Demonstration

This code snippet demonstrates everything you need for a simple map - of course, FlutterMap is much more customisable than just this!

return FlutterMap(
    options: MapOptions(
        center: LatLng(51.509364, -0.128928),
        zoom: 9.2,
    ),
    nonRotatedChildren: [
        AttributionWidget.defaultWidget(
            source: 'OpenStreetMap contributors',
            onSourceTapped: null,
        ),
    ],
    children: [
        TileLayer(
            urlTemplate: 'https://tile.openstreetmap.org/{z}/{x}/{y}.png',
            userAgentPackageName: 'com.example.app',
        ),
    ],
);

Feature Highlights

Get Help

If you're not sure where to get help, feel free to ask anywhere, and we'll try to point you in the right direction.

General Support

If you're not sure how to do something, the best place to get help is on the Discord server! We're here to answer your questions as quickly as possible, so please give us as much information as you can! Please remember that we are volunteers, so we cannot guarantee (fast) support.

Use the link/button at the top of this page, or the link in the footer on all pages to join.

Bugs & Feature Requests

For suspected bugs or feature requests, visit the issue tracker on GitHub and ask away! We'll try to get back to you relatively quickly, but it may take longer for larger issues.

All Platforms

This can then be imported like this in any required files:

import 'package:latlong2/latlong.dart';

Additionally, other plugins (see Plugins List) might require other setup and/or permissions.

Android

On Android, additional setup may be required. To access the Internet to reach tile servers, ensure your app is configured to use the INTERNET permission. Check (and if necessary add) the following lines in the manifest file located at '/android/app/src/main/AndroidManifest.xml':

<uses-permission android:name="android.permission.INTERNET"/>

You may also need to do this in any other applicable manifests, such as the profile one, if not already in there.

Center (center)

Takes a LatLng object, specifying the latitude and longitude of the center of the map when it is first built. For example:

        center: LatLng(0.0, 0.0),

Defaults to LatLng(50.5, 30.51).

Zooms (zoom, minZoom, maxZoom)

Takes doubles, but should usually be set initially to integers (in double format).

zoom specifies what the zoom level of the map should be when it is first built, defaulting to level 13. maxZoom specifies what the maximum zoom level can be, and should depend on your use case and/or tile server. minZoom specifies what the minimum zoom level can be, and should usually be set to 0/null default.

        zoom: 13.0,
        maxZoom: 19.0,

Boundaries (bounds, maxBounds)

Takes LatLngBounds to restrict the map view within a rectangular area.

bounds is only effective on first build, and is an alternative to using center and zoom to initialise the map. maxBounds is persistent and prevents the view moving outside of the area. For example:

        bounds: LatLngBounds(
            LatLng(51.74920, -0.56741),
            LatLng(51.25709, 0.34018),
        ),
        maxBounds: LatLngBounds(
            LatLng(-90, -180.0),
            LatLng(90.0, 180.0),
        ),

will make the map center on London at first, and ensure that the gray void around the world cannot appear on screen (in the default projection).

Rotation (rotation)

Takes a double specifying the bearing of the map when it is first built. For example:

        rotation: 180.0,

will put the South of the map at the top of the device.

Defaults to 0(°).

Keep Alive (keepAlive)

If you are using a more complex layout in your application - such as using the map inside a ListView, a PageView, or a tabbed layout - you may find that the map resets when it appears/scrolls back into view. This option is designed to prevent that.

Takes a bool flag, toggling whether the internal map state should wantKeepAlive.

        keepAlive: true,

Defaults to false.

This has a default of NetworkNoRetryTileProvider, which is recommended for most setups for better performance, unless your tile server is especially unreliable, or you need a local tile provider.

Custom TileProviders can be implemented by your application or other libraries. These may not conform to the usual rules above, and may additionally have their own parameters.

Network Tile Providers

Whilst not on the web, network tile providers can take a custom HttpClient/RetryClient, if you need to use it for whatever reason.

NetworkNoRetryTileProvider()

This is the default tile provider.

This tile provider uses the templateUrl to get the appropriate tile from the Internet, and it won't retry the request if it fails.

There is no guarantee about the default caching behaviour, but tiles should be cached until an application restart.

NetworkTileProvider()

This tile provider uses the templateUrl to get the appropriate tile from the Internet, but it will retry the request as specified in the RetryClient (which can be customised as needed when not on the web).

