Can't update GridPane from Button Action

Question

I'm making a simple gui for Conway's Game of Life with a grid (GridPane) and a simple toolbar with Start/Stop buttons. My start button action looks like this:
startButton.setOnAction(new EventHandler<ActionEvent>() {
        @Override
        public void handle(ActionEvent actionEvent) {
            grid.change();
    });So when i click it the grid updates ones as i expect. But i when i add something like a Service/Platform.runLater/Runnable inside it evaluates generations, grid model, but refuses to update the grid view. My Service code looks like this:
private Service task = new Service(){
    @Override
    protected Task createTask() {
        System.out.println("Task created");
        return new Task<Void>() {
            @Override
            protected Void call() throws Exception {
                for (int i = 0; i < 3; i++) {
                    System.out.println("calling");
                    Platform.runLater(new Runnable(){
                        @Override
                        public void run() {
                            System.out.println("running");
                           grid.changeGeneration();
                            try {
                                Thread.sleep(1500L);
                            } catch (InterruptedException e) {
                                e.printStackTrace(); 
                return null;
};It prints Task created calling calling calling running running running to the console, but doesn't update the GridPane after each running, only after everything is done it updates it (in this case after the third "running"). Where am i making a mistake and how to fix this. I don't want to use Swing =)
Same question on [http://stackoverflow.com/questions/13820734/cant-update-gridpane]
Edited by: Riddle on 11.12.2012 7:21

Answer 1

public void changeGeneration() {
        Cell[][] newGen = new Cell[rows][cols];
        Cell cell;
        for (int i = 0; i < newGen.length; i++) {
            for (int j = 0; j < newGen.length; j++) {
cell = new Cell(destiny(cells, i, j));
newGen[i][j] = cell;
add(cell, i, j);
curGen = newGen;
My grid class is a subclass of GridPane
So when i click button it's working, but not from other Runnable
Edited by: Riddle on 11.12.2012 9:11