/*
                            Conway.java ( version 1.0 )

   Copyright F. P. Marin ( April 07 13:12:53 1997 )
   E-mail: felix@bloch.ciens.ucv.ve
   
   Permission to use, copy, modify and distribute this software and its
   documentation for NON-COMERCIAL purposes and without fee is hereby
   granted provided that this copyright notice appears in all copies.

   F. P. Marin makes no representations or warranties about the suitability
   of the software, either express or implied, including but no limited to
   the implied warranties of merchantability, fitness for a particular
   purpose, or non-infringement. F. P. Marin shall not be liable for any
   damage suffered by license as a result of using, modifying or
   distributing this software or its derivatives.

   HTML code is

   <applet archive="Conway.jar"
              code="Conway.class"
            height=500
             width=500>
   You should see the Conway Applet !!!
   </applet>

*/
import java.awt.*;


public class Conway extends java.applet.Applet implements Runnable
{
       final Color ALIVE=Color.yellow.brighter(),DEAD=Color.red.brighter();
       final Color SCOLOR=Color.blue.brighter();
       boolean mup=false,ns[][],os[][];
       Button startb=new Button("Start"),stopb=new Button("Stop");
       double prob=0.5;
       Font fnt=new Font("TimesRoman",Font.BOLD + Font.ITALIC,20);
       FontMetrics fm=getFontMetrics(fnt);
       Graphics gr;
       Image img;
       int delay=42,dx,dy,last=21,nALIVE,ncells=484,nrc=22,olddelay;
       int totalalive,x0,y0,x1,y1,xs,ys;
       String s="Conway's life game = ",sta;
       Thread conwaythread=null;
       

       public void init()
       {
        update();
        setLayout(new BorderLayout());
        add("North",new NorthPanel(prob,this));
        add("South",new SouthPanel(this));
        add("East",stopb);
        add("West",startb);
        img=createImage(size().width,size().height);
        gr=img.getGraphics();
        repaint();
       }


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


       public void run()
       {
        int i,j;

        repaint();
        while ( true ) {
              for ( i=0 ; i<nrc ; ++i ) {
                  for ( j=0 ; j<nrc ; ++j ) newState(i,j);
              }
              repaint();
              try {
                   Thread.sleep(delay);
              } catch ( InterruptedException ie ) {}
        }
       }


       final public void update(Graphics g)
       {
        paint(g);
       }


       final public void paint(Graphics g)
       {
        int i,j,x,y=y0;
        
        gr.setColor(DEAD);
        gr.fillRect(0,0,size().width,size().height);
        totalalive=0;
        for ( i=0 ; i<nrc ; ++i,y+=dy ) {
            x=x0;
            for ( j=0 ; j<nrc ; ++j,x+=dx ) {
                os[i][j]=ns[i][j];
                if ( ns[i][j] ) {
                   gr.setColor(ALIVE);
                   gr.fillRect(x,y,dx,dy);
                   ++totalalive;
                }
                gr.setColor(Color.blue.brighter());
                gr.drawRect(x,y,dx,dy);
            }
        }
        gr.setColor(SCOLOR);
        gr.setFont(fnt);
        sta=s + totalalive + "/" + ncells;
        xs=(int)(0.5*(size().width - fm.stringWidth(sta) + 1));
        gr.drawString(s,xs,ys);
        gr.setColor(Color.yellow.brighter());
        xs+=fm.stringWidth(s);
        gr.drawString(String.valueOf(totalalive),xs,ys);
        gr.setColor(SCOLOR);
        xs+=fm.stringWidth(String.valueOf(totalalive));
        gr.drawString("/" + ncells,xs,ys);
        g.drawImage(img,0,0,this);
       }

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


       public boolean action(Event e,Object arg)
       {
        if ( e.target==startb ) {
           if ( conwaythread==null ) {
              if ( !mup ) update(); else mup=false; 
              conwaythread=new Thread(this);
              conwaythread.start();
           }
        } else {
           if ( conwaythread!=null ) {
              conwaythread.stop();
              conwaythread=null;
           }
        }
        return true;
       }


       public boolean mouseDown(Event e,int xmd,int ymd)
       {
        if (  ( x0<=xmd ) && ( xmd<=x1 ) && ( y0<=ymd ) && ( ymd<=y1 )  ) {
           if ( conwaythread!=null ) {
              conwaythread.stop();
              conwaythread=null;
           }
        } 
        return true;
       }


