bundles/org.eclipse.swt/Eclipse SWT Custom Widgets/common/org/eclipse/swt/custom/CBanner.java - platform/eclipse.platform.swt - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2016 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.custom;


 import org.eclipse.swt.*;
 import org.eclipse.swt.graphics.*;
 import org.eclipse.swt.widgets.*;

 /**
  * Instances of this class implement a Composite that lays out its
  * children and allows programmatic control of the layout. It draws
  * a separator between the left and right children which can be dragged
  * to resize the right control.
  * CBanner is used in the workbench to layout the toolbar area and
  * perspective switching toolbar.
  * <p>
  * Note that although this class is a subclass of <code>Composite</code>,
  * it does not make sense to set a layout on it.
  * </p><p>
  * <dl>
  * <dt><b>Styles:</b></dt>
  * <dd>NONE</dd>
  * <dt><b>Events:</b></dt>
  * <dd>(None)</dd>
  * </dl>
  * <p>
  * IMPORTANT: This class is <em>not</em> intended to be subclassed.
  * </p>
  *
  * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
  *
  * @since 3.0
  * @noextend This class is not intended to be subclassed by clients.
  */

 public class CBanner extends Composite {

 	Control left;
 	Control right;
 	Control bottom;

 	boolean simple = true;

 	int[] curve = new int[0];
 	int curveStart = 0;
 	Rectangle curveRect = new Rectangle(0, 0, 0, 0);
 	int curve_width = 5;
 	int curve_indent = -2;

 	int rightWidth = SWT.DEFAULT;
 	int rightMinWidth = 0;
 	int rightMinHeight = 0;
 	Cursor resizeCursor;
 	boolean dragging = false;
 	int rightDragDisplacement = 0;
 	Listener listener;

 	static final int OFFSCREEN = -200;
 	static final int BORDER_BOTTOM = 2;
 	static final int BORDER_TOP = 3;
 	static final int BORDER_STRIPE = 1;
 	static final int CURVE_TAIL = 200;
 	static final int BEZIER_RIGHT = 30;
 	static final int BEZIER_LEFT = 30;
 	static final int MIN_LEFT = 10;
 	static int BORDER1 = SWT.COLOR_WIDGET_HIGHLIGHT_SHADOW;


 /**
  * Constructs a new instance of this class given its parent
  * and a style value describing its behavior and appearance.
  * <p>
  * The style value is either one of the style constants defined in
  * class <code>SWT</code> which is applicable to instances of this
  * class, or must be built by <em>bitwise OR</em>'ing together
  * (that is, using the <code>int</code> "|" operator) two or more
  * of those <code>SWT</code> style constants. The class description
  * lists the style constants that are applicable to the class.
  * Style bits are also inherited from superclasses.
  * </p>
  *
  * @param parent a widget which will be the parent of the new instance (cannot be null)
  * @param style the style of widget to construct
  *
  * @exception IllegalArgumentException <ul>
  *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
  * </ul>
  * @exception SWTException <ul>
  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
  * </ul>
  *
  */
 public CBanner(Composite parent, int style) {
 	super(parent, checkStyle(style));
 	super.setLayout(new CBannerLayout());
 	resizeCursor = getDisplay().getSystemCursor(SWT.CURSOR_SIZEWE);

