// Purpose.  Flyweight design pattern

// 1. Identify shareable state (intrinsic) and non-shareable state (extrinsic)
// 2. Create a Factory that can return an existing object or a new object
// 3. The client must use the Factory instead of "new" to request objects
// 4. The client (or a third party) must compute the extrinsic state

import java.awt.*;
import java.awt.event.*;
import java.io.StringWriter;

class FlyweightFactory {
   private static java.util.Hashtable ht = new java.util.Hashtable();
   private static ButtonListener bl = new ButtonListener();
   public static Button makeButton( String num ) {
      if (ht.containsValue( num ))
         return (Button) ht.get( num );        // 2. Return an existing object
      Button btn = new Button( num );          // 1. Identify intrinsic state
      btn.addMouseListener( bl );
      ht.put( num, btn );
      return btn;                              // 2. Return a new object
   }
   public static void report() {
      System.out.print( "size=" + ht.size() + "   " );
      for (java.util.Enumeration e = ht.keys(); e.hasMoreElements(); )
         System.out.print( e.nextElement() + " " );
      System.out.println();
}  }

class ButtonListener implements MouseListener {
    
    ButtonProxy bp = new ButtonProxy();
    public void mouseClicked(MouseEvent e)
    {
	Button btn = (Button) e.getSource();
	Component[] btns = btn.getParent().getComponents();
	int i = 0;
	for ( ; i < btns.length; i++)
	    if (btn == btns[i]) break;

	int x = i/ButtonFlyweight.NUM;
	int y = i%ButtonFlyweight.NUM;	

	String label = btn.getActionCommand();
	String s = (new Integer(x)).toString();
	String t = (new Integer(y)).toString();

	StringWriter sw = new StringWriter();
	sw.write(label);
	sw.write(",");
	sw.write(s);
	sw.write(",");
	sw.write(t);

	String sendLine = null; 

	if ((e.getModifiers() & e.BUTTON3_MASK) > 0)
	    {
		//right click happened
		System.out.println("right click detected");
		//		System.out.println("label-" + e.getActionCommand()
		//		    *       + "  x-" + i/ButtonFlyweight.NUM   + "  y-" + i%ButtonFlyweight.NUM );
		sw.write(",right");
		sendLine = sw.toString();
		System.out.println(sendLine);
		String answer = bp.compute(sendLine);
		System.out.println("Our result: "+answer);
		// 1. Identify extrinsic state
	    }
	else if ((e.getModifiers() & e.BUTTON1_MASK) > 0)
	    {
		System.out.println("left click detected");
		//		System.out.println("label-" + e.getActionCommand()
		//    *       + "  x-" + i/ButtonFlyweight.NUM   + "  y-" + i%ButtonFlyweight.NUM );

		sw.write(",left");
		sendLine = sw.toString();
		System.out.println(sendLine);
		String answer = bp.compute(sendLine);
		System.out.println("Our result: "+answer);
	    }
	else 
	    {
		System.out.println("weird click detected");
	    }
    }
    public void mouseEntered (MouseEvent e){};
    public void mouseExited (MouseEvent e){};
    public void mouseReleased (MouseEvent e){};
    public void mousePressed (MouseEvent e){};
}

class ButtonFlyweight {
   public static final int NUM = 30;
   public static final int RAN = 100;

   public static void main( String[] args ) {
      Frame frame = new Frame( "Flyweight Demo" );
      frame.setLayout( new GridLayout( NUM, NUM ) );
      for (int i=0; i < NUM; i++)
         for (int j=0; j < NUM; j++)
            // 3. The client must use the Factory to request objects
            frame.add( FlyweightFactory.makeButton( 
               Integer.toString( (int)(Math.random()*RAN) ) ) );
      frame.pack();
      frame.setVisible( true );
      FlyweightFactory.report();
}  }

// size=25   24 23 22 21 20 19 18 17 16 9 15 8 14 13 7 12 6 5 11 10 4 3 2 1 0
// label-23  x-0  y-0
// label-7  x-0  y-1
// label-21  x-1  y-1
// label-21  x-4  y-6
// label-7  x-9  y-9