How to clip a line?

Question

Here is my following code:

 public void start(Stage primaryStage) throws Exception {
    Pane pane = new Pane();
    Scene scene = new Scene(pane, 500, 500);
    Line line = new Line(0, 200, 500, 200);

    line.setStrokeWidth(2);
    line.setStroke(Color.RED);
    pane.getChildren().add(line);
    primaryStage.setScene(scene);
    primaryStage.show();

}

It outputs a line, but I wanna clip that line. For example: If I have a line which starts from (0, 200) and ends at (500, 200), then I want to clip it from (200, 200) to (400, 200). Is there any way I can clip the line? Any help is appreciated! Thank you.

Answer 1

If clipping is really what you want to do (you did not tell us your real use-case) I'd still tend to use a solution that Sedrick has already shown in his code but commented out for some reason. Every shape has a setClip method, so why not use it?

import javafx.application.Application;
import javafx.geometry.Bounds;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Line;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;


public class LineChartSample extends Application {

    int clickCount = 0;

    @Override public void start(Stage stage) {
        Pane pane = new Pane();
        Scene scene = new Scene(pane, 500, 500);
        Line line = new Line(0, 200, 500, 200);

        line.setStrokeWidth(2);
        line.setStroke(Color.RED);

        Bounds b = line.getBoundsInParent();
        System.out.println(b);

        pane.getChildren().add(line);

        pane.setOnMouseClicked((event)->{
            ++clickCount;
            double d = clickCount*20.0;
            Rectangle clipRect = new Rectangle(b.getMinX() + d, b.getMinY(), b.getWidth() - 2*d, b.getHeight());
            line.setClip(clipRect);
        });

        stage.setWidth(700);
        stage.setScene(scene);
        stage.show();
    }

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

Answer 2

I used a setEndX inside a setOnMouseClicked listener to demostrate this. You may need to do some math and use both setEndX and setEndY to get your desired outcome.

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Line;
import javafx.stage.Stage;


public class LineChartSample extends Application {

    @Override public void start(Stage stage) {
        Pane pane = new Pane();
        Scene scene = new Scene(pane, 500, 500);
        Line line = new Line(0, 200, 500, 200);

        line.setStrokeWidth(2);
        line.setStroke(Color.RED);
        pane.getChildren().add(line);

//        Rectangle clipRect = new Rectangle(line.getBoundsInParent().getWidth(), line.getBoundsInParent().getHeight());
//        line.setClip(clipRect);

        line.setOnMouseClicked((event)->{
            line.setEndX(line.getBoundsInLocal().getWidth() - 100);
        });

        stage.setWidth(700);
        stage.setScene(scene);
        stage.show();
    }

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