widget traversal.  By default, all
 * traversal keys (such as the tab key and so on) are
 * delivered to the control.  In order for a control to take
 * part in traversal, it should listen for traversal events.
 * Otherwise, the user can traverse into a control but not
 * out.  Note that native controls such as table and tree
 * implement key traversal in the operating system.  It is
 * not necessary to add traversal listeners for these controls,
 * unless you want to override the default traversal.
 * </p>
 * @param listener the listener which should 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 KeyListener
 * @see #removeKeyListener
 */
public void addKeyListener (KeyListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.KeyUp,typedListener);
	addListener (SWT.KeyDown,typedListener);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when the platform-specific context menu trigger
 * has occurred, by sending it one of the messages defined in
 * the <code>MenuDetectListener</code> interface.
 *
 * @param listener the listener which should 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 MenuDetectListener
 * @see #removeMenuDetectListener
 *
 * @since 3.3
 */
public void addMenuDetectListener (MenuDetectListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.MenuDetect, typedListener);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when mouse buttons are pressed and released, by sending
 * it one of the messages defined in the <code>MouseListener</code>
 * interface.
 *
 * @param listener the listener which should 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 MouseListener
 * @see #removeMouseListener
 */
public void addMouseListener (MouseListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.MouseDown,typedListener);
	addListener (SWT.MouseUp,typedListener);
	addListener (SWT.MouseDoubleClick,typedListener);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when the mouse moves, by sending it one of the
 * messages defined in the <code>MouseMoveListener</code>
 * interface.
 *
 * @param listener the listener which should 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 MouseMoveListener
 * @see #removeMouseMoveListener
 */
public void addMouseMoveListener (MouseMoveListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.MouseMove,typedListener);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when the mouse passes or hovers over controls, by sending
 * it one of the messages defined in the <code>MouseTrackListener</code>
 * interface.
 *
 * @param listener the listener which should 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 MouseTrackListener
 * @see #removeMouseTrackListener
 */
public void addMouseTrackListener (MouseTrackListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.MouseEnter,typedListener);
	addListener (SWT.MouseExit,typedListener);
	addListener (SWT.MouseHover,typedListener);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when the mouse wheel is scrolled, by sending
 * it one of the messages defined in the
 * <code>MouseWheelListener</code> interface.
 *
 * @param listener the listener which should 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 MouseWheelListener
 * @see #removeMouseWheelListener
 *
 * @since 3.3
 */
public void addMouseWheelListener (MouseWheelListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.MouseWheel, typedListener);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when the receiver needs to be painted, by sending it
 * one of the messages defined in the <code>PaintListener</code>
 * interface.
 *
 * @param listener the listener which should 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 PaintListener
 * @see #removePaintListener
 */
public void addPaintListener (PaintListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.Paint,typedListener);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when touch events occur, by sending it
 * one of the messages defined in the <code>TouchListener</code>
 * interface.
 * <p>
 * NOTE: You must also call <code>setTouchEnabled(true)</code> to 
 * specify that touch events should be sent, which will cause gesture
 * events to not be sent.
 * </p>
 * 
 * @param listener the listener which should 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 TouchListener
 * @see #removeTouchListener
 * @see #setTouchEnabled
 * 
 * @since 3.7
 */
public void addTouchListener (TouchListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.Touch,typedListener);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when traversal events occur, by sending it
 * one of the messages defined in the <code>TraverseListener</code>
 * interface.
 *
 * @param listener the listener which should 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 TraverseListener
 * @see #removeTraverseListener
 */
public void addTraverseListener (TraverseListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.Traverse,typedListener);
}

/**
 * Forces the receiver to have the <em>keyboard focus</em>, causing
 * all keyboard events to be delivered to it.
 *
 * @return <code>true</code> if the control got focus, and <code>false</code> if it was unable to.
 *
 * @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 #setFocus
 */
public boolean forceFocus () {
	checkWidget();
	/*
	* Bug in Photon. Photon will stop sending key
	* events, if a menu is up and focus is given to
	* a widget by calling PtContainerGiveFocus(). The
	* fix is to detect when a menu is up and avoid
	* calling this function.
	*/
	Shell shell = getShell ();
	if (shell.activeMenu != null) return false;
	shell.bringToTop (false);
	OS.PtContainerGiveFocus (handle, null);
	return hasFocus ();
}

void checkBuffered () {
	style &= ~SWT.DOUBLE_BUFFERED;
}

/**
 * Returns the preferred size of the receiver.
 * <p>
 * The <em>preferred size</em> of a control is the size that it would
 * best be displayed at. The width hint and height hint arguments
 * allow the caller to ask a control questions such as "Given a particular
 * width, how high does the control need to be to show all of the contents?"
 * To indicate that the caller does not wish to constrain a particular 
 * dimension, the constant <code>SWT.DEFAULT</code> is passed for the hint. 
 * </p>
 *
 * @param wHint the width hint (can be <code>SWT.DEFAULT</code>)
 * @param hHint the height hint (can be <code>SWT.DEFAULT</code>)
 * @return the preferred size of the control
 *
 * @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 Layout
 * @see #getBorderWidth
 * @see #getBounds
 * @see #getSize
 * @see #pack(boolean)
 * @see "computeTrim, getClientArea for controls that implement them"
 */
public Point computeSize (int wHint, int hHint) {
	return computeSize (wHint, hHint, true);
}

/**
 * Returns the preferred size of the receiver.
 * <p>
 * The <em>preferred size</em> of a control is the size that it would
 * best be displayed at. The width hint and height hint arguments
 * allow the caller to ask a control questions such as "Given a particular
 * width, how high does the control need to be to show all of the contents?"
 * To indicate that the caller does not wish to constrain a particular 
 * dimension, the constant <code>SWT.DEFAULT</code> is passed for the hint. 
 * </p><p>
 * If the changed flag is <code>true</code>, it indicates that the receiver's
 * <em>contents</em> have changed, therefore any caches that a layout manager
 * containing the control may have been keeping need to be flushed. When the
 * control is resized, the changed flag will be <code>false</code>, so layout
 * manager caches can be retained. 
 * </p>
 *
 * @param wHint the width hint (can be <code>SWT.DEFAULT</code>)
 * @param hHint the height hint (can be <code>SWT.DEFAULT</code>)
 * @param changed <code>true</code> if the control's contents have changed, and <code>false</code> otherwise
 * @return the preferred size of the control.
 *
 * @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 Layout
 * @see #getBorderWidth
 * @see #getBounds
 * @see #getSize
 * @see #pack(boolean)
 * @see "computeTrim, getClientArea for controls that implement them"
 */
public Point computeSize (int wHint, int hHint, boolean changed) {
	checkWidget();
	int width = DEFAULT_WIDTH;
	int height = DEFAULT_HEIGHT;
	if (wHint != SWT.DEFAULT) width = wHint;
	if (hHint != SWT.DEFAULT) height = hHint;
	int border = getBorderWidth ();
	width += border * 2;
	height += border * 2;
	return new Point (width, height);
}

Control computeTabGroup () {
	if (isTabGroup ()) return this;
	return parent.computeTabGroup ();
}

Control computeTabRoot () {
	Control [] tabList = parent._getTabList ();
	if (tabList != null) {
		int index = 0;
		while (index < tabList.length) {
			if (tabList [index] == this) break;
			index++;
		}
		if (index == tabList.length) {
			if (isTabGroup ()) return this;
		}
	}
	return parent.computeTabRoot ();
}

Control [] computeTabList () {
	if (isTabGroup ()) {
		if (getVisible () && getEnabled ()) {
			return new Control [] {this};
		}
	}
	return new Control [0];
}

void createWidget (int index) {
	checkOrientation (parent);
	super.createWidget (index);
	checkBuffered ();
	setZOrder ();
	realizeWidget ();
	setDefaultFont ();
}

int defaultBackground () {
	return display.WIDGET_BACKGROUND;
}

byte [] defaultFont () {
	return display.TEXT_FONT;
}

int defaultForeground () {
	return display.WIDGET_FOREGROUND;
}

boolean drawGripper (GC gc, int x, int y, int width, int height, boolean vertical) {
	return false;
}

/**
 * Detects a drag and drop gesture.  This method is used
 * to detect a drag gesture when called from within a mouse
 * down listener.
 * 
 * <p>By default, a drag is detected when the gesture
 * occurs anywhere within the client area of a control.
 * Some controls, such as tables and trees, override this
 * behavior.  In addition to the operating system specific
 * drag gesture, they require the mouse to be inside an
 * item.  Custom widget writers can use <code>setDragDetect</code>
 * to disable the default detection, listen for mouse down,
 * and then call <code>dragDetect()</code> from within the
 * listener to conditionally detect a drag.
 * </p>
 *
 * @param event the mouse down event
 * 
 * @return <code>true</code> if the gesture occurred, and <code>false</code> otherwise.
 *
 * @exception IllegalArgumentException <ul>
 *   <li>ERROR_NULL_ARGUMENT if the event 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 DragDetectListener
 * @see #addDragDetectListener
 * 
 * @see #getDragDetect
 * @see #setDragDetect
 * 
 * @since 3.3
 */
public boolean dragDetect (Event event) {
	checkWidget ();
	if (event == null) error (SWT.ERROR_NULL_ARGUMENT);
	return dragDetect (event.button, event.count, event.stateMask, event.x, event.y);
}

/**
 * Detects a drag and drop gesture.  This method is used
 * to detect a drag gesture when called from within a mouse
 * down listener.
 * 
 * <p>By default, a drag is detected when the gesture
 * occurs anywhere within the client area of a control.
 * Some controls, such as tables and trees, override this
 * behavior.  In addition to the operating system specific
 * drag gesture, they require the mouse to be inside an
 * item.  Custom widget writers can use <code>setDragDetect</code>
 * to disable the default detection, listen for mouse down,
 * and then call <code>dragDetect()</code> from within the
 * listener to conditionally detect a drag.
 * </p>
 *
 * @param event the mouse down event
 * 
 * @return <code>true</code> if the gesture occurred, and <code>false</code> otherwise.
 *
 * @exception IllegalArgumentException <ul>
 *   <li>ERROR_NULL_ARGUMENT if the event 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 DragDetectListener
 * @see #addDragDetectListener
 * 
 * @see #getDragDetect
 * @see #setDragDetect
 * 
 * @since 3.3
 */
public boolean dragDetect (MouseEvent event) {
	checkWidget ();
	if (event == null) error (SWT.ERROR_NULL_ARGUMENT);
	return dragDetect (event.button, event.count, event.stateMask, event.x, event.y);
}

boolean dragDetect (int button, int count, int stateMask, int x, int y) {
	//TODO - not implemented
	return false;
}

