event handling

[Lefteris Moussiades]

Below is a test code that I wrote trying to understand events. When I press the mouse on the circle the event follows  the bubbling road back to the anchor pane but when I press the mouse on button1 the event seems to be consumed on the button1 and does not bubble back to anchor pane. Why? What is happen?

package events2;

import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TextArea;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.AnchorPane;
import javafx.scene.layout.Background;
import javafx.scene.layout.HBox;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.stage.Stage;

/**
 *
 * @author Lefteris
 */
public class Events2 extends Application {

    @Override
    public void start(Stage primaryStage) {
        Button btn = new Button();
        btn.setText("Say 'Hello World'");
        btn.setOnAction(new EventHandler<ActionEvent>() {

            @Override
            public void handle(ActionEvent event) {
                System.out.println("Hello World!");
            }
        });

        AnchorPane aP = new AnchorPane();

        VBox vB = new VBox();
        vB.setStyle("-fx-background-color: orange;");
        vB.setPrefWidth(171);
        vB.setPrefHeight(160);

        AnchorPane.setBottomAnchor(vB, 20.0);
        AnchorPane.setLeftAnchor(vB, 100.0);
        AnchorPane.setRightAnchor(vB, 45.0);
        AnchorPane.setTopAnchor(vB, 20.0);
        Button btn1 = new Button();
        btn1.setText("Button1");
        HBox hB = new HBox();
        hB.setStyle("-fx-background-color: blue;");

        TextArea txt = new TextArea();
        txt.setStyle("-fx-background-color: red;");
        txt.setPrefWidth(44.0);
        txt.setPrefHeight(51.0);
        HBox.setMargin(txt, new Insets(4, 4, 4, 4));

        Circle c = new Circle();
        c.setFill(Color.CHARTREUSE);
        c.setRadius(45.0);

        hB.getChildren().addAll(txt, c);
        vB.getChildren().addAll(btn1, hB);
        aP.getChildren().add(vB);

        aP.addEventHandler(MouseEvent.MOUSE_PRESSED, handler);
        vB.addEventHandler(MouseEvent.MOUSE_PRESSED, handler);
        btn1.addEventHandler(MouseEvent.MOUSE_PRESSED, handler);
        txt.addEventHandler(MouseEvent.MOUSE_PRESSED, handler);
        hB.addEventHandler(MouseEvent.MOUSE_PRESSED, handler);
        c.addEventHandler(MouseEvent.MOUSE_PRESSED, handler);
        
        aP.addEventFilter(MouseEvent.MOUSE_PRESSED, filter);
        vB.addEventFilter(MouseEvent.MOUSE_PRESSED, filter);
        btn1.addEventFilter(MouseEvent.MOUSE_PRESSED, filter);
        txt.addEventFilter(MouseEvent.MOUSE_PRESSED, filter);
        hB.addEventFilter(MouseEvent.MOUSE_PRESSED, filter);
        c.addEventFilter(MouseEvent.MOUSE_PRESSED, filter);

        Scene scene = new Scene(aP, 320, 200);

        primaryStage.setTitle("Event Handling");
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    EventHandler handler = new EventHandler<MouseEvent>() {
        @Override
        public void handle(MouseEvent e) {
            System.out.println("handling....");
            System.out.println(e.getSource());
            System.out.println(e.getTarget());
            System.out.println(e.getEventType());
            System.out.println(e.isConsumed());
            System.out.println("-------------------------");
        }
    };

    EventHandler filter = new EventHandler<MouseEvent>() {
        @Override
        public void handle(MouseEvent e) {
            System.out.println("filtering....");
            System.out.println(e.getSource());
            System.out.println(e.getTarget());
            System.out.println(e.getEventType());
            System.out.println(e.isConsumed());
            System.out.println("-------------------------");
        }
    };
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        launch(args);
    }

}

[John Damien Smith]

See answers on StackOverflow:
 http://stackoverflow.com/questions/41132015/why-by-default-button-mouse-event-handler-consume-an-event/41132604#41132604
 http://stackoverflow.com/questions/23777186/javafx-button-event-bubbling

[Campbell Ritchie]

...and welcome to the Ranch