graphicsexample.java

SUN公司eclipse3.2.2经典例子

/*******************************************************************************
 * Copyright (c) 2000, 2006 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.examples.graphics;

import java.io.*;
import java.util.*;

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

/**
 * This class is the main class of the graphics application. Various "tabs" are
 * created and made visible by this class.
 */
public class GraphicsExample {
		
	Composite parent;
	GraphicsTab[] tabs;				// tabs to be found in the application
	GraphicsTab tab;				// the current tab
	GraphicsBackground background;	// used to store information about the background
	
	ToolBar toolBar;				// toolbar that contains backItem and dbItem
	Tree tabList;					// tree structure of tabs
	Text tabDesc;					// multi-line text widget that displays a tab description
	Sash hSash, vSash;
	Canvas canvas;
	Composite tabControlPanel;
	ToolItem backItem, dbItem;		// background, double buffer items
	Menu backMenu;					// background menu item
	
	ArrayList resources;			// stores resources that will be disposed
	ArrayList tabs_in_order;		// stores GraphicsTabs in the order that they appear in the tree
	boolean animate = true;			// whether animation should happen

	static boolean advanceGraphics, advanceGraphicsInit;
	
	static final int MARGIN = 5;
	static final int SASH_SPACING = 1;
	static final int TIMER = 30;
	static final ResourceBundle RESOURCE_BUNDLE = ResourceBundle.getBundle("examples_graphics"); //$NON-NLS-1$

/*
 * Default constructor is needed so that example launcher can create an instance. 
 */
public GraphicsExample() {
	super();
}

public GraphicsExample(final Composite parent) {
	this.parent = parent;
	resources = new ArrayList();
	createControls(parent);
	setTab(tab);
	startAnimationTimer();
}

boolean checkAdvancedGraphics() {
	if (advanceGraphicsInit) return advanceGraphics;
	advanceGraphicsInit = true;
	Display display = parent.getDisplay();
	try {
		Path path = new Path(display);
		path.dispose();
	} catch (SWTException e) {
		Shell shell = display.getActiveShell(), newShell = null;
		if (shell == null) shell = newShell = new Shell(display);
		MessageBox dialog = new MessageBox(shell, SWT.ICON_WARNING | SWT.OK);
		dialog.setText(RESOURCE_BUNDLE.getString("Warning")); //$NON-NLS-1$
		dialog.setMessage(RESOURCE_BUNDLE.getString("LibNotFound")); //$NON-NLS-1$
		dialog.open();
		if (newShell != null) newShell.dispose();
		return false;
	}
	return advanceGraphics = true;
}

void createControls(final Composite parent) {
	tabs = createTabs();
	createToolBar(parent);
	createTabList(parent);
	hSash = new Sash(parent, SWT.HORIZONTAL);
	createTabDesc(parent);	
	vSash = new Sash(parent, SWT.VERTICAL);
	createCanvas(parent);
	createControlPanel(parent);
	
	FormData data;
	FormLayout layout = new FormLayout();
	parent.setLayout(layout);
	
	data = new FormData();
	data.left = new FormAttachment(0, MARGIN);
	data.top = new FormAttachment(0, MARGIN);
	data.right = new FormAttachment(100, -MARGIN);
	toolBar.setLayoutData(data);

	data = new FormData();
	data.left = new FormAttachment(0, MARGIN);
	data.top = new FormAttachment(toolBar, MARGIN);
	data.right = new FormAttachment(vSash, -SASH_SPACING);
	data.bottom = new FormAttachment(hSash, -SASH_SPACING);
	tabList.setLayoutData(data);

	data = new FormData();
	data.left = new FormAttachment(0, MARGIN);
	int offset = parent.getBounds().height - tabDesc.computeSize(SWT.DEFAULT, tabDesc.getLineHeight() * 10).y;
	data.top = new FormAttachment(null, offset);
	data.right = new FormAttachment(vSash, -SASH_SPACING);
	hSash.setLayoutData(data);

