//******************************************************************************
// anim.java:	Applet
//
//******************************************************************************
import java.applet.*;
import java.awt.*;

//==============================================================================
// Main Class for applet anim
//
//==============================================================================
public class anim extends Applet implements Runnable
{
	// THREAD SUPPORT:
	//		m_anim	is the Thread object for the applet
	//--------------------------------------------------------------------------
	Thread	 m_anim = null;

	private Graphics	m_mainScreen;
	private Graphics	m_bufferGraphic;
	private Image		m_bufferImage;
	private Image		m_pic;
	Dimension			m_dimImage;

	private int 		m_nCurrImage;
	private int 		m_nImgWidth  = 0;
	private int 		m_nImgHeight = 0;
	private boolean		m_fAllLoaded = false;
	private int			x = 0;
	private int			y = 0;
	private int			x_direction = 1;
	private int			y_direction = 1;



	// anim Class Constructor
	//--------------------------------------------------------------------------
	public anim()
	{
		// TODO: Add constructor code here
	}

	// APPLET INFO SUPPORT:
	//		The getAppletInfo() method returns a string describing the applet's
	// author, copyright date, or miscellaneous information.
    //--------------------------------------------------------------------------
	public String getAppletInfo()
	{
		return "Name: anim\r\n" +
		       "Author: George Macdonald\r\n";
	}


	// The init() method is called by the AWT when an applet is first loaded or
	// reloaded.  Override this method to perform whatever initialization your
	// applet needs, such as initializing data structures, loading images or
	// fonts, creating frame windows, setting the layout manager, or adding UI
	// components.
    //--------------------------------------------------------------------------
	public void init()
	{
		resize(320, 240);
	}

	public void destroy()
	{
	}

    // ANIMATION SUPPORT:
    //		Displays the image at the correct location 
    private void displayImage(Graphics g)
	{
		if (!m_fAllLoaded)
			return;

		// Draw Image 
		g.drawImage(m_pic, x, y, null);

		// Update x and change direction if necessary
		if (x > (size().width - m_nImgWidth))
			x_direction = -1;

		if (x < 0)
			x_direction = 1;

		x += x_direction;

		// Update y and change direction if necessary
		if (y > (size().height - m_nImgHeight))
			y_direction = -1;

		if (y < 0)
			y_direction = 1;

		y += y_direction;
	}

	// anim Paint Handler
	//--------------------------------------------------------------------------
	public void paint(Graphics g)
	{
		if (m_fAllLoaded)
		{
			// Check that the image is the right size
			ResizeImage();

			// Clear the buffer
			m_bufferGraphic.clearRect(0, 0, 320, 240);

			// Display the image on the buffer
			displayImage(m_bufferGraphic);

			// Copy the buffer onto the main screen
			g.drawImage(m_bufferImage, 0, 0, null);
		}
		else
			g.drawString("Loading images...", 10, 20);
	}

	//		The start() method is called when the page containing the applet
	// first appears on the screen. 
	public void start()
	{
		if (m_anim == null)
		{
			m_anim = new Thread(this);
			m_anim.start();
		}
	}
	
	//		The stop() method is called when the page containing the applet is
	// no longer on the screen. 
	public void stop()
	{
		if (m_anim != null)
		{
			m_anim.stop();
			m_anim = null;
		}
	}

	// THREAD SUPPORT
	//		The run() method is called when the applet's thread is started. If
	// your applet performs any ongoing activities without waiting for user
	// input, the code for implementing that behavior typically goes here. For
	// example, for an applet that performs animation, the run() method controls
	// the display of images.
	//--------------------------------------------------------------------------
	public void run()
	{
		m_nCurrImage = 0;
		
		// If re-entering the page, then the images have already been loaded.
		// m_fAllLoaded == TRUE.
		//----------------------------------------------------------------------
        if (!m_fAllLoaded)
		{
    		repaint();
    		m_mainScreen = getGraphics();
   
    		// Load in all the images
    		//------------------------------------------------------------------
    		MediaTracker tracker = new MediaTracker(this);
    		String strImage;

			m_pic = getImage(getDocumentBase(), "../graphic/paint/paint01.GIF");
            tracker.addImage(m_pic, 0);
 

    		// Wait until all images are fully loaded
    		//------------------------------------------------------------------
			try
			{
				tracker.waitForAll();
				m_fAllLoaded = !tracker.isErrorAny();
			}
			catch (InterruptedException e)
			{
			}
			
			if (!m_fAllLoaded)
			{
			    stop();
			    m_mainScreen.drawString("Error loading images!", 10, 40);
			    return;
			}
			

			// Get the image width and height
			m_nImgWidth  = m_pic.getWidth(this);
		    m_nImgHeight = m_pic.getHeight(this);
        }		
		repaint();

		while (true)
		{
			try
			{
				paint(m_mainScreen);
			}
			catch (InterruptedException e)
			{
				stop();
			}
		}
	}

	private void ResizeImage()
	{
		// get the window size
		Dimension dim = size();
		int nWidth = dim.width;
		int nHeight = dim.height;

		if (m_dimImage != null &&
			m_dimImage.width == nWidth &&
			m_dimImage.height == nHeight)
		{
			return;
		}

		m_dimImage = new Dimension(nWidth, nHeight);
		m_bufferImage = createImage(nWidth, nHeight);
		m_bufferGraphic = m_bufferImage.getGraphics();
	}


	// MOUSE SUPPORT:
	//		The mouseDown() method is called if the mouse button is pressed
	// while the mouse cursor is over the applet's portion of the screen.
	//--------------------------------------------------------------------------
	public boolean mouseDown(Event evt, int x, int y)
	{
		// TODO: Place applet mouseDown code here
		return true;
	}

	// MOUSE SUPPORT:
	//		The mouseUp() method is called if the mouse button is released
	// while the mouse cursor is over the applet's portion of the screen.
	//--------------------------------------------------------------------------
	public boolean mouseUp(Event evt, int x, int y)
	{
		// TODO: Place applet mouseUp code here
		return true;
	}

	// MOUSE SUPPORT:
	//		The mouseDrag() method is called if the mouse cursor moves over the
	// applet's portion of the screen while the mouse button is being held down.
	//--------------------------------------------------------------------------
	public boolean mouseDrag(Event evt, int x, int y)
	{
		// TODO: Place applet mouseDrag code here
		return true;
	}

	// MOUSE SUPPORT:
	//		The mouseMove() method is called if the mouse cursor moves over the
	// applet's portion of the screen and the mouse button isn't being held down.
	//--------------------------------------------------------------------------
	public boolean mouseMove(Event evt, int x, int y)
	{
		// TODO: Place applet mouseMove code here
		return true;
	}

	// MOUSE SUPPORT:
	//		The mouseEnter() method is called if the mouse cursor enters the
	// applet's portion of the screen.
	//--------------------------------------------------------------------------
	public boolean mouseEnter(Event evt, int x, int y)
	{
		// TODO: Place applet mouseEnter code here
		return true;
	}

	// MOUSE SUPPORT:
	//		The mouseExit() method is called if the mouse cursor leaves the
	// applet's portion of the screen.
 	//--------------------------------------------------------------------------
	public boolean mouseExit(Event evt, int x, int y)
	{
		// TODO: Place applet mouseExit code here
		return true;
	}


	// TODO: Place additional applet code here

}