jump.java

J2ME核心类及MIDlet类 MIDP用户界面对象 图形处理及低级事件处理 多线程编程 I/O及网络编程 数据库RMS编程 浮点数编程 多媒体及GAME API编程 安全、加密及

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

public class Jump extends MIDlet implements CommandListener {

  private Command myExitCommand = 
	  new Command("Exit", Command.EXIT, 99);
	private Command myGoCommand = 
		new Command("Go", Command.SCREEN, 1);
	private Command myPauseCommand = 
		new Command("暂停", Command.SCREEN, 1);
	private Command myNewCommand = 
		new Command("重新开始", Command.SCREEN, 1);

	JumpCanvas myCanvas;
	GameThread myGameThread;

	public Jump() {
		myCanvas = new JumpCanvas(this);
		myCanvas.addCommand(myExitCommand);
		myCanvas.addCommand(myGoCommand);
		myCanvas.setCommandListener(this);
	}

	void setNewCommand() {
		myCanvas.removeCommand(myPauseCommand);
		myCanvas.removeCommand(myGoCommand);
		myCanvas.addCommand(myNewCommand);
	}

	void setGoCommand() {
		myCanvas.removeCommand(myPauseCommand);
		myCanvas.removeCommand(myNewCommand);
		myCanvas.addCommand(myGoCommand);
	}

	void setPauseCommand() {
		myCanvas.removeCommand(myNewCommand);
		myCanvas.removeCommand(myGoCommand);
		myCanvas.addCommand(myPauseCommand);
	}

	public void startApp() throws MIDletStateChangeException {
		myGameThread = new GameThread(myCanvas);
		myCanvas.start();
	}
	
	public void destroyApp(boolean unconditional) 
			throws MIDletStateChangeException {
		myGameThread.requestStop();
		myGameThread = null;
		myCanvas = null;
		System.gc();
	}

	public void pauseApp() {
		setGoCommand();
		myGameThread.pause();
	}

	public void commandAction(Command c, Displayable s) {
		if(c == myGoCommand) {
			myCanvas.removeCommand(myGoCommand);
			myCanvas.addCommand(myPauseCommand);
			myGameThread.go();
		} else if(c == myPauseCommand) {
			myCanvas.removeCommand(myPauseCommand);
			myCanvas.addCommand(myGoCommand);
			myGameThread.go();
		} else if(c == myNewCommand) {
			myCanvas.removeCommand(myNewCommand);
			myCanvas.addCommand(myGoCommand);
			myGameThread.requestStop();
			myGameThread = new GameThread(myCanvas);
			System.gc();
			myCanvas.reset();
		} else if(c == myExitCommand) {
			try {
				destroyApp(false);
				notifyDestroyed();
			} catch (MIDletStateChangeException ex) {
			}
		}
	}
	
}