// Anim - stripped-down animation applet
//
// Based on Animator.java, but a bunch of bells and whistles have
// been removed:
//  - no sound support
//  - no background image
//  - no startup image
//  - no positions
//  - no variable pauses
//  - no MediaTracker
//  - always repeats
//
// By Jef Poskanzer
//
// Original Animator.java by Herb Jellinek
//
// Copyright (c) 1994-1995 Sun Microsystems, Inc. All Rights Reserved.
//
// Permission to use, copy, modify, and distribute this software
// and its documentation for NON-COMMERCIAL or COMMERCIAL purposes and
// without fee is hereby granted.
// Please refer to the file http://java.sun.com/copy_trademarks.html
// for further important copyright and trademark information and to
// http://java.sun.com/licensing.html for further important licensing
// information for the Java (tm) Technology.
//
// SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
// THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
// TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
// PARTICULAR PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR
// ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
// DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
//
// THIS SOFTWARE IS NOT DESIGNED OR INTENDED FOR USE OR RESALE AS ON-LINE
// CONTROL EQUIPMENT IN HAZARDOUS ENVIRONMENTS REQUIRING FAIL-SAFE
// PERFORMANCE, SUCH AS IN THE OPERATION OF NUCLEAR FACILITIES, AIRCRAFT
// NAVIGATION OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL, DIRECT LIFE
// SUPPORT MACHINES, OR WEAPONS SYSTEMS, IN WHICH THE FAILURE OF THE
// SOFTWARE COULD LEAD DIRECTLY TO DEATH, PERSONAL INJURY, OR SEVERE
// PHYSICAL OR ENVIRONMENTAL DAMAGE ("HIGH RISK ACTIVITIES").  SUN
// SPECIFICALLY DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR
// HIGH RISK ACTIVITIES.

import java.applet.*;
import java.awt.*;
import java.awt.image.*;
import java.util.*;
import java.net.*;

// An applet that plays a sequence of images as a loop.
public class Anim extends Applet implements Runnable
    {

    // The directory or URL from which the images are loaded.
    URL imageSource = null;

    // How many images.
    int frameCount = 0;

    // The image URLs.
    URL[] imageURLs;

    // The images.
    Image[] images;

    // All images combined into one.
    Image combinedImage = null;

    // The thread animating the images.
    Thread thread = null;

    // The default number of milliseconds to wait between frames.
    public static final int defaultPause = 3900;

    // The global delay between images, which can be overridden by
    // the PAUSE parameter.
    int globalPause = defaultPause;

    // The current loop slot - index into 'images.'
    int frameNum;

    /// Applet info.
    public String getAppletInfo()
	{
	return getClass().getName() +
", by Jef Poskanzer <jef@mail.acme.com> - stripped-down version of Animator v1.5, by Herb Jellinek";
	}

    // Parameter info.
    public String[][] getParameterInfo()
	{
	String[][] info =
	    {
            { "pause",         "int", "milliseconds between frames" },
            { "imagesource",   "URL", "directory where images live" },
            { "startimage",    "int", "first index" },
            { "endimage",      "int", "last index" },
            { "namepattern",   "URL", "used to generate indexed names" },
            { "combinedimage", "URL", "all image frames combined into one" },
            { "combinedcount", "int", "how many frames in the combined image" },
            };
        return info;
        }

    // Fetch the images.
    void fetchImages()
	{
	images = new Image[frameCount];
	for ( int i = 0; i < frameCount; ++i )
	    images[i] = getImage( imageURLs[i] );
	}

    // Substitute an integer some number of times in a string, subject to
    // parameter strings embedded in the string.
    // Parameter strings:
    //   %N - substitute the integer as is, with no padding.
    //   %<digit>, for example %5 - substitute the integer left-padded with
    //        zeros to <digits> digits wide.
    //   %% - substitute a '%' here.
    // @param inStr the String to substitute within
    // @param theInt the int to substitute.
    String doSubst( String inStr, int theInt )
	{
	String padStr = "0000000000";
	int length = inStr.length();
	StringBuffer result = new StringBuffer( length );

	for ( int i = 0; i < length; )
	    {
	    char ch = inStr.charAt( i );
	    if ( ch == '%' )
		{
		++i;
		if ( i == length )
		    result.append(ch);
		else
		    {
		    ch = inStr.charAt( i );
		    if ( ch == 'N' )
			{
			// Just stick in the number, unmolested.
			result.append( theInt + "" );
			++i;
			}
		    else
			{
			int pad = Character.digit( ch, 10 );
			if ( pad != -1 )
			    {
			    // We've got a width value.
			    String numStr = theInt + "";
			    String scr = padStr + numStr;
			    result.append(
				scr.substring( scr.length() - pad ) );
			    ++i;
			    }
			else
			    {
			    result.append( ch );
			    ++i;
			    }
			}
		    }
		}
	    else
		{
		result.append( ch );
		++i;
		}
	    }
	return result.toString();
	}

    // Create a range of image URLs.
    void prepareImageURLs( int startImage, int endImage, String pattern )
	throws MalformedURLException
	{
	frameCount = Math.abs( endImage - startImage ) + 1;
	imageURLs = new URL[frameCount];
	if ( pattern == null )
	    pattern = "T%N.gif";
	int j = 0;
	if ( startImage > endImage )
	    {
	    for ( int i = startImage; i >= endImage; --i )
		imageURLs[j++] =
		    new URL( imageSource, doSubst( pattern, i ) );
	    }
	else
	    {
	    for ( int i = startImage; i <= endImage; ++i)
		imageURLs[j++] =
		    new URL( imageSource, doSubst( pattern, i ) );
	    }
	}


