Controller
To programatically interact with the map (such as panning, zooming and rotating) and receive it's events, you'll need a
MapController.
To use a
MapController, it must initialised like any other object and then passed to the FlutterMap. This attaches them until the map is disposed.final mapController = MapController();
@override
Widget build(BuildContext context) =>
FlutterMap(
mapController: mapController,
...
);
Avoid disconnecting the map from the controller, as it can cause problems. If you need to change the map's contents:
- Change its
children(layers) individually - Re-initialise a new
MapController, and keep it in an external state system
If you still get issues, and
FlutterMap is located inside a PageView, ListView or another complex lazy layout, try setting keepAlive true in MapOptions: Permanent Rules.It is a fairly common requirement to need to use the
MapController in initState(), before the map has been built. Unfortunately, this is not possible, as the map must be built for the controller to be attached.This isn't a problem however! The
MapOptions contains an onMapReady callback (see Event Handling) is called once when the map is initialised, and the initialised map controller can be used freely within it.final mapController = MapController();
@override
Widget build(BuildContext context) =>
FlutterMap(
mapController: mapController,
options: MapOptions(
onMapReady: () {
mapController.mapEventStream.listen((evt) {});
// And any other `MapController` dependent non-movement methods
},
),
);
It may also be possible to use
SchedulerBinding or WidgetsBinding in initState to run a method after the first frame has been built, as detailed here: https://stackoverflow.com/a/64186549/11846040. You'll probably see this approach in many older projects.That method will, however, not work if the map is not built on the first frame. This may be the case if it is, for example, in a
FutureBuilder.MapController methods that change the position of the map should not be used instantly in onMapReady - see issue #1507.Using them as a reaction to a map event is still fine.
Whilst animated movements through
MapControllers aren't built-in, the community maintained plugin flutter_map_animations provides this, and much more!The example application also includes a page demonstrating a custom animated map movement without the plugin.
Last modified 3mo ago