/**

* Copyright (c) 1998 Daniel Dee

* Description:

Puzzle game. Objective is to shift tiles around until you

arrange them in numerical order. Click on the tile to shift, and

the empty space to shift it to. A tile can be shifted only if

a space is adjacent to it.

*/

import java.applet.Applet;

import java.awt.Event;

import java.awt.Frame;

import java.awt.CardLayout;

import java.awt.Container;

import java.awt.Dimension;

import java.awt.Insets;

import java.awt.Point;

import com.wigitek.vivigraphics.widget.common.*;

import com.wigitek.vivigraphics.widget.gui.*;

/**

* This class extends the java.awt.Button class to support

the callback mechanism by implementing the Widget interface.

* @version $Revision$

* @author Originally written by Daniel Dee, 6/4/98

* @author Last updated by $Author$, $Date$

*/

public class Puzzle extends Applet

{

private Panel panel;

private PositionableGridLayout layout;

public void init()

{

panel = new Panel();

layout = new PositionableGridLayout();

panel.addCallback( Panel.ACTIVATE_CALLBACK,

new PuzzleCallbackable(null,layout,panel,this) );

panel.setLayout( layout );

createPuzzle(this,panel,layout);

CardLayout clayout = new CardLayout();

setLayout( clayout );

add( "Puzzle", panel );

}

public void destroy()

{

panel = null;

}

/**

* Create the Puzzle.

* @param c the Container for this Puzzle

* @param l the PositionableGridLayout manager for this Puzzle

*/

private static void createPuzzle( Container f, Container c,

PositionableGridLayout l )

{

PositionableGridConstraints constraints =

new PositionableGridConstraints();

constraints.gridwidth = constraints.gridheight =

PositionableGridConstraints.FILL_SIZE;

// Create 8 tiles in order.

for( int i=0; i < 3; i++ )

for( int j=0; j < 2 || (j == 2 && i != 2); j++ )

{

constraints.gridx = j;

constraints.gridy = i;

Button button = new Button(

new Integer(i*3+(j+1)).toString() );

button.addCallback( Button.ACTIVATE_CALLBACK,

new PuzzleCallbackable(button,l,c,f) );

l.setConstraints( button, constraints );

c.add( button );

}

}

/**

* This is the main program to test the

PositionableGridLayout/Constraints class.

* @param args unused

*/

public static void main( String args[] )

{

Frame applic = new Frame( "Eva Puzzle" );

Panel panel = new Panel();

PositionableGridLayout layout = new PositionableGridLayout();

panel.addCallback( Panel.ACTIVATE_CALLBACK,

new PuzzleCallbackable(null,layout,panel,applic) );

panel.setLayout( layout );

Puzzle.createPuzzle(applic,panel,layout);

CardLayout clayout = new CardLayout();

applic.setLayout( clayout );

applic.add( "Puzzle", panel );

Dimension d = layout.minimumLayoutSize(panel);

applic.setSize(d.width,d.height);

applic.setVisible(true);

Insets i = applic.getInsets();

applic.setSize(d.width+i.left+i.right,d.height+i.top+i.bottom);

applic.setVisible(true);

}

}

/**

* Extension of Callbackable class to handle tile selection. If an empty

space is selected, that means the previously selected tile should be

moved to the empty location. Does nothing if that is not possible, i.e.,

the empty space is not adjacent to the previously selected tile.

*/

class PuzzleCallbackable extends Callbackable

{

/**

* Constructs a PuzzleCallbackable.

* @param b the button for which this Callback is created

* @param i the PositionableGridLayout for this Puzzle's Container

* @param f the Container for this Puzzle

*/

public PuzzleCallbackable( Button b, PositionableGridLayout l,

Container f, Container c )

{

this.b = b;

this.l = l;

this.f = f;

this.c = c;

}

/**

* Activates this Callbackable.

* @param e the event that triggers this callback

*/

public boolean activate( Event e )

{

if( b == null ) // an empty space is selected, probably a

tile move

{

if( selected != null ) // a tile was selected for moving

{

// Check if tile move is valid

PositionableGridConstraints c =

l.lookupConstraints(selected);

Point p = l.getLocation( e.x, e.y );

if( (c.gridx == p.x+1 || c.gridx == p.x-1) &&

c.gridy == p.y )

c.gridx = p.x;

else if((c.gridy == p.y+1 || c.gridy == p.y-1) && c.gridx ==

p.x)

c.gridy = p.y;

f.doLayout();

f.repaint();

}

}

else // a selection

selected = b;

return true;

}

private Container c, f;

private PositionableGridLayout l;

private Button b;

private static Button selected;

}