int drawProc (int widget, int damage) {
	if (widget <=0) return OS.Pt_CONTINUE; 
	drawWidget (widget, damage );
	if (!hooks(SWT.Paint) && !filters (SWT.Paint)) return OS.Pt_CONTINUE;
	/* Send the paint event */
	PhPoint_t pt = new PhPoint_t ();  
	PhRect_t widRect = new PhRect_t();    
	OS.PtWidgetExtent(widget, widRect) ;
	OS.PtWidgetOffset(widget, pt);
	pt.x += widRect.ul_x;
	pt.y += widRect.ul_y;
	damage = OS.PhCopyTiles( damage );
	PhTile_t tile = new PhTile_t ();
	OS.memmove (tile, damage, PhTile_t.sizeof);
	int transPoint = OS.malloc ( PhPoint_t.sizeof);
	OS.memmove(transPoint, pt, PhPoint_t.sizeof);
	OS.PhDeTranslateTiles(damage, transPoint);
	OS.free(transPoint);
	OS.memmove (tile, damage, PhTile_t.sizeof);
	boolean noMerge = (style & SWT.NO_MERGE_PAINTS) != 0 && (state & CANVAS) != 0;
	if (tile.next != 0 && noMerge) 
	{
		OS.memmove (tile, tile.next, PhTile_t.sizeof);
		while (tile.next != 0) 
		{
			Event event = new Event ();
			event.width = tile.rect_lr_x - tile.rect_ul_x + 1;
			event.height = tile.rect_lr_y - tile.rect_ul_y + 1;
			event.x = tile.rect_ul_x;
			event.y = tile.rect_ul_y; 
			GC gc = event.gc = new GC (this);
			gc.setClipping(event.x, event.y, event.width, event.height);
			sendEvent (SWT.Paint, event);
			if (isDisposed ()) break;
			gc.dispose ();
			event.gc = null;
			if ( tile.next != 0 )
				OS.memmove (tile, tile.next, PhTile_t.sizeof);
		}
	} 
	else 
	{
		int rect1 = OS.malloc (PhRect_t.sizeof);
		int rect2 = OS.malloc (PhRect_t.sizeof);
		OS.memmove (rect1, tile, PhRect_t.sizeof);
		OS.memmove (rect2, widRect, PhRect_t.sizeof);
		int inter = OS.PhRectIntersect(rect1, rect2);
		if ( inter == 1 )
		{
			OS.memmove(widRect, rect1, PhRect_t.sizeof);
			Event event = new Event ();
			event.x = widRect.ul_x;
			event.y = widRect.ul_y; 
			event.width = widRect.lr_x - widRect.ul_x + 1;
			event.height = widRect.lr_y - widRect.ul_y + 1;
            GC gc = event.gc = new GC (this);
            gc.setClipping(event.x, event.y, event.width, event.height );
			sendEvent (SWT.Paint, event);
			gc.dispose ();
			event.gc = null;
		}
		OS.free(rect1);
		OS.free(rect2);
	}
	OS.PhFreeTiles( damage );
	return OS.Pt_CONTINUE;
}

void drawWidget (int widget, int damage) {
	int widgetClass = widgetClass ();
	if (widgetClass != 0) OS.PtSuperClassDraw (widgetClass, handle, damage);
}

void enableWidget (boolean enabled) {
	int topHandle = topHandle ();
	int flags = enabled ? 0 : OS.Pt_BLOCKED | OS.Pt_GHOST;
	OS.PtSetResource (topHandle, OS.Pt_ARG_FLAGS, flags, OS.Pt_BLOCKED | OS.Pt_GHOST);
}

/**
 * Returns the accessible object for the receiver.
 * <p>
 * If this is the first time this object is requested,
 * then the object is created and returned. The object
 * returned by getAccessible() does not need to be disposed.
 * </p>
 *
 * @return the accessible object
 *
 * @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 Accessible#addAccessibleListener
 * @see Accessible#addAccessibleControlListener
 * 
 * @since 2.0
 */
public Accessible getAccessible () {
	checkWidget ();
	if (accessible == null) {
		accessible = Accessible.internal_new_Accessible (this);
	}
	return accessible;
}

/**
 * Returns the receiver's background color.
 * <p>
 * Note: This operation is a hint and may be overridden by the platform.
 * For example, on some versions of Windows the background of a TabFolder,
 * is a gradient rather than a solid color.
 * </p>
 * @return the background color
 *
 * @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 Color getBackground () {
	checkWidget();
	int [] args = {OS.Pt_ARG_FILL_COLOR, 0, 0};
	OS.PtGetResources (handle, args.length / 3, args);
	return Color.photon_new (display, args [1]);
}

/**
 * Returns the receiver's background image.
 *
 * @return the background image
 *
 * @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 3.2
 */
public Image getBackgroundImage () {
	checkWidget ();
	return backgroundImage;
}

/**
 * Returns the font that the receiver will use to paint textual information.
 *
 * @return the receiver's font
 *
 * @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 Font getFont () {
	checkWidget();
	if (font != null) return font;
	int [] args = {
		OS.Pt_ARG_TEXT_FONT, 0, 0,
		OS.Pt_ARG_LIST_FONT, 0, 0,
		OS.Pt_ARG_TITLE_FONT, 0, 0,
		OS.Pt_ARG_GAUGE_FONT, 0, 0,
	};
	OS.PtGetResources (handle, args.length / 3, args);
	byte [] font;
	int ptr = args [1];
	if (ptr == 0) ptr = args [4];
	if (ptr == 0) ptr = args [7];
	if (ptr == 0) ptr = args [11];
	if (ptr == 0) {
		font = defaultFont ();
	} else {
		int length = OS.strlen (ptr);
		font = new byte [length + 1];
		OS.memmove (font, ptr, length);
	}
	return Font.photon_new (display, font);
}

/**
 * Returns the foreground color that the receiver will use to draw.
 *
 * @return the receiver's foreground color
 *
 * @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 Color getForeground () {
	checkWidget();
	int [] args = {OS.Pt_ARG_COLOR, 0, 0};
	OS.PtGetResources (handle, args.length / 3, args);
	return Color.photon_new (display, args [1]);
}

/**
 * Returns the receiver's border width.
 *
 * @return the border width
 *
 * @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 getBorderWidth () {
	checkWidget();
	int topHandle = topHandle ();
	int [] args = {
		OS.Pt_ARG_BASIC_FLAGS, 0, 0,
		OS.Pt_ARG_FLAGS, 0, 0,
//		OS.Pt_ARG_BEVEL_WIDTH, 0, 0,
	};
	OS.PtGetResources (topHandle, args.length / 3, args);
	if ((args [4] & OS.Pt_HIGHLIGHTED) == 0) return 0;
	int border = 0;
	int flags = args [1];
	if ((flags & OS.Pt_ALL_ETCHES) != 0) border++;
	if ((flags & OS.Pt_ALL_OUTLINES) != 0) border++;
	if ((flags & OS.Pt_ALL_INLINES) != 0) border++;
//	if ((flags & OS.Pt_ALL_BEVELS) != 0) border += args [7];
	return border;
}

/**
 * Returns a rectangle describing the receiver's size and location
 * relative to its parent (or its display if its parent is null),
 * unless the receiver is a shell. In this case, the location is
 * relative to the display.
 *
 * @return the receiver's bounding rectangle
 *
 * @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 Rectangle getBounds () {
	checkWidget();
	int topHandle = topHandle ();
	PhArea_t area = new PhArea_t ();
	OS.PtWidgetArea (topHandle, area);
	return new Rectangle (area.pos_x, area.pos_y, area.size_w, area.size_h);
}

/**
 * Returns the receiver's cursor, or null if it has not been set.
 * <p>
 * When the mouse pointer passes over a control its appearance
 * is changed to match the control's cursor.
 * </p>
 *
 * @return the receiver's cursor or <code>null</code>
 *
 * @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 3.3
 */
public Cursor getCursor () {
	checkWidget ();
	return cursor;
}

/**
 * Returns <code>true</code> if the receiver is detecting
 * drag gestures, and  <code>false</code> otherwise. 
 *
 * @return the receiver's drag detect state
 * 
 * @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 3.3
 */
public boolean getDragDetect () {
	checkWidget ();
	//TODO - not implemented
	return true;
}

/**
 * Returns <code>true</code> if the receiver is enabled, and
 * <code>false</code> otherwise. A disabled control is typically
 * not selectable from the user interface and draws with an
 * inactive or "grayed" look.
 *
 * @return the receiver's enabled state
 *
 * @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 #isEnabled
 */
public boolean getEnabled () {
	checkWidget ();
	return (state & DISABLED) == 0;
}

/**
 * Returns layout data which is associated with the receiver.
 *
 * @return the receiver's layout 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>
 */
public Object getLayoutData () {
	checkWidget();
	return layoutData;
}

/**
 * Returns a point describing the receiver's location relative
 * to its parent (or its display if its parent is null), unless
 * the receiver is a shell. In this case, the point is 
 * relative to the display. 
 *
 * @return the receiver's location
 *
 * @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 Point getLocation () {
	checkWidget();
	int topHandle = topHandle ();
	PhArea_t area = new PhArea_t ();
	OS.PtWidgetArea (topHandle, area);
	return new Point (area.pos_x, area.pos_y);
}

/**
 * Returns the receiver's pop up menu if it has one, or null
 * if it does not. All controls may optionally have a pop up
 * menu that is displayed when the user requests one for
 * the control. The sequence of key strokes, button presses
 * and/or button releases that are used to request a pop up
 * menu is platform specific.
 *
 * @return the receiver's menu
 *
 * @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 Menu getMenu () {
	checkWidget();
	return menu;
}

/**
 * Returns the receiver's monitor.
 * 
 * @return the receiver's monitor
 * 
 * @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 3.0
 */
public Monitor getMonitor () {
	checkWidget();
	Monitor [] monitors = display.getMonitors ();
	if (monitors.length == 1) return monitors [0];
	int index = -1, value = -1;
	Rectangle bounds = getBounds ();
	if (this != getShell ()) {
		bounds = display.map (this.parent, null, bounds);
	}
	for (int i=0; i<monitors.length; i++) {
		Rectangle rect = bounds.intersection (monitors [i].getBounds ());
		int area = rect.width * rect.height;
		if (area > 0 && area > value) {
			index = i;
			value = area;
		}
	}
	if (index >= 0) return monitors [index];
	int centerX = bounds.x + bounds.width / 2, centerY = bounds.y + bounds.height / 2;
	for (int i=0; i<monitors.length; i++) {
		Rectangle rect = monitors [i].getBounds ();
		int x = centerX < rect.x ? rect.x - centerX : centerX > rect.x + rect.width ? centerX - rect.x - rect.width : 0;
		int y = centerY < rect.y ? rect.y - centerY : centerY > rect.y + rect.height ? centerY - rect.y - rect.height : 0;
		int distance = x * x + y * y;
		if (index == -1 || distance < value) {
			index = i;
			value = distance;
		} 
	}
	return monitors [index];
}

/**
 * Returns the orientation of the receiver, which will be one of the
 * constants <code>SWT.LEFT_TO_RIGHT</code> or <code>SWT.RIGHT_TO_LEFT</code>.
 *
 * @return the orientation style
 * 
 * @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 3.7
 */
public int getOrientation () {
	checkWidget ();
	return style & (SWT.LEFT_TO_RIGHT | SWT.RIGHT_TO_LEFT);
}

/**
 * Returns the receiver's parent, which must be a <code>Composite</code>
 * or null when the receiver is a shell that was created with null or
 * a display for a parent.
 *
 * @return the receiver's parent
 *
 * @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 Composite getParent () {
	checkWidget();
	return parent;
}

