cbanner.java

源码为Eclipse开源开发平台桌面开发工具SWT的源代码,

/*******************************************************************************
 * Copyright (c) 2000, 2004 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.custom;


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

/**
 * 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 at the top of the workbench.
 * <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>
 * 
 * @since 3.0
 */

public class CBanner extends Composite {	

	Control left;
	Control right;
	Control bottom;
	
	boolean simple = true;
	
	int[] curve;
	int curveStart = 0;
	Rectangle curveRect = new Rectangle(0, 0, 0, 0);
	int curve_width = 5;
	int curve_indent = -2;
	
	int rightWidth = SWT.DEFAULT;
	Cursor resizeCursor;
	boolean dragging = false;
	int rightDragDisplacement = 0;
	
	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 final int MIN_RIGHT = 160;
	
	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));
	resizeCursor = new Cursor(getDisplay(), SWT.CURSOR_SIZEWE);
	
	Listener listener = new Listener() {
		public void handleEvent(Event e) {
			switch (e.type) {
				case SWT.Dispose:
					onDispose(); 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^3+(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;
}
public Point computeSize(int wHint, int hHint, boolean changed) {
	checkWidget();
	boolean showCurve = left != null && right != null;
	int height = hHint;
	int width = wHint;
	
	Point bottomSize = new Point(0, 0);
	if (bottom != null) {
		Point trim = bottom.computeSize(width, SWT.DEFAULT);
		trim.x = trim.x - width;
		bottomSize = bottom.computeSize(width == SWT.DEFAULT ? SWT.DEFAULT : width - trim.x, SWT.DEFAULT);
		if (height != SWT.DEFAULT) {
			bottomSize.y = Math.min(bottomSize.y, height);
			height -= bottomSize.y + BORDER_TOP + BORDER_STRIPE + BORDER_BOTTOM;
		}
	}
	if (showCurve && height != SWT.DEFAULT ) height -= BORDER_TOP + BORDER_BOTTOM + 2*BORDER_STRIPE;
	Point rightSize = new Point(0, 0);
	if (right != null) {
		Point trim = right.computeSize(rightWidth, height);
		trim.x = trim.x - rightWidth;
		rightSize = right.computeSize(rightWidth == SWT.DEFAULT ? SWT.DEFAULT : rightWidth - trim.x, rightWidth == SWT.DEFAULT ? SWT.DEFAULT : height);
		if (width != SWT.DEFAULT) {
			rightSize.x = Math.min(rightSize.x, width);
			width -= rightSize.x + curve_width - 2* curve_indent;
			width = Math.max(width, MIN_LEFT);
		}
	}
	Point leftSize = new Point(0, 0);
	if (left != null) {
		Point trim = left.computeSize(width, SWT.DEFAULT);
		trim.x = trim.x - width;
		leftSize = left.computeSize(width == SWT.DEFAULT ? SWT.DEFAULT : width - trim.x, SWT.DEFAULT);
	}
	int w = 0, h = 0;
	h += bottomSize.y;
	if (bottom != null && (left != null || right != null)) h += BORDER_TOP + BORDER_BOTTOM + BORDER_STRIPE;
	w += leftSize.x + rightSize.x;
	if (showCurve) {
		w += curve_width - 2*curve_indent;
		h +=  BORDER_TOP + BORDER_BOTTOM + 2*BORDER_STRIPE;
	}
	h += left != null ? leftSize.y : rightSize.y;
	
	if (wHint != SWT.DEFAULT) w = wHint;
	if (hHint != SWT.DEFAULT) h = hHint;
	
	return new Point(w, h);
}
public Rectangle computeTrim (int x, int y, int width, int height) {
	checkWidget ();
	return new Rectangle(x, y, width, height);
}
/**
* 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;
}
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 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) return right.computeSize(SWT.DEFAULT, getSize().y).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;
}
public void layout (boolean changed) {
	checkWidget();
	Point size = getSize();
	boolean showCurve = left != null && right != null;
	int width = size.x;
	int height = size.y;
	
	Point bottomSize = new Point(0, 0);
	if (bottom != null) {
		Point trim = bottom.computeSize(width, SWT.DEFAULT);
		trim.x = trim.x - width;
		bottomSize = bottom.computeSize(width - trim.x, SWT.DEFAULT);
		bottomSize.y = Math.min(bottomSize.y, height);
		height -= bottomSize.y + BORDER_TOP + BORDER_BOTTOM + BORDER_STRIPE;
	}
	
	if (showCurve) height -=  BORDER_TOP + BORDER_BOTTOM + 2*BORDER_STRIPE;
	height = Math.max(0, height);
	Point rightSize = new Point(0,0);
	if (right != null) {
		Point trim = right.computeSize(rightWidth, height);
		trim.x = trim.x - rightWidth;
		rightSize = right.computeSize(rightWidth == SWT.DEFAULT ? SWT.DEFAULT : rightWidth - trim.x, rightWidth == SWT.DEFAULT ? SWT.DEFAULT : height);
		rightSize.x = Math.min(rightSize.x, width);
		width -= rightSize.x + curve_width - 2*curve_indent;
		width = Math.max(width, MIN_LEFT); 
	}