 	listener = e -> {
 		switch (e.type) {
 			case SWT.Dispose:
 				onDispose(e); break;
 			case SWT.MouseDown:
 				onMouseDown (e.x, e.y); break;
 			case SWT.MouseExit:
 				onMouseExit(); break;
 			case SWT.MouseMove:
 				onMouseMove(e.x, e.y); break;
 			case SWT.MouseUp:
 				onMouseUp(); break;
 			case SWT.Paint:
 				onPaint(e.gc); break;
 			case SWT.Resize:
 				onResize(); break;
 		}
 	};
 	int[] events = new int[] {SWT.Dispose, SWT.MouseDown, SWT.MouseExit, SWT.MouseMove, SWT.MouseUp, SWT.Paint, SWT.Resize};
 	for (int i = 0; i < events.length; i++) {
 		addListener(events[i], listener);
 	}
 }
 static int[] bezier(int x0, int y0, int x1, int y1, int x2, int y2, int x3, int y3, int count) {
 	// The parametric equations for a Bezier curve for x[t] and y[t] where  0 <= t <=1 are:
 	// x[t] = x0+3(x1-x0)t+3(x0+x2-2x1)t^2+(x3-x0+3x1-3x2)t^3
 	// y[t] = y0+3(y1-y0)t+3(y0+y2-2y1)t^2+(y3-y0+3y1-3y2)t^3
 	double a0 = x0;
 	double a1 = 3*(x1 - x0);
 	double a2 = 3*(x0 + x2 - 2*x1);
 	double a3 = x3 - x0 + 3*x1 - 3*x2;
 	double b0 = y0;
 	double b1 = 3*(y1 - y0);
 	double b2 = 3*(y0 + y2 - 2*y1);
 	double b3 = y3 - y0 + 3*y1 - 3*y2;

 	int[] polygon = new int[2*count + 2];
 	for (int i = 0; i <= count; i++) {
 		double t = (double)i / (double)count;
 		polygon[2*i] = (int)(a0 + a1*t + a2*t*t + a3*t*t*t);
 		polygon[2*i + 1] = (int)(b0 + b1*t + b2*t*t + b3*t*t*t);
 	}
 	return polygon;
 }
 static int checkStyle (int style) {
 	return SWT.NONE;
 }
 /*
 * This class was not intended to be subclassed but this restriction
 * cannot be enforced without breaking backward compatibility.
 */
 //protected void checkSubclass () {
 //	String name = getClass ().getName ();
 //	int index = name.lastIndexOf ('.');
 //	if (!name.substring (0, index + 1).equals ("org.eclipse.swt.custom.")) {
 //		SWT.error (SWT.ERROR_INVALID_SUBCLASS);
 //	}
 //}
 /**
 * Returns the Control that appears on the bottom side of the banner.
 *
 * @return the control that appears on the bottom side of the banner 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 3.0
 */
 public Control getBottom() {
 	checkWidget();
 	return bottom;
 }
 @Override
 public Rectangle getClientArea() {
 	return new Rectangle(0, 0, 0, 0);
 }

 /**
 * Returns the Control that appears on the left side of the banner.
 *
 * @return the control that appears on the left side of the banner 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 3.0
 */
 public Control getLeft() {
 	checkWidget();
 	return left;
 }

 /**
 * Returns the Control that appears on the right side of the banner.
 *
 * @return the control that appears on the right side of the banner 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 3.0
 */
 public Control getRight() {
 	checkWidget();
 	return right;
 }
 /**
  * Returns the minimum size of the control that appears on the right of the banner.
  *
  * @return the minimum size of the control that appears on the right of the banner
  *
  * @since 3.1
  */
 public Point getRightMinimumSize() {
 	checkWidget();
 	return new Point(rightMinWidth, rightMinHeight);
 }
 /**
  * Returns the width of the control that appears on the right of the banner.
  *
  * @return the width of the control that appears on the right of the banner
  *
  * @since 3.0
  */
 public int getRightWidth() {
 	checkWidget();
 	if (right == null) return 0;
 	if (rightWidth == SWT.DEFAULT) {
 		Point size = right.computeSize(SWT.DEFAULT, SWT.DEFAULT, false);
 		return size.x;
 	}
 	return rightWidth;
 }
 /**
  * Returns <code>true</code> if the CBanner is rendered
  * with a simple, traditional shape.
  *
  * @return <code>true</code> if the CBanner is rendered with a simple shape
  *
  * @since 3.0
  */
 public boolean getSimple() {
 	checkWidget();
 	return simple;
 }
 void onDispose(Event event) {
 	removeListener(SWT.Dispose, listener);
 	notifyListeners(SWT.Dispose, event);
 	event.type = SWT.None;

