Added Main class and separate class to check rules

src/gameoflife/GameOfLife.java

@@ -10,37 +10,26 @@ import javafx.animation.AnimationTimer;
 
 public class GameOfLife extends Application{
     private static Cell[][] cells;
-    private static boolean pause;
     @Override
     public void start(Stage primaryStage) throws Exception {
-    	pause = true;
         cells = new Cell[64][64];
-        Button button = new Button("Resume/Pause");
+        
-        button.setOnAction(event->{
-        	pause = !pause;
-        });
         GridPane root = new GridPane();
         root.setAlignment(Pos.CENTER);
+        
         for(int i = 0; i < cells.length; i++){
             for(int j = 0; j < cells[i].length; j++){
                 cells[i][j] = new Cell((double)10,(double)10, i, j);
                 root.add(cells[i][j], i, j);
             }
         }
-        root.add(button, cells.length, cells[cells.length-1].length);
         
-        Scene scene = new Scene(root);
+        AnimationTimer animate = new AnimationTimer(){
-        primaryStage.setTitle("Conway's Game of Life");
-        primaryStage.setScene(scene);
-        primaryStage.show();
-
-        new AnimationTimer(){
             @Override
             public void handle(long currentNanoTime){
-            	if(!pause) {
                 for(int i = 0; i< cells.length; i++){
                     for(int j = 0; j < cells[i].length; j++){
-	                        checkRules(i,j);
+                        GameOfLifeRules.checkRules(cells, i, j);
                     }
                 }
                 for(int i = 0; i< cells.length; i++){
@@ -51,43 +40,23 @@ public class GameOfLife extends Application{
                 try {Thread.sleep(50);}
                 catch(Exception e) {}
         	}
-            }
+        };
-        }.start();
-    }
         
-    public void checkRules(int x, int y){
+        Button stop = new Button("Stop");
-        int aliveNeighbors = 0;
+        stop.setOnAction(event->{
-        for(int i = y-1; i <= y + 1; i++){
+        	animate.stop();
-            if(i >= 0 && i < cells[x].length){
+        });
-                if(x-1 >= 0){
+        Button start = new Button("Start");
-                    if(cells[x-1][i].getStatus() == Cell.Status.ALIVE){
+        start.setOnAction(event->{
-                        aliveNeighbors++;
+        	animate.start();
-                    }
+        });
-                }
-                if(i != y){
-                    if(cells[x][i].getStatus() == Cell.Status.ALIVE){
-                        aliveNeighbors++;
-                    }
-                }
-                if(x+1 < cells.length){
-                    if(cells[x+1][i].getStatus() == Cell.Status.ALIVE){
-                        aliveNeighbors++;
-                    }
-                }
-            }
-        }
-        if((aliveNeighbors == 2 || aliveNeighbors == 3) && cells[x][y].getStatus() == Cell.Status.ALIVE){
-            cells[x][y].makeAliveNextCycle(true);
-        }
-        else if((aliveNeighbors < 2 || aliveNeighbors > 3) && cells[x][y].getStatus() == Cell.Status.ALIVE){
-            cells[x][y].makeDeadNextCycle(true);
-        }
-        if(aliveNeighbors == 3 && cells[x][y].getStatus() == Cell.Status.DEAD){
-            cells[x][y].makeAliveNextCycle(true);
-        }
-    }
         
-    public static void main(String[] args){
+        root.add(start, cells.length, cells[cells.length-1].length);
-        launch(args);
+        root.add(stop, cells.length, cells[cells.length-1].length+1);
+        
+        Scene scene = new Scene(root);
+        primaryStage.setTitle("Conway's Game of Life");
+        primaryStage.setScene(scene);
+        primaryStage.show();
     }
 }

src/gameoflife/GameOfLifeRules.java

@@ -0,0 +1,35 @@
+package gameoflife;
+
+public class GameOfLifeRules {
+	public static void checkRules(Cell[][] cells, int x, int y) {
+		int aliveNeighbors = 0;
+        for(int i = y-1; i <= y + 1; i++){
+            if(i >= 0 && i < cells[x].length){
+                if(x-1 >= 0){
+                    if(cells[x-1][i].getStatus() == Cell.Status.ALIVE){
+                        aliveNeighbors++;
+                    }
+                }
+                if(i != y){
+                    if(cells[x][i].getStatus() == Cell.Status.ALIVE){
+                        aliveNeighbors++;
+                    }
+                }
+                if(x+1 < cells.length){
+                    if(cells[x+1][i].getStatus() == Cell.Status.ALIVE){
+                        aliveNeighbors++;
+                    }
+                }
+            }
+        }
+        if((aliveNeighbors == 2 || aliveNeighbors == 3) && cells[x][y].getStatus() == Cell.Status.ALIVE){
+            cells[x][y].makeAliveNextCycle(true);
+        }
+        else if((aliveNeighbors < 2 || aliveNeighbors > 3) && cells[x][y].getStatus() == Cell.Status.ALIVE){
+            cells[x][y].makeDeadNextCycle(true);
+        }
+        if(aliveNeighbors == 3 && cells[x][y].getStatus() == Cell.Status.DEAD){
+            cells[x][y].makeAliveNextCycle(true);
+        }
+	}
+}

src/gameoflife/Main.java

@@ -0,0 +1,9 @@
+package gameoflife;
+
+import javafx.application.Application;
+
+public class Main {
+	public static void main(String[] args) {
+		Application.launch(GameOfLife.class, args);
+	}
+}