import java.awt.*;
import java.applet.*;
import java.awt.image.*;
/* Author Carlos Esteban Yaguna
  Departamento de Fisica
   Universidad de Antioquia
   Medellin , COLOMBIA
   E-mail yaguna@pegasus.udea.edu.co  */
public class Area extends Applet
{
  private AreaCanva theCanvas;
  private Panel p1,p3,p4;
  private Button b1;
  private Scrollbar s1,s2;
  private Choice lista1;
  private TextField t1,t2;

  public void init()
  {
   theCanvas=new AreaCanva();
   theCanvas.resize(450,400);
   theCanvas.setBackground(Color.black);
   p1=new Panel();
   p3=new Panel();
   p4=new Panel();
   t1=new TextField("a=100");
   t1.setEditable(false);
   t2=new TextField("b=2000");
   t2.setEditable(false);
   b1=new Button("Run");
   lista1=new Choice();
   lista1.addItem("Figure");
   lista1.addItem("Square");
   lista1.addItem("Circle");
   lista1.addItem("Oval");
   lista1.addItem("Triangle");
   s2=new Scrollbar(Scrollbar.HORIZONTAL,20,0,0,120);
   s1=new Scrollbar(Scrollbar.VERTICAL,0,0,0,120);
   p1.setLayout(new GridLayout(12,1));
   p3.setLayout(new BorderLayout());
   p4.setLayout(new GridLayout(1,2));
   p1.add(b1);
   p1.add(t1);
   p1.add(t2);
   p1.add(lista1);
   p3.add("Center",p1);
   p3.add("West",s1);

   setLayout(new BorderLayout());
   add("East",p3);
   add("Center",theCanvas);
   add("South",s2);
   theCanvas.bb=0;
   theCanvas.dd=0;
   theCanvas.init();
   theCanvas.start();
       }

   public boolean handleEvent(Event e){
        double Area;
        int ar;
        Area=100;
        ar=0;
      if(e.target instanceof Scrollbar){

          if(e.target==s1){
           theCanvas.xp=s1.getValue();
           theCanvas.yp=s1.getValue();
           if(theCanvas.cc==1)
            ar=(int)(Math.pow(100+theCanvas.xp,2.0));
           else if(theCanvas.cc==2)
             ar=(int)(3.1416*Math.pow(50+theCanvas.xp/2,2.0));
           else if(theCanvas.cc==3)
             ar=(int)(3.1416*0.25*(150+theCanvas.xp)*(100+theCanvas.xp));
           else if(theCanvas.cc==4)
             ar=(int)(0.5*(150+theCanvas.xp)*(150+theCanvas.xp)*0.86666);
           Area=ar/100.0;
           t1.setText("a="+Double.toString(Area));
          }
          if(e.target==s2){
            theCanvas.num=s2.getValue()*100;
            t2.setText("n="+Integer.toString(theCanvas.num));
          }

                theCanvas.repaint();

			return true;
		}

		return super.handleEvent(e);
        }


  public boolean action(Event e, Object o)
  {
   double Area;
   int ar;
   ar=0;
   Area=0;

   if(e.target instanceof Choice){
      if(lista1.getSelectedIndex()==0){
       theCanvas.cc=0;
      }
      if(lista1.getSelectedIndex()==1){
        theCanvas.cc=1;
        ar=(int)(Math.pow(100+theCanvas.xp,2.0));
      }
     else if(lista1.getSelectedIndex()==2){
         theCanvas.cc=2;
         ar=(int)(3.1416*Math.pow(50+theCanvas.xp/2,2.0));
       }
     else if(lista1.getSelectedIndex()==3){
       theCanvas.cc=3;
       ar=(int)(3.1416*0.25*(150+theCanvas.xp)*(100+theCanvas.xp));
       }
     else if(lista1.getSelectedIndex()==4){
       theCanvas.cc=4;
       ar=(int)(0.5*(150+theCanvas.xp)*(150+theCanvas.xp)*0.86);
      }
     Area=ar/100.0;
     t1.setText("a="+Double.toString(Area));

     theCanvas.repaint();
     return true;
   }


   if(e.target instanceof Button){

   if(e.target == b1){
     theCanvas.dd=1;
     theCanvas.repaint();
     return true;}

   theCanvas.repaint();
   return false;
   }

    return false;
   }

 }
 class AreaCanva extends Canvas implements Runnable{


  int bb,dd,nn,num,cc,xp,yp,x1,y1,x2,y2,x3,y3;
  double area;
  Thread hilo;
  Image offScreenImage;


  public void init()
  {
   cc=0;
   num=2000;
   bb=0;
   nn=0;
   xp=0;
   yp=0;
   offScreenImage=createImage(size().width,size().height);
   }

  public void start()
  {
    if(hilo==null);
    {
     hilo=new Thread(this);
     hilo.start();
    }

