mycanvas.java

java手机/PDA程序开发与设计用户界面UI_Low3.rar

// 程序名MyCanvas.java
// 一个简单的Canvas的子类
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
public class MyCanvas extends Canvas {
  private UI_Low3 midlet;
  private String message;

  public MyCanvas( UI_Low3 midlet ){
    this.midlet = midlet;
    message = new String();
  } 
 
  protected void showNotify() {
  }
  
  protected void hideNotify() {
  }

  protected void paint( Graphics g ){
    g.setColor(0xffffff);
    g.fillRect( 0, 0, getWidth(), getHeight());
    g.setColor(0x000000);
    if (hasPointerEvents()) {
      message += "support prointer Events";
    }
    if (hasPointerMotionEvents()) {
      message += " and prointer dragged Events";
    }
    g.drawString( message, getWidth()/2, 0,g.TOP | g.HCENTER );
  }

  protected void keyRepeated(int keyCode) {
    System.out.println("key "+getKeyName(keyCode)+" is hold down.");
  }

  protected void keyReleased(int keyCode) {
    //System.out.println("key "+getKeyName(keyCode)+" is pressed then released.");
  }
  protected void keyPressed( int keyCode ){
    if( keyCode == getKeyCode(FIRE)){
      message = "FIRE";
    }else if( keyCode == getKeyCode(LEFT)){
      message = "LEFT";
    } else if( keyCode == getKeyCode(RIGHT)){
      message = "RIGHT";
    } else if( keyCode == getKeyCode(UP)){
      message = "UP";
    } else if( keyCode == getKeyCode(DOWN)){
      message = "DOWN";
    } else {
      message = "OTHER";
    }
    repaint();
    //System.out.println("GameAction: "+getGameAction(keyCode));
    /*
    if (keyCode == 0) {
    }
    //或者
    if (keyCode == KEY_NUM0) {
    }
    switch (keyCode) {
      case -1: {
        fighter.forward();
        return;
      }
      case -2: {
        fighter.backward();
        return;
      }
      case -3: {
        fighter.left();
        return;
      }
      case -4: {
        fighter.right();
        return;
      }
      case -5: {
        fighter.fire();
      }
      case ..//战士的其它动作，或者调用系统命令
      default: {
        return;
      }
    }
    */
  }
}