translatemidlet.java.svn-base

example2 众多JAVA实例源码...学习java基础的好帮手

package opusmicro.demos.canvas;

import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Image;
import javax.microedition.midlet.MIDlet;

public class TranslateMIDlet extends MIDlet {
	private Display display; // The display
	private TranslateCanvas canvas; // Canvas

	public TranslateMIDlet() {
		display = Display.getDisplay(this);
		canvas = new TranslateCanvas(this);
	}

	protected void startApp() {
		display.setCurrent(canvas);
	}

	protected void pauseApp() {}
	protected void destroyApp(boolean unconditional) {}
	public void exitMIDlet() {
		destroyApp(true);
		notifyDestroyed();
	}
}

/*--------------------------------------------------
 * Class TranslateMIDlet
 *
 * Draw image using translated coordinates
 *-------------------------------------------------*/
class TranslateCanvas extends Canvas implements CommandListener {
	private Command cmExit; // Exit midlet
	private TranslateMIDlet midlet;
	private Image im = null;
	private int translatex = 0, translatey = 0;

	public TranslateCanvas(TranslateMIDlet midlet) {
		this.midlet = midlet;
		// Create exit command & listen for events
		cmExit = new Command("Exit", Command.EXIT, 1);
		addCommand(cmExit);
		setCommandListener(this);
		try {
			// Create immutable image
			im = Image.createImage("/welcome.png");
		}catch (java.io.IOException e) {
			System.err.println("Unable to locate or read .png file");
		}
	}

	protected void paint(Graphics g) {
		if ( im != null) {
			// Clear the background
			g.setColor(255, 255, 255);
			g.fillRect(0, 0, getWidth(), getHeight());
			// TranslateMIDlet coordinates
			g.translate(translatex, translatey);
			// Always draw at 0,0
			System.out.println("translatey= "+translatey);
			System.out.println("g.getTranslateX()="+g.getTranslateX()+" g.getTranslateY()="+g.getTranslateY());
			System.out.println("g.getClipX()= "+ g.getClipX()+" g.getClipY()= "+ g.getClipY());
			g.setClip(g.getClipX()+g.getTranslateX(), g.getClipY()+g.getTranslateY(), im.getWidth(), im.getHeight());
			g.drawImage(im, 0, 0, Graphics.LEFT | Graphics.TOP);
			System.out.println("2 g.getClipX()= "+ g.getClipX()+" g.getClipY()= "+ g.getClipY());
			g.setClip(0, 0, 240, 291);
		}
	}

	public void commandAction(Command c, Displayable d) {
		if ( c == cmExit) midlet.exitMIDlet();
	}

	protected void keyPressed(int keyCode) {
		switch ( getGameAction(keyCode)) {
			case UP:
				// If scrolling off the top, roll around to bottom
				if ( translatey - im.getHeight() < 0) translatey = getHeight() - im.getHeight();
				else translatey -= im.getHeight();
				break;
			case DOWN:
				// If scrolling off the bottom, roll around to top
				if ( (translatey + im.getHeight() + im.getHeight()) > getHeight()) translatey = 0;
				else translatey += im.getHeight();
				break;
			case LEFT:
				// If scrolling off the left, bring around to right
				if ( translatex - im.getWidth() < 0) translatex = getWidth() - im.getWidth();
				else translatex -= im.getWidth();
				break;
			case RIGHT:
				// If scrolling off the right, bring around to left
				if ( (translatex + im.getWidth() + translatex) > getWidth()) translatex = 0;
				else translatex += im.getWidth();
				break;
		}
		repaint();
	}
}