Control [] getPath () {
	int count = 0;
	Shell shell = getShell ();
	Control control = this;
	while (control != shell) {
		count++;
		control = control.parent;
	}
	control = this;
	Control [] result = new Control [count];
	while (control != shell) {
		result [--count] = control;
		control = control.parent;
	}
	return result;
}

/**
 * Returns a point describing the receiver's size. The
 * x coordinate of the result is the width of the receiver.
 * The y coordinate of the result is the height of the
 * receiver.
 *
 * @return the receiver's size
 *
 * @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 Point getSize () {
	checkWidget();
	int topHandle = topHandle ();
	PhArea_t area = new PhArea_t ();
	OS.PtWidgetArea (topHandle, area);
	return new Point (area.size_w, area.size_h);
}

/**
 * Returns the receiver's tool tip text, or null if it has
 * not been set.
 *
 * @return the receiver's tool tip text
 *
 * @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 String getToolTipText () {
	checkWidget();
	return toolTipText;
}

/**
 * Returns <code>true</code> if this control is set to send touch events, or
 * <code>false</code> if it is set to send gesture events instead.  This method
 * also returns <code>false</code> if a touch-based input device is not detected
 * (this can be determined with <code>Display#getTouchEnabled()</code>).  Use
 * {@link #setTouchEnabled(boolean)} to switch the events that a control sends
 * between touch events and gesture events.
 *
 * @return <code>true</code> if the control is set to send touch events, or <code>false</code> otherwise
 *
 * @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 #setTouchEnabled
 * @see Display#getTouchEnabled
 *
 * @since 3.7
 */
public boolean getTouchEnabled() {
	checkWidget();
	return false;
}

/** 
 * Returns the region that defines the shape of the control,
 * or null if the control has the default shape.
 *
 * @return the region that defines the shape of the shell (or null)
 *	
 * @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 3.4
 */
public Region getRegion () {
	checkWidget ();
	return region;
}

/**
 * Returns the receiver's shell. For all controls other than
 * shells, this simply returns the control's nearest ancestor
 * shell. Shells return themselves, even if they are children
 * of other shells.
 *
 * @return the receiver's shell
 *
 * @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 #getParent
 */
public Shell getShell () {
	checkWidget();
	return parent.getShell ();
}

/**
 * Returns <code>true</code> if the receiver is visible, and
 * <code>false</code> otherwise.
 * <p>
 * If one of the receiver's ancestors is not visible or some
 * other condition makes the receiver not visible, this method
 * may still indicate that it is considered visible even though
 * it may not actually be showing.
 * </p>
 *
 * @return the receiver's visibility state
 *
 * @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 boolean getVisible () {
	checkWidget ();
	int topHandle = topHandle ();
	return (OS.PtWidgetFlags (topHandle) & OS.Pt_DELAY_REALIZE) == 0;
}

boolean hasFocus () {
	return OS.PtIsFocused (handle) != 0;
}

void hookEvents () {
	int windowProc = display.windowProc;
	int focusHandle = focusHandle ();
	OS.PtAddFilterCallback (handle, OS.Ph_EV_KEY, windowProc, OS.Ph_EV_KEY);
	OS.PtAddEventHandler (handle, OS.Ph_EV_BUT_PRESS, windowProc, OS.Ph_EV_BUT_PRESS);
	OS.PtAddEventHandler (handle, OS.Ph_EV_BUT_RELEASE, windowProc, OS.Ph_EV_BUT_RELEASE);
	OS.PtAddEventHandler (handle, OS.Ph_EV_PTR_MOTION, windowProc, OS.Ph_EV_PTR_MOTION);
	OS.PtAddEventHandler (handle, OS.Ph_EV_BOUNDARY, windowProc, OS.Ph_EV_BOUNDARY);
	if ((state & GRAB) != 0) {
		OS.PtAddEventHandler (handle, OS.Ph_EV_DRAG, windowProc, OS.Ph_EV_DRAG);
		OS.PtAddCallback (handle, OS.Pt_CB_OUTBOUND, windowProc, OS.Pt_CB_OUTBOUND);
	}
	OS.PtAddCallback (focusHandle, OS.Pt_CB_GOT_FOCUS, windowProc, OS.Pt_CB_GOT_FOCUS);
	OS.PtAddCallback (focusHandle, OS.Pt_CB_LOST_FOCUS, windowProc, OS.Pt_CB_LOST_FOCUS);
}

int focusHandle () {
	return handle;
}

/**	 
 * Invokes platform specific functionality to allocate a new GC handle.
 * <p>
 * <b>IMPORTANT:</b> This method is <em>not</em> part of the public
 * API for <code>Control</code>. 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 called from
 * application code.
 * </p>
 *
 * @param data the platform specific GC data 
 * @return the platform specific GC handle
 * 
 * @noreference This method is not intended to be referenced by clients.
 */
public int internal_new_GC (GCData data) {
	checkWidget();
	int phGC = OS.PgCreateGC(0); // NOTE: PgCreateGC ignores the parameter
	if (phGC == 0) SWT.error(SWT.ERROR_NO_HANDLES);

	int mask = SWT.LEFT_TO_RIGHT | SWT.RIGHT_TO_LEFT;
	if ((data.style & mask) == 0) {
		data.style |= style & (mask | SWT.MIRRORED);
	}
	int [] args = {OS.Pt_ARG_COLOR, 0, 0, OS.Pt_ARG_FILL_COLOR, 0, 0};
	OS.PtGetResources (handle, args.length / 3, args);
	data.device = display;
	data.widget = handle;
	int disjoint = OS.PtFindDisjoint( handle );
	if( disjoint != 0 )
		OS.PgSetRegion( OS.PtWidgetRid( disjoint ) );
	data.topWidget = topHandle ();
	data.foreground = args [1];
	data.background = args [4];
	data.font = getFont ();
	return phGC;
}

/**	 
 * Invokes platform specific functionality to dispose a GC handle.
 * <p>
 * <b>IMPORTANT:</b> This method is <em>not</em> part of the public
 * API for <code>Control</code>. 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 called from
 * application code.
 * </p>
 *
 * @param hDC the platform specific GC handle
 * @param data the platform specific GC data 
 * 
 * @noreference This method is not intended to be referenced by clients.
 */
public void internal_dispose_GC (int phGC, GCData data) {
	checkWidget ();
	OS.PgDestroyGC(phGC);
}

/**
 * Returns <code>true</code> if the receiver is enabled and all
 * ancestors up to and including the receiver's nearest ancestor
 * shell are enabled.  Otherwise, <code>false</code> is returned.
 * A disabled control is typically not selectable from the user
 * interface and draws with an inactive or "grayed" look.
 *
 * @return the receiver's enabled state
 *
 * @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 #getEnabled
 */
public boolean isEnabled () {
	checkWidget();
	return getEnabled () && parent.isEnabled ();
}

/**
 * Returns <code>true</code> if the receiver has the user-interface
 * focus, and <code>false</code> otherwise.
 *
 * @return the receiver's focus state
 *
 * @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 boolean isFocusControl () {
	checkWidget();
	return hasFocus ();
}

/**
 * Returns <code>true</code> if the underlying operating
 * system supports this reparenting, otherwise <code>false</code>
 *
 * @return <code>true</code> if the widget can be reparented, otherwise <code>false</code>
 *
 * @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 boolean isReparentable () {
	checkWidget();
	return false;
}

boolean isShowing () {
	/*
	* This is not complete.  Need to check if the
	* widget is obscurred by a parent or sibling.
	*/
	if (!isVisible ()) return false;
	Control control = this;
	while (control != null) {
		Point size = control.getSize ();
		if (size.x == 0 || size.y == 0) {
			return false;
		}
		control = control.parent;
	}
	return true;
	/*
	* Check to see if current damage is included.
	*/
//	if (!OS.IsWindowVisible (handle)) return false;
//	int flags = OS.DCX_CACHE | OS.DCX_CLIPCHILDREN | OS.DCX_CLIPSIBLINGS;
//	int hDC = OS.GetDCEx (handle, 0, flags);
//	int result = OS.GetClipBox (hDC, new RECT ());
//	OS.ReleaseDC (handle, hDC);
//	return result != OS.NULLREGION;
}

boolean isTabGroup () {
	Control [] tabList = parent._getTabList ();
	if (tabList != null) {
		for (int i=0; i<tabList.length; i++) {
			if (tabList [i] == this) return true;
		}
	}
	int code = traversalCode (0, null);
	if ((code & (SWT.TRAVERSE_ARROW_PREVIOUS | SWT.TRAVERSE_ARROW_NEXT)) != 0) return false;
	return (code & (SWT.TRAVERSE_TAB_PREVIOUS | SWT.TRAVERSE_TAB_NEXT)) != 0;
}

boolean isTabItem () {
	Control [] tabList = parent._getTabList ();
	if (tabList != null) {
		for (int i=0; i<tabList.length; i++) {
			if (tabList [i] == this) return false;
		}
	}
	int code = traversalCode (0, null);
	return (code & (SWT.TRAVERSE_ARROW_PREVIOUS | SWT.TRAVERSE_ARROW_NEXT)) != 0;
}

/**
 * Returns <code>true</code> if the receiver is visible and all
 * ancestors up to and including the receiver's nearest ancestor
 * shell are visible. Otherwise, <code>false</code> is returned.
 *
 * @return the receiver's visibility state
 *
 * @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 #getVisible
 */
public boolean isVisible () {
	checkWidget();
	return OS.PtWidgetIsRealized (handle);
}

void markLayout (boolean changed, boolean all) {
	/* Do nothing */
}

Decorations menuShell () {
	return parent.menuShell ();
}

/**
 * Moves the receiver above the specified control in the
 * drawing order. If the argument is null, then the receiver
 * is moved to the top of the drawing order. The control at
 * the top of the drawing order will not be covered by other
 * controls even if they occupy intersecting areas.
 *
 * @param control the sibling control (or null)
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the control has been disposed</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 Control#moveBelow
 * @see Composite#getChildren
 */
public void moveAbove (Control control) {
	checkWidget();
	int topHandle1 = topHandle ();
	if (control == null) {
		OS.PtWidgetToFront (topHandle1);
		OS.PtWindowToFront (topHandle1);
		return;
	}
	if (control.isDisposed()) error(SWT.ERROR_INVALID_ARGUMENT);
	if (parent != control.parent) return;
	int topHandle2 = control.topHandle ();
	OS.PtWidgetInsert (topHandle1, topHandle2, 0);
}

/**
 * Moves the receiver below the specified control in the
 * drawing order. If the argument is null, then the receiver
 * is moved to the bottom of the drawing order. The control at
 * the bottom of the drawing order will be covered by all other
 * controls which occupy intersecting areas.
 *
 * @param control the sibling control (or null)
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the control has been disposed</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 Control#moveAbove
 * @see Composite#getChildren
 */
public void moveBelow (Control control) {
	checkWidget();
	int topHandle1 = topHandle ();
	if (control == null) {
		if (parent != null) parent.moveToBack (topHandle1);
		OS.PtWindowToBack (topHandle1);
		return;
	}
	if (control.isDisposed()) error(SWT.ERROR_INVALID_ARGUMENT);
	if (parent != control.parent) return;
	int topHandle2 = control.topHandle ();
	OS.PtWidgetInsert (topHandle1, topHandle2, 1);
}