 	resizeCursor = null;
 	left = null;
 	right = null;
 	bottom = null;
 }
 void onMouseDown (int x, int y) {
 	if (curveRect.contains(x, y)) {
 		dragging = true;
 		rightDragDisplacement = curveStart - x + curve_width - curve_indent;
 	}
 }
 void onMouseExit() {
 	if (!dragging) setCursor(null);
 }
 void onMouseMove(int x, int y) {
 	if (dragging) {
 		Point size = getSize();
 		if (!(0 < x && x < size.x)) return;
 		rightWidth = Math.max(0, size.x - x - rightDragDisplacement);
 		if (rightMinWidth == SWT.DEFAULT) {
 			Point minSize = right.computeSize(rightMinWidth, rightMinHeight);
 			rightWidth = Math.max(minSize.x, rightWidth);
 		} else {
 			rightWidth = Math.max(rightMinWidth, rightWidth);
 		}
 		layout(false);
 		return;
 	}
 	if (curveRect.contains(x, y)) {
 		setCursor(resizeCursor);
 	} else {
 		setCursor(null);
 	}
 }
 void onMouseUp () {
 	dragging = false;
 }
 void onPaint(GC gc) {
 //	 Useful for debugging paint problems
 //	{
 //	Point size = getSize();
 //	gc.setBackground(getDisplay().getSystemColor(SWT.COLOR_GREEN));
 //	gc.fillRectangle(-10, -10, size.x+20, size.y+20);
 //	}
 	if (left == null && right == null) return;
 	Point size = getSize();
 	Color border1 = getDisplay().getSystemColor(BORDER1);
 	if (bottom != null) {
 		int y = bottom.getBounds().y - BORDER_STRIPE - 1;
 		gc.setForeground(border1);
 		gc.drawLine(0, y, size.x, y);
 	}
 	if (left == null || right == null) return;
 	int[] line1 = new int[curve.length+6];
 	int index = 0;
 	int x = curveStart;
 	line1[index++] = x + 1;
 	line1[index++] = size.y - BORDER_STRIPE;
 	for (int i = 0; i < curve.length/2; i++) {
 		line1[index++]=x+curve[2*i];
 		line1[index++]=curve[2*i+1];
 	}
 	line1[index++] = x + curve_width;
 	line1[index++] = 0;
 	line1[index++] = size.x;
 	line1[index++] = 0;

 	Color background = getBackground();

 	if (getDisplay().getDepth() >= 15) {
 		// Anti- aliasing
 		int[] line2 = new int[line1.length];
 		index = 0;
 		for (int i = 0; i < line1.length/2; i++) {
 			line2[index] = line1[index++]  - 1;
 			line2[index] = line1[index++];
 		}
 		int[] line3 = new int[line1.length];
 		index = 0;
 		for (int i = 0; i < line1.length/2; i++) {
 			line3[index] = line1[index++] + 1;
 			line3[index] = line1[index++];
 		}
 		RGB from = border1.getRGB();
 		RGB to = background.getRGB();
 		int red = from.red + 3*(to.red - from.red)/4;
 		int green = from.green + 3*(to.green - from.green)/4;
 		int blue = from.blue + 3*(to.blue - from.blue)/4;
 		Color color = new Color(getDisplay(), red, green, blue);
 		gc.setForeground(color);
 		gc.drawPolyline(line2);
 		gc.drawPolyline(line3);
 		color.dispose();

 		// draw tail fading to background
 		int x1 = Math.max(0, curveStart - CURVE_TAIL);
 		gc.setForeground(background);
 		gc.setBackground(border1);
 		gc.fillGradientRectangle(x1, size.y - BORDER_STRIPE, curveStart-x1+1, 1, false);
 	} else {
 		// draw solid tail
 		int x1 = Math.max(0, curveStart - CURVE_TAIL);
 		gc.setForeground(border1);
 		gc.drawLine(x1, size.y - BORDER_STRIPE, curveStart+1, size.y - BORDER_STRIPE);
 	}

