// Checkerboard.java
// Solution to Short Assignment 8 by THC.
// Draws a checkerboard with black and red squares.

import java.applet.Applet;
import java.awt.*;

public class Checkerboard extends Applet {
  private final int DIMENSION = 8; // Want 8 x 8 board
  private final int SQUARE_SIZE = 30; // Each square is 30 x 30 pixels

  public void init() {
    // Set the size of the applet to be exactly the checkerboard size.
    setSize(DIMENSION * SQUARE_SIZE, DIMENSION * SQUARE_SIZE);

    // Draw the checkerboard.
    repaint();
  }

  public void paint(Graphics page) {
    // Draw all the black and red squares.
    Color squareColor; // Color of the current square

    for (int row = 0; row < DIMENSION; row++) {
      for (int column = 0; column < DIMENSION; column++) {
        // A square is black if the row and column numbers are both even
        // or both odd. Otherwise, the square is red.
        if (row % 2 == column % 2)
          squareColor = Color.black;
        else
          squareColor = Color.red;

        drawSquare(page, row, column, squareColor);
      }
    }
  }

  // Draw a given square of the checkerboard. Row and column numbers start
  // from 0.
  public void drawSquare(Graphics page, int row, int column, Color color) {
    page.setColor(color);
    page.fillRect(column * SQUARE_SIZE, row * SQUARE_SIZE, SQUARE_SIZE,
        SQUARE_SIZE);
  }
}