    // Initialize the applet.  Get parameters.
    public void init()
	{
	Acme.GuiUtils.handleBgcolor( this );

	try
	    {
	    String param = getParameter( "imagesource" );
	    imageSource =
		( param == null ) ?
		    getDocumentBase() :
		    new URL( getDocumentBase(), param + "/" );

	    param = getParameter( "pause" );
	    globalPause =
		( param == null ) ?
		    defaultPause :
		    Integer.parseInt( param );

	    int startImage = 1;
	    int endImage = 1;
	    param = getParameter( "startimage" );
	    if ( param != null )
		startImage = Integer.parseInt( param );
	    param = getParameter( "endimage" );
	    if ( param != null )
		endImage = Integer.parseInt( param );
	    param = getParameter( "combinedimages" );
	    if ( param != null )
		{
		URL url = new URL( imageSource, param );
		combinedImage = getImage( url );
		param = getParameter( "combinedcount" );
		if ( param != null )
		    frameCount = Integer.parseInt( param );
		else
		    showError(
			"combinedcount required with combinedimages" );
		}
	    else
		{
		param = getParameter( "namepattern" );
		prepareImageURLs( startImage, endImage, param );
		fetchImages();
		}
	    }
	catch ( Exception e ) 
	    {
	    showError( "Anim initialization error: " + e );
	    }

	frameNum = 0;
	}

    void showError( String errorMsg )
	{
	showStatus( errorMsg );
	System.err.println( errorMsg );
	}


    /// Start the applet by forking an animation thread.
    public void start()
	{
        if ( thread == null )
	    {
            thread = new Thread( this );
            thread.start();
	    }
	}

    /// Called when the applet should stop itself.
    public void stop()
	{
        if ( thread != null )
	    {
	    // Stop the thread.
	    if ( thread.isAlive() )
		thread.stop();
	    thread = null;
	    }
	}

    
    /// Event handler.
    public boolean handleEvent( Event event )
	{
	if ( event.id == Event.MOUSE_UP )
	    {
	    // Toggle the run state.
	    if ( thread == null )
		start();
	    else
		stop();
	    return true;
	    }
	return super.handleEvent( event );
	}


    /// Run the animation. This method is called by class Thread.
    public synchronized void run()
	{
	Thread me = Thread.currentThread();
	me.setPriority( Thread.MIN_PRIORITY );

	if ( frameCount >= 1 )
	    {
	    while ( thread == me )
		{
		if ( frameNum >= frameCount )
		    frameNum = 0;
		repaint();
		try
		    {
		    wait( globalPause );
		    }
		catch ( InterruptedException e ) {}
		++frameNum;
		}
	    }
	}

    // The default update() clears the background and then calls paint().
    // This one doesn't clear the background.
    public void update( Graphics graphics )
	{
	paint( graphics );
	}

    Image offScrImage = null;
    int offScrWidth = 0;
    int offScrHeight = 0;
    Graphics offScrGC;

    // Called when the applet should paint itself.
    public synchronized void paint( Graphics graphics )
	{
	if ( combinedImage != null )
	    paintCombined( graphics );
	else if ( images != null )
	    paintSeparate( graphics );
	}

    // Paint routine for combined images.
    public void paintCombined( Graphics graphics )
	{
	int width = combinedImage.getWidth( this );
	int height = combinedImage.getHeight( this );
	if ( width == -1 || height == -1 )
	    {
	    brokenImage( graphics, this );
	    return;
	    }
	width /= frameCount;
	checkOffScr( width, height );
	offScrGC.fillRect( 0, 0, offScrWidth, offScrHeight );
	offScrGC.drawImage( combinedImage, -frameNum * width, 0, this );
	graphics.drawImage( offScrImage, 0, 0, this );
	}
    
    // Paint routine for separate images.
    public void paintSeparate( Graphics graphics )
	{
	Image img = images[frameNum];
	if ( img == null )
	    {
	    brokenImage( graphics, this );
	    return;
	    }
	int width = img.getWidth( this );
	int height = img.getHeight( this );
	if ( width == -1 || height == -1 )
	    {
	    brokenImage( graphics, this );
	    return;
	    }
	checkOffScr( width, height );
	offScrGC.fillRect( 0, 0, offScrWidth, offScrHeight );
	offScrGC.drawImage( img, 0, 0, this );
	graphics.drawImage( offScrImage, 0, 0, this );
	}
    
    int brokenCount = 0;
    void brokenImage( Graphics graphics, Component comp )
	{
	++brokenCount;
	if ( brokenCount > 10 )
	    Acme.GuiUtils.drawImage(
		graphics, comp, Acme.GuiUtils.brokenIcon( comp ) );
	}

    // Make sure we have an off-screen image and it's big enough.
    void checkOffScr( int width, int height )
	{
	if ( offScrImage == null ||
	     width > offScrWidth || height > offScrHeight )
	    {
	    if ( width > offScrWidth ) offScrWidth = width;
	    if ( height > offScrHeight ) offScrHeight = height;
	    offScrImage = createImage( offScrWidth, offScrHeight );
	    offScrGC = offScrImage.getGraphics();
	    offScrGC.setColor( getBackground() );
	    }
	}

    }