/**
 * Causes the receiver to be resized to its preferred size.
 * For a composite, this involves computing the preferred size
 * from its layout, if there is one.
 *
 * @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 #computeSize(int, int, boolean)
 */
public void pack () {
	checkWidget();
	pack (true);
}

/**
 * Causes the receiver to be resized to its preferred size.
 * For a composite, this involves computing the preferred size
 * from its layout, if there is one.
 * <p>
 * If the changed flag is <code>true</code>, it indicates that the receiver's
 * <em>contents</em> have changed, therefore any caches that a layout manager
 * containing the control may have been keeping need to be flushed. When the
 * control is resized, the changed flag will be <code>false</code>, so layout
 * manager caches can be retained. 
 * </p>
 *
 * @param changed whether or not the receiver's contents have changed
 * 
 * @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 #computeSize(int, int, boolean)
 */
public void pack (boolean changed) {
	checkWidget();
	setSize (computeSize (SWT.DEFAULT, SWT.DEFAULT, changed));
}

/**
 * Prints the receiver and all children.
 * 
 * @param gc the gc where the drawing occurs
 * @return <code>true</code> if the operation was successful and <code>false</code> otherwise
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the gc is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the gc has been disposed</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>
 * 
 * @since 3.4
 */
public boolean print (GC gc) {
	checkWidget ();
	if (gc == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (gc.isDisposed ()) error (SWT.ERROR_INVALID_ARGUMENT);
	return false;
}

int Ph_EV_BOUNDARY (int widget, int info) {
	if (info == 0) return OS.Pt_END;
	PtCallbackInfo_t cbinfo = new PtCallbackInfo_t ();
	OS.memmove (cbinfo, info, PtCallbackInfo_t.sizeof);
	if (cbinfo.event == 0) return OS.Pt_END;
	PhEvent_t ev = new PhEvent_t ();
	OS.memmove (ev, cbinfo.event, PhEvent_t.sizeof);
	int data = OS.PhGetData (cbinfo.event);
	if (data == 0) return OS.Pt_END;
	PhPointerEvent_t pe = new PhPointerEvent_t ();
	OS.memmove (pe, data, PhPointerEvent_t.sizeof);
	switch ((int) ev.subtype) {
		case OS.Ph_EV_PTR_ENTER:
		case OS.Ph_EV_PTR_ENTER_FROM_CHILD:{
			Event event = new Event ();
			event.time = ev.timestamp;
			setMouseState (event, SWT.MouseEnter, pe, ev);
			sendEvent (SWT.MouseEnter, event);
			break;
		}
		case OS.Ph_EV_PTR_LEAVE:
		case OS.Ph_EV_PTR_LEAVE_TO_CHILD: {
			Event event = new Event ();
			event.time = ev.timestamp;
			setMouseState (event, SWT.MouseExit, pe, ev);
			sendEvent (SWT.MouseExit, event);
			break;
		}
		case OS.Ph_EV_PTR_STEADY: {
			Event event = new Event ();
			event.time = ev.timestamp;
			setMouseState (event, SWT.MouseHover, pe, ev);
			postEvent (SWT.MouseHover, event);
			destroyToolTip (toolTipHandle);
			toolTipHandle = createToolTip (toolTipText, handle, getFont ().handle);
			break;
		}
		case OS.Ph_EV_PTR_UNSTEADY:
			destroyToolTip (toolTipHandle);
			toolTipHandle = 0;
			break;		
	}
	return OS.Pt_END;
}

int Ph_EV_BUT_PRESS (int widget, int info) {
	if (info == 0) return OS.Pt_END;
	PtCallbackInfo_t cbinfo = new PtCallbackInfo_t ();
	OS.memmove (cbinfo, info, PtCallbackInfo_t.sizeof);
	if (cbinfo.event == 0) return OS.Pt_END;
	PhEvent_t ev = new PhEvent_t ();
	OS.memmove (ev, cbinfo.event, PhEvent_t.sizeof);
	if ((ev.processing_flags & OS.Ph_FAKE_EVENT) != 0) {
		return OS.Pt_CONTINUE;
	}
	ev.processing_flags |= OS.Ph_CONSUMED;
	OS.memmove (cbinfo.event, ev, PhEvent_t.sizeof);
	int data = OS.PhGetData (cbinfo.event);
	if (data == 0) return OS.Pt_END;
	PhPointerEvent_t pe = new PhPointerEvent_t ();
	OS.memmove (pe, data, PhPointerEvent_t.sizeof);
	Event event = new Event ();
	event.count = pe.click_count;
	event.time = ev.timestamp;
	setMouseState (event, SWT.MouseDown, pe, ev);
	postEvent (SWT.MouseDown, event);
	if (pe.click_count == 2) {
		Event clickEvent = new Event ();
		clickEvent.count = pe.click_count;
		clickEvent.time = ev.timestamp;
		setMouseState (clickEvent, SWT.MouseDoubleClick, pe, ev);
		postEvent (SWT.MouseDoubleClick, clickEvent);
	}
	if (event.button == 3) {
		Event menuEvent = new Event ();
		menuEvent.x = pe.pos_x;
		menuEvent.y = pe.pos_y;
		sendEvent (SWT.MenuDetect, menuEvent);
		if (menuEvent.doit) {
			if (menu != null && !menu.isDisposed ()) {
				if (menuEvent.x != event.x || menuEvent.y != event.y) {
					menu.setLocation (menuEvent.x, menuEvent.y);
				}
				menu.setVisible (true);
			}
		}
	}
	display.dragStartX = pe.pos_x + ev.translation_x;
	display.dragStartY = pe.pos_y + ev.translation_y;
	/*
	* It is possible that the shell may be
	* disposed at this point.  If this happens
	* don't send the activate and deactivate
	* events.
	*/
	Shell shell = getShell ();
	if (!shell.isDisposed ()) {
		shell.setActiveControl (this);
	}
	return OS.Pt_CONTINUE;
}

int Ph_EV_BUT_RELEASE (int widget, int info) {
	if (info == 0) return OS.Pt_END;
	PtCallbackInfo_t cbinfo = new PtCallbackInfo_t ();
	OS.memmove (cbinfo, info, PtCallbackInfo_t.sizeof);
	if (cbinfo.event == 0) return OS.Pt_END;
	PhEvent_t ev = new PhEvent_t ();
	OS.memmove (ev, cbinfo.event, PhEvent_t.sizeof);
	if ((ev.processing_flags & OS.Ph_FAKE_EVENT) != 0) {
		return OS.Pt_CONTINUE;
	}
	ev.processing_flags |= OS.Ph_CONSUMED;
	OS.memmove (cbinfo.event, ev, PhEvent_t.sizeof);
	if (ev.subtype != OS.Ph_EV_RELEASE_PHANTOM) {
		return OS.Pt_CONTINUE;
	}
	int data = OS.PhGetData (cbinfo.event);
	if (data == 0) return OS.Pt_END;
	PhPointerEvent_t pe = new PhPointerEvent_t ();
	OS.memmove (pe, data, PhPointerEvent_t.sizeof);
	Event event = new Event ();
	event.count = pe.click_count;
	event.time = ev.timestamp;
	setMouseState (event, SWT.MouseUp, pe, ev);
	postEvent (SWT.MouseUp, event);
	return OS.Pt_CONTINUE;
}

int Ph_EV_DRAG (int widget, int info) {
	if (info == 0) return OS.Pt_END;
	PtCallbackInfo_t cbinfo = new PtCallbackInfo_t ();
	OS.memmove (cbinfo, info, PtCallbackInfo_t.sizeof);
	if (cbinfo.event == 0) return OS.Pt_END;
	PhEvent_t ev = new PhEvent_t ();
	OS.memmove (ev, cbinfo.event, PhEvent_t.sizeof);
	if ((ev.processing_flags & OS.Ph_FAKE_EVENT) != 0) {
		return OS.Pt_CONTINUE;
	}
	if (ev.subtype != OS.Ph_EV_DRAG_MOTION_EVENT) {
		return OS.Pt_CONTINUE;
	}
	int data = OS.PhGetData (cbinfo.event);
	if (data == 0) return OS.Pt_END;
	PhPointerEvent_t pe = new PhPointerEvent_t ();
	OS.memmove (pe, data, PhPointerEvent_t.sizeof);
	Event event = new Event ();
	event.time = ev.timestamp;
	setMouseState (event, SWT.MouseMove, pe, ev);
	postEvent (SWT.MouseMove, event);
	return OS.Pt_CONTINUE;
}

int Ph_EV_KEY (int widget, int info) {
	if (!hasFocus ()) return OS.Pt_PROCESS;
	if (info == 0) return OS.Pt_PROCESS;
	PtCallbackInfo_t cbinfo = new PtCallbackInfo_t ();
	OS.memmove (cbinfo, info, PtCallbackInfo_t.sizeof);
	if (cbinfo.event == 0) return OS.Pt_PROCESS;
	PhEvent_t ev = new PhEvent_t ();
	OS.memmove (ev, cbinfo.event, PhEvent_t.sizeof);
	if ((ev.processing_flags & OS.Ph_FAKE_EVENT) != 0) {
		return OS.Pt_PROCESS;
	}
	int data = OS.PhGetData (cbinfo.event);
	if (data == 0) return OS.Pt_PROCESS;
	PhKeyEvent_t ke = new PhKeyEvent_t ();
	OS.memmove (ke, data, PhKeyEvent_t.sizeof);

	/*
	* Feature in Photon.  When the user presses certain keys
	* (such as the arrow keys), Photon sends 2 event for one
	* key press.  The first event has only the scan code while
	* the second has the keysym and other information.  This
	* also happens for key release.  The fix is to ignore the
	* first event.
	*/
	if (ke.key_flags == OS.Pk_KF_Scan_Valid) {
		return OS.Pt_PROCESS;
	}

	/* Ignore repeating modifier keys */
	if ((ke.key_flags & OS.Pk_KF_Key_Repeat) != 0) {
		if ((ke.key_flags & OS.Pk_KF_Sym_Valid) != 0) {
			switch (ke.key_sym) {
				case OS.Pk_Alt_L:
				case OS.Pk_Alt_R:
				case OS.Pk_Control_L:
				case OS.Pk_Control_R:
				case OS.Pk_Shift_L:
				case OS.Pk_Shift_R:
					return OS.Pt_PROCESS;
			}
		}
	}
						
	/* Determine event type */
	int type = SWT.KeyUp;
	if ((ke.key_flags & (OS.Pk_KF_Key_Down | OS.Pk_KF_Key_Repeat)) != 0) {
		type = SWT.KeyDown;
	}

