JavaFX how to cut polygon that is out of AnchorPane

Question

Is there a way to cut a Polygon if a part of it is getting out of it's AnchorPane?

I could try subtracting the Polygon with a rectangular shape but I wonder if there is a simpler way.

The image shows an example of a polygon getting out of the AnchorPane.

Edit: I tried setting max width and height to the AnchorPane, but it's not working.

Answer 1

You need to use clip.

    import javafx.application.Application;
    import javafx.scene.Scene;
    import javafx.scene.control.Button;
    import javafx.scene.layout.AnchorPane;
    import javafx.scene.layout.Region;
    import javafx.scene.layout.StackPane;
    import javafx.scene.layout.VBox;
    import javafx.scene.paint.Color;
    import javafx.scene.shape.Polygon;
    import javafx.scene.shape.Rectangle;
    import javafx.stage.Stage;

    public class ClipApp extends Application {

        public static void main(String[] args) {
            launch(args);
        }

        @Override
        public void start(Stage stage) throws Exception {

            Polygon hexagon = new Polygon();
            hexagon.getPoints().addAll(new Double[]{        
                    50., 0., 
                    150.0, 0., 
                    200.0, 100.0,          
                    150.0, 200.0, 
                    50.0, 200.0,                   
                    0., 100.0, 
                 });
            hexagon.setFill(Color.YELLOW);

            AnchorPane anchorPane = new AnchorPane(hexagon);
            anchorPane.setStyle("-fx-background-color: purple");
            anchorPane.setPrefSize(200, 200);
            anchorPane.setMinSize(Region.USE_PREF_SIZE, Region.USE_PREF_SIZE);
            anchorPane.setMaxSize(Region.USE_PREF_SIZE, Region.USE_PREF_SIZE);

            Rectangle rectangle = new Rectangle();
            rectangle.widthProperty().bind(anchorPane.widthProperty());
            rectangle.heightProperty().bind(anchorPane.heightProperty());

            AnchorPane.setLeftAnchor(hexagon, 50.);
            AnchorPane.setTopAnchor(hexagon, 50.);

            StackPane stackPane = new StackPane(anchorPane);
            stackPane.setStyle("-fx-background-color: blue");
            stackPane.setPrefSize(400, 400);

            Button button = new Button("Clip");

            VBox vBox = new VBox(stackPane, button);

            Scene scene = new Scene(vBox);
            stage.setScene(scene);
            stage.show();

            button.setOnAction(event -> {
                if (anchorPane.getClip() == null) {
                    button.setText("Unclip");
                    anchorPane.setClip(rectangle);
                } else {
                    button.setText("Clip");
                    anchorPane.setClip(null);
                }
            });
        }
    }