doggy.java

来自「用Java/C#开发手机程序及移动应用光盘代码。J2ME核心类及MIDlet类；」· Java 代码 · 共 88 行

import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.Image;

public class Doggy extends Canvas implements Runnable {

	static final int FRAME_COUNT = 17;

	static final int FRAME_DELAY = 180;

	static final int LAST_FRAME_DELAY = 3000;

	static final int[] framePositions = {
		0, 50, 186, 372, 558, 744, 930, 1024, 1024,
		834, 651, 465, 279, 93, 0, 0, 0
	};

	Image doggyImages = null;

	int frameWidth = 0;
	int frameHeight = 0;
	int frameIndex = 0;
	int runLength = 0;

	boolean running = false;

	protected void showNotify() {
		if (doggyImages == null) {
			try {
				doggyImages =
					Image.createImage("/Doggy.png");
				frameWidth = doggyImages.getWidth();
				frameHeight = doggyImages.getHeight() / FRAME_COUNT;
			} catch (Exception ioe) {
				return; 
			}
		}

		runLength = getWidth() - frameWidth;
		running = true;
		frameIndex = 0;

		new Thread(this).start();
	}

	protected void hideNotify() {
		running = false;
	}

	public void run() {
		try {
			while (running) {
				Thread.sleep((frameIndex == FRAME_COUNT - 1) ?
							 LAST_FRAME_DELAY : FRAME_DELAY);

				int lastFrameIndex = frameIndex;
				frameIndex = (frameIndex + 1) % FRAME_COUNT;

				int repaintLeft = framePositions[lastFrameIndex];
				int repaintRight = framePositions[frameIndex];
				if (framePositions[lastFrameIndex] > framePositions[frameIndex]) {
					repaintLeft = framePositions[frameIndex];
					repaintRight = framePositions[lastFrameIndex];
				}

				repaintLeft = (repaintLeft * runLength) >> 10;
				repaintRight = (repaintRight * runLength) >> 10;

				repaint(repaintLeft, 0,
						frameWidth + repaintRight - repaintLeft, frameHeight);
			}
		} catch (InterruptedException e) {}
	}

	public void paint(Graphics g) {

		g.setColor(0xFFFFFF);
		g.fillRect(0, 0, getWidth(), getHeight());

		g.translate((framePositions[frameIndex] * runLength) >> 10, 0);

		g.clipRect(0, 0, frameWidth, frameHeight);

		g.drawImage(doggyImages, 0, -(frameIndex * frameHeight),
					Graphics.LEFT + Graphics.TOP);
	}
}