There is no guarantee about the default caching behaviour, but tiles should be cached until an application restart.

Local Tile Providers

These tile providers use the templateUrl to get the appropriate tile from the asset store of the application, or from a file on the users device, respectively

AssetTileProvider()

This tile providers uses the templateUrl to get the appropriate tile from the asset store of the application.

FileTileProvider()

This tile providers uses the templateUrl to get the appropriate tile from the a path/directory/file on the user's device - either internal application storage or external storage.

Offline Mapping

Bundled Map Tiles

If you have a set of custom raster tiles that you need to provide to all your users, you may want to consider bundling them together, to make a them easier to deploy to your users. Note that this is different to the #caching section below.

There is essentially two options for doing this:

• Using AssetTileProvider, you can bundle a set of map tiles and register them as an asset within your app's pubspec.yaml. This means that they will be downloaded together with your application, keeping setup simple, but at the expense of a larger application bundle size.

• Using FileTileProvider, you can bundle a set of map tiles and store them on a remote web server, that can be downloaded from later. This means that the setup may be more complicated for users, but the application's bundle size will be much smaller.

Either way, the filesystem should be structured like this: 'offlineMap/{z}/{x}/{y}.png', where every .png image is a tile.

Caching & Bulk Downloading

However, using simpler packages in a DIY solution can be a better option in some cases. You'll need to implement a custom TileProvider backed by an alternative image provider or cache lookup system: see Creating New Tile Providers.

To help choose whether FMTC or DIY is more appropriate for your usecase, please see:

If you prefer to offer a set of map tiles to all your users before runtime, consider using the Bundled Map Tiles solution instead.

A tile layer displays raster map tiles in a grid pattern, from a tile source such as a remote server or file system. This might look something like this:

FlutterMap(
    options: MapOptions(),
    children: [
        TileLayer(
          urlTemplate: "https://tile.openstreetmap.org/{z}/{x}/{y}.png",
          userAgentPackageName: 'dev.fleaflet.flutter_map.example',
        ),
    ],
),

This is the recommended method of installing this package as it ensures you only receive stable versions, and you can be sure pub.dev is reliable. It also keeps the size of your pubspec.yaml small.

Just import the package as you would normally, from the command line:

If you urgently need the latest version, a specific branch, or a specific fork, you can use this method.

Import

After installing the package, import it into the necessary files in your project:

There are 2 main types of tiles a server can serve: raster and vector; each has their own advantages and drawbacks. This page is designed to help you choose a type for your app, and help you use vector tiles if you choose to.

Raster Tiles

Raster tiles are the 'older' type of tile, and are raster images (usually .png or .jpg). These tiles are good because they can render quickly and easily, can be viewed without special software, and are readily available from most mapping services. As such, this makes them the popular choice for beginners.

However, raster tiles cannot be easily themed: a theme needs a whole new set of map tiles. This makes apps using light and dark themes have mismatching maps. As well as this, raster tiles usually have larger file sizes meaning slower download times, and they can become blurred/pixelated when viewed at a larger scale: a problem for users when zooming between zoom levels. Another issue is that shapes/text inside tiles cannot be rotated, hence the name 'static tiles': therefore, rotating the map will not rotate the name of a road, for example.

Vector Tiles

Vector tiles can be considered the 'newer' standard. These images might contain a specialised format (such as .pbf) dictating the mathematics and coordinates used to draw lines and shapes. Because these tiles are drawn at render time instead of at request/server time, theming can be used to make the map fit in better with an app's theme. The math-based image means that the images/tiles can be scaled without any loss of clarity.

However it does add complexity to the rendering process as each element needs to be parsed and painted individually, meaning an impact to performance. Text elements and certain shapes can also be rotated (unlike raster tiles) to match the user's orientation, not the orientation of the map; but calculating this rotation needs to be done every frame, meaning an even larger impact on performance.

Using Vector Tiles

This library is similar to most other mapping libraries in other languages, so this applies to most other mapping libraries as well.

A mapping library is usually just a wrapper for a particular language that handles requests to servers called 'tile servers', and displays it in an interactive view for the user.

What is a Tile Server?

A tile server is a server accessible on the Internet by everyone, or by only people holding the correct API key.