	data = new FormData();
	data.left = new FormAttachment(0, MARGIN);
	data.top = new FormAttachment(hSash, SASH_SPACING);
	data.right = new FormAttachment(vSash, -SASH_SPACING);
	data.bottom = new FormAttachment(100, -MARGIN);
	tabDesc.setLayoutData(data);
	
	data = new FormData();
	data.left = new FormAttachment(null, tabList.computeSize(SWT.DEFAULT, SWT.DEFAULT).x + 50);
	data.top = new FormAttachment(toolBar, MARGIN);
	data.bottom = new FormAttachment(100, -MARGIN);
	vSash.setLayoutData(data);

	data = new FormData();
	data.left = new FormAttachment(vSash, SASH_SPACING);
	data.top = new FormAttachment(toolBar, MARGIN);
	data.right = new FormAttachment(100, -MARGIN);
	data.bottom = new FormAttachment(tabControlPanel);
	canvas.setLayoutData(data);

	data = new FormData();
	data.left = new FormAttachment(vSash, SASH_SPACING);
	data.right = new FormAttachment(100, -MARGIN);
	data.bottom = new FormAttachment(100, -MARGIN);
	tabControlPanel.setLayoutData(data);
	
	vSash.addListener(SWT.Selection, new Listener() {
		public void handleEvent(Event event) {
			Rectangle rect = hSash.getParent().getClientArea();
			event.x = Math.min (Math.max (event.x, 60), rect.width - 60);
			System.out.println(event.x);
			if (event.detail != SWT.DRAG) {
				FormData data = (FormData)vSash.getLayoutData();
				data.left.offset = event.x;
				parent.layout(true);
				animate = true;
			} else {
				animate = false;
			}
		}
	});
	hSash.addListener (SWT.Selection, new Listener () {
		public void handleEvent (Event event) {
			Rectangle rect = vSash.getParent().getClientArea();
			event.y = Math.min (Math.max (event.y, tabList.getLocation().y + 60), rect.height - 60);
			if (event.detail != SWT.DRAG) {
				FormData data = (FormData)hSash.getLayoutData();
				data.top.offset = event.y;
				parent.layout(true);
			}
		}
	});
}

void createCanvas(Composite parent) {
	int style = SWT.NO_BACKGROUND;
	if (dbItem.getSelection()) style |= SWT.DOUBLE_BUFFERED;
	canvas = new Canvas(parent, style);
	canvas.addListener(SWT.Paint, new Listener() {
		public void handleEvent(Event event) {
			GC gc = event.gc;
			Rectangle rect = canvas.getClientArea();			
			Device device = gc.getDevice();
			Pattern pattern = null;
			if (background.getBgColor1() != null) {
				if (background.getBgColor2() != null) { // gradient
					pattern = new Pattern(device, 0, 0, rect.width, 
							rect.height,
							background.getBgColor1(),
							background.getBgColor2());
					gc.setBackgroundPattern(pattern);
				} else {	// solid color
					gc.setBackground(background.getBgColor1());
				}
			} else if (background.getBgImage() != null) {		// image
				pattern = new Pattern(device, background.getBgImage());
				gc.setBackgroundPattern(pattern);
			}
			gc.fillRectangle(rect);
			GraphicsTab tab = getTab();
			if (tab != null) tab.paint(gc, rect.width, rect.height);
			if (pattern != null) pattern.dispose();
		}
	});
}

void recreateCanvas() {
	if (dbItem.getSelection() == ((canvas.getStyle() & SWT.DOUBLE_BUFFERED) != 0)) return;
	Object data = canvas.getLayoutData();
	if (canvas != null) canvas.dispose();
	createCanvas(parent);
	canvas.setLayoutData(data);
	parent.layout(true, true);
}