	/* Determine if this is a traverse event */
	if (type == SWT.KeyDown) {
		/*
		* Fetuare in Photon.  The key_sym value is not valid when Ctrl
		* or Alt is pressed. The fix is to detect this case and try to
		* use the key_cap value.
		*/
		int key = ke.key_sym;
		if ((ke.key_flags & OS.Pk_KF_Sym_Valid) == 0) {
			key = 0;
			if ((ke.key_flags & OS.Pk_KF_Cap_Valid) != 0) {
				if (ke.key_cap == OS.Pk_Tab && (ke.key_mods & OS.Pk_KM_Ctrl) != 0) {
					key = OS.Pk_Tab;
				}
			}
		}

		switch (key) {
			case OS.Pk_Escape:
			case OS.Pk_Return:
			case OS.Pk_KP_Tab:
			case OS.Pk_Tab:
			case OS.Pk_Up:
			case OS.Pk_Down:
			case OS.Pk_Left:
			case OS.Pk_Right:
			case OS.Pk_Pg_Up:
			case OS.Pk_Pg_Down: {
				if (key != OS.Pk_Return) {
					ev.processing_flags |= OS.Ph_NOT_CUAKEY;
					OS.memmove (cbinfo.event, ev, PhEvent_t.sizeof);
				}
				if (translateTraversal (key, ke)) {
					ev.processing_flags |= OS.Ph_CONSUMED;
					OS.memmove (cbinfo.event, ev, PhEvent_t.sizeof);
					return OS.Pt_PROCESS;
				}
				// widget could be disposed at this point
				if (isDisposed ()) return OS.Pt_CONSUME;
			}
		}
	}

	Event event = new Event ();
	event.time = ev.timestamp;
	if (!setKeyState (event, type, ke)) return OS.Pt_PROCESS;
	if (type == SWT.KeyDown) {
		display.lastKey = event.keyCode;
		display.lastAscii = event.character;
	} else {
		if (event.keyCode == 0) event.keyCode = display.lastKey;
		if (event.character == 0) event.character = (char) display.lastAscii;
	}
	sendEvent (type, event);
	// widget could be disposed at this point
	if (isDisposed ()) return OS.Pt_CONSUME;
	return event.doit ? OS.Pt_PROCESS :OS.Pt_CONSUME; 
}

int Ph_EV_PTR_MOTION (int widget, int info) {
	if (info == 0) return OS.Pt_END;
	PtCallbackInfo_t cbinfo = new PtCallbackInfo_t ();
	OS.memmove (cbinfo, info, PtCallbackInfo_t.sizeof);
	if (cbinfo.event == 0) return OS.Pt_END;
	PhEvent_t ev = new PhEvent_t ();
	OS.memmove (ev, cbinfo.event, PhEvent_t.sizeof);
	if ((ev.processing_flags & OS.Ph_FAKE_EVENT) != 0) {
		return OS.Pt_CONTINUE;
	}
	ev.processing_flags |= OS.Ph_CONSUMED;
	OS.memmove (cbinfo.event, ev, PhEvent_t.sizeof);
	if (ev.type == OS.Ph_EV_PTR_MOTION_BUTTON) {
		if ((state & CANVAS) != 0) return OS.Pt_CONTINUE;
	}
	int data = OS.PhGetData (cbinfo.event);
	if (data == 0) return OS.Pt_END;
	PhPointerEvent_t pe = new PhPointerEvent_t ();
	OS.memmove (pe, data, PhPointerEvent_t.sizeof);
	Event event = new Event ();
	event.time = ev.timestamp;
	setMouseState (event, SWT.MouseMove, pe, ev);
	postEvent (SWT.MouseMove, event);
	return OS.Pt_CONTINUE;
}

int Pt_CB_GOT_FOCUS (int widget, int info) {
	Shell shell = getShell ();
	sendEvent (SWT.FocusIn);
	if (isDisposed ()) return OS.Pt_CONTINUE;

	/*
	* It is possible that the shell may be
	* disposed at this point.  If this happens
	* don't send the activate and deactivate
	* events.
	*/	
	if (!shell.isDisposed ()) {
		shell.setActiveControl (this);
	}

	/*
	* Feature in Photon.  Cannot return Pt_END
	* or the text widget will not take focus.
	*/
	return OS.Pt_CONTINUE;
}

int Pt_CB_LOST_FOCUS (int widget, int info) {
	Shell shell = getShell ();
	sendEvent (SWT.FocusOut);
	if (isDisposed ()) return OS.Pt_CONTINUE;

	/*
	* It is possible that the shell may be
	* disposed at this point.  If this happens
	* don't send the activate and deactivate
	* events.
	*/
	if (!shell.isDisposed ()) {
		Display display = shell.display;
		Control control = display.getFocusControl ();
		if (control == null || shell != control.getShell () ) {
			shell.setActiveControl (null);
		}
	}

	/*
	* Feature in Photon.  Cannot return Pt_END
	* or the text widget will not take focus.
	*/
	return OS.Pt_CONTINUE;
}

void realizeWidget() {
	int parentHandle = parent.handle;
	if (OS.PtWidgetIsRealized (parentHandle)) {
		OS.PtRealizeWidget (topHandle ());
	}
}

void releaseHandle () {
	super.releaseHandle ();
	parent = null;
}

void releaseParent () {
	super.releaseParent ();
	parent.removeControl (this);
}

void releaseWidget () {
	super.releaseWidget ();
	if (toolTipHandle != 0) destroyToolTip (toolTipHandle);
	toolTipHandle = 0;
	if (menu != null && !menu.isDisposed ()) {
		menu.dispose ();
	}
	menu = null;
	cursor = null;
	layoutData = null;
	region = null;
}

/**
 * Causes the entire bounds of the receiver to be marked
 * as needing to be redrawn. The next time a paint request
 * is processed, the control will be completely painted,
 * including the background.
 *
 * @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 #update()
 * @see PaintListener
 * @see SWT#Paint
 * @see SWT#NO_BACKGROUND
 * @see SWT#NO_REDRAW_RESIZE
 * @see SWT#NO_MERGE_PAINTS
 * @see SWT#DOUBLE_BUFFERED
 */
public void redraw () {
	checkWidget();
	OS.PtDamageWidget (handle);
}

/**
 * Causes the rectangular area of the receiver specified by
 * the arguments to be marked as needing to be redrawn. 
 * The next time a paint request is processed, that area of
 * the receiver will be painted, including the background.
 * If the <code>all</code> flag is <code>true</code>, any
 * children of the receiver which intersect with the specified
 * area will also paint their intersecting areas. If the
 * <code>all</code> flag is <code>false</code>, the children
 * will not be painted.
 *
 * @param x the x coordinate of the area to draw
 * @param y the y coordinate of the area to draw
 * @param width the width of the area to draw
 * @param height the height of the area to draw
 * @param all <code>true</code> if children should redraw, and <code>false</code> otherwise
 *
 * @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 #update()
 * @see PaintListener
 * @see SWT#Paint
 * @see SWT#NO_BACKGROUND
 * @see SWT#NO_REDRAW_RESIZE
 * @see SWT#NO_MERGE_PAINTS
 * @see SWT#DOUBLE_BUFFERED
 */
public void redraw (int x, int y, int width, int height, boolean allChildren) {
	checkWidget ();
	if (width <= 0 || height <= 0) return;
	PhRect_t rect = new PhRect_t ();
	rect.ul_x = (short) x;
	rect.ul_y = (short) y;
	rect.lr_x = (short) (x + width - 1);
	rect.lr_y = (short) (y + height - 1);
	OS.PtDamageExtent (handle, rect);
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when the control is moved or resized.
 *
 * @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 ControlListener
 * @see #addControlListener
 */
public void removeControlListener (ControlListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.Move, listener);
	eventTable.unhook (SWT.Resize, listener);
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when a drag gesture occurs.
 *
 * @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 DragDetectListener
 * @see #addDragDetectListener
 * 
 * @since 3.3
 */
public void removeDragDetectListener(DragDetectListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.DragDetect, listener);
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when the control gains or loses focus.
 *
 * @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 FocusListener
 * @see #addFocusListener
 */
public void removeFocusListener(FocusListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.FocusIn, listener);
	eventTable.unhook (SWT.FocusOut, listener);
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when gesture events are generated for the control.
 *
 * @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 GestureListener
 * @see #addGestureListener
 * 
 * @since 3.7
 */
public void removeGestureListener (GestureListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook(SWT.Gesture, listener);
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when the help events are generated for the control.
 *
 * @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 HelpListener
 * @see #addHelpListener
 */
public void removeHelpListener (HelpListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.Help, listener);
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when keys are pressed and released on the system keyboard.
 *
 * @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 KeyListener
 * @see #addKeyListener
 */
public void removeKeyListener(KeyListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.KeyUp, listener);
	eventTable.unhook (SWT.KeyDown, listener);
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when the platform-specific context menu trigger has
 * occurred.
 *
 * @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 MenuDetectListener
 * @see #addMenuDetectListener
 *
 * @since 3.3
 */
public void removeMenuDetectListener (MenuDetectListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.MenuDetect, listener);
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when mouse buttons are pressed and released.
 *
 * @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 MouseListener
 * @see #addMouseListener
 */
public void removeMouseListener (MouseListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.MouseDown, listener);
	eventTable.unhook (SWT.MouseUp, listener);
	eventTable.unhook (SWT.MouseDoubleClick, listener);
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when the mouse moves.
 *
 * @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 MouseMoveListener
 * @see #addMouseMoveListener
 */
public void removeMouseMoveListener(MouseMoveListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.MouseMove, listener);
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when the mouse passes or hovers over controls.
 *
 * @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 MouseTrackListener
 * @see #addMouseTrackListener
 */
public void removeMouseTrackListener(MouseTrackListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.MouseEnter, listener);
	eventTable.unhook (SWT.MouseExit, listener);
	eventTable.unhook (SWT.MouseHover, listener);
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when the mouse wheel is scrolled.
 *
 * @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 MouseWheelListener
 * @see #addMouseWheelListener
 *
 * @since 3.3
 */
public void removeMouseWheelListener (MouseWheelListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.MouseWheel, listener);
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when the receiver needs to be painted.
 *
 * @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 PaintListener
 * @see #addPaintListener
 */
public void removePaintListener(PaintListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook(SWT.Paint, listener);
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when touch events occur.
 *
 * @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 TouchListener
 * @see #addTouchListener
 * 
 * @since 3.7
 */
public void removeTouchListener(TouchListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.Touch, listener);
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when traversal events occur.
 *
 * @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 TraverseListener
 * @see #addTraverseListener
 */
public void removeTraverseListener(TraverseListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.Traverse, listener);
}

int setBounds (int x, int y, int width, int height, boolean move, boolean resize, boolean events) {
	int topHandle = topHandle ();
	PhArea_t area = new PhArea_t ();
	OS.PtWidgetArea (topHandle, area);
	width = Math.max (width, 0);
	height = Math.max (height, 0);
	boolean sameOrigin = x == area.pos_x && y == area.pos_y;
	boolean sameExtent = width == area.size_w && height == area.size_h;
	if (move && resize) {
		if (sameOrigin && sameExtent) return 0;
		area.pos_x = (short) x;
		area.pos_y = (short) y;
		area.size_w = (short) width;
		area.size_h = (short) height;
		int ptr = OS.malloc (PhArea_t.sizeof);
		OS.memmove (ptr, area, PhArea_t.sizeof);
		OS.PtSetResource (topHandle, OS.Pt_ARG_AREA, ptr, 0);
		OS.free (ptr);
	} else {
		if (move) {
			if (sameOrigin) return 0;
			PhPoint_t pt = new PhPoint_t ();
			pt.x = (short) x;
			pt.y = (short) y;
			int ptr = OS.malloc (PhPoint_t.sizeof);
			OS.memmove (ptr, pt, PhPoint_t.sizeof);
			OS.PtSetResource (topHandle, OS.Pt_ARG_POS, ptr, 0);
			OS.free (ptr);
		} else if (resize) {
			if (sameExtent) return 0;
			int [] args = {
				OS.Pt_ARG_WIDTH, width, 0,
				OS.Pt_ARG_HEIGHT, height, 0,
			};
			OS.PtSetResources (topHandle, args.length / 3, args);
		}
	}
	if (!OS.PtWidgetIsRealized (topHandle)) {
		OS.PtExtentWidgetFamily (topHandle);
	}
	int result = 0;
	if (move && !sameOrigin) {
		sendEvent (SWT.Move);
		result |= MOVED;
	}
	if (resize && !sameExtent) {
		sendEvent (SWT.Resize);
		result |= RESIZED;
	}
	return result;
}

