import java.awt.*;
import java.awt.image.*;

public class Graphics5
{
   public static final int RED    = 0xFF0000;
   public static final int GREEN  = 0x00FF00;
   public static final int BLUE   = 0x0000FF;
   public static final int YELLOW = 0xFFFF00;
   public static final int BLACK  = 0x000000;

   static public void pause(int n) throws Exception
   {
      Thread.sleep( 100 * n );
   }

   static public void main(String[] args) throws Exception
   {
      /* ------------------------------------------------
         Preparing to draw picture...
         ------------------------------------------------ */
      Canvas pic = new MyCanvas();          // Make a canvas (2 dim array)
      Frame f = new Frame( "My image" );    // Create a window

      f.add("Center", pic);                 // Put the canvas in the window
      f.setSize(MyCanvas.MAX_X, MyCanvas.MAX_Y); // Set size of the window
      f.setVisible(true);                   // Make window visible 

      /* ------------------------------------------------
         Draw a 10x10 box at (100,100)
         ------------------------------------------------ */
      for (int i = 0; i < 10; i++ ) 
         for (int j = 0; j < 10; j++ ) 
            MyCanvas.Image.setRGB(100+i, 100+j, YELLOW); 

      pic.repaint();   // Repaint the picture

      pause(20);
      /* ------------------------------------------------
         ERASE the 10x10 box at (100,100)
         ------------------------------------------------ */
      for (int i = 0; i < 10; i++ )
         for (int j = 0; j < 10; j++ )
            MyCanvas.Image.setRGB(100+i, 100+j, BLACK);

      pic.repaint();   // Repaint the picture

      /* ------------------------------------------------
         Draw the same 10x10 box at (200,100)
         ------------------------------------------------ */
      for (int i = 0; i < 10; i++ )
         for (int j = 0; j < 10; j++ )
            MyCanvas.Image.setRGB(200+i, 100+j, YELLOW);

      pic.repaint();   // Repaint the picture
      pause(50);
   }
}