 	// draw border
 	gc.setForeground(border1);
 	gc.drawPolyline(line1);
 }

 void onResize() {
 	updateCurve(getSize().y);
 }
 /**
 * Set the control that appears on the bottom side of the banner.
 * The bottom control is optional.  Setting the bottom control to null will remove it from
 * the banner - however, the creator of the control must dispose of the control.
 *
 * @param control the control to be displayed on the bottom 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>
 *    <li>ERROR_INVALID_ARGUMENT - if the bottom control was not created as a child of the receiver</li>
 * </ul>
 *
 * @since 3.0
 */
 public void setBottom(Control control) {
 	checkWidget();
 	if (control != null && control.getParent() != this) {
 		SWT.error(SWT.ERROR_INVALID_ARGUMENT);
 	}
 	if (bottom != null && !bottom.isDisposed()) {
 		Point size = bottom.getSize();
 		bottom.setLocation(OFFSCREEN - size.x, OFFSCREEN - size.y);
 	}
 	bottom = control;
 	layout(false);
 }
 /**
  * Sets the layout which is associated with the receiver to be
  * the argument which may be null.
  * <p>
  * Note: No Layout can be set on this Control because it already
  * manages the size and position of its children.
  * </p>
  *
  * @param layout the receiver's new layout 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>
  */
 @Override
 public void setLayout (Layout layout) {
 	checkWidget();
 	return;
 }

 /**
 * Set the control that appears on the left side of the banner.
 * The left control is optional.  Setting the left control to null will remove it from
 * the banner - however, the creator of the control must dispose of the control.
 *
 * @param control the control to be displayed on the left 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>
 *    <li>ERROR_INVALID_ARGUMENT - if the left control was not created as a child of the receiver</li>
 * </ul>
 *
 * @since 3.0
 */
 public void setLeft(Control control) {
 	checkWidget();
 	if (control != null && control.getParent() != this) {
 		SWT.error(SWT.ERROR_INVALID_ARGUMENT);
 	}
 	if (left != null && !left.isDisposed()) {
 		Point size = left.getSize();
 		left.setLocation(OFFSCREEN - size.x, OFFSCREEN - size.y);
 	}
 	left = control;
 	layout(false);
 }
 /**
 * Set the control that appears on the right side of the banner.
 * The right control is optional.  Setting the right control to null will remove it from
 * the banner - however, the creator of the control must dispose of the control.
 *
 * @param control the control to be displayed on the right 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>
 *    <li>ERROR_INVALID_ARGUMENT - if the right control was not created as a child of the receiver</li>
 * </ul>
 *
 * @since 3.0
 */
 public void setRight(Control control) {
 	checkWidget();
 	if (control != null && control.getParent() != this) {
 		SWT.error(SWT.ERROR_INVALID_ARGUMENT);
 	}
 	if (right != null && !right.isDisposed()) {
 		Point size = right.getSize();
 		right.setLocation(OFFSCREEN - size.x, OFFSCREEN - size.y);
 	}
 	right = control;
 	layout(false);
 }
 /**
  * Set the minimum height of the control that appears on the right side of the banner.
  *
  * @param size the minimum size of the control on the right
  *
  * @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>
  *    <li>ERROR_INVALID_ARGUMENT - if the size is null or the values of size are less than SWT.DEFAULT</li>
  * </ul>
  *
  * @since 3.1
  */
 public void setRightMinimumSize(Point size) {
 	checkWidget();
 	if (size == null || size.x < SWT.DEFAULT || size.y < SWT.DEFAULT) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
 	rightMinWidth = size.x;
 	rightMinHeight = size.y;
 	layout(false);
 }
 /**
  * Set the width of the control that appears on the right side of the banner.
  *
  * @param width the width of the control on the right
  *
  * @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>
  *    <li>ERROR_INVALID_ARGUMENT - if width is less than SWT.DEFAULT</li>
  * </ul>
  *
  * @since 3.0
  */
 public void setRightWidth(int width) {
 	checkWidget();
 	if (width < SWT.DEFAULT) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
 	rightWidth = width;
 	layout(false);
 }
 /**
  * Sets the shape that the CBanner will use to render itself.
  *
  * @param simple <code>true</code> if the CBanner should render itself in a simple, traditional 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 3.0
  */
 public void setSimple(boolean simple) {
 	checkWidget();
 	if (this.simple != simple) {
 		this.simple = simple;
 		if (simple) {
 			curve_width = 5;
 			curve_indent = -2;
 		} else {
 			curve_width = 50;
 			curve_indent = 5;
 		}
 		updateCurve(getSize().y);
 		layout(false);
 		redraw();
 	}
 }
 void updateCurve(int height) {
 	int h = height - BORDER_STRIPE;
 	if (simple) {
 		curve = new int[] {0,h, 1,h, 2,h-1, 3,h-2,
 			                       3,2, 4,1, 5,0,};
 	} else {
 		curve = bezier(0, h+1, BEZIER_LEFT, h+1,
 				             curve_width-BEZIER_RIGHT, 0, curve_width, 0,
 		                     curve_width);
 	}
 }
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2016 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.custom;


