appletdemo6.java

java程序设计语言源代码

//Example 6 of Chapter 6

import  java.applet.*;
import  java.awt.*;
import  java.awt.event.*;
import  javax.swing.event.*;
import  javax.swing.*;

public  class  AppletDemo6  extends  JApplet
{
	private  AudioClip  currentSound;
	private  JList  choose;
	private  JButton  play, loop, stop;
	private  String  choices[] = { "danger.au", "wrong.wav", "popped.aif" };
	private  int  switchkey = 0;
	
	public  void  init()
	{
		Container  container = getContentPane();
		container.setLayout( new FlowLayout() );
		currentSound = getAudioClip( getDocumentBase(), choices[ 0 ] );
		choose = new JList( choices );
		
		choose.addListSelectionListener
		(
			new  ListSelectionListener()
			{
				public  void  valueChanged(ListSelectionEvent e)
				{
					int  k = -1;
					for(int i=0; i<choices.length; i++)
					{
						if ( choices[ i ]==choose.getSelectedValue()) k = i;
					}
					
					currentSound.stop();
					currentSound = getAudioClip( getDocumentBase(), choices[ k ] );
				}
			}
		);
		container.add( choose );
		
		ButtonHandler handler = new ButtonHandler();
		
		play = new JButton( "Play" );
		play.addActionListener( handler );
		container.add( play );
		
		loop = new JButton( "Loop" );
		loop.addActionListener( handler );
		container.add( loop );
		
		stop = new JButton( "Stop" );
		stop.addActionListener( handler );
		container.add( stop );
	}
	
	public  void  start()
	{
		switch(switchkey)
		{
			case 1:
				currentSound.play();
				play.setSelected( true );
				break;
			case 2:
				currentSound.loop();
				loop.setSelected( true );
				break;
			case 3:
				currentSound.stop();
				stop.setSelected( true );
		}
	}
	
	public  void  stop()
	{
		currentSound.stop();
	}
	
	private  class  ButtonHandler  implements  ActionListener
	{
		public  void  actionPerformed( ActionEvent actionEvent )
		{
			if ( actionEvent.getSource() == play )
			{
				switchkey = 1;
				currentSound.play();
			}
			if ( actionEvent.getSource() == loop )
			{
				switchkey = 2;
				currentSound.loop();
			}
			if ( actionEvent.getSource() == stop )
			{
				switchkey = 3;
				currentSound.stop();
			}
		}
	}
}