/**
 * Applet to play audio URL
 *
 * R. Perry, March 2005
 */

import java.io.*;
import java.net.*;
import java.awt.*;
import java.awt.event.*;
import java.applet.*;

public class audio extends Applet
implements ActionListener
{
 // GUI
 //
  Button bstart, bstop;
  TextArea output;

 // network
 //
  String base, file;
  URL url;
  AudioClip a;

  public void init()
  {
    output = new TextArea();
    output.setEditable( false);
    output.setBackground( Color.white);

    bstart = new Button( "Start");
    bstop = new Button( "Stop");

    GridBagLayout gridBag = new GridBagLayout();
    setLayout( gridBag);
    GridBagConstraints c = new GridBagConstraints();

    c.fill = GridBagConstraints.BOTH;
    c.gridwidth = GridBagConstraints.REMAINDER;
    c.weightx = 1.0;
    c.weighty = 1.0;
    gridBag.setConstraints( output, c);
    add( output);

    c.fill = GridBagConstraints.HORIZONTAL;
    c.weighty = 0.0;

    c.gridwidth = 1;
    gridBag.setConstraints( bstart, c);
    add( bstart);
    gridBag.setConstraints( bstop, c);
    add( bstop);

    validate();

    bstart.addActionListener(this);
    bstop.addActionListener(this);
  }

  public void start()
  {
    bstart.setEnabled( false);
    bstop.setEnabled( true);

    try
    {
      String newfile = getParameter( "file");

      if( base == null)
      {
	base = getParameter( "base");
	output.append( "Base for audio files is:\n" + base + "\n");
      }

      if( file == null || file.compareTo(newfile) != 0)
      {
	file = newfile;
	output.append( "File is: " + file + "\n");
	if( url == null) url = new URL( base);
        a = getAudioClip( url, file);
      }

      output.append( "Playing...\n");
      a.loop();
    }
    catch (Exception ex)
    {
      ByteArrayOutputStream error = new ByteArrayOutputStream();
      ex.printStackTrace( new PrintStream( error));
      output.append( error.toString());
    }
  }


  public void stop()
  {
    if( a != null) a.stop();
    bstart.setEnabled( true);
    bstop.setEnabled( false);
  }


 // handle action events
 //
  public void actionPerformed( ActionEvent e)
  {
    Object source = e.getSource();

    try
    {
      if( source == bstart)
      {
	if( a != null) a.stop();
	output.append( "Playing...\n");
	if( a != null) a.loop();
	bstart.setEnabled( false);
	bstop.setEnabled( true);
      }
      else if( source == bstop)
      {
	output.append( "Stop.\n");
	stop();
      }
    }
    catch (Exception ex)
    {
      ByteArrayOutputStream error = new ByteArrayOutputStream();
      ex.printStackTrace( new PrintStream( error));
      output.append( error.toString());
    }
  } 

}