//******************************************************************************
// Javamation.java:	An Applet that plays a series of animation frames and sound
// specified in the HTML page that calls the applet.
//******************************************************************************
import java.applet.*;
import java.awt.*;

//==============================================================================
// Main Class for applet Javamation
//
//==============================================================================
public class Javamation extends Applet implements Runnable
{
	// m_Javamation	is the Thread object for the applet
	private Thread	 m_Javamation = null;

	// The following variables are used to store the values of the
	// parameters input from the HTML page.
	private int m_fps = 5;
	private int m_numImages = 21;
	private String m_imageFile = "pg_a";

    // Parameter names.
	private final String PARAM_fps = "fps";
	private final String PARAM_numImages = "numImages";
	private final String PARAM_imageFile = "imageFile";

	// Use a mediatracker to monitor image file loading
	MediaTracker m_mediaTracker = new MediaTracker(this);

	// variables to store frame information
	int m_nFrameNumber = 0;
	Image m_frame[];

	// AudioClip objects
	AudioClip jabber;
	AudioClip silence;

	// Button to stop animation
	Button m_stopButton = new Button("Stop");

	// Button to rewind animation
	Button m_rewindButton = new Button("Rewind");

	// Button to play animation
	Button m_playButton = new Button("Play");


	// Javamation Class Constructor
	public Javamation()
	{
	}

	// The getAppletInfo() method returns a string describing the applet's
	// author, copyright date, or miscellaneous information.
	public String getAppletInfo()
	{
		return "Name: Javamation\r\n" +
		       "Author: Tom Sephton\r\n" +
		       "Created with Microsoft Visual J++ Version 1.1";
	}

	// The getParameterInfo() method returns an array of strings describing
	// the parameters understood by this applet.
    // Javamation Parameter Information:
    //  { "Name", "Type", "Description" },
	public String[][] getParameterInfo()
	{
		String[][] info =
		{
			{ PARAM_fps, "int", "Frames per second" },
			{ PARAM_numImages, "int", "Total frames in this animation" },
			{ PARAM_imageFile, "String", "Image file base name" },
		};
		return info;		
	}

	// The init() method is called by the AWT when an applet is first loaded or reloaded
	public void init()
	{
		//The following code retrieves the value of each parameter
		// specified with the <PARAM> tag and stores it in a member
		// variable.
		String param;
		// fps: Frames per second
		param = getParameter(PARAM_fps);
		if (param != null)
			m_fps = Integer.parseInt(param);

		// numImages: Total frames in this animation
		param = getParameter(PARAM_numImages);
		if (param != null)
			m_numImages = Integer.parseInt(param);

		// imageFile: Image file base name
		param = getParameter(PARAM_imageFile);
		if (param != null)
			m_imageFile = param;

     	resize(320, 240);

		// Set up a BorderLayout manager
		setLayout(new BorderLayout());

		// Create a Panel to contain the play control buttons
		Panel controlPanel = new Panel();
		controlPanel.setLayout(new FlowLayout());
		controlPanel.add(m_stopButton);
		controlPanel.add(m_rewindButton);
		controlPanel.add(m_playButton);

		// Add the Control Panel to the applet layout
		add("South", controlPanel);
		
		// Load animation image frames
		m_frame = new Image[m_numImages];
		String sImageFile;
		int nImageNum;
		for (int i = 0; i < m_numImages; i++)
		{
			nImageNum = i + 1;
			sImageFile = m_imageFile + ((nImageNum < 10)? "000":"00") + nImageNum + ".jpg";
			m_frame[i] = getImage(getDocumentBase(), sImageFile);

			// add this frame to the mediatracker
			m_mediaTracker.addImage(m_frame[i], 0);
		}
	}

	// destroy() is called when applet is terminating and being unloaded.
	public void destroy()
	{
	}

	// Javamation Paint Handler
	public void paint(Graphics g)
	{
		if (m_mediaTracker.checkAll())
		{
			// see if there was an error
			if (m_mediaTracker.isErrorAny())
			{
				// report the error if any
				g.drawString("Error loading image", 100, 120);
				return;
			}

			// draw the current frame
			g.drawImage(m_frame[m_nFrameNumber], 0, 0, null);

			// update the frame number until the last frame is reached
			m_nFrameNumber++;
			if (m_nFrameNumber > m_numImages)
			{
				m_nFrameNumber = 0;
			}	
		}
		else
		{
			g.drawString("Loading Images...", 100, 100);
		}
	}

	// Update method simply calls paint
	public void update(Graphics g)
	{
		paint(g);
	}

	// Javamation event handler reacts to control buttons
	public boolean handleEvent(Event evt)
	{
		// If the action was a button push...
		if (evt.target instanceof Button)
		{
			// ...check which button was pushed
			switch(evt.id)
			{
			case Event.ACTION_EVENT:
				Button button = (Button)evt.target;
				// If it was the Stop button...
				if(button.getLabel().equals("Stop"))
				{
					stop();
					break;
				}
				// If it was the Rewind button...
				else if(button.getLabel().equals("Rewind"))
				{
					stop();
					m_nFrameNumber = 0;
					repaint();
					break;
				}				
				// If it was the Play button...
				else if(button.getLabel().equals("Play"))
				{
					start();
					break;
				}
			default:
				return false;
			}
			return true;
		}
		else return false;
	}

	// The start() method is called when the page containing the applet
	// first appears on the screen. This method starts execution of the
	// applet's thread.
	public void start()
	{
		if (m_Javamation == null)
		{
			m_Javamation = new Thread(this);
			m_Javamation.start();
		}
	}
	
	// The stop() method is called when the page containing the applet is
	// no longer on the screen or when a button press calls this method.
	// This method stops execution of the applet's thread.
	public void stop()
	{
		if (m_Javamation != null)
		{
			m_Javamation.stop();
			m_Javamation = null;
		}
		else if (m_nFrameNumber == m_numImages)
		{
			m_Javamation.stop();
			m_Javamation = null;
		}
	}

	// The run() method is called when the applet's thread is started.
	// This starts display of animation images by updating frame number then calling repaint.
	// The run() method also loads and plays the sound file connected to the animation.
	public void run()
	{
		try
		{
			// Set the frame number to 0
			m_nFrameNumber = 0;

			// force a repaint
			repaint();

			// force all images to be loaded first
			m_mediaTracker.waitForAll();

			// resize screen to match loaded image size
			resize(m_frame[0].getWidth(null), m_frame[0].getHeight(null));

			// Set up sleep delay time based on frame rate
			int nDelay = 1000/m_fps;

			// Get audio clip that goes with the animation
			String sSoundClip = new String(m_imageFile + ".au");
			AudioClip jabber = getAudioClip(getCodeBase( ), sSoundClip);

			// Play the audio clip
			jabber.play( );
			
			while (true)
			{
				repaint();
				Thread.sleep(nDelay);
			}
		}
		catch (InterruptedException e)
		{
			stop();
		}
	}
}