/**
 * Sets the receiver's size and location to the rectangular
 * area specified by the arguments. The <code>x</code> and 
 * <code>y</code> arguments are relative to the receiver's
 * parent (or its display if its parent is null), unless 
 * the receiver is a shell. In this case, the <code>x</code>
 * and <code>y</code> arguments are relative to the display.
 * <p>
 * Note: Attempting to set the width or height of the
 * receiver to a negative number will cause that
 * value to be set to zero instead.
 * </p>
 *
 * @param x the new x coordinate for the receiver
 * @param y the new y coordinate for the receiver
 * @param width the new width for the receiver
 * @param height the new height for the receiver
 *
 * @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 void setBounds (int x, int y, int width, int height) {
	checkWidget();
	setBounds (x, y, width, height, true, true, true);
}

/**
 * Sets the receiver's size and location to the rectangular
 * area specified by the argument. The <code>x</code> and 
 * <code>y</code> fields of the rectangle are relative to
 * the receiver's parent (or its display if its parent is null).
 * <p>
 * Note: Attempting to set the width or height of the
 * receiver to a negative number will cause that
 * value to be set to zero instead.
 * </p>
 *
 * @param rect the new bounds for the receiver
 *
 * @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 void setBounds (Rectangle rect) {
	if (rect == null) error (SWT.ERROR_NULL_ARGUMENT);
	setBounds (rect.x, rect.y, rect.width, rect.height);
}

/**
 * If the argument is <code>true</code>, causes the receiver to have
 * all mouse events delivered to it until the method is called with
 * <code>false</code> as the argument.  Note that on some platforms,
 * a mouse button must currently be down for capture to be assigned.
 *
 * @param capture <code>true</code> to capture the mouse, and <code>false</code> to release it
 *
 * @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 void setCapture (boolean capture) {
	checkWidget();
}

/**
 * Sets the receiver's cursor to the cursor specified by the
 * argument, or to the default cursor for that kind of control
 * if the argument is null.
 * <p>
 * When the mouse pointer passes over a control its appearance
 * is changed to match the control's cursor.
 * </p>
 *
 * @param cursor the new cursor (or null)
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the argument has been disposed</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>
 */
public void setCursor (Cursor cursor) {
	checkWidget();
	int type = OS.Ph_CURSOR_INHERIT;
	int bitmap = 0;
	if (cursor != null) {
		if (cursor.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
		type = cursor.type;
		bitmap = cursor.bitmap;
	}
	this.cursor = cursor;
	int [] args = new int []{
		OS.Pt_ARG_CURSOR_TYPE, type, 0,
		OS.Pt_ARG_BITMAP_CURSOR, bitmap, 0,
	};
	OS.PtSetResources (handle, args.length / 3, args);
	
	/*
	* Bug in Photon. For some reason, the widget cursor will
	* not change, when the new cursor is a bitmap cursor, if
	* the flag Ph_CURSOR_NO_INHERIT is reset. The fix is to reset
	* this flag after changing the cursor type to Ph_CURSOR_BITMAP.
	*/
	if (type == OS.Ph_CURSOR_BITMAP) {
		type &= ~OS.Ph_CURSOR_NO_INHERIT;
		OS.PtSetResource (handle, OS.Pt_ARG_CURSOR_TYPE, type, 0);
	}
}

/**
 * Sets the receiver's drag detect state. If the argument is
 * <code>true</code>, the receiver will detect drag gestures,
 * otherwise these gestures will be ignored.
 *
 * @param dragDetect the new drag detect state
 *
 * @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 3.3
 */
public void setDragDetect (boolean dragDetect) {
	checkWidget ();
	//TODO - not implemented
}

/**
 * Enables the receiver if the argument is <code>true</code>,
 * and disables it otherwise. A disabled control is typically
 * not selectable from the user interface and draws with an
 * inactive or "grayed" look.
 *
 * @param enabled the new enabled state
 *
 * @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 void setEnabled (boolean enabled) {
	checkWidget ();
	if (enabled) {
		if ((state & DISABLED) == 0) return;
		state &= ~DISABLED;
	} else {
		if ((state & DISABLED) != 0) return;
		state |= DISABLED;
	}
	enableWidget (enabled);
}

/**
 * Causes the receiver to have the <em>keyboard focus</em>, 
 * such that all keyboard events will be delivered to it.  Focus
 * reassignment will respect applicable platform constraints.
 *
 * @return <code>true</code> if the control got focus, and <code>false</code> if it was unable to.
 *
 * @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 #forceFocus
 */
public boolean setFocus () {
	checkWidget();
	if ((style & SWT.NO_FOCUS) != 0) return false;
	return forceFocus ();
}

/**
 * Sets the receiver's background color to the color specified
 * by the argument, or to the default system color for the control
 * if the argument is null.
 * <p>
 * Note: This operation is a hint and may be overridden by the platform.
 * For example, on Windows the background of a Button cannot be changed.
 * </p>
 * @param color the new color (or null)
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the argument has been disposed</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>
 */
public void setBackground (Color color) {
	checkWidget();
	int pixel;
	if (color == null) {
		pixel = defaultBackground ();
	} else {
		if (color.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
		pixel = color.handle;
	}
	setBackgroundPixel (pixel);
}

/**
 * Sets the receiver's background image to the image specified
 * by the argument, or to the default system color for the control
 * if the argument is null.  The background image is tiled to fill
 * the available space.
 * <p>
 * Note: This operation is a hint and may be overridden by the platform.
 * For example, on Windows the background of a Button cannot be changed.
 * </p>
 * @param image the new image (or null)
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the argument has been disposed</li> 
 *    <li>ERROR_INVALID_ARGUMENT - if the argument is not a bitmap</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>
 * 
 * @since 3.2
 */
public void setBackgroundImage (Image image) {
	checkWidget ();
	if (image != null) {
		if (image.isDisposed ()) error (SWT.ERROR_INVALID_ARGUMENT);
		if (image.type != SWT.BITMAP) error (SWT.ERROR_INVALID_ARGUMENT);
	}
	if (backgroundImage == image) return;
	backgroundImage = image;
}

void setBackgroundPixel (int pixel) {
	OS.PtSetResource (handle, OS.Pt_ARG_FILL_COLOR, pixel, 0);
}

void setDefaultFont () {
	if (display.defaultFont != null) setFont (defaultFont ());
}

/**
 * Sets the font that the receiver will use to paint textual information
 * to the font specified by the argument, or to the default font for that
 * kind of control if the argument is null.
 *
 * @param font the new font (or null)
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the argument has been disposed</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>
 */
public void setFont (Font font) {
	checkWidget();
	byte[] buffer;
	if (font != null) {
		if (font.isDisposed ()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
		buffer = font.handle;
	} else {
		buffer = defaultFont ();
	}
	this.font = font;
	setFont (buffer);
}

void setFont (byte [] font) {
	int ptr = OS.malloc (font.length);
	OS.memmove (ptr, font, font.length);
	setFont (ptr);
	OS.free (ptr);
}

void setFont (int font) {
	int [] args = {
		OS.Pt_ARG_TEXT_FONT, font, 0,
		OS.Pt_ARG_LIST_FONT, font, 0,
		OS.Pt_ARG_TITLE_FONT, font, 0,
		OS.Pt_ARG_GAUGE_FONT, font, 0,
	};
	OS.PtSetResources (handle, args.length / 3, args);
}

/**
 * Sets the receiver's foreground color to the color specified
 * by the argument, or to the default system color for the control
 * if the argument is null.
 * <p>
 * Note: This operation is a hint and may be overridden by the platform.
 * </p>
 * @param color the new color (or null)
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the argument has been disposed</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>
 */
public void setForeground (Color color) {
	checkWidget();
	int pixel;
	if (color == null) {
		pixel = defaultForeground ();
	} else {
		if (color.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
		pixel = color.handle;
	}
	setForegroundPixel (pixel);
}

void setForegroundPixel (int pixel) {
	OS.PtSetResource (handle, OS.Pt_ARG_COLOR, pixel, 0);
}

/**
 * Sets the layout data associated with the receiver to the argument.
 * 
 * @param layoutData the new layout data for the receiver.
 * 
 * @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 void setLayoutData (Object layoutData) {
	checkWidget();
	this.layoutData = layoutData;
}

/**
 * Sets the receiver's location to the point specified by
 * the arguments which are relative to the receiver's
 * parent (or its display if its parent is null), unless 
 * the receiver is a shell. In this case, the point is 
 * relative to the display. 
 *
 * @param x the new x coordinate for the receiver
 * @param y the new y coordinate for the receiver
 *
 * @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 void setLocation (int x, int y) {
	checkWidget();
	setBounds (x, y, 0, 0, true, false, true);
}

/**
 * Sets the receiver's location to the point specified by
 * the arguments which are relative to the receiver's
 * parent (or its display if its parent is null), unless 
 * the receiver is a shell. In this case, the point is 
 * relative to the display. 
 *
 * @param location the new location for the receiver
 *
 * @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 void setLocation (Point location) {
	checkWidget();
	if (location == null) error (SWT.ERROR_NULL_ARGUMENT);
	setLocation (location.x, location.y);
}

/**
 * Sets the receiver's pop up menu to the argument.
 * All controls may optionally have a pop up
 * menu that is displayed when the user requests one for
 * the control. The sequence of key strokes, button presses
 * and/or button releases that are used to request a pop up
 * menu is platform specific.
 * <p>
 * Note: Disposing of a control that has a pop up menu will
 * dispose of the menu.  To avoid this behavior, set the
 * menu to null before the control is disposed.
 * </p>
 *
 * @param menu the new pop up menu
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_MENU_NOT_POP_UP - the menu is not a pop up menu</li>
 *    <li>ERROR_INVALID_PARENT - if the menu is not in the same widget tree</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the menu has been disposed</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>
 */
public void setMenu (Menu menu) {
	checkWidget();
	int flags = 0;
	if (menu != null) {
		if (menu.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
		flags = OS.Pt_MENUABLE;
	}
	OS.PtSetResource (handle, OS.Pt_ARG_FLAGS, flags, OS.Pt_ALL_BUTTONS | OS.Pt_MENUABLE);
	this.menu = menu;
}

