maincanvas.java

J2ME编程的50个例子,适合掌上系统的编程

package demo;
import PuzzleMidlet;

import java.util.Random;

import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Image;
import javax.microedition.lcdui.game.TiledLayer;
import javax.microedition.lcdui.game.GameCanvas;

public class MainCanvas extends GameCanvas 
				implements Runnable, CommandListener{
	public static final int GAME_UI				= 0;	//进入用户界面
	public static final int GAME_GAMING			= 1;	//进行游戏
	public static final int GAME_BUTTON			= 2;	//游戏时显示界面按钮
	public static final int GAME_END				= 3;	//游戏结束
	public static final int GAME_STATE_NUM 		= 4;	//状态总数
	private int m_nState	= GAME_UI;						//存储当前的游戏状态
	
	private boolean		m_bRunning;			    		//控制线程运行
	private MyUI			m_UI;							//界面对象
	private TiledLayer 	m_TLayer;						//管理图块
	private static int 	ROW_NUM = 4;					//总行数
	private static int 	COL_NUM = 4;					//总列数
	private int 			m_nCol = 0;						//空图块所在的列
	private int 			m_nRow = 0;						//空图块所在的行
	private Random m_Random;								//随机数对象
	private Command MenuCommand;							//高级按钮对象
	public MainCanvas( ){
		super(true);		
		m_Random = new Random();		
		try{
			//读取图像，创建图块
			Image img = Image.createImage("/demo/img.png");
			if( img.getWidth() % COL_NUM != 0 )
				System.out.print("图片宽度不符合规定");
			if( img.getHeight() % ROW_NUM != 0 )
				System.out.print("图片高度不符合规定");
			int width = img.getWidth() / COL_NUM;
			int height = img.getHeight() / ROW_NUM;
			m_TLayer = new TiledLayer( COL_NUM, ROW_NUM, img, width, height );
			int x = getWidth()/2 - m_TLayer.getWidth()/2;
			int y = getHeight()/2 - m_TLayer.getHeight()/2;
			m_TLayer.setPosition(x, y);
			