/**
 * Creates the control panel 
 * @param parent
 */
void createControlPanel(Composite parent) {
	Group group;
	tabControlPanel = group = new Group(parent, SWT.NONE);
	group.setText(getResourceString("Settings")); //$NON-NLS-1$
	tabControlPanel.setLayout(new RowLayout());
}

void createToolBar(final Composite parent) {
	final Display display = parent.getDisplay();
	
	toolBar = new ToolBar(parent, SWT.FLAT);
	
	ToolItem  back = new ToolItem(toolBar, SWT.PUSH);
	back.setText(getResourceString("Back")); //$NON-NLS-1$
	back.setImage(loadImage(display, "back.gif")); //$NON-NLS-1$
	
	back.addListener(SWT.Selection, new Listener() {
		public void handleEvent(Event event) {
			int index = tabs_in_order.indexOf(tab) - 1;
			if (index < 0)
				index = tabs_in_order.size() - 1;
			setTab((GraphicsTab)tabs_in_order.get(index));
		}
	});
	
	ToolItem  next = new ToolItem(toolBar, SWT.PUSH);
	next.setText(getResourceString("Next")); //$NON-NLS-1$
	next.setImage(loadImage(display, "next.gif")); //$NON-NLS-1$
	next.addListener(SWT.Selection, new Listener() {
		public void handleEvent(Event event) {
			int index = (tabs_in_order.indexOf(tab) + 1)%tabs_in_order.size();
			setTab((GraphicsTab)tabs_in_order.get(index));
		}
	});
	
	ColorMenu colorMenu = new ColorMenu();
	
	// setup items to be contained in the background menu
	colorMenu.setColorItems(true);
	colorMenu.setPatternItems(checkAdvancedGraphics());
	colorMenu.setGradientItems(checkAdvancedGraphics());
	
	// create the background menu
	backMenu = colorMenu.createMenu(parent, new ColorListener() {
		public void setColor(GraphicsBackground gb) {
			background = gb;
			backItem.setImage(gb.getThumbNail());
			if (canvas != null) canvas.redraw();
		}
	});
	
	// initialize the background to the first item in the menu
	background = (GraphicsBackground)backMenu.getItem(0).getData();
	
	// background tool item
	backItem = new ToolItem(toolBar, SWT.PUSH);
	backItem.setText(getResourceString("Background")); //$NON-NLS-1$
	backItem.setImage(background.getThumbNail());
	backItem.addListener(SWT.Selection, new Listener() {
		public void handleEvent(Event event) {
			if (event.widget == backItem) {
				final ToolItem toolItem = (ToolItem) event.widget;
				final ToolBar  toolBar = toolItem.getParent();
				Rectangle toolItemBounds = toolItem.getBounds();
				Point point = toolBar.toDisplay(new Point(toolItemBounds.x, toolItemBounds.y));
				backMenu.setLocation(point.x, point.y + toolItemBounds.height);
				backMenu.setVisible(true);
			}
		}
	});
	
	// double buffer tool item
	dbItem = new ToolItem(toolBar, SWT.CHECK);
	dbItem.setText(getResourceString("DoubleBuffer")); //$NON-NLS-1$
	dbItem.setImage(loadImage(display, "db.gif")); //$NON-NLS-1$
	dbItem.addListener(SWT.Selection, new Listener() {
		public void handleEvent(Event event) {
			setDoubleBuffered(dbItem.getSelection());
		}
	});
}

/**
 * Creates and returns a thumbnail image.
 * 
 * @param device
 * 			a device
 * @param name
 * 			filename of the image
 */
static Image createThumbnail(Device device, String name) {
	Image image = new Image(device, name);
	Rectangle src = image.getBounds();
	Image result = null;
	if (src.width != 16 || src.height != 16) {
		result = new Image(device, 16, 16);
		GC gc = new GC(result);
		Rectangle dest = result.getBounds();
		gc.drawImage(image, src.x, src.y, src.width, src.height, dest.x, dest.y, dest.width, dest.height);
		gc.dispose();				
	}
	if (result != null) {
		image.dispose();
		return result;
	}
	return image;