// This exercise midlet creates an application to translate coordinate

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

public class Trans extends MIDlet {

  private Display display;
  private TransCanvas canvas;

  // constructor
  public Trans(){
    display = Display.getDisplay(this);
    canvas = new TransCanvas(this);
  }

  // startApp
  protected void startApp(){
    display.setCurrent(canvas);
  }

  // pauseApp
  protected void pauseApp(){

  }

  // detsroyApp
  protected void destroyApp(boolean unconditional){

  }
  // exitMIDlet
  public void exitMIDlet(){
    destroyApp(true);
    notifyDestroyed();
  }
}

// Class TRanCanvas  --- Draw image using translate coordinates
class TransCanvas extends Canvas implements CommandListener{

  private Command cmExit;
  private Trans midlet;
  private Image sub = null;
  private int tranx = 0;
  private int trany = 0;

  // constructor
  public TransCanvas(Trans midlet){
    this.midlet = midlet;
    // Create command and listen for events
    cmExit = new Command("Exit", Command.EXIT, 1);
    addCommand(cmExit);
    setCommandListener(this);

    // try and catch exception
    try
    {
      // Create image
      sub = Image.createImage("/sub.png");
      }
      catch(java.io.IOException e)
      {
        System.err.println("Unable to find or read *.png file");
      }
  }

  // Paint the image on canvas
  protected void paint(Graphics g){
    if(sub !=null){
      // Clear the background by setting color to Light blue and fill the display
      g.setColor(0, 255, 255);
      g.fillRect(0, 0, getWidth(), getHeight());

      //Translate cooridinates
      g.translate(tranx, trany);

      // Draw from 5, 5 coordinates
      g.drawImage(sub, 5, 5, Graphics.LEFT | Graphics.TOP);
    }
  }

  // command action
  public void commandAction(Command c, Displayable s){
    if(c == cmExit)
      midlet.exitMIDlet();
  }

  // keyPressed game actions
  protected void keyPressed(int keyCode){
    switch(getGameAction(keyCode)){
      case UP:
        // if scrolling on tthe top, roll around to bottom
        if(trany - sub.getHeight() < 0)
          trany = getHeight() - sub.getHeight();
        // else go one image height up
        else
            trany -= sub.getHeight();
            break;

      case DOWN:
        // if scrolling off the bottom roll arounf the top
        if((trany + sub.getHeight() + sub.getHeight()) > getHeight())
          trany = 0;
        // esle go one image height down
        else
            trany += sub.getHeight();
            break;

        case LEFT:
          // if scrolling off the left bring around to right
          if(tranx - sub.getWidth() < 0)
            tranx = getWidth() - sub.getWidth();
            else
              tranx -= sub.getWidth();
              break;

        case RIGHT:
          // if scrolling goes off the right bring round to the left
          if((tranx + sub.getWidth() + tranx) > getWidth())
            tranx = 0;
            else
              tranx += sub.getWidth();
              break;
    }
    repaint();
  }
}