There are four main types of server configuration, two of which are used together by any server: WMS or WMTS (aka. CARTO) & vector or raster. This wiki will focus on WMTS raster servers, such as the main OpenStreetMaps server, as it is the most commonly used option and is easier to setup and explain for beginners, but you can read about the options for WMS later on in this wiki. At the moment, support of vector tiles is limited, but experimental functionality can be added through an existing community maintained plugin.

Simplified, the server holds multiple images in a directory structure that makes it easy to find tiles without searching for references in a database beforehand (see below). These images put together make up the whole world, or area that that tile server supports. One tile is usually really small when rendered, under 20KB for most tiles. However, the entire planet data consumes 1.5TB when un-rendered and uncompressed from the 110GB download archive. When all tiles are rendered, they add up to over 54TB! Most servers render tiles on-the-fly to get around this.

'Slippy Map' Convention

The standard Slippy Map path looks like this: '/zoom/x/y.png' or '/x/y/zoom.png'. To note, the image format does not have to be '.png', tile servers also commonly serve as '.jpg' images.

You may also see '/?x={x}&y={y}&zoom={z}', which isn't quite the same as the Slippy Map convention, but it works in essentially the same way, so the below text still applies.

Zoom

X & Y

These images show the mathematics required to convert between Latitude and Longitude & the x/y/z format and vice-versa respectively. All credit for the above images goes to the Open Street Maps foundation.

Tile Providers

In this 'flutter_map' package, the classes that conduct this maths to get these tiles are called 'tile providers'.

However, these do a lot more than just the maths. They do the maths, format the appropriate URL, potentially stagger the URL (not to get rate limited by the browser or engine), make the request, get the image, process (and potentially store) the image and finally give it back to the main process to paint onto the map for the user to see.

Unless you choose to implement your own custom tile provider, you should never need to handle this yourself.

Map Layers

Once the tile provider has dealt with the tile, it sends it to a map layer to get painted onto the map. This can be done using canvases (such as in HTML5 for the web), or, in the case of 'flutter_map', Flutter widgets.

The map layers also handle user interaction, such as panning, zooming, rotating and tapping.

You can add markers to maps to display specific points to users using MarkerLayer().

FlutterMap(
    options: MapOptions(),
    children: [
        MarkerLayer(
            markers: [
                Marker(
                  point: LatLng(30, 40),
                  width: 80,
                  height: 80,
                  builder: (context) => FlutterLogo(),
                ),
            ],
        ),
    ],
),

Markers (markers)

As you can see MarkerLayerOptions() accepts list of Markers which determines render widget, position and transformation details like size and rotation.

You can add lines to maps to display paths/ways made out of points to users using PolylineLayer().

FlutterMap(
    options: MapOptions(),
    children: [
        PolylineLayer(
            polylineCulling: false,
            polylines: [
                Polyline(
                  points: [LatLng(30, 40), LatLng(20, 50), LatLng(25, 45),],
                  color: Colors.blue,
                ),
            ],
        ),
    ],
),

Polylines (polylines)

As you can see PolylineLayerOptions() accepts list of Polylines. Each determines the shape of a polyline by defining the LatLng of each point. 'flutter_map' will then draw a line between each coordinate.

Converting Formats

You may have a polyline with 'Google Polyline Encoding' (which is a lossy compression algorithm to convert coordinates into a string and back). These are often returned from routing engines, for example. In this case, you'll need to decode the polyline to the correct format first, before you can use it in a Polyline's points argument.

import 'package:latlong2/latlong.dart';
export 'package:google_polyline_algorithm/google_polyline_algorithm.dart'
    show decodePolyline;

extension PolylineExt on List<List<num>> {
  List<LatLng> unpackPolyline() =>
      map((p) => LatLng(p[0].toDouble(), p[1].toDouble())).toList();
}

You can then use the package and the above snippet by doing:

import '<code_snippet_path>'

decodePolyline('<encoded-polyline>').unpackPolyline(); // Returns `List<LatLng>` for a map polyline

The options property takes a MapOptions() object.

This is where you'll configure most of your global map settings, but not settings that depend on, or affect a specific, map layer.

None of the options are required, but the options property on the FlutterMap() is required.

You can add circle polygons to maps to users using CircleLayer().

FlutterMap(
    options: MapOptions(),
    children: [
        CircleLayer(
            circles: [],
        ),
    ],
),

Interactivity Settings (interactiveFlags)

Takes an integer bitfield, which can be treated similar to enumerables. For example:

        InteractiveFlag.all & ~InteractiveFlag.rotate

allows/enables all interactions except for rotation (keeping the map at the heading specified by rotation).

