import java.awt.*;
import java.applet.*;
import java.awt.event.*;
public class ActiveImages extends Applet implements Runnable,ActionListener
{
    Image iImages[];                     //圖像數組
    Thread aThread;
    int iFrame;                          //圖像數組下標
    int sleeptime;                       //參數,線程sleep時間
    String graphfile;                    //圖片文件名
    int graphcount;                      //圖片張數
    AudioClip au;                        //定義一個聲音對象
    Button b1,b2;
    public void init() 
    {
        int i,j;
        iFrame=0;
        aThread=null;
        sleeptime=Integer.parseInt(getParameter("sleeptime"));
        graphfile = getParameter("graphfile");
        graphcount = Integer.parseInt(getParameter("graphcount"));
        iImages = new Image[graphcount];
        String fname = graphfile;
        j = fname.indexOf(".");
        for (i=0;i<graphcount;i++)
        {
            fname = fname.substring(0,j-1)+i+fname.substring(j);
            iImages[i] = getImage(getDocumentBase(),"Images/"+fname);
        }
        au=getAudioClip(getDocumentBase(),"Wav/Sound.wav");
        au.play();                       //播放一次聲音文件
        Panel p1 = new Panel();
        b1 = new Button("Start");
        b2 = new Button("Stop");
        p1.add(b1);
        p1.add(b2);
        b1.addActionListener(this);
        b2.addActionListener(this);
        setLayout(new BorderLayout());
        add(p1,"South");
    }
    public void start() 
    {
        if (aThread == null) 
        {
            aThread = new Thread(this);
            aThread.start();             //線程啟動
            b1.setEnabled(false);
        }
    }
    public void stop() 
    {
        if (aThread != null) 
        {
            aThread.interrupt();         //線程中斷
            aThread = null;
            au.stop();                   //停止播放聲音文件
        }
    }
    public void run() 
    {
        while (true) 
        {
            iFrame++;
            iFrame %= (iImages.length);  //下一幅圖像的下標
            repaint();
            try 
            {
                Thread.sleep(sleeptime);
            }
            catch (InterruptedException e) 
            {                            //中斷時拋出
                break;                   //退出循環
            }
        }
    }
    public void update(Graphics g)
    {
        g.drawImage(iImages[iFrame],0,0,this);
    }
    public void actionPerformed(ActionEvent e)
    {
        if ((e.getSource()==b1) && (aThread == null) )
        {                                //單擊Start按鈕時觸發
            aThread = new Thread(this);
            aThread.start();             //線程啟動
            b1.setEnabled(false);
            b2.setEnabled(true);
            au.loop();                   //循環播放聲音文件
        }
        if ((e.getSource()==b2) && (aThread != null) )
        {                                //單擊Stop按鈕時觸發
            aThread.interrupt();         //線程中斷
            aThread = null;
            b1.setEnabled(true);
            b2.setEnabled(false);
            au.stop();                   //停止播放聲音文件
        }
    }
}