viewform.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 three
 * children horizontally and allows programmatic control of layout and
 * border parameters. ViewForm is used in the workbench to implement a
 * view's label/menu/toolbar local bar.
 * <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>BORDER, FLAT</dd>
 * <dt><b>Events:</b></dt>
 * <dd>(None)</dd>
 * </dl>
 * <p>
 * IMPORTANT: This class is <em>not</em> intended to be subclassed.
 * </p>
 */

public class ViewForm extends Composite {

	/**
	 * marginWidth specifies the number of pixels of horizontal margin
	 * that will be placed along the left and right edges of the form.
	 *
	 * The default value is 0.
	 */
 	public int marginWidth = 0;
	/**
	 * marginHeight specifies the number of pixels of vertical margin
	 * that will be placed along the top and bottom edges of the form.
	 *
	 * The default value is 0.
	 */
 	public int marginHeight = 0;
 	/**
	 * horizontalSpacing specifies the number of pixels between the right
	 * edge of one cell and the left edge of its neighbouring cell to
	 * the right.
	 *
	 * The default value is 1.
	 */
 	public int horizontalSpacing = 1;
	/**
	 * verticalSpacing specifies the number of pixels between the bottom
	 * edge of one cell and the top edge of its neighbouring cell underneath.
	 *
	 * The default value is 1.
	 */
 	public int verticalSpacing = 1;
	
	/**
	 * Color of innermost line of drop shadow border.
	 * 
	 * NOTE This field is badly named and can not be fixed for backwards compatability.
	 * It should be capitalized.
	 * 
	 * @deprecated
	 */
	public static RGB borderInsideRGB  = new RGB (132, 130, 132);
	/**
	 * Color of middle line of drop shadow border.
	 * 
	 * NOTE This field is badly named and can not be fixed for backwards compatability.
	 * It should be capitalized.
	 * 
	 * @deprecated
	 */
	public static RGB borderMiddleRGB  = new RGB (143, 141, 138);
	/**
	 * Color of outermost line of drop shadow border.
	 * 
	 * NOTE This field is badly named and can not be fixed for backwards compatability.
	 * It should be capitalized.
	 * 
	 * @deprecated
	 */
	public static RGB borderOutsideRGB = new RGB (171, 168, 165);
	
	// SWT widgets
	private Control topLeft;
	private Control topCenter;
	private Control topRight;
	private Control content;
	
	// Configuration and state info
	private boolean separateTopCenter = false;
	private boolean showBorder = false;
	
	private int separator = -1;
	private int borderTop = 0;
	private int borderBottom = 0;
	private int borderLeft = 0;
	private int borderRight = 0;
	private int highlight = 0;
	private Rectangle oldArea;
	
	private Color selectionBackground;
	
	static final int OFFSCREEN = -200;
	static final int BORDER1_COLOR = SWT.COLOR_WIDGET_NORMAL_SHADOW;
	static final int SELECTION_BACKGROUND = SWT.COLOR_LIST_BACKGROUND;
/**
 * 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>
 *
 * @see SWT#BORDER
 * @see SWT#FLAT
 * @see #getStyle()
 */		
public ViewForm(Composite parent, int style) {
	super(parent, checkStyle(style));
	
	setBorderVisible((style & SWT.BORDER) != 0);
	
	Listener listener = new Listener() {
		public void handleEvent(Event e) {
			switch (e.type) {
				case SWT.Dispose: onDispose(); break;
				case SWT.Paint: onPaint(e.gc); break;
				case SWT.Resize: onResize(); break;
			}
		}
	};
	
	int[] events = new int[] {SWT.Dispose, SWT.Paint, SWT.Resize};
	
	for (int i = 0; i < events.length; i++) {
		addListener(events[i], listener);
	}
}

static int checkStyle (int style) {
	int mask = SWT.FLAT | SWT.LEFT_TO_RIGHT | SWT.RIGHT_TO_LEFT;
	return style & mask | SWT.NO_REDRAW_RESIZE;
}