	import org.eclipse.swt.*;
	import org.eclipse.swt.graphics.*;
	import org.eclipse.swt.widgets.*;

	/**
	* Instances of this class implement a Composite that lays out its
	* children and allows programmatic control of the layout. It draws
	* a separator between the left and right children which can be dragged
	* to resize the right control.
	* CBanner is used in the workbench to layout the toolbar area and
	* perspective switching toolbar.
	* <p>
	* Note that although this class is a subclass of <code>Composite</code>,
	* it does not make sense to set a layout on it.
	* </p><p>
	* <dl>
	* <dt><b>Styles:</b></dt>
	* <dd>NONE</dd>
	* <dt><b>Events:</b></dt>
	* <dd>(None)</dd>
	* </dl>
	* <p>
	* IMPORTANT: This class is <em>not</em> intended to be subclassed.
	* </p>
	*
	* @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
	*
	* @since 3.0
	* @noextend This class is not intended to be subclassed by clients.
	*/

	public class CBanner extends Composite {

	Control left;
	Control right;
	Control bottom;

	boolean simple = true;

	int[] curve = new int[0];
	int curveStart = 0;
	Rectangle curveRect = new Rectangle(0, 0, 0, 0);
	int curve_width = 5;
	int curve_indent = -2;

	int rightWidth = SWT.DEFAULT;
	int rightMinWidth = 0;
	int rightMinHeight = 0;
	Cursor resizeCursor;
	boolean dragging = false;
	int rightDragDisplacement = 0;
	Listener listener;

	static final int OFFSCREEN = -200;
	static final int BORDER_BOTTOM = 2;
	static final int BORDER_TOP = 3;
	static final int BORDER_STRIPE = 1;
	static final int CURVE_TAIL = 200;
	static final int BEZIER_RIGHT = 30;
	static final int BEZIER_LEFT = 30;
	static final int MIN_LEFT = 10;
	static int BORDER1 = SWT.COLOR_WIDGET_HIGHLIGHT_SHADOW;


	/**
	* Constructs a new instance of this class given its parent
	* and a style value describing its behavior and appearance.
	* <p>
	* The style value is either one of the style constants defined in
	* class <code>SWT</code> which is applicable to instances of this
	* class, or must be built by <em>bitwise OR</em>'ing together
	* (that is, using the <code>int</code> "\|" operator) two or more
	* of those <code>SWT</code> style constants. The class description
	* lists the style constants that are applicable to the class.
	* Style bits are also inherited from superclasses.
	* </p>
	*
	* @param parent a widget which will be the parent of the new instance (cannot be null)
	* @param style the style of widget to construct
	*
	* @exception IllegalArgumentException <ul>
	* <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
	* </ul>
	* @exception SWTException <ul>
	* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
	* </ul>
	*
	*/
	public CBanner(Composite parent, int style) {
	super(parent, checkStyle(style));
	super.setLayout(new CBannerLayout());
	resizeCursor = getDisplay().getSystemCursor(SWT.CURSOR_SIZEWE);

