bundles/org.eclipse.swt/Eclipse SWT/wpf/org/eclipse/swt/widgets/Caret.java - platform/eclipse.platform.swt - Git at Google

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


 import org.eclipse.swt.internal.wpf.*;
 import org.eclipse.swt.*;
 import org.eclipse.swt.graphics.*;

 /**
  * Instances of this class provide an i-beam that is typically used
  * as the insertion point for text.
  * <dl>
  * <dt><b>Styles:</b></dt>
  * <dd>(none)</dd>
  * <dt><b>Events:</b></dt>
  * <dd>(none)</dd>
  * </dl>
  * <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/#caret">Caret snippets</a>
  * @see <a href="http://www.eclipse.org/swt/examples.php">SWT Example: ControlExample, Canvas tab</a>
  * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
  */

 public class Caret extends Widget {
 	Canvas parent;
 	int x, y, width, height;
 	int imageHandle;
 	boolean isVisible;
 	Image image;
 	Font font;

 /**
  * 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
  * @see Widget#checkSubclass
  * @see Widget#getStyle
  */
 public Caret (Canvas parent, int style) {
 	super (parent, style);
 	this.parent = parent;
 	createWidget ();
 }

 void createWidget () {
 	createHandle ();
 	if (parent.getCaret () == null) {
 		parent.setCaret (this);
 	}
 }

 void createHandle() {
 	handle = OS.gcnew_StackPanel ();
 	//handle = OS.gcnew_ContentControl ();
 	if (handle == 0) error (SWT.ERROR_NO_HANDLES);

 	int animation = OS.gcnew_DoubleAnimationUsingKeyFrames ();
 	if (animation == 0) error (SWT.ERROR_NO_HANDLES);
 	int timespan = OS.gcnew_TimeSpan (6000000);
 	if (timespan == 0) error (SWT.ERROR_NO_HANDLES);
 	int duration = OS.gcnew_Duration (timespan);
 	if (duration == 0) error (SWT.ERROR_NO_HANDLES);
 	int repeatBehavior = OS.RepeatBehavior_Forever();

 	OS.Timeline_AutoReverse(animation, true);
 	OS.Timeline_Duration(animation, duration);
 	OS.Timeline_RepeatBehavior(animation, repeatBehavior);
 	int keyFrames = OS.DoubleAnimationUsingKeyFrames_KeyFrames(animation);
 	int keyTime = OS.KeyTime_Uniform();
 	int keyFrame0 = OS.gcnew_DiscreteDoubleKeyFrame(0, keyTime);
 	int keyFrame1 = OS.gcnew_DiscreteDoubleKeyFrame(0, keyTime);
 	OS.DoubleKeyFrameCollection_Add(keyFrames, keyFrame0);
 	OS.DoubleKeyFrameCollection_Add(keyFrames, keyFrame1);
 	int opacityProperty = OS.UIElement_OpacityProperty();
 	OS.UIElement_BeginAnimation(handle, opacityProperty, animation);

 	int brush = OS.SystemColors_ControlTextBrush ();
 	OS.Panel_Background(handle, brush);

 	imageHandle = OS.gcnew_Image ();
 	if (imageHandle == 0) error (SWT.ERROR_NO_HANDLES);
 	OS.Image_Stretch (imageHandle, OS.Stretch_None);
 	OS.UIElement_Visibility (imageHandle, OS.Visibility_Collapsed);

 	int children = OS.Panel_Children (handle);
 	OS.UIElementCollection_Add (children, imageHandle);
 	OS.GCHandle_Free (children);
 	hide ();
 	OS.GCHandle_Free(brush);
 	OS.GCHandle_Free(opacityProperty);
 	OS.GCHandle_Free(keyFrames);
 	OS.GCHandle_Free(keyTime);
 	OS.GCHandle_Free(keyFrame0);
 	OS.GCHandle_Free(keyFrame1);
 	OS.GCHandle_Free(animation);
 	OS.GCHandle_Free(duration);
 	OS.GCHandle_Free(timespan);
 	OS.GCHandle_Free(repeatBehavior);
 }

 /**
  * Returns a rectangle describing the receiver's size and location
  * relative to its parent (or its display if its parent is null).
  *
  * @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();
 	if (image != null) {
 		Rectangle rect = image.getBounds ();
 		return new Rectangle (x, y, rect.width, rect.height);
 	}
 	return new Rectangle (x, y, width, height);
 }

 /**
  * 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 parent.display.systemFont;
 	}
 	return font;
 }

