/**
 * Light is a JavaBean that displays a status light (it can blink, if
 *ænecessary).  Adapted from Mastering Java Beans.
 *
 * Copyright &copy; 1996-1998 Martin Minow. All Rights Reserved.<p>
 *
 * Permission to use, copy, modify, and redistribute this software and its
 * documentation for personal, non-commercial use is hereby granted provided that
 * this copyright notice and appropriate documentation appears in all copies. This
 * software may not be distributed for fee or as part of commercial, "shareware,"
 * and/or not-for-profit endevors including, but not limited to, CD-ROM collections,
 * online databases, and subscription services without specific license.<p>
 *
 * @author <a href="mailto:minow@apple.com">Martin Minow</a>
 * @version 1.0
 * Set tabs every 4 characters.
 */
import java.awt.*;
import java.awt.event.*;
import java.beans.*;

public class Light extends java.awt.Canvas
		implements java.io.Serializable,
					ActionListener,
					Runnable
{
	protected Color				lightColor;
	protected Color				lightOnColor;
	protected Color				lightOffColor;
	protected int				pulseTimeMSec;		/* Zero means no blink	*/
	protected boolean			lightOn;
	protected boolean			showCounter;
	protected int				counter;
	protected Thread			runner;
	protected ActionListener	actionListeners;
	
	public static final int		defaultPulseTimeMSec	= 800;
	
	/*
	 * Constructors
	 */
	public Light()
	{
		this(Color.green);
	}
	public Light(
			Color			lightColor
		)
	{
		this(lightColor, false, defaultPulseTimeMSec);
	}
	public Light(
			Color			lightColor,
			boolean			showCounter
		)
	{
		this(lightColor, showCounter, defaultPulseTimeMSec);
	}
	public Light(
			Color			lightColor,
			int				pulseTimeMSec
		)
	{
		this(lightColor, false, pulseTimeMSec);
	}
	public Light(
			Color			lightColor,
			boolean			showCounter,
			int				pulseTimeMSec
		)
	{
		this.pulseTimeMSec	= pulseTimeMSec;
		this.lightOn		= false;
		this.showCounter	= showCounter;
		actionListeners		= null;
		setLightColor(lightColor);
		resetCounter();
	}
	/*
	 * Implement the runnable interface
	 */
	public void run()
	{
		try {
			Thread.sleep(pulseTimeMSec);
		}
		catch (InterruptedException e) { };
		setLightOn(false);
		runner = null;	/* Kill the thread	*/
	}
	/*
	 * Manage the lightOn property
	 */
	public void setLightOn(
			boolean			value
		)
	{
		if (showCounter && value) {
			++counter;
		}
		lightOn = value;
		repaint();
		/*
		 * If the light is now on and it's an "auto-off" light,
		 * start a timer to turn it off after the pulse time.
		 */
		if (lightOn && pulseTimeMSec > 0 && runner == null) {
			runner = new Thread(this);
			runner.setName("Light");
			runner.start();
		}
	}
	public boolean isLightOn()
	{
		return (lightOn);
	}
	/*
	 * Manage the CounterOn property.
	 */
	public void setShowCounter(
			boolean			value
		)
	{
		showCounter	= value;
	}
	public boolean isShowCounter()
	{
		return (showCounter);
	}
	/*
	 * Mange the LightColor property
	 */
	public void setLightColor(
			Color			value
		)
	{
		lightColor		= value;
		lightOnColor	= lightColor.brighter();
		lightOffColor	= lightColor.darker().darker();
		repaint();
	}
	public Color getLightColor()
	{
		return (lightColor);
	}
	/*
	 * Manage the PulseTime property.
	 */
	public void setPulseTime(
			int				value
		)
	{
		this.pulseTimeMSec	= value;
	}
	public int getPulseTime()
	{
		return (pulseTimeMSec);
	}
	/*
	 * Manage the Count property (This version does not range-limit
	 * the counter value).
	 */
	public void setCounter(
			int				value
		)
	{
		counter = value;
	}
	public int getCounter()
	{
		return (counter);
	}
	public void resetCounter()
	{
		counter = 0;
	}
	/*
	 * Light is an ActionListener. When it receives an ActionEvent,
	 * the light comes on, and the event is passed through to
	 * other listeners, so that the light can act as a probe for
	 * unicast action sources as wel as multicast.
	 */
	public void actionPerformed(
			ActionEvent		event
		)
	{
		setLightOn(true);
		if (actionListeners != null) {
			actionListeners.actionPerformed(event);
		}
	}
	/*
	 * Manage the ActionListener event chain.
	 */
	public void removeActionListener(
			ActionListener	listener
		)
	{
		actionListeners = AWTEventMulticaster.add(actionListeners, listener);
	}
	public void addActionListener(
			ActionListener	listener
		)
	{
		actionListeners = AWTEventMulticaster.remove(actionListeners, listener);
	}
	/*
	 * Draw the light
	 */
	public void paint(
			Graphics		g
		)
	{
		Dimension size		= getSize();
		int		width		= size.width;
		int		height		= size.height;
		if (lightOn) {
			g.setColor(lightOnColor);
			g.fillOval(2, 2, width - 5, height - 5);
		}
		else {
			g.setColor(lightOffColor);
			g.fillOval(3, 3, width - 7, height - 7);
		}
		/*
		 * Add a rectangular outline
		 */
		g.setColor(Color.gray);
		g.drawRect(0, 0, width - 1, height - 1);
		/*
		 * If the event counter is enabled, draw that, too.
		 */
		if (showCounter) {
			g.setColor((lightOn) ? Color.black : Color.white);
			String text		= String.valueOf(counter % 100);
			FontMetrics fm	= g.getFontMetrics();
			g.drawString(
					text,
					(width - fm.stringWidth(text)) / 2,
					(height / 2) + fm.getDescent()
				);
		}
	}
	public Dimension preferredSize()
	{
		return (new Dimension(25, 25));
	}
	public Dimension getPreferredSize()
	{
		return (preferredSize());
	}
}