	listener = e -> {
	switch (e.type) {
	case SWT.Dispose:
	onDispose(e); break;
	case SWT.MouseDown:
	onMouseDown (e.x, e.y); break;
	case SWT.MouseExit:
	onMouseExit(); break;
	case SWT.MouseMove:
	onMouseMove(e.x, e.y); break;
	case SWT.MouseUp:
	onMouseUp(); break;
	case SWT.Paint:
	onPaint(e.gc); break;
	case SWT.Resize:
	onResize(); break;
	}
	};
	int[] events = new int[] {SWT.Dispose, SWT.MouseDown, SWT.MouseExit, SWT.MouseMove, SWT.MouseUp, SWT.Paint, SWT.Resize};
	for (int i = 0; i < events.length; i++) {
	addListener(events[i], listener);
	}
	}
	static int[] bezier(int x0, int y0, int x1, int y1, int x2, int y2, int x3, int y3, int count) {
	// The parametric equations for a Bezier curve for x[t] and y[t] where 0 <= t <=1 are:
	// x[t] = x0+3(x1-x0)t+3(x0+x2-2x1)t^2+(x3-x0+3x1-3x2)t^3
	// y[t] = y0+3(y1-y0)t+3(y0+y2-2y1)t^2+(y3-y0+3y1-3y2)t^3
	double a0 = x0;
	double a1 = 3*(x1 - x0);
	double a2 = 3(x0 + x2 - 2x1);
	double a3 = x3 - x0 + 3x1 - 3x2;
	double b0 = y0;
	double b1 = 3*(y1 - y0);
	double b2 = 3(y0 + y2 - 2y1);
	double b3 = y3 - y0 + 3y1 - 3y2;

	int[] polygon = new int[2*count + 2];
	for (int i = 0; i <= count; i++) {
	double t = (double)i / (double)count;
	polygon[2i] = (int)(a0 + a1t + a2tt + a3tt*t);
	polygon[2i + 1] = (int)(b0 + b1t + b2tt + b3tt*t);
	}
	return polygon;
	}
	static int checkStyle (int style) {
	return SWT.NONE;
	}
	/*
	* This class was not intended to be subclassed but this restriction
	* cannot be enforced without breaking backward compatibility.
	*/
	//protected void checkSubclass () {
	// String name = getClass ().getName ();
	// int index = name.lastIndexOf ('.');
	// if (!name.substring (0, index + 1).equals ("org.eclipse.swt.custom.")) {
	// SWT.error (SWT.ERROR_INVALID_SUBCLASS);
	// }
	//}
	/**
	* Returns the Control that appears on the bottom side of the banner.
	*
	* @return the control that appears on the bottom side of the banner 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 3.0
	*/
	public Control getBottom() {
	checkWidget();
	return bottom;
	}
	@Override
	public Rectangle getClientArea() {
	return new Rectangle(0, 0, 0, 0);
	}

	/**
	* Returns the Control that appears on the left side of the banner.
	*
	* @return the control that appears on the left side of the banner 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 3.0
	*/
	public Control getLeft() {
	checkWidget();
	return left;
	}

	/**
	* Returns the Control that appears on the right side of the banner.
	*
	* @return the control that appears on the right side of the banner 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 3.0
	*/
	public Control getRight() {
	checkWidget();
	return right;
	}
	/**
	* Returns the minimum size of the control that appears on the right of the banner.
	*
	* @return the minimum size of the control that appears on the right of the banner
	*
	* @since 3.1
	*/
	public Point getRightMinimumSize() {
	checkWidget();
	return new Point(rightMinWidth, rightMinHeight);
	}
	/**
	* Returns the width of the control that appears on the right of the banner.
	*
	* @return the width of the control that appears on the right of the banner
	*
	* @since 3.0
	*/
	public int getRightWidth() {
	checkWidget();
	if (right == null) return 0;
	if (rightWidth == SWT.DEFAULT) {
	Point size = right.computeSize(SWT.DEFAULT, SWT.DEFAULT, false);
	return size.x;
	}
	return rightWidth;
	}
	/**
	* Returns <code>true</code> if the CBanner is rendered
	* with a simple, traditional shape.
	*
	* @return <code>true</code> if the CBanner is rendered with a simple shape
	*
	* @since 3.0
	*/
	public boolean getSimple() {
	checkWidget();
	return simple;
	}
	void onDispose(Event event) {
	removeListener(SWT.Dispose, listener);
	notifyListeners(SWT.Dispose, event);
	event.type = SWT.None;

