snakecanvas.java~174~

j2me源代码

package snake;

import java.io.*;
import java.util.*;
import javax.microedition.lcdui.*;

public class SnakeCanvas extends Canvas implements Runnable, CommandListener {
  public final static int CELL_SIZE = 5;   //蛇的宽度
  public final static int BACK_COLOR = 0x00e0f0f0;  //背景颜色
  public final static int PANEL_COLOR = 0x00e8d8ba; //面板颜色
  public final static int FOOD_COLOR = 0x00308020;  //豆子颜色
  public final static int SNAKE_COLOR = 0x000000FF;  //蛇的颜色
  private final static int WAIT_PERIOD = 300;        //默认最长的刷新时间间隔
  private final static int MAX_LEVEL = 4;   //游戏的最高等级
  private final static int PANEL_YPOS = 50; //面板的起点纵坐标
  private final static int [] nLevelNum = {32,64,128,256};

  public final static byte GAME_INIT = 1;
  public final static byte GAME_RUN = 2;
  public final static byte GAME_PAUSE = 3;
  public final static byte GAME_OVER = 4;

  private int nWidth, nHeight;  //游戏区域的宽和高
  private int xCellNum, yCellNum; //游戏区域x,y方向的单元格数目
  private int wWhite = 0;    //屏幕横向的空白区域宽度

  private int nLevel = 1;    //游戏等级
  private int nScore = 0;    //游戏得分
  private int nFoodEaten = 0;  //游戏当中总共吃到的豆子的数目
  private String user = ""; //游戏者信息
  private byte nState = GAME_INIT;  //游戏运行状态
  private boolean bRefreshAll = true;  //是否需要全部刷新

  private Snake snake;  //贪吃蛇
  private Food food;    //豆子
  private Thread thread;

  private Image imgBox;  //用于显示信息的方框
  private Font ft;       //系统字体
  private boolean bGameOver = false; //标识游戏是否结束

  private Command exit;  //退出命令
  private Command pause; //暂停命令
  private Command start; //开始命令
  private Command TopScore;  //查看积分榜命令

  public SnakeCanvas(int level, String name) {
    nLevel = level;
    user = name;
    //处理游戏区域大小
    try {
      imgBox = Image.createImage("/res/box.png");
    }
    catch (IOException ex) {
    }
    ft = Font.getFont(Font.FACE_PROPORTIONAL,
                           Font.STYLE_BOLD, Font.SIZE_MEDIUM);
    int nPanelWidth = imgBox.getWidth();
    int temp = (getWidth() - nPanelWidth) % CELL_SIZE;
    wWhite = temp + nPanelWidth;
    nWidth = getWidth() - wWhite;
    nHeight = getHeight();

    xCellNum = nWidth / CELL_SIZE;
    yCellNum = nHeight / CELL_SIZE;
    thread = new Thread(this);
    thread.start();
    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }

  /**
   * 初始化可能出现异常的数据
   * @throws Exception
   */
  private void jbInit() throws Exception {
    setCommandListener(this);
    exit = new Command("exit", Command.EXIT, 0);
    pause = new Command("pause", Command.OK, 1);
    start = new Command("start", Command.OK, 1);
    TopScore = new Command("TopScore", Command.OK, 1);
    // add command
    addCommand(exit);
    addCommand(pause);

    snake = new Snake(this);
    food = new Food(this);

    int x = food.getX();
    int y = food.getY();

    //确保所产生的食物不在蛇身上
    while(snake.isPtInSnake(x,y)){
      food.createFood();
      x = food.getX();
      y = food.getY();
    }
  }

  /**
   * 命令响应函数
   * @param command Command
   * @param displayable Displayable
   */
  public void commandAction(Command command, Displayable displayable) {
    switch(command.getCommandType()){
      case Command.EXIT:
        SnakeMIDlet.quitApp();
        break;
      case Command.OK:
        if (command == pause && nState == GAME_RUN) {
          nState = GAME_PAUSE;
          removeCommand(pause);
          addCommand(start);
        }
        else if (command == start) {
          nState = GAME_RUN;
          removeCommand(start);
          addCommand(pause);
        } else if(command == TopScore){
          viewScore();
        }
        break;
    }
  }

  /**
   * 创建积分榜查看界面，显示最高分信息
   */
  private void viewScore() {
    ScoreRecordStore srs = new ScoreRecordStore();
    Vector v = new Vector();
    v = srs.loadScoreRecord("SnakeScore10");
    ScoreRecordView srv = new ScoreRecordView(v);
    SnakeMIDlet.setCurrent(srv);
  }

  /**
   * 响应键盘操作
   * @param keyCode int
   */
  protected void keyPressed(int keyCode){
    int action = getGameAction(keyCode);
    switch(action){
      case Canvas.DOWN:
      case Canvas.KEY_NUM8:
        snake.setDirection(Snake.DOWN);
        break;
      case Canvas.UP:
      case Canvas.KEY_NUM2:
        snake.setDirection(Snake.UP);
        break;
      case Canvas.LEFT:
      case Canvas.KEY_NUM4:
        snake.setDirection(Snake.LEFT);
        break;
      case Canvas.RIGHT:
      case Canvas.KEY_NUM6:
        snake.setDirection(Snake.RIGHT);
        break;
    }
  }