/**
 * Sets the orientation of the receiver, which must be one
 * of the constants <code>SWT.LEFT_TO_RIGHT</code> or <code>SWT.RIGHT_TO_LEFT</code>.
 * <p>
 *
 * @param orientation new orientation style
 * 
 * @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 3.7
 */
public void setOrientation (int orientation) {
	checkWidget ();
}

/**
 * Changes the parent of the widget to be the one provided if
 * the underlying operating system supports this feature.
 * Returns <code>true</code> if the parent is successfully changed.
 *
 * @param parent the new parent for the control.
 * @return <code>true</code> if the parent is changed and <code>false</code> otherwise.
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the argument has been disposed</li>
 *    <li>ERROR_NULL_ARGUMENT - if the parent is <code>null</code></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>
 */
public boolean setParent (Composite parent) {
	checkWidget();
	if (parent.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	reskin (SWT.ALL);
	return false;
}

/**
 * Sets the receiver's size to the point specified by the argument.
 * <p>
 * Note: Attempting to set the width or height of the
 * receiver to a negative number will cause them to be
 * set to zero instead.
 * </p>
 *
 * @param size the new size for the receiver
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the point 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>
 */
public void setSize (Point size) {
	checkWidget();
	if (size == null) error (SWT.ERROR_NULL_ARGUMENT);
	setSize (size.x, size.y);
}

boolean setTabGroupFocus () {
	return setTabItemFocus ();
}

boolean setTabItemFocus () {
	if (!isShowing ()) return false;
	return forceFocus ();
}

boolean setRadioSelection (boolean value) {
	return false;
}

/**
 * If the argument is <code>false</code>, causes subsequent drawing
 * operations in the receiver to be ignored. No drawing of any kind
 * can occur in the receiver until the flag is set to true.
 * Graphics operations that occurred while the flag was
 * <code>false</code> are lost. When the flag is set to <code>true</code>,
 * the entire widget is marked as needing to be redrawn.  Nested calls
 * to this method are stacked.
 * <p>
 * Note: This operation is a hint and may not be supported on some
 * platforms or for some widgets.
 * </p>
 *
 * @param redraw the new redraw state
 *
 * @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 #redraw(int, int, int, int, boolean)
 * @see #update()
 */
public void setRedraw (boolean redraw) {
	checkWidget();
	if (redraw) {
		OS.PtContainerRelease (handle);
	} else {
		OS.PtContainerHold (handle);
	}
}

/**
 * Sets the shape of the control to the region specified
 * by the argument.  When the argument is null, the
 * default shape of the control is restored.
 *
 * @param region the region that defines the shape of the control (or null)
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the region has been disposed</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>
 *
 * @since 3.4
 */
public void setRegion (Region region) {
	checkWidget ();
	if (region != null && region.isDisposed()) error (SWT.ERROR_INVALID_ARGUMENT);
	// TODO implement setRegion
	this.region = region;
}
/**
 * Sets the receiver's size to the point specified by the arguments.
 * <p>
 * Note: Attempting to set the width or height of the
 * receiver to a negative number will cause that
 * value to be set to zero instead.
 * </p>
 *
 * @param width the new width for the receiver
 * @param height the new height for the receiver
 *
 * @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 void setSize (int width, int height) {
	checkWidget();
	setBounds (0, 0, width, height, false, true, true);
}

/**
 * Sets whether this control should send touch events (by default controls do not).
 * Setting this to <code>false</code> causes the receiver to send gesture events
 * instead.  No exception is thrown if a touch-based input device is not
 * detected (this can be determined with <code>Display#getTouchEnabled()</code>).
 * 
 * @param enabled the new touch-enabled state
 * 
 * @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>
 *
 * @see Display#getTouchEnabled
 *
 * @since 3.7
 */
public void setTouchEnabled(boolean enabled) {
	checkWidget();
}

/**
 * Marks the receiver as visible if the argument is <code>true</code>,
 * and marks it invisible otherwise. 
 * <p>
 * If one of the receiver's ancestors is not visible or some
 * other condition makes the receiver not visible, marking
 * it visible may not actually cause it to be displayed.
 * </p>
 *
 * @param visible the new visibility state
 *
 * @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 void setVisible (boolean visible) {
	checkWidget ();
	int topHandle = topHandle ();
	int oldFlags = OS.PtWidgetFlags (topHandle);
	int flags = visible ? 0 : OS.Pt_DELAY_REALIZE;
	OS.PtSetResource (topHandle, OS.Pt_ARG_FLAGS, flags, OS.Pt_DELAY_REALIZE);
	if ((oldFlags & OS.Pt_DELAY_REALIZE) == flags) return;
	if (visible) {
		sendEvent (SWT.Show);
		if (isDisposed ()) return;
		OS.PtRealizeWidget (topHandle);
	} else {
		OS.PtUnrealizeWidget (topHandle);
		/*
		 * It is possible (but unlikely), that application
		 * code could have disposed the widget in the FocusOut
		 * event that is triggered by PtUnrealizeWidget if the widget
		 * being hidden has focus.  If this happens, just return.
		 */
		if (isDisposed ()) return;
		sendEvent(SWT.Hide);
	}
}

/**
 * Sets the receiver's tool tip text to the argument, which
 * may be null indicating that the default tool tip for the 
 * control will be shown. For a control that has a default
 * tool tip, such as the Tree control on Windows, setting
 * the tool tip text to an empty string replaces the default,
 * causing no tool tip text to be shown.
 * <p>
 * The mnemonic indicator (character '&amp;') is not displayed in a tool tip.
 * To display a single '&amp;' in the tool tip, the character '&amp;' can be 
 * escaped by doubling it in the string.
 * </p>
 * 
 * @param string the new tool tip text (or null)
 *
 * @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 void setToolTipText (String string) {
	checkWidget();
	toolTipText = string;
}

void setZOrder() {
	if (parent != null) parent.moveToBack (topHandle ());
}

void sort (int [] items) {
	/* Shell Sort from K&R, pg 108 */
	int length = items.length;
	for (int gap=length/2; gap>0; gap/=2) {
		for (int i=gap; i<length; i++) {
			for (int j=i-gap; j>=0; j-=gap) {
		   		if (items [j] <= items [j + gap]) {
					int swap = items [j];
					items [j] = items [j + gap];
					items [j + gap] = swap;
		   		}
	    	}
	    }
	}
}

/**
 * Returns a point which is the result of converting the
 * argument, which is specified in display relative coordinates,
 * to coordinates relative to the receiver.
 * <p>
 * @param x the x coordinate to be translated
 * @param y the y coordinate to be translated
 * @return the translated coordinates
 *
 * @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 2.1
 */
public Point toControl (int x, int y) {
	checkWidget();
	short [] position_x = new short [1], position_y = new short [1];
	OS.PtGetAbsPosition (handle, position_x, position_y);
	return new Point (x - position_x [0], y - position_y [0]);
}

/**
 * Returns a point which is the result of converting the
 * argument, which is specified in display relative coordinates,
 * to coordinates relative to the receiver.
 * <p>
 * @param point the point to be translated (must not be null)
 * @return the translated coordinates
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the point 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>
 */
public Point toControl (Point point) {
	checkWidget();
	if (point == null) error (SWT.ERROR_NULL_ARGUMENT);
	return toControl (point.x, point.y);
}

/**
 * Returns a point which is the result of converting the
 * argument, which is specified in coordinates relative to
 * the receiver, to display relative coordinates.
 * <p>
 * @param x the x coordinate to be translated
 * @param y the y coordinate to be translated
 * @return the translated coordinates
 *
 * @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 2.1
 */
public Point toDisplay (int x, int y) {
	checkWidget();
	short [] position_x = new short [1], position_y = new short [1];
	OS.PtGetAbsPosition (handle, position_x, position_y);
	return new Point (x + position_x [0], y + position_y [0]);
}

/**
 * Returns a point which is the result of converting the
 * argument, which is specified in coordinates relative to
 * the receiver, to display relative coordinates.
 * <p>
 * @param point the point to be translated (must not be null)
 * @return the translated coordinates
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the point 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>
 */
public Point toDisplay (Point point) {
	checkWidget();
	if (point == null) error (SWT.ERROR_NULL_ARGUMENT);
	return toDisplay (point.x, point.y);
}

boolean translateTraversal (int key_sym, PhKeyEvent_t phEvent) {
	int detail = SWT.TRAVERSE_NONE;
	int code = traversalCode (key_sym, phEvent);
	boolean all = false;
	switch (key_sym) {
		case OS.Pk_Escape: {
			all = true;
			detail = SWT.TRAVERSE_ESCAPE;
			break;
		}
		case OS.Pk_Return: {
			all = true;
			detail = SWT.TRAVERSE_RETURN;
			break;
		}
		case OS.Pk_Tab:
		case OS.Pk_KP_Tab: {
			boolean next = (phEvent.key_mods & OS.Pk_KM_Shift) == 0;
			detail = next ? SWT.TRAVERSE_TAB_NEXT : SWT.TRAVERSE_TAB_PREVIOUS;
			break;
		}
		case OS.Pk_Up:
		case OS.Pk_Left: {
			detail = SWT.TRAVERSE_ARROW_PREVIOUS;
			break;
		}
		case OS.Pk_Down:
		case OS.Pk_Right: {
			detail = SWT.TRAVERSE_ARROW_NEXT;
			break;
		}
		case OS.Pk_Pg_Down:
		case OS.Pk_Pg_Up: {
			all = true;
			if ((phEvent.key_mods & OS.Pk_KM_Ctrl) == 0) return false;
			detail = key_sym == OS.Pk_Pg_Down ? SWT.TRAVERSE_PAGE_NEXT : SWT.TRAVERSE_PAGE_PREVIOUS;
			break;
		}
		default:
			return false;
	}
	Event event = new Event ();
	event.doit = (code & detail) != 0;
	event.detail = detail;
	if (!setKeyState (event, SWT.Traverse, phEvent)) return false;
	Shell shell = getShell ();
	Control control = this;
	do {
		if (control.traverse (event)) return true;
		if (!event.doit && control.hooks (SWT.Traverse)) {
			return false;
		}
		if (control == shell) return false;
		control = control.parent;
	} while (all && control != null);
	return false;
}

int traversalCode (int key_sym, PhKeyEvent_t ke) {
//	if ((OS.PtWidgetFlags (handle) & OS.Pt_GETS_FOCUS) == 0) return 0;	
	int code = SWT.TRAVERSE_RETURN | SWT.TRAVERSE_TAB_NEXT | SWT.TRAVERSE_TAB_PREVIOUS;
	Shell shell = getShell ();
	if (shell.parent != null) code |= SWT.TRAVERSE_ESCAPE;
	return code;
}