       public boolean mouseDrag(Event e,int xmd,int ymd)
       {
        if (  ( x0<=xmd ) && ( xmd<=x1 ) && ( y0<=ymd ) && ( ymd<=y1 )  ) {
           int j=(xmd - x0)/dx,i=(ymd - y0)/dy;
           if ( i<0 ) i=0 ; else if ( i>last ) i=last;
           if ( j<0 ) j=0 ; else if ( j>last ) j=last;
           if ( !ns[i][j] ) {
              ns[i][j]=true;
              repaint();
           }
        }
        return true;
       }


       public boolean mouseUp(Event e,int xmd,int ymd)
       {
        if (  ( x0<=xmd ) && ( xmd<=x1 ) && ( y0<=ymd ) && ( ymd<=y1 )  ) {
           if ( conwaythread==null ) mup=true;
        } 
        return true;
       }


       final public void newState(int i,int j)
       {
        nALIVE=state(i - 1,j - 1) + state(i,j - 1) + state(i + 1,j - 1) + 
               state(i - 1,j)     + state(i + 1,j) +
               state(i - 1,j + 1) + state(i,j + 1) + state(i + 1,j + 1);
        if ( !os[i][j] ) ns[i][j]=( nALIVE==3 ); 
                    else ns[i][j]=(  ( 1<nALIVE ) && ( nALIVE<4 )  );
       }


       final public int state(int i,int j)
       {
        if ( i<0 ) i=last; else if ( i>last ) i=0;
        if ( j<0 ) j=last; else if ( j>last ) j=0;
        return ( os[i][j] ) ? 1:0;
       }


       final public void update()
       {
        dx=(int)((0.8*size().width)/nrc);
        dy=(int)((0.8*size().height)/nrc);
        x0=(int)(0.5*(size().width - nrc*dx + 1));
        y0=(int)(0.5*(size().height - nrc*dy + 1));
        x1=x0 + nrc*dx;
        y1=y0 + nrc*dy;
        ys=y0 - 7;
        ns=new boolean[nrc][nrc];
        os=new boolean[nrc][nrc];
        int i,j;
        for ( i=0 ; i<nrc ; ++i ) {
            for ( j=0 ; j<nrc ; ++j )
                os[i][j]=ns[i][j]=( Math.random()<prob );
        }
       }
}


class NorthPanel extends Panel
{
      Conway mother;
      TextField ncells=new TextField(10),prob=new TextField(10);


      public NorthPanel(double probability,Conway mother)
      {
       super();
       this.mother=mother;
       setLayout(new GridLayout(1,4));
       add(new Label("Ncells = ",Label.CENTER));
       ncells.setText(String.valueOf(mother.ncells));
       add(ncells);
       add(new Label("Probability = ",Label.CENTER));
       prob.setText(String.valueOf(probability));
       add(prob);
      }

      
      public boolean action(Event e,Object arg)
      {
       if ( mother.conwaythread==null ) {
          if ( e.target==ncells ) {
             int n=Integer.valueOf(ncells.getText()).intValue();
             if ( n<9 ) n=9;
             mother.nrc=(int)(Math.sqrt((double)n) + 0.5);
             mother.last=mother.nrc - 1;
             mother.ncells=mother.nrc*mother.nrc;
          }
          else {
             double p=Double.valueOf(prob.getText()).doubleValue();
             if ( p<0.0 ) p=0.0; else if ( p>1.0 ) p=1.0;
             mother.prob=p;
          }
       }
       ncells.setText(String.valueOf(mother.ncells));
       prob.setText(String.valueOf(mother.prob));
       return true;
      }
}


class SouthPanel extends Panel
{
      Conway mother;
      double ax;
      int minsb;
      Label l;
      Scrollbar sb=new Scrollbar(Scrollbar.HORIZONTAL,0,5,0,255);


      public SouthPanel(Conway mother)
      {
       super();
       this.mother=mother;
       setLayout(new GridLayout(1,3));
       add(new Label("Delay = ",Label.RIGHT));
       add(sb);
       l=new Label(String.valueOf(mother.delay) + " msecs.",Label.LEFT);
       add(l);
       minsb=sb.getMinimum();
       ax=4958.0/(sb.getMaximum() - minsb);
      } 


      public boolean handleEvent(Event e)
      {
       int delay=(int)(42.5 + ax*(sb.getValue() - minsb));
       if ( delay<42 ) delay=42; else if ( delay>5000 ) delay=5000;
       mother.delay=delay;
       l.setText(String.valueOf(mother.delay) + " msecs.");
       return true;        
      }
}