 /**
  * Returns the image that the receiver will use to paint the caret.
  *
  * @return the receiver's 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>
  */
 public Image getImage () {
 	checkWidget();
 	return image;
 }

 /**
  * Returns a point describing the receiver's location relative
  * to its parent (or its display if its parent is null).
  *
  * @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();
 	return new Point (x, y);
 }

 /**
  * Returns the receiver's parent, which must be a <code>Canvas</code>.
  *
  * @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 Canvas getParent () {
 	checkWidget();
 	return parent;
 }

 /**
  * Returns a point describing the receiver's size.
  *
  * @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();
 	if (image != null) {
 		Rectangle rect = image.getBounds ();
 		return new Point (rect.width, rect.height);
 	}
 	return new Point (width, height);
 }

 /**
  * 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 ();
 	return isVisible;
 }

 boolean hasFocus () {
 	return OS.UIElement_IsKeyboardFocused (parent.handle);
 }

 boolean isFocusCaret () {
 	return parent.caret == this && hasFocus ();
 }

 /**
  * Returns <code>true</code> if the receiver is visible and all
  * of the receiver's ancestors are visible and <code>false</code>
  * otherwise.
  *
  * @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.UIElement_IsVisible (handle) && parent.isVisible () && hasFocus ();
 }

 void hide () {
 	OS.UIElement_Visibility (handle, OS.Visibility_Collapsed);
 }

 void move (int x, int y) {
 	OS.Canvas_SetLeft (handle, x);
 	OS.Canvas_SetTop (handle, y);
 }

 void releaseHandle() {
 	if (handle != 0) OS.GCHandle_Free (handle);
 	handle = 0;
 	if (imageHandle != 0) OS.GCHandle_Free (imageHandle);
 	imageHandle = 0;
 	super.releaseHandle ();
 }

 void releaseParent () {
 	super.releaseParent ();
 	if (this == parent.getCaret ()) parent.setCaret (null);
 }

 void releaseWidget () {
 	super.releaseWidget ();
 	parent = null;
 	image = null;
 	font = null;
 }

 void resize (int width, int height) {
 	if (image != null) {
 		Rectangle rect = image.getBounds();
 		width = rect.width;
 		height = rect.height;
 	}
 	if (width == 0) width = 1;
 	OS.FrameworkElement_Width (handle, width);
 	OS.FrameworkElement_Height (handle, height);
 }

 /**
  * 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).
  *
  * @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();
 	boolean samePosition = this.x == x && this.y == y;
 	boolean sameExtent = this.width == width && this.height == height;
 	if (samePosition && sameExtent) return;
 	this.x = x;  this.y = y;
 	this.width = width;  this.height = height;
 	if (!sameExtent) resize (width, height);
 	if (!samePosition) move (x, y);
 }

 /**
  * 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).
  *
  * @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);
 }

 void show () {
 	OS.UIElement_Visibility (handle, OS.Visibility_Visible);
 }

 /**
  * 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 font 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();
 	if (font != null && font.isDisposed ()) {
 		error (SWT.ERROR_INVALID_ARGUMENT);
 	}
 	this.font = font;
 }

 /**
  * Sets the image that the receiver will use to paint the caret
  * to the image specified by the argument, or to the default
  * which is a filled rectangle if the argument is null
  *
  * @param image the new image (or null)
  *
  * @exception IllegalArgumentException <ul>
  *    <li>ERROR_INVALID_ARGUMENT - if the image 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 setImage (Image image) {
 	checkWidget();
 	if (image != null && image.isDisposed ()) {
 		error (SWT.ERROR_INVALID_ARGUMENT);
 	}
 	this.image = image;
 	if (image != null) {
 		OS.Image_Source (imageHandle, image.handle);
 		OS.UIElement_Visibility (imageHandle, OS.Visibility_Visible);
 	} else {
 		OS.Image_Source (imageHandle, 0);
 		OS.UIElement_Visibility (imageHandle, OS.Visibility_Collapsed);
 	}
 	resize (width, height);
 }

 /**
  * 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).
  *
  * @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();
 	if (this.x == x && this.y == y) return;
 	this.x = x;  this.y = y;
 	move (x, y);
 }

 /**
  * Sets the receiver's location to the point specified by
  * the argument which is relative to the receiver's
  * parent (or its display if its parent is null).
  *
  * @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 size to the point specified by the arguments.
  *
  * @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();
 	if (this.width == width && this.height == height) return;
 	this.width = width;  this.height = height;
 	resize (width, height);
 }

 /**
  * Sets the receiver's size to the point specified by the argument.
  *
  * @param size the new extent 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);
 }