  }
  public void stop()
  {
     if(hilo != null){
       hilo.suspend();
       hilo=null;
     }

  }
  public void run()
  {
    while(true){ if(bb==1)
                 repaint();

      try{ Thread.sleep(300);

      }
      catch(InterruptedException e){ }


	}

  }

    public void update(Graphics g)
  { //To avoid flicker

    Graphics offScreenGraphics=offScreenImage.getGraphics();
    offScreenGraphics.setColor(getBackground());
    offScreenGraphics.fillRect(0,0,size().width,size().height);
    offScreenGraphics.setColor(g.getColor());
    paint(offScreenGraphics);
    g.drawImage(offScreenImage,0,0,this);

  }

 void Primero(Graphics g)
 {
  int j,xpos[],ypos[];
  xpos=new int[3];ypos=new int[3];
  ypos[0]=105;ypos[1]=15;ypos[2]=60;
  xpos[0]=180;xpos[1]=180;xpos[2]=270;
  g.setColor(Color.blue);
  g.fillRect(150,150,100,100);
  g.setColor(Color.green);
  g.fillOval(50,50,75,75);
  g.setColor(Color.yellow);
  g.fillPolygon(xpos,ypos,3);
  g.setColor(Color.red);
  g.fillOval(30,170,90,120);
  g.setColor(Color.cyan);
  g.setFont(new Font("TimesRoman",Font.BOLD,36));
  g.drawString("A R E A S",110,135);
  g.setColor(Color.magenta);
    for(j=0;j<5;j++)
    g.drawRect(0+j,0+j,300-2*j,300-2*j);
 }

 void Square(Graphics g)
 {
  int i,j,xx,yy,ar;
  g.setColor(Color.red);
  x1=100-xp/2;
  y1=100-yp/2;
  g.fillRect(x1,y1,100+xp,100+yp);
  g.setColor(Color.green);
  if(dd==1){
  for(i=0;i<num;i++){
    xx=(int)(Math.random()*300);
    yy=(int)(Math.random()*300);
    g.drawLine(xx,yy,xx,yy);
    if(xx>x1 && xx<x1+100+xp && yy>y1 & yy<y1+100+yp)
    nn+=1;
    }
  ar=(int)(90000*(double)nn/num);
  area=ar/100.0;
  g.setColor(Color.black);
  g.fillRect(30,30,50,11);
  g.setFont(new Font("TimesRoman",Font.BOLD,14));
  g.setColor(Color.lightGray);
  g.drawString("m="+Integer.toString(nn),30,40);
  g.setColor(Color.red);
  g.fillRect(113,105,60,11);
  g.setColor(Color.yellow);
  g.setFont(new Font("TimesRoman",Font.BOLD,14));
  g.drawString("A="+Double.toString(area),115,115);

   nn=0;
   dd=0;
  }
  g.setColor(Color.blue);
    for(j=0;j<5;j++)
    g.drawRect(0+j,0+j,300-2*j,300-2*j);
 }

 void Circle(Graphics g)
 {
  int i,j,xx,yy,ar,dist;
  x1=100-xp/2;
  y1=100-yp/2;
  g.setColor(Color.green);
  g.fillOval(x1,y1,100+xp,100+yp);
  g.setColor(Color.magenta);
  if(dd==1){
  for(i=0;i<num;i++){
    xx=(int)(Math.random()*300);
    yy=(int)(Math.random()*300);
    g.drawLine(xx,yy,xx,yy);
    dist=(int)Math.sqrt(Math.pow(xx-150,2)+Math.pow(yy-150,2));
    if(dist<50+xp/2)
    nn+=1;
    }
  ar=(int)(90000*(double)nn/num);
  area=ar/100.0;
  g.setColor(Color.black);
  g.fillRect(30,30,50,11);
  g.setFont(new Font("TimesRoman",Font.BOLD,14));
  g.setColor(Color.lightGray);
  g.drawString("m="+Integer.toString(nn),30,40);
  g.setColor(Color.green);
  g.fillRect(113,115,60,11);
  g.setColor(Color.blue);
  g.setFont(new Font("TimesRoman",Font.BOLD,14));
  g.drawString("A="+Double.toString(area),115,125);

