Grid.java

-import java.util.Arrays;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Random;
+import java.util.*;
 
 /**
  * {@code Grid} instances represent the grid in <i>The Game of Life</i>.
@@ -98,29 +95,68 @@ public class Grid implements Iterable<Cell> {
     }
 
     private boolean[][] calculateNextStates() {
-        return null;
+        boolean[][] newState = new boolean[getNumberOfRows()][getNumberOfColumns()];
+        for (int r=0; r<numberOfRows; r++) {
+            for (int c=0; c<numberOfColumns; c++) {
+                newState[r][c] = this.calculateNextState(r,c,this.getCell(r,c));
+            }
+        }
+
+        return newState;
+    }
+
+    private void goToNextState(boolean[][] nextState) {
+        for (int r=0; r<numberOfRows; r++) {
+            for (int c=0; c<numberOfColumns; c++) {
+                if (nextState[r][c]) {
+                    this.getCell(r,c).setAlive();
+                }
+                else {
+                    this.getCell(r,c).setDead();
+                }
+            }
+        }
     }
 
     private boolean calculateNextState(int rowIndex, int columnIndex, Cell cell) {
-	return false;
+        return cell.isAliveInNextState(this.countAliveNeighbours(rowIndex, columnIndex));
     }
 
     private int countAliveNeighbours(int rowIndex, int columnIndex) {
-        return 0;
+        int CounterAliveCell = 0;
+        for (Cell NeighboursCell : this.getNeighbours(rowIndex, columnIndex)) {
+            if (NeighboursCell.isAlive()) {
+                CounterAliveCell+=1;
+            }
+        }
+        return CounterAliveCell;
     }
 
 
     private List<Cell> getNeighbours(int rowIndex, int columnIndex) {
-	return null;
+        List<Cell> Neighbours = new ArrayList<>();
+        for (int r=-1; r<=1; r++) {
+            for (int c=-1; c<=1; c++) {
+                if ((r != 0) || (c != 0)) {
+                    Neighbours.add(this.getCell(rowIndex + r, columnIndex + c));
+                }
+            }
         }
 
-    private void goToNextState(boolean[][] nextState) {
+        return Neighbours;
     }
 
+
+
     /**
      * Sets all {@link Cell}s in this {@code Grid} as dead.
      */
     void clear() {
+
+        for (Iterator<Cell> it = this.iterator(); it.hasNext(); ) {
+            Cell cell = it.next();
+            cell.setDead();
+        }
     }
 
     /**
@@ -131,6 +167,15 @@ public class Grid implements Iterable<Cell> {
      */
 
     void randomGeneration(Random random) {
+        for (Iterator<Cell> it = this.iterator(); it.hasNext(); ) {
+            Cell cell = it.next();
+            if (random.nextBoolean()) {
+                cell.setAlive();
+            }
+            else {
+                cell.setDead();
+            }
+        }
     }
 
 }
\ No newline at end of file