//protected void checkSubclass () {
//	String name = getClass().getName ();
//	String validName = ViewForm.class.getName();
//	if (!validName.equals(name)) {
//		SWT.error (SWT.ERROR_INVALID_SUBCLASS);
//	}
//}

public Point computeSize(int wHint, int hHint, boolean changed) {
	checkWidget();
	// size of title bar area
	Point leftSize = new Point(0, 0);
	if (topLeft != null) {
		leftSize = topLeft.computeSize(SWT.DEFAULT, SWT.DEFAULT);
	}
	Point centerSize = new Point(0, 0);
	if (topCenter != null) {
		 centerSize = topCenter.computeSize(SWT.DEFAULT, SWT.DEFAULT);
	}
	Point rightSize = new Point(0, 0);
	if (topRight != null) {
		 rightSize = topRight.computeSize(SWT.DEFAULT, SWT.DEFAULT);
	}
	Point size = new Point(0, 0);
	// calculate width of title bar
	if (separateTopCenter ||
	    (wHint != SWT.DEFAULT &&  leftSize.x + centerSize.x + rightSize.x > wHint)) {
		size.x = leftSize.x + rightSize.x;
		if (leftSize.x > 0 && rightSize.x > 0) size.x += horizontalSpacing;
		size.x = Math.max(centerSize.x, size.x);
		size.y = Math.max(leftSize.y, rightSize.y);
		if (topCenter != null){
			size.y += centerSize.y;
			if (topLeft != null ||topRight != null)size.y += verticalSpacing;
		}	
	} else {
		size.x = leftSize.x + centerSize.x + rightSize.x;
		int count = -1;
		if (leftSize.x > 0) count++;
		if (centerSize.x > 0) count++;
		if (rightSize.x > 0) count++;
		if (count > 0) size.x += count * horizontalSpacing;
		size.y = Math.max(leftSize.y, Math.max(centerSize.y, rightSize.y));
	}
	
	if (content != null) {
		if (topLeft != null || topRight != null || topCenter != null) size.y += 1; // allow space for a vertical separator
		Point contentSize = new Point(0, 0);
		contentSize = content.computeSize(SWT.DEFAULT, SWT.DEFAULT); 
		size.x = Math.max (size.x, contentSize.x);
		size.y += contentSize.y;
		if (size.y > contentSize.y) size.y += verticalSpacing;
	}
	
	size.x += 2*marginWidth;
	size.y += 2*marginHeight;
	
	if (wHint != SWT.DEFAULT) size.x  = wHint;
	if (hHint != SWT.DEFAULT) size.y = hHint;
	
	Rectangle trim = computeTrim(0, 0, size.x, size.y);
	return new Point (trim.width, trim.height);
}
public Rectangle computeTrim (int x, int y, int width, int height) {
	checkWidget ();
	int trimX = x - borderLeft - highlight;
	int trimY = y - borderTop - highlight;
	int trimWidth = width + borderLeft + borderRight + 2*highlight;
	int trimHeight = height + borderTop + borderBottom + 2*highlight;
	return new Rectangle(trimX, trimY, trimWidth, trimHeight);
}
public Rectangle getClientArea() {
	checkWidget();
	Rectangle clientArea = super.getClientArea();
	clientArea.x += borderLeft;
	clientArea.y += borderTop;
	clientArea.width -= borderLeft + borderRight;
	clientArea.height -= borderTop + borderBottom;
	return clientArea;
}
/**
* Returns the content area.
* 
* @return the control in the content area of the pane or null
*/
public Control getContent() {
	//checkWidget();
	return content;
}
/**
* Returns Control that appears in the top center of the pane.
* Typically this is a toolbar.
* 
* @return the control in the top center of the pane or null
*/
public Control getTopCenter() {
	//checkWidget();
	return topCenter;
}
/**
* Returns the Control that appears in the top left corner of the pane.
* Typically this is a label such as CLabel.
* 
* @return the control in the top left corner of the pane or null
*/
public Control getTopLeft() {
	//checkWidget();
	return topLeft;
}
/**
* Returns the control in the top right corner of the pane.
* Typically this is a Close button or a composite with a Menu and Close button.
* 
* @return the control in the top right corner of the pane or null
*/
public Control getTopRight() {
	//checkWidget();
	return topRight;
}
public void layout (boolean changed) {
	checkWidget();
	Rectangle rect = getClientArea();
	
	Point leftSize = new Point(0, 0);
	if (topLeft != null && !topLeft.isDisposed()) {
		leftSize = topLeft.computeSize(SWT.DEFAULT, SWT.DEFAULT);
	}
	Point centerSize = new Point(0, 0);
	if (topCenter != null && !topCenter.isDisposed()) {
		 centerSize = topCenter.computeSize(SWT.DEFAULT, SWT.DEFAULT);
	}
	Point rightSize = new Point(0, 0);
	if (topRight != null && !topRight.isDisposed()) {
		 rightSize = topRight.computeSize(SWT.DEFAULT, SWT.DEFAULT);
	}