 /**
  * 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();
 	if (visible == isVisible) return;
 	isVisible = visible;
 	if (!hasFocus()) return;
 	OS.UIElement_Visibility(handle, visible ? OS.Visibility_Visible : OS.Visibility_Hidden);
 }

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


	import org.eclipse.swt.internal.wpf.*;
	import org.eclipse.swt.*;
	import org.eclipse.swt.graphics.*;

	/**
	* Instances of this class provide an i-beam that is typically used
	* as the insertion point for text.
	* <dl>
	* <dt><b>Styles:</b></dt>
	* <dd>(none)</dd>
	* <dt><b>Events:</b></dt>
	* <dd>(none)</dd>
	* </dl>
	* <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/#caret">Caret snippets</a>
	* @see <a href="http://www.eclipse.org/swt/examples.php">SWT Example: ControlExample, Canvas tab</a>
	* @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
	*/

	public class Caret extends Widget {
	Canvas parent;
	int x, y, width, height;
	int imageHandle;
	boolean isVisible;
	Image image;
	Font font;

	/**
	* 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
	* @see Widget#checkSubclass
	* @see Widget#getStyle
	*/
	public Caret (Canvas parent, int style) {
	super (parent, style);
	this.parent = parent;
	createWidget ();
	}

	void createWidget () {
	createHandle ();
	if (parent.getCaret () == null) {
	parent.setCaret (this);
	}
	}

	void createHandle() {
	handle = OS.gcnew_StackPanel ();
	//handle = OS.gcnew_ContentControl ();
	if (handle == 0) error (SWT.ERROR_NO_HANDLES);

	int animation = OS.gcnew_DoubleAnimationUsingKeyFrames ();
	if (animation == 0) error (SWT.ERROR_NO_HANDLES);
	int timespan = OS.gcnew_TimeSpan (6000000);
	if (timespan == 0) error (SWT.ERROR_NO_HANDLES);
	int duration = OS.gcnew_Duration (timespan);
	if (duration == 0) error (SWT.ERROR_NO_HANDLES);
	int repeatBehavior = OS.RepeatBehavior_Forever();

	OS.Timeline_AutoReverse(animation, true);
	OS.Timeline_Duration(animation, duration);
	OS.Timeline_RepeatBehavior(animation, repeatBehavior);
	int keyFrames = OS.DoubleAnimationUsingKeyFrames_KeyFrames(animation);
	int keyTime = OS.KeyTime_Uniform();
	int keyFrame0 = OS.gcnew_DiscreteDoubleKeyFrame(0, keyTime);
	int keyFrame1 = OS.gcnew_DiscreteDoubleKeyFrame(0, keyTime);
	OS.DoubleKeyFrameCollection_Add(keyFrames, keyFrame0);
	OS.DoubleKeyFrameCollection_Add(keyFrames, keyFrame1);
	int opacityProperty = OS.UIElement_OpacityProperty();
	OS.UIElement_BeginAnimation(handle, opacityProperty, animation);

	int brush = OS.SystemColors_ControlTextBrush ();
	OS.Panel_Background(handle, brush);

	imageHandle = OS.gcnew_Image ();
	if (imageHandle == 0) error (SWT.ERROR_NO_HANDLES);
	OS.Image_Stretch (imageHandle, OS.Stretch_None);
	OS.UIElement_Visibility (imageHandle, OS.Visibility_Collapsed);

	int children = OS.Panel_Children (handle);
	OS.UIElementCollection_Add (children, imageHandle);
	OS.GCHandle_Free (children);
	hide ();
	OS.GCHandle_Free(brush);
	OS.GCHandle_Free(opacityProperty);
	OS.GCHandle_Free(keyFrames);
	OS.GCHandle_Free(keyTime);
	OS.GCHandle_Free(keyFrame0);
	OS.GCHandle_Free(keyFrame1);
	OS.GCHandle_Free(animation);
	OS.GCHandle_Free(duration);
	OS.GCHandle_Free(timespan);
	OS.GCHandle_Free(repeatBehavior);
	}

	/**
	* Returns a rectangle describing the receiver's size and location
	* relative to its parent (or its display if its parent is null).
	*
	* @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();
	if (image != null) {
	Rectangle rect = image.getBounds ();
	return new Rectangle (x, y, rect.width, rect.height);
	}
	return new Rectangle (x, y, width, height);
	}

	/**
	* 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 parent.display.systemFont;
	}
	return font;
	}

	/**
	* Returns the image that the receiver will use to paint the caret.
	*
	* @return the receiver's 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>
	*/
	public Image getImage () {
	checkWidget();
	return image;
	}

