import java.applet.*;
import java.awt.*;
import java.awt.image.*;
import java.awt.event.*;
public class hoshi extends Applet implements AdjustmentListener,Runnable {
    Label ltkei = new Label("星の大きさ",Label.CENTER);
    Label ltsuu = new Label("星の数",Label.CENTER);
    Label ltiro = new Label("星の色",Label.CENTER);
    Label lkei = new Label("",Label.CENTER);
    Label lsuu = new Label("",Label.CENTER);
    Label liro = new Label("",Label.CENTER);
    Scrollbar skei  = new Scrollbar(Scrollbar.HORIZONTAL,30,10,1,60);
    Scrollbar ssuu  = new Scrollbar(Scrollbar.HORIZONTAL,60,10,1,210);
    Scrollbar siro  = new Scrollbar(Scrollbar.HORIZONTAL,50,10,1,110);
    Panel p;
    Image img,imgw;
    Graphics gw;
    Thread th;
    int kei =30;
    int suu =60;
    float iro =50f/100f;  
    int w = 0;
    int h = 0;
    int n =200;
    int s[] = new int[n];        //星のサイズ
    int x[] = new int[n];        //星の位置x
    int y[] = new int[n];        //星の位置y
    float hue[] = new float[n];  //星の色相
    public void init(){
      p = new Panel();
      p.setLayout(new GridLayout(3,3));
      p.add(ltkei);
      p.add(ltsuu);
      p.add(ltiro);
      p.add(skei);
      p.add(ssuu);
      p.add(siro);
      p.add(lkei);
      p.add(lsuu);
      p.add(liro);
      setLayout(new BorderLayout());
      add ("South",p);
      skei.addAdjustmentListener(this);
      ssuu.addAdjustmentListener(this);
      siro.addAdjustmentListener(this);
      lkei.setText(""+kei);  
      lsuu.setText(""+suu); 
      liro.setText("Hue "+iro); 
      w=getSize().width;
      h=getSize().height;
      imgw = createImage(w,h);gw = imgw.getGraphics();
      img  = getImage(getDocumentBase(),"hoshi.jpg");
    }
    public void start() {               //アプレットの開始
      th = new Thread(this);            //スレッドの開始
      th.start();
    }
    public void stop() {th = null;}     //スレッドの終了
    public void paint(Graphics g) {
      gw.drawImage(img,0,0,this);
      for(int i=0;i<suu;i++) {
        if(s[i]>0){
          for(int j=s[i];j>0;j--){       //外側から内側に向かって明るくする
            gw.setColor(Color.getHSBColor(hue[i],1f,(float)(s[i]-j)/s[i]));
            gw.drawLine(x[i]  ,y[i]-j,x[i]  ,y[i]+j);    //十字の描画
            gw.drawLine(x[i]-j,y[i]  ,x[i]+j,y[i]  );
          }
          s[i]--;    //星のサイズを小さくする
        }
      }
      g.drawImage(imgw,0,0,this);
    }
    public void run() {                //スレッドの実行
      System.out.println("run");
      while (th !=null) {
        str();
        try {th.sleep(50);}
        catch (InterruptedException e){}
      repaint();
      }
    }
    public void update(Graphics g) {paint(g);}  //再描画
    void str(){                                 //星の作成
      for (int i=0;i<suu;i++){
        if(s[i]<=0) { 
          s[i]=(int)(Math.random()*kei+1); //星のサイズ設定
          x[i]=(int)(Math.random()*w);     //星の位置設定
          y[i]=(int)(Math.random()*h);
          hue[i]=iro;                      //星の色（色相）設定
        }
      }
    }
    public void adjustmentValueChanged(AdjustmentEvent z){  //ボタンの処理
      if(z.getSource()==skei){
        kei = skei.getValue();
        lkei.setText(""+kei);
      }
      if(z.getSource()==ssuu){
        suu =ssuu.getValue();
        lsuu.setText(""+suu);
      }
      if(z.getSource()==siro){
        iro = siro.getValue()/100f;
        liro.setText("Hue "+iro);
      }
      repaint();
    }
}