Using Polyline for making custom route with google_maps_flutter plugin – Flutter

Issue

google_maps_flutter 0.5.6 Added support for Polylines on GoogleMap.
But there is no code or documentation available under my view.

A plugin named maps_view exists which supports polylines

import 'package:map_view/map_view.dart';
import 'package:map_view/polyline.dart';
...
MapView mapView = MapView();
mapView.addPolyline(Polyline('my_polyline', [
  Location(45.52309483308097, -122.67339684069155),
  Location(45.52298442915803, -122.66339991241693),
]));

I need the same function that’s built-in with google_maps_flutter.

Solution

Try this in your StatefulWidget subclass.

Map<PolylineId, Polyline> _mapPolylines = {};
int _polylineIdCounter = 1;

void _add() {
  final String polylineIdVal = 'polyline_id_$_polylineIdCounter';
  _polylineIdCounter++;
  final PolylineId polylineId = PolylineId(polylineIdVal);

  final Polyline polyline = Polyline(
    polylineId: polylineId,
    consumeTapEvents: true,
    color: Colors.red,
    width: 5,
    points: _createPoints(),
  );

  setState(() {
    _mapPolylines[polylineId] = polyline;
  });
}

@override
Widget build(BuildContext context) {
  return Scaffold(
    appBar: AppBar(
      title: Text("Maps"),
      actions: <Widget>[IconButton(icon: Icon(Icons.add), onPressed: _add)],
    ),
    body: GoogleMap(
      initialCameraPosition: const CameraPosition(target: LatLng(0, 0), zoom: 4.0),
      polylines: Set<Polyline>.of(_mapPolylines.values),
    ),
  );
}

List<LatLng> _createPoints() {
  final List<LatLng> points = <LatLng>[];
  points.add(LatLng(1.875249, 0.845140));
  points.add(LatLng(4.851221, 1.715736));
  points.add(LatLng(8.196142, 2.094979));
  points.add(LatLng(12.196142, 3.094979));
  points.add(LatLng(16.196142, 4.094979));
  points.add(LatLng(20.196142, 5.094979));
  return points;
}

Answered By – CopsOnRoad

Answer Checked By – Clifford M. (FlutterFixes Volunteer)