/**
 * Performs a platform traversal action corresponding to a <code>KeyDown</code> event.
 * 
 * <p>Valid traversal values are
 * <code>SWT.TRAVERSE_NONE</code>, <code>SWT.TRAVERSE_MNEMONIC</code>,
 * <code>SWT.TRAVERSE_ESCAPE</code>, <code>SWT.TRAVERSE_RETURN</code>,
 * <code>SWT.TRAVERSE_TAB_NEXT</code>, <code>SWT.TRAVERSE_TAB_PREVIOUS</code>, 
 * <code>SWT.TRAVERSE_ARROW_NEXT</code>, <code>SWT.TRAVERSE_ARROW_PREVIOUS</code>,
 * <code>SWT.TRAVERSE_PAGE_NEXT</code> and <code>SWT.TRAVERSE_PAGE_PREVIOUS</code>.
 * If <code>traversal</code> is <code>SWT.TRAVERSE_NONE</code> then the Traverse
 * event is created with standard values based on the KeyDown event.  If
 * <code>traversal</code> is one of the other traversal constants then the Traverse
 * event is created with this detail, and its <code>doit</code> is taken from the
 * KeyDown event. 
 * </p>
 *
 * @param traversal the type of traversal, or <code>SWT.TRAVERSE_NONE</code> to compute
 * this from <code>event</code>
 * @param event the KeyDown event
 * 
 * @return <code>true</code> if the traversal succeeded
 *
 * @exception IllegalArgumentException <ul>
 *   <li>ERROR_NULL_ARGUMENT if the event 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>
 *
 * @since 3.6
 */
public boolean traverse (int traversal, Event event) {
	checkWidget ();
	if (event == null) error (SWT.ERROR_NULL_ARGUMENT);
	return traverse (traversal, event.character, event.keyCode, event.keyLocation, event.stateMask, event.doit);
}

/**
 * Performs a platform traversal action corresponding to a <code>KeyDown</code> event.
 * 
 * <p>Valid traversal values are
 * <code>SWT.TRAVERSE_NONE</code>, <code>SWT.TRAVERSE_MNEMONIC</code>,
 * <code>SWT.TRAVERSE_ESCAPE</code>, <code>SWT.TRAVERSE_RETURN</code>,
 * <code>SWT.TRAVERSE_TAB_NEXT</code>, <code>SWT.TRAVERSE_TAB_PREVIOUS</code>, 
 * <code>SWT.TRAVERSE_ARROW_NEXT</code>, <code>SWT.TRAVERSE_ARROW_PREVIOUS</code>,
 * <code>SWT.TRAVERSE_PAGE_NEXT</code> and <code>SWT.TRAVERSE_PAGE_PREVIOUS</code>.
 * If <code>traversal</code> is <code>SWT.TRAVERSE_NONE</code> then the Traverse
 * event is created with standard values based on the KeyDown event.  If
 * <code>traversal</code> is one of the other traversal constants then the Traverse
 * event is created with this detail, and its <code>doit</code> is taken from the
 * KeyDown event. 
 * </p>
 *
 * @param traversal the type of traversal, or <code>SWT.TRAVERSE_NONE</code> to compute
 * this from <code>event</code>
 * @param event the KeyDown event
 * 
 * @return <code>true</code> if the traversal succeeded
 *
 * @exception IllegalArgumentException <ul>
 *   <li>ERROR_NULL_ARGUMENT if the event 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>
 *
 * @since 3.6
 */
public boolean traverse (int traversal, KeyEvent event) {
	checkWidget ();
	if (event == null) error (SWT.ERROR_NULL_ARGUMENT);
	return traverse (traversal, event.character, event.keyCode, event.keyLocation, event.stateMask, event.doit);
}

boolean traverse (int traversal, char character, int keyCode, int keyLocation, int stateMask, boolean doit) {
	// the following should work but is not tested

//	if (traversal == SWT.TRAVERSE_NONE) {
//		switch (keyCode) {
//			case SWT.ESC: {
//				traversal = SWT.TRAVERSE_ESCAPE;
//				doit = true;
//				break;
//			}
//			case SWT.CR: {
//				traversal = SWT.TRAVERSE_RETURN;
//				doit = true;
//				break;
//			}
//			case SWT.ARROW_DOWN:
//			case SWT.ARROW_RIGHT: {
//				traversal = SWT.TRAVERSE_ARROW_NEXT;
//				doit = false;
//				break;
//			}
//			case SWT.ARROW_UP:
//			case SWT.ARROW_LEFT: {
//				traversal = SWT.TRAVERSE_ARROW_PREVIOUS;
//				doit = false;
//				break;
//			}
//			case SWT.TAB: {
//				traversal = (stateMask & SWT.SHIFT) != 0 ? SWT.TRAVERSE_TAB_PREVIOUS : SWT.TRAVERSE_TAB_NEXT;
//				doit = true;
//				break;
//			}
//			case SWT.PAGE_DOWN: {
//				if ((stateMask & SWT.CTRL) != 0) {
//					traversal = SWT.TRAVERSE_PAGE_NEXT;
//					doit = true;
//				}
//				break;
//			}
//			case SWT.PAGE_UP: {
//				if ((stateMask & SWT.CTRL) != 0) {
//					traversal = SWT.TRAVERSE_PAGE_PREVIOUS;
//					doit = true;
//				}
//				break;
//			}
//			default: {
//				if (character != 0 && (stateMask & (SWT.ALT | SWT.CTRL)) == SWT.ALT) {
//					traversal = SWT.TRAVERSE_MNEMONIC;
//					doit = true;
//				}
//				break;
//			}
//		}
//	}
//
//	Event event = new Event ();
//	event.character = character;
//	event.detail = traversal;
//	event.doit = doit;
//	event.keyCode = keyCode;
//	event.keyLocation = keyLocation;
//	event.stateMask = stateMask;
//	Shell shell = getShell ();
//
//	boolean all = false;
//	switch (traversal) {
//		case SWT.TRAVERSE_ESCAPE:
//		case SWT.TRAVERSE_RETURN:
//		case SWT.TRAVERSE_PAGE_NEXT:
//		case SWT.TRAVERSE_PAGE_PREVIOUS: {
//			all = true;
//			// FALL THROUGH
//		}
//		case SWT.TRAVERSE_ARROW_NEXT:
//		case SWT.TRAVERSE_ARROW_PREVIOUS:
//		case SWT.TRAVERSE_TAB_NEXT:
//		case SWT.TRAVERSE_TAB_PREVIOUS: {
//			/* traversal is a valid traversal action */
//			break;
//		}
//		case SWT.TRAVERSE_MNEMONIC: {
//			return translateMnemonic (event, null) || shell.translateMnemonic (event, this);
//		}
//		default: {
//			/* traversal is not a valid traversal action */
//			return false;
//		}
//	}
//
//	Control control = this;
//	do {
//		if (control.traverse (event)) return true;
//		if (!event.doit && control.hooks (SWT.Traverse)) return false;
//		if (control == shell) return false;
//		control = control.parent;
//	} while (all && control != null);
	return false;
}

boolean traverse (Event event) {
	/*
	* It is possible (but unlikely), that application
	* code could have disposed the widget in the traverse
	* event.  If this happens, return true to stop further
	* event processing.
	*/	
	sendEvent (SWT.Traverse, event);
	if (isDisposed ()) return true;
	if (!event.doit) return false;
	switch (event.detail) {
		case SWT.TRAVERSE_NONE:				return true;
		case SWT.TRAVERSE_ESCAPE:			return traverseEscape ();
		case SWT.TRAVERSE_RETURN:			return traverseReturn ();
		case SWT.TRAVERSE_TAB_NEXT:			return traverseGroup (true);
		case SWT.TRAVERSE_TAB_PREVIOUS:		return traverseGroup (false);
		case SWT.TRAVERSE_ARROW_NEXT:		return traverseItem (true);
		case SWT.TRAVERSE_ARROW_PREVIOUS:	return traverseItem (false);
		case SWT.TRAVERSE_MNEMONIC:			return traverseMnemonic (event.character);	
		case SWT.TRAVERSE_PAGE_NEXT:		return traversePage (true);
		case SWT.TRAVERSE_PAGE_PREVIOUS:	return traversePage (false);
	}
	return false;
}

/**
 * Based on the argument, perform one of the expected platform
 * traversal action. The argument should be one of the constants:
 * <code>SWT.TRAVERSE_ESCAPE</code>, <code>SWT.TRAVERSE_RETURN</code>, 
 * <code>SWT.TRAVERSE_TAB_NEXT</code>, <code>SWT.TRAVERSE_TAB_PREVIOUS</code>, 
 * <code>SWT.TRAVERSE_ARROW_NEXT</code>, <code>SWT.TRAVERSE_ARROW_PREVIOUS</code>,
 * <code>SWT.TRAVERSE_PAGE_NEXT</code> and <code>SWT.TRAVERSE_PAGE_PREVIOUS</code>.
 *
 * @param traversal the type of traversal
 * @return true if the traversal succeeded
 *
 * @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 boolean traverse (int traversal) {
	checkWidget ();
	Event event = new Event ();
	event.doit = true;
	event.detail = traversal;
	return traverse (event);
}

boolean traverseEscape () {
	return false;
}

boolean traverseGroup (boolean next) {
	Control root = computeTabRoot ();
	Control group = computeTabGroup ();
	Control [] list = root.computeTabList ();
	int length = list.length;
	int index = 0;
	while (index < length) {
		if (list [index] == group) break;
		index++;
	}
	/*
	* It is possible (but unlikely), that application
	* code could have disposed the widget in focus in
	* or out events.  Ensure that a disposed widget is
	* not accessed.
	*/
	if (index == length) return false;
	int start = index, offset = (next) ? 1 : -1;
	while ((index = ((index + offset + length) % length)) != start) {
		Control control = list [index];
		if (!control.isDisposed () && control.setTabGroupFocus ()) {
			return true;
		}
	}
	if (group.isDisposed ()) return false;
	return group.setTabGroupFocus ();
}

boolean traverseItem (boolean next) {
	Control [] children = parent._getChildren ();
	int length = children.length;
	int index = 0;
	while (index < length) {
		if (children [index] == this) break;
		index++;
	}
	/*
	* It is possible (but unlikely), that application
	* code could have disposed the widget in focus in
	* or out events.  Ensure that a disposed widget is
	* not accessed.
	*/
	if (index == length) return false;
	int start = index, offset = (next) ? 1 : -1;
	while ((index = (index + offset + length) % length) != start) {
		Control child = children [index];
		if (!child.isDisposed () && child.isTabItem ()) {
			if (child.setTabItemFocus ()) return true;
		}
	}
	return false;
}

boolean traversePage (boolean next) {
	return false;
}

boolean traverseMnemonic (char key) {
//	return mnemonicHit (key);
	return false;
}

boolean traverseReturn () {
	return false;
}

/**
 * Forces all outstanding paint requests for the widget
 * to be processed before this method returns. If there
 * are no outstanding paint request, this method does
 * nothing.
 * <p>
 * Note: This method does not cause a redraw.
 * </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>
 *
 * @see #redraw()
 * @see #redraw(int, int, int, int, boolean)
 * @see PaintListener
 * @see SWT#Paint
 */
public void update () {
	checkWidget();
	OS.PtFlush ();
}

void updateLayout (boolean all) {
	/* Do nothing */
}

int widgetClass () {
	return 0;
}

}