Moving a circle on a map using Observer pattern

I have a (probably an easy) problem with my java program. I'm trying to create a circle that will move from one place to another. The map is a part of an easy dialogue game that says "go here" and the map should react to it. It has to be using an Observer design pattern.

So far I have the map in the game implemented but I just can't fathom how to make the circle function as it should, while using Observer, too. Thanks for any help

package GUI;

import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.AnchorPane;
import javafx.scene.paint.Paint;
import javafx.scene.shape.Circle;
import logika.Game;
import logika.IGame;
import main.Main;
import utils.Observer;


public class Mapa extends AnchorPane implements Observer{

    private IGame game;
    private Circle dot;
    //private double posTop = 0.0;
    //private double posLeft = 0.0;

    public Mapa(IGame game){
            this.game = game;
            game.getGamePlan().registerObserver(this);
            init();
    }

    private void init(){

        ImageView obrazekImageView = new ImageView(new Image(Main.class.getResourceAsStream("/zdroje/mapa.gif"),255,255,false,true));

        tecka = new Circle(10, Paint.valueOf("red"));

       //this.setTopAnchor(tecka, 15.0);
       //this.setLeftAnchor(tecka, 20.0);

        this.getChildren().addAll(obrazekImageView, dot);
        update();
    }

    public void newGame(IGame newGame){
        game.getGamePlan().removeObserver(this);
        game= newGame;
        game.getGamePlan().registerObserver(this);
        update();

    }

    @Override
    public void update(){
        this.setTopAnchor(this, game.getGamePlan().getCurrentPlace().getPosTop());
        this.setLeftAnchor(this, game.getGamePlan().getCurrentPlace().getPosLeft());
    }
}