The flags below are available:

Use & for 'AND' logic and ~ for 'NOT' logic. Combining these two gates, as shown in the example, can lead to many combinations, each easy to put together.

Defaults to enabling all interactions (all).

Scroll Wheel Settings (enableScrollWheel & scrollWheelVelocity)

Used together to enable scroll wheel scrolling, and set it's sensitivity/speed.

The first parameter takes a bool, enabling or disabling scroll wheel zooming. The second takes a double, which is used as a multiplier for changing the zoom level internally.

        enableScrollWheel: true,
        scrollWheelVelocity: 0.005,

Defaults to true and 0.005.

When Position Changed (onPositionChanged)

Takes a function with two arguments. Gets called whenever the map position is changed, even if it is not changed by the user.

        onPositionChanged: (MapPosition position, bool hasGesture) {
            // Your logic here. `hasGesture` dictates whether the change
            // was due to a user interaction or something else. `position` is
            // the new position of the map.
        }

When Map Tapped (onTap)

Takes a function with one argument. Gets called whenever the the user taps/clicks/presses on the map.

        onTap: (TapPosition position, LatLng location) {
            // Your logic here. `location` dictates the coordinate at which the user tapped.
        }

When Map Ready (onMapReady)

See Usage In initState() before using this callback.

This callback can be registered if you need to do something with the map controller as soon as the map is available and initialized; generally though it isn't needed and the map is available after first build.

Takes a function with zero arguments. Gets called from the initState() method of the FlutterMap.

The mapController property takes a MapController, and whilst it is optional, it is strongly recommended for any map other than the most basic. It allows you to programmatically interact with the map, such as panning, zooming and rotating.

Initialisation

To use a MapController, it must initialised and then passed to the FlutterMap. This attaches them until the widget is destroyed/disposed.

final mapController = MapController();

@override
Widget build(BuildContext context) =>
    FlutterMap(
        mapController: mapController,
        ...
    );

Usage In initState()

It is a fairly common requirement to need to use the MapController before the map has been built, or to initialise a listener for one of it's streams inside the initState() StatefulWidget method. Unfortunately, this is not possible, as the map must be built for the controller to be attached.

Recommended Usage

Luckily, Flutter provides methods to wait until the first frame has been built, which usually means the FlutterMap widget will have been built (see exception circumstances below). This makes it trivially easy to implement the desired behaviour.

@override
void initState(){
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) {
        // Use `MapController` as needed
    });
}

Alternative Usage

In some cases, the FlutterMap widget may not have been built on the first frame - for example when using a FutureBuilder around the map.

In this case, an alternative method is required to use the MapController on build. This method uses the When Map Ready (onMapReady) callback.

@override
Widget build(BuildContext context) =>
    FlutterMap(
        mapController: mapController,
        options: MapOptions(
            onMapReady: () {
                // Use `MapController` as needed
            },
        ),
    );

Available Methods

FlutterMap(
    mapController: _mapController,
    options: MapOptions(),
    children: [],
    nonRotatedChildren: [],
);

Placement Recommendations

It is recommended to make the map as large as possible, to allow it to display a lot of useful information easily.

As such, we recommend using a depth-based layout (eg. using Stacks) instead of a flat-based layout (eg. using Columns). The following 3rd party packages might help with creating a modern design:

If you must restrict the widget's size, you won't find a height or width property. Instead, use a SizedBox or Column/Row & Expanded.

There are many independently maintained 'plugins' created by the 'flutter_map' community that give extra, prebuilt functionality, saving you even more time and potentially money.

Some pages in this documentation provide direct links to these plugins to make it easier for you to find a suitable plugin.

However, if you're just browsing, a full list is provided below (in no particular order), containing many of the available plugins. You can click on any of the tiles to visit its GitHub repo or pub.dev package.

Miscellaneous

From more layers to whole heaps of new functionality, it's all here - assuming it's not in one of the other sections!

Marker Clustering

Marker clustering groups markers together under bigger markers when zoomed further out, decluttering your UI and giving a performance boost.

