//Piano.java

import java.applet.*;

import java.awt.*;

import java.awt.event.*;

 

public Piano extends Applet implements MouseListener,KeyListener,MouseMotionListener

{

    //变量声明

    Image m_ImgUp;//键盘、鼠标松开时显示的键盘图片

    Image m_ImgDown;//键盘、鼠标按下时显示的键盘图片

    AudioClip[] m_AudioClip=new AudioClip[14];

    int[] m_nState=new int[14];

    int m_nOldDownCount=-1;

    final int IMG_WIDTH=17;

    final int IMG_HEIGHT=85;

    final int STATE_UP=0;

    final int STATE_DOWN=1;

    //初始化小程序

    public void init()

    {

        for(int i=0;i<14;i++)

        {

            m_nState[i]=0;

        }

        m_ImgUp=getImage(getDocumentBase(),"img/up.gif");

        m_ImgDown=getImage(getDocumentBase(),"img/down.gif");

        MediaTracker mediaTracker=new MediaTracker(this);

        mediaTracker.addImage(m_ImgUp,0);

        mediaTracker.addImage(m_ImgDown,1);

        try

        {

            mediaTracker.waitForID(0);

        }

        catch(Exception e)

        {

            System.out.println("m_ImgUp is not loaded right");

        }

        try

        {

            mediaTracker.waitForID(1);

        }

        catch(Exception e)

        {

            System.out.println("m_ImgDown is not loaded right");

        }

 

        for(int i=0;i<14;i++)

        {

            String sUrl=new String("au/"+i+".au");

            m_AudioClip[i]=getAudioClip(getCodeBase(),sUrl);

        }

        addKeyListener(this);

        addMouseListener(this);

        addMouseMotionListener(this);

    }

 

 

    //画屏函数

    public void paint(Graphics g)

    {

        for(int i=0;i<14;i++)

        {

            switch(m_nState[i])

            {

                case STATE_UP:

                    g.drawImage(m_ImgUp,i*IMG_WIDTH,0,this);

                    break;

                case STATE_DOWN:

                    g.drawImage(m_ImgDown,i*IMG_WIDTH,0,this);

                    break;

            }

 

        }

    }

 

 

    //主函数

    public static void main(String[] args)

    {

        Frame frame=new Frame();

        Piano piano=new Piano();

        frame.add(piano);

        Dimension dimension=new Dimension(40,200);

        frame.setSize(dimension);

        frame.addWindowListener(new WindowAdapter()

        {

            public void windowClosing(WindowEvent e)

            {

                       System.exit(0);

            }

       });

        frame.setVisible(true);

        frame.repaint() ;

    }

    void showSound(int nCount)

    {

        m_AudioClip[nCount].play();

    }

    

 

 

 //响应点击鼠标

    public void mouseClicked(MouseEvent e)

    {

            int nMouseCount=e.getClickCount();

    }

    //响应鼠标进入

    public void mouseEntered(MouseEvent e)

    {

    }

    //响应鼠标退出

    public void mouseExited(MouseEvent e)

    {

        if(m_nOldDownCount!=-1)m_nState[m_nOldDownCount]=STATE_UP;

        m_nOldDownCount=-1;

    }

    //响应按下鼠标

    public void mousePressed(MouseEvent e)

    {

        int nX=e.getX();

        int nY=e.getY();

 

        int nCount=nX/IMG_WIDTH;

        m_nState[nCount]=STATE_DOWN;

        showSound(nCount);

        m_nOldDownCount=nCount;

        Graphics g=getGraphics();

        g.drawImage(m_ImgDown,nCount*IMG_WIDTH,0,this);

    }

    //响应松开鼠标

    public void mouseReleased(MouseEvent e)

    {

        int nX=e.getX();

        int nY=e.getY();

        int nCount=nX/IMG_WIDTH;

        m_nState[nCount]=STATE_UP;

        m_nOldDownCount=-1;

        Graphics g=getGraphics();

        g.drawImage(m_ImgUp,nCount*IMG_WIDTH,0,this);

    }

 

 

 //响应按下键盘

    public void keyPressed(KeyEvent e)

    {

        int nKeyCode=e.getKeyCode();

        String sKeyName=e.getKeyText(nKeyCode);

        boolean bControlDown=e.isControlDown();

 

        int nCount=-1;

        switch(nKeyCode)

        {

            case KeyEvent.VK_1:

                nCount=0;

                break;

            case KeyEvent.VK_2:

                nCount=1;

                break;

            case KeyEvent.VK_3:

                nCount=2;

                break;

            case KeyEvent.VK_4:

                nCount=3;

                break;

            case KeyEvent.VK_5:

                nCount=4;

                break;

            case KeyEvent.VK_6:

                nCount=5;

                break;

            case KeyEvent.VK_7:

                nCount=6;

                break;

            default:

                return;

        }

        if(bControlDown)nCount=nCount+7;

        setPianoKeyDown(nCount);

        showSound(nCount);

        Graphics g=getGraphics();

        g.drawImage(m_ImgDown,nCount*IMG_WIDTH,0,this);

 

    }

 

 

  public void keyTyped(KeyEvent e)
       {
       }

       void setPianoKeyDown(int nCount)
       {
          for(int i=0;i<14;i++)
          {
              m_nState[i]=STATE_UP;
          }
          m_nState[nCount]=STATE_DOWN;
       }
       void setAllPianoKeyUp()
       {
           for(int i=0;i<14;i++)
           {
              m_nState[i]=STATE_UP;
           }
       }

    //响应拖动鼠标
    public void mouseDragged(MouseEvent e)
    {
        int nX=e.getX();
        int nY=e.getY();
        System.out.println("鼠标拖动到：x="+nX+"   y="+nY);
        int m_nTempCount=nX/IMG_WIDTH;
        if(m_nTempCount==m_nOldDownCount)return;
        m_nState[m_nTempCount]=STATE_DOWN;
        m_nState[m_nOldDownCount]=STATE_UP;
        showSound(m_nTempCount);
        Graphics g=getGraphics();
        g.drawImage(m_ImgDown,m_nTempCount*IMG_WIDTH,0,this);
        g.drawImage(m_ImgUp,m_nOldDownCount*IMG_WIDTH,0,this);
        m_nOldDownCount=m_nTempCount;
    }

    //响应移动鼠标
    public void mouseMoved(MouseEvent e)
    {
        int nX=e.getX();
        int nY=e.getY();
        System.out.println("鼠标移动到：x="+nX+"   y="+nY);

    }
    }

 

 

 

 

 

//July/整理/06.09/。