  /**
   * 绘制函数
   * @param g Graphics
   */
  protected void paint(Graphics g) {
    switch (nState) {
      case GAME_INIT:
        g.setColor(this.BACK_COLOR);
        g.fillRect(0, 0, nWidth, nHeight);
        g.setColor(this.PANEL_COLOR);
        g.fillRect(getWidth()-wWhite, 0, wWhite, getHeight());
        drawPanel(g);
        nState = GAME_RUN;
        break;
      case GAME_RUN:
        if (bRefreshAll) {
          bRefreshAll = false;
          snake.paint(g);
          food.paint(g);
          drawPanel(g);
        }
        else {
          g.setClip(0, 0, nWidth, nHeight);
          snake.update(g);
        }

        if (food.getX() == snake.getXHead() &&
            food.getY() == snake.getYHead()) {
          snake.eat();
          nScore += nLevel;
          nFoodEaten++;
          bRefreshAll = true;

          if(nFoodEaten > nLevelNum[nLevel-1]){
            nFoodEaten = 0;
            nLevel ++;

            if(nLevel > MAX_LEVEL)
              nState = GAME_OVER;
          }

          food.createFood();
          int x = food.getX();
          int y = food.getY();

          //确保所产生的食物不在蛇身上
          while (snake.isPtInSnake(x, y)) {
            food.createFood();
            x = food.getX();
            y = food.getY();
          }

          food.paint(g);
        }
        break;
      case GAME_PAUSE:
        break;
      case GAME_OVER:
        removeCommand(pause);
        addCommand(TopScore);
        g.setColor(255, 0, 0);
        g.setFont(Font.getDefaultFont());
        g.drawString("Game Over", nWidth/2, nHeight/2,
            Graphics.HCENTER | Graphics.BASELINE);
        saveScore();
        break;
      default:
        break;
    }
  }

  /**
   * 保存分数记录
   */
  private void saveScore() {
    if(nScore <=0)
      return;
    ScoreRecordStore srs = new ScoreRecordStore();
    Vector v = new Vector();
    v = srs.loadScoreRecord("SnakeScore10");
    if (v.size() < 10) {
      Record r = new Record( (short) nScore, user);
      v.addElement(r);
      srs.saveScoreRecord(v, "SnakeScore10");
    }
    else {
      Record rt = (Record) v.lastElement();
      if (nScore > rt.nScore) {
        v.removeElementAt(9);
        Record r = new Record( (short) nScore, user);
        v.addElement(r);
        srs.saveScoreRecord(v, "SnakeScore10");
      }
    }
  }

  /**
   * 绘制左侧的面板
   */
  private void drawPanel(Graphics g) {
    int yPos = PANEL_YPOS;
    int x,y;
    String str;
    g.setFont(ft);
    g.setColor(255, 0, 0);
    int ftHeight = ft.getHeight();
    int imgSpace = imgBox.getHeight();
    int space = ftHeight + imgSpace + 15;

    //绘制用户名
    g.drawString("user", nWidth, yPos, Graphics.LEFT|Graphics.TOP);
    g.drawImage(imgBox, nWidth, yPos + ftHeight, Graphics.LEFT | Graphics.TOP);
    x = nWidth + imgBox.getWidth()/2;
    y = yPos +ftHeight + 5;
    str = user;
    g.drawString(user, x, y, Graphics.HCENTER | Graphics.TOP);

    //绘制LEVEL
    yPos += space;
    g.drawString("level", nWidth, yPos, Graphics.LEFT|Graphics.TOP);
    g.drawImage(imgBox, nWidth, yPos + ftHeight, Graphics.LEFT | Graphics.TOP);
    str = "" + nLevel;
    y = yPos +ftHeight + 5;
    g.drawString(str, x, y, Graphics.HCENTER | Graphics.TOP);

    //绘制分数
    yPos += space;
    g.drawString("score", nWidth, yPos, Graphics.LEFT|Graphics.TOP);
    g.drawImage(imgBox, nWidth, yPos + ftHeight, Graphics.LEFT | Graphics.TOP);
    str = "" + nScore;
    y = yPos +ftHeight + 5;
    g.drawString(str, x, y, Graphics.HCENTER | Graphics.TOP);
  }

  public int getXCellNum(){
    return xCellNum;
  }

  public int getYCellNum(){
    return yCellNum;
  }

  public void run() {
    while(!bGameOver){
      synchronized (snake) {
        try {
          thread.sleep(WAIT_PERIOD - 50 * nLevel);
        }
        catch (InterruptedException ex) {
        }
        repaint();
      }
    }
  }

  /**
   * 测试蛇是否超出游戏区域
   * @param x int
   * @param y int
   * @return boolean
   */
  public boolean isPtInBound(int x, int y){
    if(x<0 || x > xCellNum)
      return false;

    if(y<0 || y > yCellNum)
      return false;

    return true;
  }

  /**
   * 设置游戏结束标志
   */
  public void setGameOver() {
    bGameOver = true;
    nState = GAME_OVER;
    repaint();
  }
}