Better Markers

Better Polylines & Polygons

Parsing & Creating Map Features

Mapbox is a popular pay-as-you-go tile provider solution, especially for commercial applications. However, setup with 'flutter_map' can be a bit finicky, so this page is here to help you get going with Mapbox. Note that these methods use up your 'Static Tiles API' quota.

Pre-made Styles

Custom Styles

Then make the map style public, and open the share dialog, as seen below:

Scroll to the bottom of the dialog, and select Third Party. Then from the drop down box, select 'CARTO':

You'll then need to copy the URL and use it in 'flutter_map', like in the code below.

Usage

You should remove the 'access_token' (found at the end of the URL, usually beginning with 'pk.') from the URL for readability. Instead, pass it to additionalOptions.

FlutterMap(
    options: MapOptions(
      center: LatLng(51.5, -0.09),
      zoom: 13.0,
    ),
    nonRotatedChildren: [
        // This does NOT fulfill Mapbox's requirements for attribution
        // See https://docs.mapbox.com/help/getting-started/attribution/
        AttributionWidget.defaultWidget(
            source: '© Mapbox © OpenStreetMap',
            onSourceTapped: () async {
                // Requires 'url_launcher'
                if (!await launchUrl(Uri.parse("https://docs.mapbox.com/help/getting-started/attribution/"))) {
                    if (kDebugMode) print('Could not launch URL');
                }
            },
        )
    ],
    children: [
      TileLayer(
        urlTemplate: "https://api.mapbox.com/styles/v1/<user>/<tile-set-id>/tiles/<256/512>/{z}/{x}/{y}@2x?access_token={access_token}",
        additionalOptions: {
            "access_token": "<ACCESS-TOKEN>",
        },
        userAgentPackageName: 'com.example.app',
      ),
    ],
);

There are many independently maintained plugins created by the 'flutter_map' community that give extra, prebuilt functionality, saving you even more time and potentially money.

Unfortunately, you may need more niche functionality that hasn't been provided by an existing plugin or by 'flutter_map' itself. Alternatively, you may have found a gap in functionality that not everyone will need, but some people will: in this case, it's likely the maintainers will ask you to submit a plugin instead of a pull request.

Plugins can add/change a wide variety of functionality, so this guide is not exhaustive. However, it will help with the most common requirements. Each subpage covers a specific part of the plugin API, and the section below sets out requirements for plugins to be accepted into the list.

Submitting A New Plugin

If you've made your own plugin that you're willing to share, you can add it to this list by creating a pull request in GitHub. We're always looking forward to see what you've made!

When submitting a plugin & PR, please ensure the plugin:

• preferably includes 'flutter_map_' in the name

• preferably available via a pub.dev installation

• has good documentation

• includes a runnable example, and/or screenshots or recordings

• has a description that accurately and concisely represents your plugin

If you want to provide extra assistance to your users in a shared space, consider the official 'flutter_map' Discord server! Join using the link at the bottom of this page, and ping '@Github Maintainer' to be added to the 'Plugin Owner' role. You can then be easily identified and provide help or announcements in a dedicated plugins channel.

This class of errors is usually caused by mis-configuring MapControllers (see Controller), or using them in complex layouts.

If you're having these issues - which can manifest as LateInitializationErrors and/or BadState errors - there are a few things you can try to help out:

• Fully read the Controller page, and choose the right implementation/usage for your situation.

• In complex layouts, such as with PageViews or ListViews, use the Keep Alive (keepAlive) property.

• If sharing the map controller, for example through Provider, make sure that the shared controller is initialised and destroyed/uninitialised at the same time as the FlutterMap.

Subdomains (subdomains)

Takes a list of strings specifying the available subdomains. For example:

One will be chosen differently every request by the tile provider to replace the '{s}' part of the urlTemplate.

If you are not sure of the correct values for your server, don't specify anything. For example, the urlTemplate used in the example above will work without the '{s}' part and any subdomains specified.

Tile Bounds (tileBounds)

Takes a LatLngBounds to restrict the layer to only loading tiles within that area. For example:

will restrict the tiles to only loading Egypt (a square-ish country). Note that the map can still be moved freely outside of this range.

An example use-case might therefore be loading a specialised map for a region and just a basic map style elsewhere (different urlTemplates). In this case, the bounded layer should go beneath the unbounded layer. Setting backgroundColor: Colors.transparent is also necessary on the bounded layer to ensure the other layer is visible elsewhere.

