canvasdemo5.java

一本介绍手机游戏开发的书中的源代码

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

public class canvasDemo5 extends MIDlet
{
   Display display;
   canvasTranslate canvastranslate;

   public canvasDemo5()
   {
      canvastranslate=new canvasTranslate();
      display=Display.getDisplay(this);
   }

   public void startApp()
   {
      display.setCurrent(canvastranslate);
   }

   public void pauseApp(){}

   public void destroyApp(boolean unconditional){}

   class canvasTranslate extends Canvas 
   {
      int    gameaction=0;
      int    x;
      int    y;
      boolean view;
      Image  pictureImage;

      public canvasTranslate()
      {
         try{
             pictureImage=Image.createImage("/picture.png");
         }catch(Exception ex){}
      }
      
      public void keyPressed(int keyCode) 
      {
         gameaction=getGameAction(keyCode);
         switch(gameaction)
         {
            case UP:
                 view=false;
                 repaint();                 
                 break;
            case DOWN:
                 view=true;
                 x=50;
                 y=60;
                 repaint();                 
                 break;
          }
      }

      public void paint(Graphics g)
      { 
         g.setColor(0xFFFFFF);
         g.fillRect(0,0,getWidth(),getHeight());
         g.setColor(0);
         if(view)
         {
           g.translate(x,y);
           g.drawString("X轴位移"+String.valueOf(g.getTranslateX()), -10, -40, Graphics.LEFT | Graphics.TOP);
           g.drawString("Y轴位移"+String.valueOf(g.getTranslateY()), -10, -20, Graphics.LEFT | Graphics.TOP);
         }
         g.drawImage(pictureImage, 0, 0, Graphics.LEFT | Graphics.TOP);
      }
   }
}