package Puzzle;

import java.awt.*;
import java.awt.event.*;


/**
 * PuzzleTile - a class that mimics a button for use
 *              in the 15-puzzle (actually N-puzzle)
 */

public class PuzzleTile extends Canvas
{
    /**
     * Constructs a PuzzleTile with the specified label
     * @param label the label shown on the PuzzleTile
     */
    
    public PuzzleTile(String label)
    {
	myLabel = label;
	enableEvents(AWTEvent.MOUSE_EVENT_MASK);   // get mouse events
    }

    /**
     * paints the PuzzleTile
     * override this function for different appearance
     */
    
    public void paint(Graphics g)
    {
	if (myLabel != PuzzleConsts.BLANK)
	{
	    g.setColor(Color.blue);
	    g.fill3DRect(0,0,SIZE,SIZE,true);
	    g.setColor(Color.yellow);
	    g.fill3DRect(OFFSET,OFFSET,SIZE,SIZE,true);
	    g.setColor(Color.black);
	}
	else
	{
	    g.setColor(getBackground());
	    g.fill3DRect(0,0,SIZE+OFFSET,SIZE+OFFSET,true);
	}
	g.drawString(myLabel,OFFSET + SIZE/2,OFFSET + SIZE/2);	    
    }

    /** 
     * the preferred size of the PuzzleTile
     * @return Dimension that encapsulates the preferred size
     */
    
    public Dimension getPreferredSize()
    {
	return new Dimension(SIZE+OFFSET+2,SIZE+OFFSET+2);
    }

    /**
     * if mouse is released, generate an action event
     */
    
    public void processMouseEvent(MouseEvent ev)
    {
	switch (ev.getID())
	{
	    case MouseEvent.MOUSE_RELEASED:
		if (myListener != null)
		{
		    myListener.actionPerformed(new ActionEvent(
			this,ActionEvent.ACTION_PERFORMED,myLabel));
		}
		break;
		
	    case MouseEvent.MOUSE_PRESSED:
		break;
		
	    case MouseEvent.MOUSE_ENTERED:
		break;
		
 	    case MouseEvent.MOUSE_EXITED:
		break;
	}
	super.processMouseEvent(ev);
    }

    /**
     * Adds an action listener to the PuzzleTile
     * @param listener the action listener added
     */
    
    public void addActionListener(ActionListener listener)
    {
	myListener =
	    AWTEventMulticaster.add(myListener,listener);
	enableEvents(AWTEvent.MOUSE_EVENT_MASK);
    }

    /**
     * Removes an action listener from the PuzzleTile
     * @param listener the action listener to remove
     */
    
    public void removeActionListner(ActionListener listener)
    {
	myListener = AWTEventMulticaster.remove(myListener,listener);
    }

    /**
     * set the label to the specified string
     * @param label the label displayed
     */
    
    void setLabel(String label)
    {
	myLabel = label;
    }
    
    /**
     * returns label associated with tile
     * @return String representation of tile label
     */
    
    public String getLabel()
    {
	return myLabel;
    }

    public String paramString()
    {
	return "label " + myLabel;
    }

    private ActionListener myListener;
    private String myLabel;
    
    protected final static int SIZE = 50;
    protected final static int OFFSET = 1;
}