To programatically interact with the map (such as panning, zooming and rotating) and receive it's events, you'll need a MapController
.
If building a custom layer (Creating New Layers), consider using FlutterMapState
directly instead.
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.
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.
initState()
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 when the map is initialised, and the initialised map controller can be used freely within it.
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 MapController
s 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.