// David Eck, eck@hws.edu, August 1996

import java.awt.*;

public class MosaicCanvas extends Canvas {

   protected int rows;
   protected int columns;
   private Color[][] color;
   private int height = 0;
   private int width = 0;
   private int squareHeight;
   private int squareWidth;
   private int hOffset;
   private int vOffset;

   MosaicCanvas() {
      this(20,20);
   }
   
   MosaicCanvas(int ROWS, int COLUMNS) {
      rows = ROWS;
      columns = COLUMNS;
      setBackground(Color.white);
      setForeground(Color.black);
      color = new Color[rows][columns];
      for (int i=0; i<rows; i++)
         for (int j=0; j<columns; j++)
            color[i][j] = null;
   }
   
   void setSize(int w, int h) {
      height = h;
      width = w;
      squareHeight = height/rows;
      squareWidth = width/columns;
      vOffset = (height - rows*squareHeight) / 2;
      hOffset = (width - columns*squareWidth) / 2;
   }
   
   public synchronized void paint(Graphics g) {
       Dimension d = size();
       if (d.height != height || d.width !=width)
          setSize(d.width,d.height);
       for (int c=0; c<columns; c++)
          for (int r=0; r<rows; r++) {
             if (color[r][c] == null)
                g.setColor(getBackground());
             else
                g.setColor(color[r][c]);
             g.fillRect(hOffset + c*squareWidth, vOffset + r*squareHeight, squareWidth, squareHeight);
          }  
   }
   
   public void update(Graphics g) {
      paint(g);
   }
   
   public void clear() {
      for (int i=0; i<rows; i++)
         for (int j=0; j<columns; j++)
            color[i][j] = null;
      repaint();
   }
   
   public synchronized Color getColor(int row, int column) {
      if (color[row][column] == null)
         return color[row][column];
      else
         return getBackground();
   }
   
   public synchronized double getRed(int row, int column) {
      Color c = getColor(row,column);
      return c.getRed();
   }
   
   public synchronized double getGreen(int row, int column) {
      Color c = getColor(row,column);
      return c.getGreen();
   }
   
   public synchronized double getBlue(int row, int column) {
      Color c = getColor(row,column);
      return c.getBlue();
   }
   
   public synchronized void setColor(int row, int column, Color c) {
      if (row < 0 || row >= rows || column < 0 || column >= columns)
         return;
      Dimension d = size();
      if (d.height != height || d.width !=width)
          setSize(d.width,d.height);
      color[row][column] = c;
      Graphics g=getGraphics();
      g.setColor(c);
      g.fillRect(hOffset + column*squareWidth, vOffset + row*squareHeight, squareWidth, squareHeight);
      g.dispose();
   }
   
   public synchronized void setColor(int row, int column, double red, double green, double blue) {
      Dimension d = size();
      if (d.height != height || d.width !=width)
         setSize(d.width,d.height);
      if (red < 0.0)
         red = 0.0;
      else if (red > 1.0)
         red = 1.0;
      if (green < 0.0)
         green = 0.0;
      else if (green > 1.0)
         green = 1.0;
      if (blue < 0.0)
         blue = 0.0;
      else if (blue > 1.0)
         blue = 1.0;
      Color c = new Color((float)red, (float)green, (float)blue);
      setColor(row,column,c);
   }
   
}  // end of class MosaicWindow