line-gradient with interpolation

[WuMianzhi]

Describe the bug
I want create a example like this, the same expression like it, the line doest show like the maplibre-gl-js, I also try to change style.json file , it cant either, and hint cant parse expression.

To Reproduce
try to set gradient style

Expected behavior
show a gradient line

[louwers]

Please share more details about what platform you are using and how to reproduce the problem.

[WuMianzhi]

here is my code, and it just dark and hints Error setting property: line-color expected a literal expression

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Using MapView requires calling MapLibre.getInstance() before inflating or creating the view.
        MapLibre.getInstance(this);

        // EdgeToEdge.enable(this);
        setContentView(R.layout.activity_main);
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main), (v, insets) -> {
            Insets systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars());
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom);
            return insets;
        });

        mapView = findViewById(R.id.mapView);

        mapView.getMapAsync(map -> {
            map.setStyle("https://api.maptiler.com/maps/basic-v2-dark/style.json?key=***********", new Style.OnStyleLoaded() {
                @Override
                public void onStyleLoaded(@NonNull Style style) {
                    addLineToMap(style);
                }
            });
        });
    }

    private void addLineToMap(Style style){
        List<Point> lineCoordinates = new ArrayList<>();
        lineCoordinates.add(Point.fromLngLat(0, 120));
        lineCoordinates.add(Point.fromLngLat(0, -120));

        LineString lineString = LineString.fromLngLats(lineCoordinates);

        GeoJsonSource geoJsonSource = new GeoJsonSource("line-source",
                FeatureCollection.fromFeature(Feature.fromGeometry(lineString)));

        style.addSource(geoJsonSource);

        LineLayer lineLayer = new LineLayer("line-layer", "line-source");
        Expression expression = Expression.interpolate(linear(), Expression.lineProgress(), stop(0, color(Color.BLUE)), stop(1, color(Color.RED)));
        lineLayer.setProperties(
                lineColor(expression),
                lineWidth(5f)
        );

        style.addLayer(lineLayer);
    }

[louwers]

Try using something like this:

                        LineLayer("gradient", LINE_SOURCE)
                            .withProperties(
                                PropertyFactory.lineGradient(
                                    Expression.interpolate(
                                        Expression.linear(),
                                        Expression.lineProgress(),
                                        Expression.stop(0f, Expression.rgb(0, 0, 255)),
                                        Expression.stop(0.5f, Expression.rgb(0, 255, 0)),
                                        Expression.stop(1f, Expression.rgb(255, 0, 0))
                                    )
                                ),
                                PropertyFactory.lineColor(Color.RED),
                                PropertyFactory.lineWidth(10.0f),
                                PropertyFactory.lineCap(Property.LINE_CAP_ROUND),
                                PropertyFactory.lineJoin(Property.LINE_JOIN_ROUND)
                            )

[WuMianzhi]

I see, thank you!, I know where is the mistake is, thank you very much