   nn=0;
   dd=0;
  }
  g.setColor(Color.yellow);
    for(j=0;j<5;j++)
    g.drawRect(0+j,0+j,300-2*j,300-2*j);
 }

void Oval(Graphics g)
 {
  int i,j,xx,yy,ar;
  double dist;
  x1=75-xp/2;
  y1=100-yp/2;
  g.setColor(Color.yellow);
  g.fillOval(x1,y1,150+xp,100+yp);
  g.setColor(Color.blue);
  if(dd==1){
  for(i=0;i<num;i++){
    xx=(int)(Math.random()*300);
    yy=(int)(Math.random()*300);
    g.drawLine(xx,yy,xx,yy);
    dist=Math.pow(xx-150,2)/((75+xp/2)*(75+xp/2))+Math.pow(yy-150,2)/((50+yp/2)*(50+yp/2));
    if(dist<1)
    nn+=1;
    }
  ar=(int)(90000*(double)nn/num);
  area=ar/100.0;
  g.setColor(Color.black);
  g.fillRect(30,30,50,11);
  g.setFont(new Font("TimesRoman",Font.BOLD,14));
  g.setColor(Color.lightGray);
  g.drawString("m="+Integer.toString(nn),30,40);
  g.setColor(Color.yellow);
  g.fillRect(113,115,60,11);
  g.setColor(Color.darkGray);
  g.setFont(new Font("TimesRoman",Font.BOLD,14));
  g.drawString("A="+Double.toString(area),115,125);

   nn=0;
   dd=0;
  }
  g.setColor(Color.red);
    for(j=0;j<5;j++)
    g.drawRect(0+j,0+j,300-2*j,300-2*j);
 }

  void Triangle(Graphics g)
 {
  int i,j,xx,yy,ar,x2[],y2[],x1,y1,x3[],y3[];
  double m1,m2,m3,m4,pi;
  pi=3.14159216;
  x2=new int[3];
  y2=new int[3];
  x3=new int[3];
  y3=new int[3];
  x2[0]=75-xp/2;x2[1]=225+xp/2;x2[2]=150;
  y2[0]=225+xp/2-10;y2[1]=225+xp/2-10;y2[2]=y2[0]-(int)(0.86666*(x2[1]-x2[0]));
  x3[0]=x2[0];x3[1]=x2[1];x3[2]=x2[2];
  y3[0]=y2[0]-10;y3[1]=y2[1]-10;y3[2]=y2[2]-10;
  g.setColor(Color.magenta);
  g.fillPolygon(x3,y3,3);
  g.setColor(Color.cyan);
  if(dd==1){
  for(i=0;i<num;i++){
    xx=(int)(Math.random()*300);
    yy=(int)(Math.random()*300);
    g.drawLine(xx,yy,xx,yy);
    x1=xx-x2[0];
    y1=y2[0]-yy;
    m1=1.7320*x1;
    m2=-1.7320*x1+2*(y2[1]-y2[2]);
    if(x1>0 && x1<x2[1]-x2[0] && y1<m2 && y1<m1&& y1>0 && y1<y2[1]-y2[2])
    nn+=1;
    }
  ar=(int)(90000*(double)nn/num);
  area=ar/100.0;
  g.setColor(Color.black);
  g.fillRect(30,30,50,11);
  g.setFont(new Font("TimesRoman",Font.BOLD,14));
  g.setColor(Color.lightGray);
  g.drawString("m="+Integer.toString(nn),30,40);
  g.setColor(Color.magenta);
  g.fillRect(113,165,60,11);
  g.setColor(Color.yellow);
  g.setFont(new Font("TimesRoman",Font.BOLD,14));
  g.drawString("A="+Double.toString(area),115,175);

   nn=0;
   dd=0;
  }
  g.setColor(Color.green);
    for(j=0;j<5;j++)
    g.drawRect(0+j,0+j,300-2*j,300-2*j);
 }
 public void paint(Graphics g)
 {
  int i;
  if(cc==0)Primero(g);
  else if(cc==1)Square(g);
   else if(cc==2)Circle(g);
   else if(cc==3)Oval(g);
   else if(cc==4)Triangle(g);
  else{
  g.setColor(Color.blue);
  for(i=0;i<5;i++)
  g.drawRect(0+i,0+i,300-2*i,300-2*i);
  }
  g.setColor(Color.white);
  g.drawLine(100,0,100,300);
  g.drawLine(200,0,200,300);
  g.drawLine(0,100,300,100);
  g.drawLine(0,200,300,200);


 }

 }