// LifeBoard.java
import java.awt.*;
import java.awt.event.*;

public class LifeBoard extends Canvas implements MouseListener, MouseMotionListener
{
   private static final int FINITE = 0, TORUS = 1;
   private boolean[][] life, tempArray;
   private boolean changeable = true;
   private int boardType, width, height, imgHeight, imgWidth, ROWSIZE, COLSIZE;
   private Image image, offscreenImage;
   private ActionListener listener = null;

   public LifeBoard(int _boardType, Image _image, int _ROWSIZE, int _COLSIZE)
   {
      boardType = _boardType;
      image = _image;
      imgHeight = image.getHeight(this) + 1;
      imgWidth = image.getWidth(this) + 1;
      ROWSIZE = _ROWSIZE;
      COLSIZE = _COLSIZE;
      life = new boolean[ROWSIZE][COLSIZE];
      tempArray = new boolean[ROWSIZE][COLSIZE];
      setSize(getPreferredSize());
      for(int row = 0; row < ROWSIZE; row++)
        for(int col = 0; col < COLSIZE; col++)
          life[row][col] = tempArray[row][col] = false;
      addMouseListener(this);
      addMouseMotionListener(this);
      width = this.getSize().width;
      height = this.getSize().height;
   }

   public Dimension getPreferredSize()
   {
      return new Dimension(COLSIZE * imgWidth + 1, ROWSIZE * imgHeight + 1);
   }

   public void setPresetConfig(String pattern)
   {
      int index = 0, pos;
      String sub;
      while (index < pattern.length())
      {
         pos = pattern.indexOf(" ", index);
         sub = pattern.substring(index, pos);
         int row = Integer.parseInt(sub);
         index = pos + 1;
         pos = pattern.indexOf(" ", index);
         if (pos == -1)   // at end of string, do not specify an endIndex for substring
         {
            sub = pattern.substring(index);
            index = pattern.length();  // end while loop
         }
         else
         {
            sub = pattern.substring(index, pos);
            index = pos + 1;
         }
         int col = Integer.parseInt(sub);
         life[row][col] = true;
      }
      repaint();
   }

   public void setBoardType(int _boardType)
   {
      boardType = _boardType;
   }

   public boolean isOneAlive()
   {
      int row = 0;
      boolean done = false;
      while ((row < ROWSIZE) && (done == false))
      {
         int col = 0;
         while ((col < COLSIZE) && (done == false))
           if (life[row][col])
             done = true;
           else
             col += 1;
         row += 1;
      }
      return done;
   }

   public void setChangeable(boolean canChange)
   {
      changeable = canChange;
   }

   public void clear()
   {
      for(int row = 0; row < ROWSIZE; row++)
        for(int col = 0; col < COLSIZE; col++)
          life[row][col] = tempArray[row][col] = false;
      repaint();
   }

   public void randomize()
   {
      for(int row = 0; row < ROWSIZE; row++)
        for(int col = 0; col < COLSIZE; col++)
        {
           int number = (int)(Math.random() * 100);
           if (number < 20)
             life[row][col] = true;
           else
             life[row][col] = false;
        }
      repaint();
   }

   public void makeNextGeneration()
   {
      // better to use 2 nearly identical for-loop structures
      // check boardType once rather than in the loop

      if (boardType == FINITE)
        for(int row = 0; row < ROWSIZE; row++)
          for(int col = 0; col < COLSIZE; col++)
          {
             int ct = 0;
             for(int i = row - 1; i <= row + 1; i++)
               for(int j = col - 1; j <= col + 1; j++)
                 if (!((i == row) && (j == col)))
                   if (((i != -1) && (j != -1) && (i != ROWSIZE) && (j != COLSIZE)))
                     if (life[i][j] == true)
                       ct += 1;
             if (life[row][col] == true)
               if ((ct == 2) || (ct == 3))
                 tempArray[row][col] = true;
               else 
                 tempArray[row][col] = false;
             else
               if (ct == 3)
                 tempArray[row][col] = true;
          }
      else if (boardType == TORUS)
        for(int row = 0; row < ROWSIZE; row++)
          for(int col = 0; col < COLSIZE; col++)
          {
             int ct = 0;
             for(int i = row - 1; i <= row + 1; i++)
               for(int j = col - 1; j <= col + 1; j++)
                 if (!((i == row) && (j == col)))
                 {
                   int tempI = i, tempJ = j;
                   if (tempI == -1)
                     tempI = ROWSIZE - 1;
                   else if (tempI == ROWSIZE)
                     tempI = 0;
                   if (tempJ == -1)
                     tempJ = COLSIZE - 1;
                   else if (tempJ == COLSIZE)
                     tempJ = 0; 
                   if (life[tempI][tempJ])
                     ct += 1;
                 }
             if (life[row][col])
               if ((ct == 2) || (ct == 3))
                 tempArray[row][col] = true;
               else 
                 tempArray[row][col] = false;
             else
               if (ct == 3)
                 tempArray[row][col] = true;
          }
      for(int row = 0; row < ROWSIZE; row++)
        for(int col = 0; col < COLSIZE; col++)
          life[row][col] = tempArray[row][col];
      repaint();
   }

   public void mouseEntered(MouseEvent me){}

   public void mouseExited(MouseEvent me){}

   public void mousePressed(MouseEvent me) 
   {
      if (changeable)
      {
         int row = me.getY() / imgHeight,
             col = me.getX() / imgWidth;
         if (life[row][col])
           life[row][col] = false;
         else
           life[row][col] = true;
         repaint();
      }
   }

   public void mouseClicked(MouseEvent me){}

   public void mouseReleased(MouseEvent me){}

   public void mouseDragged(MouseEvent me) 
   {
      if (changeable)
      {
         int row = me.getY() / imgHeight,
             col = me.getX() / imgWidth;
         if (((row >= 0) && (row < ROWSIZE)) &&
             ((col >= 0) && (col < COLSIZE)))
            if (!life[row][col])
            {
               life[row][col] = true;
               repaint();
            }
      }
   }

   public void mouseMoved(MouseEvent me){}

   public void update(Graphics g)
   {
      if (offscreenImage == null)
        offscreenImage = this.createImage(width, height);
      Graphics gr = offscreenImage.getGraphics();
      paint(gr);
      g.drawImage(offscreenImage, 0, 0, this);
   }

   public void paint(Graphics g)
   {
      g.setColor(new Color(22, 107, 29));
      g.fillRect(0, 0, width, height);
      g.setColor(SystemColor.activeCaptionBorder);
      for(int row = 0; row <= ROWSIZE; row++)
        g.drawLine(0, row * imgHeight, COLSIZE * imgWidth, row * imgHeight);
      for(int col = 0; col <= COLSIZE; col++)
        g.drawLine(col * imgWidth, 0, col * imgWidth, ROWSIZE * imgWidth);

      for(int row = 0; row < ROWSIZE; row++)
        for(int col = 0; col < COLSIZE; col++)
          if (life[row][col])
            g.drawImage(image, col * imgWidth + 1, row * imgHeight + 1, this);
   }

}