Error/Fallback Tile (errorImage)

will use a sea tile on every tile that cannot be fetched.

This is an optional parameter that has no default. If this is not specified, and tiles are unable to be fetched, then the background color.

Tile Size (tileSize)

Takes a double number specifying the width and height (in pixels) of each tile. As tiles are always square, only one number is needed.

This defaults to 256, as most tile servers serve 256x256px tiles.

Custom Tile Builder (tileBuilder)

Takes a callback function, in the format Widget Function(BuildContext context, Widget tileWidget, Tile tile). For example:

will show the tile's coordinate on the tile.

There is also tilesContainerBuilder available, which works slightly differently, but is recommended when the same builder can be used on every tile, for performance reasons.

There are predefined tile builders available, such as a dark mode emulator and a loading time debugger.

Reset Stream (reset)

Takes a Stream<void>?, that causes the layer to 'reset' when an event is received. This might be necessary after updating the templateUrl. For example:

Thunderforest is a popular tiered-payment (with free tier) tile provider solution, especially for generic mapping applications. Note that using 'flutter_map' uses up your 'Map Tiles API' requests.

If you have a question you'd like to add to this page, please let us know over on the Discord server!

You should also read the How Does It Work? page for a more generalised overview of the most important facts.

URL Template (urlTemplate)

This parameter is not strictly required, but the map is essentially useless without it specified with a valid URL.

Takes a string that is a valid URL, which is the template to use when the tile provider constructs the URL to request a tile from a tile server. For example:

will use the OpenStreetMap Tile Server.

The '{s}', '{z}', '{x}' & '{y}' parts indicate where to place the subdomain, zoom level, x coordinate, and y coordinate respectively. Not providing at least the latter 3 parts won't necessarily throw an error, but the map won't show anything.

Package Name (userAgentPackageName)

Takes a String, which should be the unique package name (eg. com.example.app). For example:

This string is used to construct a 'User-Agent' header, sent with all tile requests (on platforms other than the web, due to Dart limitations), necessary to prevent blocking by tile servers.

Constructed agents are in the format: 'flutter_map (packageName)'. If the package name is not specified, 'unknown' is used in place.

Tile Provider (tileProvider)

For more information, see:

Retina Mode (retinaMode)

If true, the providers should request four tiles of half the specified size and a bigger zoom level in place of one to utilize the high resolution. In this case, you should set MapOptions's maxZoom should be maxZoom - 1 instead.

For example, this is the recommended setup:

Creating a new map layer is just as easy as it is to create a normal StatelessWidget or StatefulWidget.

Only one method call is needed to 'connect' the widget to the map state: FlutterMapState.maybeOf(). This call does two important things:

• Cause the widget/layer to rebuild automatically when required (if in the build method)

• Expose the map's internal state, meaning that it's information (such as zoom) can be accessed

You can see an example of how this is done below:

class CustomLayer extends StatelessWidget {
  const CustomLayer({super.key});

  @override
  Widget build(BuildContext context) {
    final mapState = FlutterMapState.maybeOf(context)!;
    // Use `mapState` as necessary, for example `mapState.zoom`
  }
}

Before publishing your app to users, you should credit the tile server you use, this library, and potentially and plugins you use.

FlutterMap(
    options: MapOptions(),
    nonRotatedChildren: [
      AttributionWidget.defaultWidget(
        source: '© OpenStreetMap contributors',
        onSourceTapped: () {},
      ),
    ],
),

Default Builder

The default builder, as shown above, can be used to get a classic attribution box appearance quickly without much setup. Just add a source and a function (if you want a clickable link to appear), and 'flutter_map' automatically gets credited.

Custom Builder

Alternatively, create your own box from scratch by omitting the defaultWidget constructor from the widget. Then you can build a custom widget as you would normally.

You can add polygons to maps to display shapes made out of points to users using PolygonLayer().

FlutterMap(
    options: MapOptions(),
    children: [
        PolygonLayer(
            polygonCulling: false,
            polygons: [
                Polygon(
                  points: [LatLng(30, 40), LatLng(20, 50), LatLng(25, 45),],
                  color: Colors.blue,
                ),
            ],
        ),
    ],
),

Polygons (polygons)

As you can see PolygonLayerOptions() accepts list of Polygons. Each determines the shape of a polygon by defining the LatLng of each corner. 'flutter_map' will then draw a line between each coordinate, and fill it.

