有什么方法可以在JavaFX中构建路径渐变？

Question

I need to use path gradients (vary the stroke color along a path), but currently couldn't find a way to do it with the current JavaFX API. Note that this is different than applying a linear gradient to a path element. This may seem to work for straight line segments, but fails in some arc configurations and multiple connected path elements.

Would someone offer any suggestions for an approach to this problem?

Answer 1

You can try the following approach:

@Override
public void start(Stage primaryStage) {
    Group root = new Group();

    // CREATE CANVAS
    final Canvas canvas = new Canvas(300, 250);
    // GET GRAPHICS CONTEXT
    final GraphicsContext gc = canvas.getGraphicsContext2D();


    // DRAW THE SHAPE (LINE)
    gc.beginPath();
    gc.moveTo(50, 50);     //Begin
    gc.lineTo(150, 200);   //End
    gc.closePath();

    // CREATE THE LINEAR EFFECT
    LinearGradient lg = new LinearGradient(0, 0, 1, 1, true,
            CycleMethod.REFLECT, new Stop(0.0, Color.RED), 
                                 new Stop(0.5, Color.GREEN),
                                 new Stop(1.0, Color.BLUE));
    // SET & STROKE WITH LINEAR
    gc.setLineWidth(20);
    gc.setStroke(lg);
    gc.stroke();


    //ADD CANVAS NODE TO ROOT
    root.getChildren().add(canvas);
    primaryStage.setScene(new Scene(root));
    primaryStage.show();
}