			//创建用户界面，并设置界面中的按钮
			MyButton button = new MyButton(41, 21, 0, 1, -1, 2, -1, 3);
			m_UI = new MyUI(button);
        }
        catch(Exception exception){}
        //添加菜单
        MenuCommand 	= new Command("Menu", Command.OK, 0);
        //先不添加菜单按钮
        setCommandListener(this);
        ResetImg();
        setState(GAME_UI);
		Start();
	}
	//重新设置各个图块
	private void ResetImg(){
		//设置原始图块位置
		for( int col = 0; col < COL_NUM; col ++ ){
			for( int row = 0; row < ROW_NUM; row ++){
				m_TLayer.setCell( col, row, row * ROW_NUM + col + 1 );
			}
		}
		//设置空图块
		m_TLayer.setCell( COL_NUM - 1, ROW_NUM - 1, 0 );
		m_nCol = COL_NUM - 1;
		m_nRow = ROW_NUM - 1;
		//随机移动图块
		int Rcol, Rrow, k, nTemp;
		for( int col = 0; col < COL_NUM; col ++ ){
			for( int row = 0; row < ROW_NUM; row ++){
				k = m_Random.nextInt();
				Rcol = Math.abs(k % COL_NUM);
				k = m_Random.nextInt();
				Rrow = Math.abs(k % ROW_NUM);
				if( Rcol != col || Rrow != row ){
					nTemp = m_TLayer.getCell( col, row );
					m_TLayer.setCell(col, row, m_TLayer.getCell(Rcol, Rrow ) );
					m_TLayer.setCell(Rcol, Rrow, nTemp );
					if( m_TLayer.getCell(Rcol, Rrow ) == 0 ){
						m_nCol = Rcol;
						m_nRow = Rrow;
					}
					else if( m_TLayer.getCell(col, row ) == 0 ){
						m_nCol = col;
						m_nRow = row;
					}
				}
			}
		}
	}
	private void setState( int state ){					//设置游戏状态
		if( state < 0 || state >= GAME_STATE_NUM )
			return;
		m_nState = state;
		switch( m_nState ){
		case GAME_UI:										//进入用户界面
			m_UI.setState(MyUI.UI_TITLE);					//显示标题界面
			//设置本游戏的按钮类型，本游戏有:开始、帮助和退出三种按钮
			m_UI.getButton().setShow(true, false, false, true, false, true );
			break;
		case GAME_BUTTON:									//在游戏中途显示按钮
			m_UI.setState(MyUI.UI_BUTTON);
			//游戏中途，显示复位与退出按钮
			m_UI.getButton().setShow(false, true, false, false, false, true );
			break;
		case GAME_GAMING:									//正在游戏
			addCommand(MenuCommand);
			m_UI.setState(MyUI.UI_HIDE);
			break;
		case GAME_END:										//游戏结束
			m_UI.setState(MyUI.UI_HIDE);
			break;;
		}
	}
	public void Start(){
		m_bRunning = true;
		Thread thread = new Thread(this);	//分配新线程
		thread.start();						//线程启动
	}
	public void run() {
		//得到系统当前时间,并将时间换算成毫秒
		long T1 = System.currentTimeMillis();
		long T2 = T1;
		while(m_bRunning){
			T2 = System.currentTimeMillis();
			if( T2 - T1 > 100 ){			//间隔100毫秒
				T1 = T2;
				Input();
				Logic();
				Paint();
			}
		}
	}
	public void Stop(){
		m_bRunning = false;
	}
	public void Input(){
		int keyStates = getKeyStates();
		switch( m_nState ){
		case GAME_UI:
			{
				switch( m_UI.Input( keyStates ) ){
				case MyButton.BUTTON_START:					//按下开始键
					setState(GAME_GAMING);
					break;
				case MyButton.BUTTON_EXIT:					//按下退出键
					PuzzleMidlet.midlet.notifyDestroyed();
					break;
				}
			}
			break;			
		case GAME_GAMING:									//游戏中
			if( ( keyStates & GameCanvas.UP_PRESSED ) != 0 ){
				if( m_nRow < ROW_NUM - 1 ){					//移动空图块的下边图块
					int index = m_TLayer.getCell(m_nCol, m_nRow+1);
					m_TLayer.setCell(m_nCol, m_nRow, index);
					m_TLayer.setCell(m_nCol, m_nRow+1, 0);
					m_nRow ++;
				}
			}
			if( ( keyStates & GameCanvas.DOWN_PRESSED ) != 0 ){
				if( m_nRow > 0 ){							//移动空图块的上边图块
					int index = m_TLayer.getCell(m_nCol, m_nRow-1);
					m_TLayer.setCell(m_nCol, m_nRow, index);
					m_TLayer.setCell(m_nCol, m_nRow-1, 0);
					m_nRow --;
				}
			}
			if( ( keyStates & GameCanvas.LEFT_PRESSED ) != 0 ){
				if( m_nCol < ROW_NUM - 1 ){					//移动空图块的左边图块
					int index = m_TLayer.getCell(m_nCol+1, m_nRow);
					m_TLayer.setCell(m_nCol, m_nRow, index);
					m_TLayer.setCell(m_nCol+1, m_nRow, 0);
					m_nCol ++;
				}
			}
			if( ( keyStates & GameCanvas.RIGHT_PRESSED ) != 0 ){
				if( m_nCol > 0 ){							//移动空图块的右边图块
					int index = m_TLayer.getCell(m_nCol-1, m_nRow);
					m_TLayer.setCell(m_nCol, m_nRow, index);
					m_TLayer.setCell(m_nCol-1, m_nRow, 0);
					m_nCol --;
				}
			}
			break;
		case GAME_BUTTON:									//游戏中途显示按钮
			{
				switch( m_UI.Input( keyStates ) ){
				case MyButton.BUTTON_RESET:					//按下复位键
					ResetImg();
					setState(GAME_GAMING);
					break;
				case MyButton.BUTTON_EXIT:					//按下退出键
					PuzzleMidlet.midlet.notifyDestroyed();
					break;
				}
			}
			break;
		case GAME_END:
			break;
		}
	}
	public void Logic(){
		switch( m_nState ){		
		case GAME_GAMING:									//游戏中
			//检测是否拼图成功
			for( int col = 0; col < COL_NUM; col ++ ){
				for( int row = 0; row < ROW_NUM; row ++ ){
					if( col == COL_NUM - 1 && row == ROW_NUM - 1 )
						continue;
					if( m_TLayer.getCell(col, row) != row * ROW_NUM + col ){
						return;
					}
				}
			}
			setState(GAME_END);
			break;
		default:
			break;
		}
		
	}
	public void Paint(){
		Graphics g = getGraphics();
		//用黑色清屏
		g.setColor(0);
		g.fillRect( 0, 0, getWidth(), getHeight() );
		
		g.setColor(0x0000FF);
		switch( m_nState ){
		case GAME_UI:								//显示界面
			m_UI.Paint(g, getWidth(), getHeight());
			break;			
		case GAME_GAMING:							//显示游戏画面
		case GAME_BUTTON:
		case GAME_END:
			m_TLayer.paint(g);
			m_UI.Paint(g, getWidth(), getHeight());	//MyUI类内会根据需要显示按钮
			if( m_nState == GAME_END )				//如果当前状态为游戏结束
				g.drawString("你赢了", getWidth()/2 - 10, getHeight()/2 - 10, 0);
			break;
		}
		flushGraphics();
	}
	public void commandAction(Command c, Displayable s){
		if( c == MenuCommand ){
			switch( m_nState ){	
			case GAME_END:							//游戏结束，显示按钮
			case GAME_GAMING:						//正在游戏，显示按钮	
				setState(GAME_BUTTON);
				break;
			case GAME_BUTTON:						//正显示按钮，退回游戏
				setState(GAME_GAMING);
				break;
			default:
				break;
			}
		}
	}
}