More Polygon Operations

'flutter_map' doesn't provide any public methods to manipulate polygons, as these would be deemed out of scope.

This update brings major breaking changes. Please refer to the sections below for information on how to fix problems you may encounter.

Additionally, you should implement Package Name (userAgentPackageName)as soon as possible, to prevent potential future blocking.

This update brings major breaking changes for all users.

Application Migration

Please refer to the sections below for information on how to migrate your application. This will contain the changes that most users may need to make, but not all changes.

Plugin Migration

Unfortunately, migrating plugins that implement custom layers is more difficult than just renaming in many cases. In good news, the new system requires no complex registration, and will simplify your code.

Previously, state was updated through a StreamBuilder. Since v3, state is updated using setState. This means your tile layer is now just a widget, for all intents and purposes, and anything you put in build will automatically be rebuilt when the map state changes.

To migrate, place any StreamBuilder implementation with the below code snippet, and the latest map state will automatically get passed down.

Your plugin may also now be able to be a StatelessWidget, which may increase performance and simplify your code!

In addition to that change:

If you need to update an older project, you may sequentially need to follow migration instructions to get to the latest version.

For this reason, old migrations instructions are kept as subpages beneath this page.

This documentation was partially written during this update's lifetime.

Some breaking changes were implemented. Notably:

• placeholderImage was deprecated with no replacement or workaround. Remove it from your code before the next major release.

• Some streams were changed from Stream<Null> to Stream<void>. These changes are simple to reflect in your code should you need to.

One common requirement is a custom TileProvider, and potentially a custom ImageProvider inside. This will allow your plugin to intercept all tile requests made by a map, and take your own action(s), before finally returning a tile.

Some useful steps are below, but there are more properties of a TileProvider that can be overridden.

Extending The Base TileProvider

To create your own usable TileProvider, the first step is making a class that extends the abstract class. It is not recommended to implement the base, as this will require overriding methods unnecessarily for most custom providers.

class CustomTileProvider extends TileProvider {
    // Add your own custom properties, methods, etc.
    CustomTileProvider({
        // Suitably initialise your own custom properties
        super.headers, // Use the Dart 2.17 `super` syntax to initialise the base's header `Map`
    })
}

Overriding getImage

The majority of custom TileProviders will want to implement their own method to retrieve tiles. This is done by overriding the getImage method, and usually specifying your own ImageProvider, for example:

    @override
    ImageProvider getImage(Coords<num> coords, TileLayerOptions options) =>
        CustomImageProvider(
            options: options,
            coords: coords,
            headers: {
                ...headers,
                'User-Agent': headers['User-Agent'] == null
                    ? '<pluginName> for flutter_map (unknown)'
                    : '<pluginName> for ${headers['User-Agent']}',
            },
        );

Overriding getTileUrl

Some custom TileProviders may want to change the way URLs for tiles are generated. Note that this is quite advanced usage.

    @override
    String getTileUrl(Coords coords, TileLayerOptions options) {
        // Custom generation
    }

Thanks to everyone who has contributed to flutter_map in anyway, you've helped make it the most popular non-commercially owned mapping solution for Flutter. As well as those that have contributed directly to the code, this includes everyone on the Discord server, everyone who's following the progress, and everyone that's participating in discussions and issues.

If you want to contribute to the codebase, please visit the Contributing instructions. We'd love to have your input!

In particular, thanks go to:

• John P Ryan - the founder of this project

• All the current maintainers:

  • @ibrierley

  • @JaffaKetchup

  • @mootw (previously @MooNag)

  • @TesteurManiak

• All the previous maintainers:

  • @kengu

  • @maRci002

• The original authors of this documentation:

  • @JaffaKetchup

  • @themisir

  • @comatory

• Anyone who has made plugins for flutter_map, see the Plugins List

This documentation was written during this update's lifetime, and therefore there is no migration information available for upgrading from any previous versions.

Stadia Maps is a popular tiered-payment (with free-tier) tile provider solution, especially for generic mapping applications. Setup with 'flutter_map' is relatively straightforward, but this page provides an example anyway.

Pre-made Styles

For normal usage with raster tiles, use the Raster URL for the style you like, then follow the Normal (raster) instructions.

For more information about using the vector tiles, see Vector Usage.