	/**
	* Returns a point describing the receiver's location relative
	* to its parent (or its display if its parent is null).
	*
	* @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();
	return new Point (x, y);
	}

	/**
	* Returns the receiver's parent, which must be a <code>Canvas</code>.
	*
	* @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 Canvas getParent () {
	checkWidget();
	return parent;
	}

	/**
	* Returns a point describing the receiver's size.
	*
	* @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();
	if (image != null) {
	Rectangle rect = image.getBounds ();
	return new Point (rect.width, rect.height);
	}
	return new Point (width, height);
	}

	/**
	* 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 ();
	return isVisible;
	}

	boolean hasFocus () {
	return OS.UIElement_IsKeyboardFocused (parent.handle);
	}

	boolean isFocusCaret () {
	return parent.caret == this && hasFocus ();
	}

	/**
	* Returns <code>true</code> if the receiver is visible and all
	* of the receiver's ancestors are visible and <code>false</code>
	* otherwise.
	*
	* @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.UIElement_IsVisible (handle) && parent.isVisible () && hasFocus ();
	}

	void hide () {
	OS.UIElement_Visibility (handle, OS.Visibility_Collapsed);
	}

	void move (int x, int y) {
	OS.Canvas_SetLeft (handle, x);
	OS.Canvas_SetTop (handle, y);
	}

	void releaseHandle() {
	if (handle != 0) OS.GCHandle_Free (handle);
	handle = 0;
	if (imageHandle != 0) OS.GCHandle_Free (imageHandle);
	imageHandle = 0;
	super.releaseHandle ();
	}

	void releaseParent () {
	super.releaseParent ();
	if (this == parent.getCaret ()) parent.setCaret (null);
	}

	void releaseWidget () {
	super.releaseWidget ();
	parent = null;
	image = null;
	font = null;
	}

	void resize (int width, int height) {
	if (image != null) {
	Rectangle rect = image.getBounds();
	width = rect.width;
	height = rect.height;
	}
	if (width == 0) width = 1;
	OS.FrameworkElement_Width (handle, width);
	OS.FrameworkElement_Height (handle, height);
	}

	/**
	* 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).
	*
	* @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();
	boolean samePosition = this.x == x && this.y == y;
	boolean sameExtent = this.width == width && this.height == height;
	if (samePosition && sameExtent) return;
	this.x = x; this.y = y;
	this.width = width; this.height = height;
	if (!sameExtent) resize (width, height);
	if (!samePosition) move (x, y);
	}

	/**
	* 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).
	*
	* @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);
	}

	void show () {
	OS.UIElement_Visibility (handle, OS.Visibility_Visible);
	}

	/**
	* 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 font 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();
	if (font != null && font.isDisposed ()) {
	error (SWT.ERROR_INVALID_ARGUMENT);
	}
	this.font = font;
	}

	/**
	* Sets the image that the receiver will use to paint the caret
	* to the image specified by the argument, or to the default
	* which is a filled rectangle if the argument is null
	*
	* @param image the new image (or null)
	*
	* @exception IllegalArgumentException <ul>
	* <li>ERROR_INVALID_ARGUMENT - if the image 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 setImage (Image image) {
	checkWidget();
	if (image != null && image.isDisposed ()) {
	error (SWT.ERROR_INVALID_ARGUMENT);
	}
	this.image = image;
	if (image != null) {
	OS.Image_Source (imageHandle, image.handle);
	OS.UIElement_Visibility (imageHandle, OS.Visibility_Visible);
	} else {
	OS.Image_Source (imageHandle, 0);
	OS.UIElement_Visibility (imageHandle, OS.Visibility_Collapsed);
	}
	resize (width, height);
	}

	/**
	* 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).
	*
	* @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();
	if (this.x == x && this.y == y) return;
	this.x = x; this.y = y;
	move (x, y);
	}

	/**
	* Sets the receiver's location to the point specified by
	* the argument which is relative to the receiver's
	* parent (or its display if its parent is null).
	*
	* @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 size to the point specified by the arguments.
	*
	* @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();
	if (this.width == width && this.height == height) return;
	this.width = width; this.height = height;
	resize (width, height);
	}

	/**
	* Sets the receiver's size to the point specified by the argument.
	*
	* @param size the new extent 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);
	}

	/**
	* 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();
	if (visible == isVisible) return;
	isVisible = visible;
	if (!hasFocus()) return;
	OS.UIElement_Visibility(handle, visible ? OS.Visibility_Visible : OS.Visibility_Hidden);
	}

	}