import javafx.application.Application;
import javafx.beans.InvalidationListener;
import javafx.beans.Observable;
import javafx.beans.property.SimpleBooleanProperty;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.HBox;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class Main extends Application {
    public static void main(String[] args) {
        launch(args);        
    }
    
    SimpleBooleanProperty bool = new SimpleBooleanProperty(true); 
    {        
        bool.addListener(new ChangeListener<Boolean>() {
            public void changed(ObservableValue<? extends Boolean> val,
                    Boolean oldVal, Boolean newVal) {
                System.out.println("Heard a change...");
            }
        });
        
        bool.addListener(new ChangeListener<Boolean>() {
            public void changed(ObservableValue<? extends Boolean> val,
                    Boolean oldVal, Boolean newVal) {
                System.out.println("Heard a change 2...");
            }
        });
        
        bool.addListener(new InvalidationListener() {
            public void invalidated(Observable val) {
                System.out.println("Invalidated 1");   
            }
        });
        
        bool.addListener(new InvalidationListener() {
            public void invalidated(Observable val) {
                System.out.println("Invalidated 2");   
            }
        });
    }
    
    boolean toggle = true; 
    @Override
    public void start(final Stage stage) {        
        HBox root = new HBox();
        final Scene scene = new Scene(root);
        stage.setWidth(300);
        stage.setHeight(200);
        stage.setScene(scene);        
        
        final VBox box = new VBox(40);        

        Button butt = new Button("Toggle");
        butt.setOnAction(new EventHandler<ActionEvent>() {
            public void handle(ActionEvent e) {
                toggle = !toggle;
                bool.getValue();
                bool.setValue(toggle);
            }
        });        
        
        box.getChildren().addAll(butt);
        root.getChildren().addAll(box);
        
        stage.setVisible(true);
    }
}