	resizeCursor = null;
	left = null;
	right = null;
	bottom = null;
	}
	void onMouseDown (int x, int y) {
	if (curveRect.contains(x, y)) {
	dragging = true;
	rightDragDisplacement = curveStart - x + curve_width - curve_indent;
	}
	}
	void onMouseExit() {
	if (!dragging) setCursor(null);
	}
	void onMouseMove(int x, int y) {
	if (dragging) {
	Point size = getSize();
	if (!(0 < x && x < size.x)) return;
	rightWidth = Math.max(0, size.x - x - rightDragDisplacement);
	if (rightMinWidth == SWT.DEFAULT) {
	Point minSize = right.computeSize(rightMinWidth, rightMinHeight);
	rightWidth = Math.max(minSize.x, rightWidth);
	} else {
	rightWidth = Math.max(rightMinWidth, rightWidth);
	}
	layout(false);
	return;
	}
	if (curveRect.contains(x, y)) {
	setCursor(resizeCursor);
	} else {
	setCursor(null);
	}
	}
	void onMouseUp () {
	dragging = false;
	}
	void onPaint(GC gc) {
	// Useful for debugging paint problems
	// {
	// Point size = getSize();
	// gc.setBackground(getDisplay().getSystemColor(SWT.COLOR_GREEN));
	// gc.fillRectangle(-10, -10, size.x+20, size.y+20);
	// }
	if (left == null && right == null) return;
	Point size = getSize();
	Color border1 = getDisplay().getSystemColor(BORDER1);
	if (bottom != null) {
	int y = bottom.getBounds().y - BORDER_STRIPE - 1;
	gc.setForeground(border1);
	gc.drawLine(0, y, size.x, y);
	}
	if (left == null \|\| right == null) return;
	int[] line1 = new int[curve.length+6];
	int index = 0;
	int x = curveStart;
	line1[index++] = x + 1;
	line1[index++] = size.y - BORDER_STRIPE;
	for (int i = 0; i < curve.length/2; i++) {
	line1[index++]=x+curve[2*i];
	line1[index++]=curve[2*i+1];
	}
	line1[index++] = x + curve_width;
	line1[index++] = 0;
	line1[index++] = size.x;
	line1[index++] = 0;

	Color background = getBackground();

	if (getDisplay().getDepth() >= 15) {
	// Anti- aliasing
	int[] line2 = new int[line1.length];
	index = 0;
	for (int i = 0; i < line1.length/2; i++) {
	line2[index] = line1[index++] - 1;
	line2[index] = line1[index++];
	}
	int[] line3 = new int[line1.length];
	index = 0;
	for (int i = 0; i < line1.length/2; i++) {
	line3[index] = line1[index++] + 1;
	line3[index] = line1[index++];
	}
	RGB from = border1.getRGB();
	RGB to = background.getRGB();
	int red = from.red + 3*(to.red - from.red)/4;
	int green = from.green + 3*(to.green - from.green)/4;
	int blue = from.blue + 3*(to.blue - from.blue)/4;
	Color color = new Color(getDisplay(), red, green, blue);
	gc.setForeground(color);
	gc.drawPolyline(line2);
	gc.drawPolyline(line3);
	color.dispose();

	// draw tail fading to background
	int x1 = Math.max(0, curveStart - CURVE_TAIL);
	gc.setForeground(background);
	gc.setBackground(border1);
	gc.fillGradientRectangle(x1, size.y - BORDER_STRIPE, curveStart-x1+1, 1, false);
	} else {
	// draw solid tail
	int x1 = Math.max(0, curveStart - CURVE_TAIL);
	gc.setForeground(border1);
	gc.drawLine(x1, size.y - BORDER_STRIPE, curveStart+1, size.y - BORDER_STRIPE);
	}