Custom Styles

Usage

Normal (raster)

You should remove the 'api_key' (found at the end of the URL) from the URL for readability. Instead, pass it to additionalOptions.

FlutterMap(
    options: MapOptions(
      center: LatLng(51.5, -0.09),
      zoom: 13.0,
    ),
    nonRotatedChildren: [
        AttributionWidget.defaultWidget(
            source: 'Stadia Maps © OpenMapTiles © OpenStreetMap contributors',
            onSourceTapped: () async {
                // Requires 'url_launcher'
                if (!await launchUrl(Uri.parse("https://stadiamaps.com/attribution"))) {
                    if (kDebugMode) print('Could not launch URL');
                }
            },
        )
    ],
    children: [
      TileLayer(
        urlTemplate: "https://tiles.stadiamaps.com/tiles/alidade_smooth_dark/{z}/{x}/{y}{r}.png?api_key={api_key}",
        additionalOptions: {
            "api_key": "<API-KEY>",
        },
        userAgentPackageName: 'com.example.app',
        maxNativeZoom: 20,
      ),
    ],
);

Vector Usage

Stadia Maps' also provides vector tiles. For more information about using vector tiles, please see Using Vector Tiles.

However, please note that this method of integration is still experimental. Many of the Stadia Maps styles utilize advanced features of the Mapbox GL JSON style language which are not yet well-supported.

Other servers

There are plenty of other tile servers you can choose from, free or paid. Most provide a static tile service/API, usually called Static Tiles or just Tile Requests (if no vector tiles are supported).

A good catalogue of servers (usually called Providers elsewhere) can be found at the websites below:

Serving your own tiles

Switch2OSM also provides detailed instructions on how to serve your own tiles: this can be surprisingly economical and enjoyable if you don't mind a few hours in a Linux console.

However, this will require a very high-spec computer, especially for larger areas, and hosting this might be more complicated than it's worth. It's very difficult to fully understand the technologies involved.

Therefore, your contribution would be greatly appreciated, so we've written a guide to help you contribute successfully.

Contribution Guide

Do you think your contribution is essential to 'flutter_map'/useful to all users?

If not, then creating a plugin might be a good idea. To do this, see the Plugins section in these docs: there is advice, starting templates and a few rules to bear in mind. Plugins are preferred when possible as they keep the base library lightweight and easy to understand.

If you think it might be, continue onwards.

Is the contribution to fix a bug? Do you feel comfortable coding it yourself?

If it is, and you are comfortable fixing it yourself, feel free to create an issue stating the bug, mentioning that you're working on fixing it. Then cleanly fork the main repository, and fix the bug. Make sure you only fix/add/remove what's necessary, as this helps to avoid breaking changes. If there is a quick and dirty fix, try not to use it unless the bug is a big one and might take time to fix otherwise.

If it isn't, open a discussion or an issue stating your request. It might be that other people have already found a way to do it. If people like the idea, and you are comfortable doing it yourself, cleanly fork the main repository. Instead of then working on the main branch, work in a new branch: this helps to avoid merge conflicts until the end of development. You may choose to then open a DRAFT pull request to signify that you are working on it. Make sure you only fix/add/remove what's necessary, as this helps to keep track of changes.

If you don't feel comfortable coding changes yourself, start a discussion or an issue.

I've finished coding it. What's next?

Make sure you thoroughly test your changes, and consider writing automated tests.

Then consider whether you need to write documentation. If you do, make sure you follow a similar format to all the other pages in these docs, and use correct spelling and grammar (consider getting a spell checker for Markdown). Then remember to change the documentation version at 'introduction/go'. Change the title of the grey box, the text version, and the link (to the newest migration page), but leave the dynamic badge and other text untouched. If no new documentation is needed, don't touch the grey box.

After that, check if you need to add a migration guide. This is only applicable if the change was a breaking change.

One last thing! Consider if you need to write examples for your changes. If it's a bug fix, you probably won't need to, unless an example also needs to be fixed. But if it's a feature addition, it needs an example, or at least the updating of an existing example. Make sure you test the example as well!

Can I publish it yet?

Yes! Open a PR (or take the existing PR out of draft stage), and link the issue that you opened.

Hopefully a maintainer will merge your changes quickly. Note that not every new merge will result in a new pub.dev release, so you may have to switch to using the GitHub installation method for your new features.

We appreciate your changes!

There are other bug fixes, but no other breaking changes associated with this release.