| /******************************************************************************* |
| * Copyright (c) 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.util.LinkedList; |
| |
| import org.eclipse.swt.SWT; |
| import org.eclipse.swt.graphics.Color; |
| import org.eclipse.swt.graphics.Device; |
| import org.eclipse.swt.graphics.GC; |
| import org.eclipse.swt.graphics.Path; |
| import org.eclipse.swt.graphics.Transform; |
| |
| /** |
| * This tab uses alpha blending to simulate "ghosting" of a ball in movement. |
| */ |
| public class BallTab extends AnimatedGraphicsTab { |
| |
| BallCollection[] bc; |
| |
| /** |
| * This inner class serves as a container for the data needed to display a |
| * collection of balls. |
| */ |
| static class BallCollection { |
| float x, y; // position of ball |
| float incX, incY; // values by which to move the ball |
| int ball_size; // size (diameter) of the ball |
| int capacity; // number of balls in the collection |
| LinkedList prevx, prevy; // collection of previous x and y positions |
| // of ball |
| Color[] colors; // colors used for this ball collection |
| |
| public BallCollection(float x, float y, float incX, float incY, |
| int ball_size, int capacity, Color[] colors) { |
| this.x = x; |
| this.y = y; |
| this.incX = incX; |
| this.incY = incY; |
| this.ball_size = ball_size; |
| this.capacity = capacity; |
| prevx = new LinkedList(); |
| prevy = new LinkedList(); |
| this.colors = colors; |
| } |
| } |
| |
| public void dispose() { |
| bc[0] = bc[1] = bc[2] = bc[3] = bc[4] = null; |
| } |
| |
| public BallTab(GraphicsExample example) { |
| super(example); |
| bc = new BallCollection[5]; |
| } |
| |
| public String getCategory() { |
| return GraphicsExample.getResourceString("Alpha"); //$NON-NLS-1$ |
| } |
| |
| public String getText() { |
| return GraphicsExample.getResourceString("Ball"); //$NON-NLS-1$ |
| } |
| |
| public String getDescription() { |
| return GraphicsExample.getResourceString("BallDescription"); //$NON-NLS-1$ |
| } |
| |
| public int getInitialAnimationTime() { |
| return 10; |
| } |
| |
| public void next(int width, int height) { |
| for (int i = 0; i < bc.length; i++) { |
| if (bc[i] == null) return; |
| if (bc[i].prevx.size() == 0) { |
| bc[i].prevx.addLast(new Float(bc[i].x)); |
| bc[i].prevy.addLast(new Float(bc[i].y)); |
| } else if (bc[i].prevx.size() == bc[i].capacity) { |
| bc[i].prevx.removeFirst(); |
| bc[i].prevy.removeFirst(); |
| } |
| |
| bc[i].x += bc[i].incX; |
| bc[i].y += bc[i].incY; |
| |
| float random = (float) Math.random(); |
| |
| // right |
| if (bc[i].x + bc[i].ball_size > width) { |
| bc[i].x = width - bc[i].ball_size; |
| bc[i].incX = random * -width / 16 - 1; |
| } |
| // left |
| if (bc[i].x < 0) { |
| bc[i].x = 0; |
| bc[i].incX = random * width / 16 + 1; |
| } |
| // bottom |
| if (bc[i].y + bc[i].ball_size > height) { |
| bc[i].y = (height - bc[i].ball_size) - 2; |
| bc[i].incY = random * -height / 16 - 1; |
| } |
| // top |
| if (bc[i].y < 0) { |
| bc[i].y = 0; |
| bc[i].incY = random * height / 16 + 1; |
| } |
| bc[i].prevx.addLast(new Float(bc[i].x)); |
| bc[i].prevy.addLast(new Float(bc[i].y)); |
| } |
| } |
| |
| public void paint(GC gc, int width, int height) { |
| if (!example.checkAdvancedGraphics()) return; |
| Device device = gc.getDevice(); |
| |
| if (bc[0] == null) { |
| bc[0] = new BallCollection(0, 0, 5, 5, 20, 20, new Color[] { device |
| .getSystemColor(SWT.COLOR_GREEN) }); |
| bc[1] = new BallCollection(50, 300, 10, -5, 50, 10, |
| new Color[] { device.getSystemColor(SWT.COLOR_BLUE) }); |
| bc[2] = new BallCollection(250, 100, -5, 8, 25, 12, |
| new Color[] { device.getSystemColor(SWT.COLOR_RED) }); |
| bc[3] = new BallCollection(150, 400, 5, 8, 35, 14, |
| new Color[] { device.getSystemColor(SWT.COLOR_BLACK) }); |
| bc[4] = new BallCollection(100, 250, -5, -18, 100, 5, |
| new Color[] { device.getSystemColor(SWT.COLOR_MAGENTA) }); |
| } |
| |
| for (int j = 0; j < bc.length; j++) { |
| for (int i = 0; i < bc[j].prevx.size(); i++) { |
| Transform transform = new Transform(device); |
| transform.translate(((Float) bc[j].prevx.get(bc[j].prevx.size() |
| - (i + 1))).floatValue(), ((Float) bc[j].prevy |
| .get(bc[j].prevy.size() - (i + 1))).floatValue()); |
| gc.setTransform(transform); |
| transform.dispose(); |
| |
| Path path = new Path(device); |
| path.addArc(0, 0, bc[j].ball_size, bc[j].ball_size, 0, 360); |
| gc.setAlpha(255 - i * (255 / bc[j].capacity)); |
| gc.setBackground(bc[j].colors[0]); |
| gc.fillPath(path); |
| gc.drawPath(path); |
| path.dispose(); |
| } |
| } |
| } |
| } |