//  SpriteDemoMIDlet.java  (c) Kari Laitinen

//  http://www.naturalprogramming.com/

//  2009-09-29  File created.
//  2011-04-28  Last modification.

/*  This midlet demonstrates:
       - animation
       - use of the Sprite class

*/

import java.io.* ;

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


class SpriteDemoCanvas extends Canvas
                       implements Runnable
{
   Thread   animation_thread ;
   boolean  thread_must_be_run  =  false ;

   int  canvas_width   =  getWidth() ; 
   int  canvas_height  =  getHeight() ;

   Image  picture_for_sprite  ;

   Sprite demo_sprite ;

   int picture_width, picture_height ;

   int sprite_frame_width, sprite_frame_height ;

   public SpriteDemoCanvas()
   {
      try
      {
         picture_for_sprite  = Image.createImage(
                                          "/four_orange_arrow_frames.png" ) ;

         picture_width =  picture_for_sprite.getWidth() ;
         picture_height =  picture_for_sprite.getHeight() ;

         sprite_frame_width  = picture_width / 4 ;
         sprite_frame_height = picture_height ;

         demo_sprite = new Sprite( picture_for_sprite,
                                   sprite_frame_width,
                                   sprite_frame_height ) ;

      }
      catch ( IOException  io_exception )
      {
         System.out.print( "\n Could not create an Image object ....  " ) ;
      }
   }


   public synchronized void start_animation_thread()
   {
      if ( animation_thread  ==  null )
      {
         animation_thread  =  new  Thread( this ) ;
         thread_must_be_run  =  true ;
         animation_thread.start() ;
      }
   }

   public void stop_animation_thread()
   {
      if ( animation_thread  !=  null )
      {
         thread_must_be_run  =  false ;
         animation_thread.interrupt() ;
         animation_thread  =  null ;
      }
   }

   public void run()
   {
      while ( thread_must_be_run  ==  true ) 
      {
         repaint() ;

         try
         {
            Thread.sleep( 2000 ) ;
         }
         catch ( InterruptedException caught_exception )
         {
            // No actions to handle the exception.
         }
      }  
   }


   protected void paint( Graphics graphics )
   {
      //  The background color is red

      graphics.setColor( 255, 0, 0 ) ; 
      graphics.fillRect( 0, 0, canvas_width, canvas_height ) ;

      demo_sprite.nextFrame() ;

      demo_sprite.paint( graphics ) ;

   }
}


public class SpriteDemoMIDlet extends MIDlet
{
   Display  midlet_display  =  Display.getDisplay( this ) ;
   SpriteDemoCanvas  sprite_demo_canvas  =  new SpriteDemoCanvas() ;

   protected void startApp() throws MIDletStateChangeException
   {
      midlet_display.setCurrent( sprite_demo_canvas ) ;
      sprite_demo_canvas.start_animation_thread() ;
   }

   protected void pauseApp()
   {
      sprite_demo_canvas.stop_animation_thread() ;
   }

   protected void destroyApp( boolean unconditional_destruction_required )
   {
      sprite_demo_canvas.stop_animation_thread() ;
   }
}