	// draw border
	gc.setForeground(border1);
	gc.drawPolyline(line1);
	}

	void onResize() {
	updateCurve(getSize().y);
	}
	/**
	* Set the control that appears on the bottom side of the banner.
	* The bottom control is optional. Setting the bottom control to null will remove it from
	* the banner - however, the creator of the control must dispose of the control.
	*
	* @param control the control to be displayed on the bottom 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>
	* <li>ERROR_INVALID_ARGUMENT - if the bottom control was not created as a child of the receiver</li>
	* </ul>
	*
	* @since 3.0
	*/
	public void setBottom(Control control) {
	checkWidget();
	if (control != null && control.getParent() != this) {
	SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	}
	if (bottom != null && !bottom.isDisposed()) {
	Point size = bottom.getSize();
	bottom.setLocation(OFFSCREEN - size.x, OFFSCREEN - size.y);
	}
	bottom = control;
	layout(false);
	}
	/**
	* Sets the layout which is associated with the receiver to be
	* the argument which may be null.
	* <p>
	* Note: No Layout can be set on this Control because it already
	* manages the size and position of its children.
	* </p>
	*
	* @param layout the receiver's new layout 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>
	*/
	@Override
	public void setLayout (Layout layout) {
	checkWidget();
	return;
	}

	/**
	* Set the control that appears on the left side of the banner.
	* The left control is optional. Setting the left control to null will remove it from
	* the banner - however, the creator of the control must dispose of the control.
	*
	* @param control the control to be displayed on the left 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>
	* <li>ERROR_INVALID_ARGUMENT - if the left control was not created as a child of the receiver</li>
	* </ul>
	*
	* @since 3.0
	*/
	public void setLeft(Control control) {
	checkWidget();
	if (control != null && control.getParent() != this) {
	SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	}
	if (left != null && !left.isDisposed()) {
	Point size = left.getSize();
	left.setLocation(OFFSCREEN - size.x, OFFSCREEN - size.y);
	}
	left = control;
	layout(false);
	}
	/**
	* Set the control that appears on the right side of the banner.
	* The right control is optional. Setting the right control to null will remove it from
	* the banner - however, the creator of the control must dispose of the control.
	*
	* @param control the control to be displayed on the right 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>
	* <li>ERROR_INVALID_ARGUMENT - if the right control was not created as a child of the receiver</li>
	* </ul>
	*
	* @since 3.0
	*/
	public void setRight(Control control) {
	checkWidget();
	if (control != null && control.getParent() != this) {
	SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	}
	if (right != null && !right.isDisposed()) {
	Point size = right.getSize();
	right.setLocation(OFFSCREEN - size.x, OFFSCREEN - size.y);
	}
	right = control;
	layout(false);
	}
	/**
	* Set the minimum height of the control that appears on the right side of the banner.
	*
	* @param size the minimum size of the control on the right
	*
	* @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>
	* <li>ERROR_INVALID_ARGUMENT - if the size is null or the values of size are less than SWT.DEFAULT</li>
	* </ul>
	*
	* @since 3.1
	*/
	public void setRightMinimumSize(Point size) {
	checkWidget();
	if (size == null \|\| size.x < SWT.DEFAULT \|\| size.y < SWT.DEFAULT) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	rightMinWidth = size.x;
	rightMinHeight = size.y;
	layout(false);
	}
	/**
	* Set the width of the control that appears on the right side of the banner.
	*
	* @param width the width of the control on the right
	*
	* @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>
	* <li>ERROR_INVALID_ARGUMENT - if width is less than SWT.DEFAULT</li>
	* </ul>
	*
	* @since 3.0
	*/
	public void setRightWidth(int width) {
	checkWidget();
	if (width < SWT.DEFAULT) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	rightWidth = width;
	layout(false);
	}
	/**
	* Sets the shape that the CBanner will use to render itself.
	*
	* @param simple <code>true</code> if the CBanner should render itself in a simple, traditional 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 3.0
	*/
	public void setSimple(boolean simple) {
	checkWidget();
	if (this.simple != simple) {
	this.simple = simple;
	if (simple) {
	curve_width = 5;
	curve_indent = -2;
	} else {
	curve_width = 50;
	curve_indent = 5;
	}
	updateCurve(getSize().y);
	layout(false);
	redraw();
	}
	}
	void updateCurve(int height) {
	int h = height - BORDER_STRIPE;
	if (simple) {
	curve = new int[] {0,h, 1,h, 2,h-1, 3,h-2,
	3,2, 4,1, 5,0,};
	} else {
	curve = bezier(0, h+1, BEZIER_LEFT, h+1,
	curve_width-BEZIER_RIGHT, 0, curve_width, 0,
	curve_width);
	}
	}
	}