Map controller

Stateful map controller for Flutter Map. Manage markers, lines and polygons.

View the web demo

Usage

import 'dart:async';
import 'package:flutter/material.dart';
import 'package:flutter_map/flutter_map.dart';
import 'package:latlong/latlong.dart';
import 'package:map_controller/map_controller.dart';

class _MapPageState extends State<MapPage> {
   MapController mapController;
   StatefulMapController statefulMapController;
   StreamSubscription<StatefulMapControllerStateChange> sub;
   
   @override
   void initState() {
      // intialize the controllers
      mapController = MapController();
      statefulMapController = StatefulMapController(mapController: mapController);

      // wait for the controller to be ready before using it
      statefulMapController.onReady.then((_) => print("The map controller is ready")));

      /// [Important] listen to the changefeed to rebuild the map on changes:
      /// this will rebuild the map when for example addMarker or any method 
      /// that mutates the map assets is called
      sub = statefulMapController.changeFeed.listen((change) => setState(() {}));
      super.initState();
   }
   
   @override
   Widget build(BuildContext context) {
      return Scaffold(
         body: SafeArea(
            child: Stack(children: <Widget>[
               FlutterMap(
                  mapController: mapController,
                  options: MapOptions(center: LatLng(48.853831, 2.348722), zoom: 11.0),
                  layers: [
                     MarkerLayerOptions(markers: statefulMapController.markers),
                     PolylineLayerOptions(polylines: statefulMapController.lines),
                     PolygonLayerOptions(polygons: statefulMapController.polygons),
                  ],
               ),
            // ...
         ])),
      );
   }
   
   @override
   void dispose() {
      sub.cancel();
      super.dispose();
   }
}
   
class MapPage extends StatefulWidget {
   @override
   _MapPageState createState() => _MapPageState();
}

Api

Api for the StatefulMapController class

Map controls

Zoom

zoom: get the current zoom value

zoomIn(): increase the zoom level by 1

zoomOut(): decrease the zoom level by 1

zoomTo(): zoom to the provided value

Center

center: get the current center LatLng value

centerOnPoint(): center on the LatLng value

Map assets

Markers

addMarker(): add a named marker on the map

addMarkers(): add several named markers on the map

removeMarker(): remove a named marker from the map

removeMarkers(): remove several named markers from the map

markers: get the markers that are on the map

namedMarkers: get the markers with their names that are on the map

getMarker(): return the marker with the corresponding name

getMarkers(): return the markers with the corresponding names

Stateful markers

New in 0.7: the stateful makers hold their own state and can be mutated

statefulMapController.addStatefulMarker(
   name: "some marker",
   statefulMarker: StatefulMarker(
      height: 80.0,
      width: 120.0,
      state: <String, dynamic>{"showText": false},
      point: LatLng(48.853831, 2.348722),
      builder: (BuildContext context, Map<String, dynamic> state) {
         Widget w;
         final markerIcon = IconButton(
            icon: const Icon(Icons.location_on),
            onPressed: () => statefulMapController.mutateMarker(
               name: "some marker",
               property: "showText",
               value: !(state["showText"] as bool)));
         if (state["showText"] == true) {
            w = Column(children: <Widget>[
               markerIcon,
               Container(
                  color: Colors.white,
                  child: Padding(
                     padding: const EdgeInsets.all(5.0),
                     child: Text(place.name, textScaleFactor: 1.3))),
            ]);
         } else {
            w = markerIcon;
         }
         return w;
      })
);

Lines

addLine(): add a line on the map

lines: get the lines that are on the map

Polygons

addPolygon: add a polygon on the map

polygons: get the polygons that are on the map

On ready callback

Execute some code right after the map is ready:

@override
void initState() {
   statefulMapController.onReady.then((_) {
      setState((_) =>_ready = true);
   });
   super.initState();
}

Changefeed

A changefeed is available: it's a stream with all state changes from the map controller. Use it to update the map when a change occurs:

statefulMapController.onReady.then((_) {
   statefulMapController.changeFeed.listen((change) => setState(() {}));
});

Geojson data

The map controller can draw on the map from geojson data:

void loadData() async {
  print("Loading geojson data");
  final data = await rootBundle.loadString('assets/airports.geojson');
  await statefulMapController.fromGeoJson(data,
    markerIcon: Icon(Icons.local_airport), verbose: true);
}

@override
void initState() {
  mapController = MapController();
  statefulMapController = StatefulMapController(mapController: mapController);
  statefulMapController.onReady.then((_) => loadData());
  sub = statefulMapController.changeFeed.listen((change) => setState(() {}));
  super.initState();
}

Tile layer management

Some predefined tile layers are available.

   FlutterMap(
      mapController: mapController,
      options: MapOptions(
         center: LatLng(48.853831, 2.348722), zoom: 11.0),
      layers: [
         // Use the map controller's tile layer
         statefulMapController.tileLayer,
         MarkerLayerOptions(markers: statefulMapController.markers),
         // ...
      ],
   )

To switch tile layers at runtime use:

   statefulMapController.switchTileLayer(TileLayerType.monochrome);

Available layers:

   TileLayerType.normal
   TileLayerType.topography
   TileLayerType.monochrome
   TileLayerType.hike

A tile layers bar is available:

   Stack(children: <Widget>[
      FlutterMap(
         mapController: mapController,
         options: MapOptions(center: LatLng(48.853831, 2.348722), zoom: 11.0),
         layers: [
         statefulMapController.tileLayer,
         MarkerLayerOptions(markers: statefulMapController.markers),
         ],
      ),
      Positioned(
         top: 15.0,
         right: 15.0,
         child: TileLayersBar(controller: statefulMapController))
   ])