animation property Null safety

Animation<double>? animation
final

Animation for the lines in MapLineLayer.

By default, lines will be rendered without any animation. The animation can be set as shown in the below code snippet. You can customise the animation flow, curve, duration and listen to the animation status.

  late AnimationController _animationController;
  late Animation<double> _animation;
  late MapZoomPanBehavior _zoomPanBehavior;
  late MapShapeSource _mapSource;
  late List<Model> _lines;

  @override
  void initState() {
    _zoomPanBehavior = MapZoomPanBehavior(
      focalLatLng: MapLatLng(40.7128, -95.3698),
      zoomLevel: 3,
    );

    _mapSource = MapShapeSource.asset(
      "assets/world_map.json",
      shapeDataField: "continent",
    );

    _lines = <Model>[
      Model(MapLatLng(40.7128, -74.0060), MapLatLng(44.9778, -93.2650)),
      Model(MapLatLng(40.7128, -74.0060), MapLatLng(33.4484, -112.0740)),
      Model(MapLatLng(40.7128, -74.0060), MapLatLng(29.7604, -95.3698)),
      Model(MapLatLng(40.7128, -74.0060), MapLatLng(39.7392, -104.9903)),
    ];

    _animationController = AnimationController(
      duration: Duration(seconds: 3),
      vsync: this,
    );

    _animation =
        CurvedAnimation(parent: _animationController,
        curve: Curves.easeInOut);

    _animationController.forward(from: 0);
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SfMaps(
        layers: [
          MapShapeLayer(
            source: _mapSource,
            zoomPanBehavior: _zoomPanBehavior,
            sublayers: [
              MapLineLayer(
                lines: List<MapLine>.generate(
                  _lines.length,
                  (int index) {
                    return MapLine(
                      from: _lines[index].from,
                      to: _lines[index].to,
                    );
                  },
                ).toSet(),
                animation: _animation,
              ),
            ],
          ),
        ],
      ),
    );
  }

  @override
  void dispose() {
    _animationController?.dispose();
    super.dispose();
  }
}

class Model {
  Model(this.from, this.to);

  MapLatLng from;
  MapLatLng to;
}

Implementation

final Animation<double>? animation;