GameOfLifeAssignment/src/Life.java

public class Life implements ILife {

  boolean[][] cells = new boolean[15][15];

  public static void main(String[] args) {
    Life l = new Life(new String[] {  "     ",
                                      "     ",
                                      " *** ",
                                      "     ",
                                      "     " });
    l = (Life) l.nextGeneration();
  }


  public Life() {
    nukeAll();
  }

  public Life(String[] setup) {
    this();
    for (int y = 0; y < setup.length; y++)
      for (int x = 0; x < setup[y].length(); x++)
        if (setup[y].charAt(x) != ' ')
          setAlive(x, y);
  }


  @Override
  public void nukeAll() {
    // TODO Auto-generated method stub
    for (int i = 0; i < 15; i++) {
      for (int j = 0; j < 15; j++) {
        cells[i][j] = false;
      }
    }
  }

  @Override
  public void setAlive(int x, int y) {
    // TODO Auto-generated method stub
    cells[x][y] = true;
  }

  @Override
  public void setDead(int x, int y) {
    // TODO Auto-generated method stub
    cells[x][y] = false;
  }

  @Override
  public boolean isAlive(int x, int y) {
    // TODO Auto-generated method stub
    return cells[x][y];
  }

  @Override
  public ILife nextGeneration() {
    // TODO Auto-generated method stub
    boolean[][] nextGen = new boolean[15][15];

    for (int y = 0; y < 15; y++) {

      for (int x = 0; x < 15; x++) {

        int aliveNeighbours = countNeighbourCells(x, y);
        if (isAlive(x, y)) {

          if (aliveNeighbours == 2 || aliveNeighbours == 3) {
            nextGen[x][y] = true;
          } else {
            nextGen[x][y] = false;
          }
        } else {
          if (aliveNeighbours == 3) {
            nextGen[x][y] = true;
          } else {
            nextGen[x][y] = false;
          }
        }
      }
    }
    cells = nextGen;
    return this;
  }

  public int countNeighbourCells(int x , int y){
    int counter = 0;

    if((x-1) >=0 && (y-1) >=0 && isAlive(x-1,y-1)) counter++;
    if((y-1) >=0 && isAlive(x,y-1)) counter++;
    if((x+1) < 15 && (y-1) >=0 && isAlive(x+1,y-1)) counter++;
    if((x-1) >=0&& isAlive(x-1,y)) counter++;
    if((x+1) < 15 && isAlive(x+1,y)) counter++;
    if((x-1) >=0 && (y+1) < 15 && isAlive(x-1,y+1)) counter++;

    if((y+1) <15 && isAlive(x,y+1)) counter++;

    if((x+1) <15 && (y+1) <15 && isAlive(x+1,y+1)) counter++;

    return counter;
  }
}