Flutter MapLibre GL

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This Flutter plugin allows to show embedded interactive and customizable vector maps as a Flutter widget.

Table of Contents

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Supported Platforms

This project only supports a subset of the API exposed by these libraries.

Supported API

Feature Android iOS Web
Style ✅ ✅ ✅
Camera ✅ ✅ ✅
Gesture ✅ ✅ ✅
User Location ✅ ✅ ✅
Symbol ✅ ✅ ✅
Circle ✅ ✅ ✅
Line ✅ ✅ ✅
Fill ✅ ✅ ✅
Fill Extrusion ✅ ✅ ✅
Heatmap Layer ✅ ✅ ✅

Getting Started

For installing the plugin, follow the instructions on pub.dev.

Platform specific setup

iOS

Location Feature

In order to access the device location, you need to add the following key to the ios/Runner/Info.plist file, to explain why you need access to their location data:


<dict>
    <key>NSLocationWhenInUseUsageDescription</key>
    <string>[Your explanation here]</string>
</dict>

Android

Kotlin Version

The minimum supported Kotlin version is 1.9.0. Accordingly, you will have to set your Kotlin version in the android/settings.gradle file like so:

plugins {
    id "org.jetbrains.kotlin.android" version "1.9.0" apply false
}
Location Feature

If you want to show the user's location on the map you need to add the ACCESS_COARSE_LOCATION or ACCESS_FINE_LOCATION permission in the application manifest android/app/src/main/AndroidManifest.xml:


<manifest>
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
</manifest>

Starting from Android API level 23 you also need to request it at runtime. This plugin does not handle this for you. Our example app uses the flutter "location" plugin for this.

Web

For the map to work in the web, include the following JavaScript and CSS files in the <head> of your web/index.html file:


<script src='https://unpkg.com/maplibre-gl@^4.3/dist/maplibre-gl.js'></script>
<link href='https://unpkg.com/maplibre-gl@^4.3/dist/maplibre-gl.css'
      rel='stylesheet'/>

In code usage

The following shows you how to add the map widget to your code and start interacting with it. For more examples, head over to the example project.


class MapParentWidgetState extends State<MapParentWidget> {
  final Completer<MapLibreMapController> mapController = Completer();
  bool canInteractWithMap = false;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      floatingActionButtonLocation: FloatingActionButtonLocation
          .miniCenterFloat,
      floatingActionButton: canInteractWithMap
          ? FloatingActionButton(
        onPressed: _moveCameraToNullIsland,
        mini: true,
        child: const Icon(Icons.restore),
      )
          : null,
      body: MapLibreMap(
        onMapCreated: (controller) => mapController.complete(controller),
        initialCameraPosition: _nullIsland,
        onStyleLoadedCallback: () => setState(() => canInteractWithMap = true),
      ),
    );
  }

  void _moveCameraToNullIsland() =>
      mapController.future.then((c) =>
          c.animateCamera(CameraUpdate.newCameraPosition(_nullIsland)));
}

Map Styles

Map styles can be supplied by setting the styleString in the MapLibreMap constructor. The following formats are supported:

  1. Passing the URL of the map style. This should be a custom map style served remotely using a URL that start with http(s)://
  2. Passing the style as a local asset. Create a JSON file in the assets and add a reference in pubspec.yml. Set the style string to the relative path for this asset in order to load it into the map.
  3. Passing the style as a local file. create an JSON file in app directory (e.g. ApplicationDocumentsDirectory). Set the style string to the absolute path of this JSON file.
  4. Passing the raw JSON of the map style. This is only supported on Android.

Tile sources requiring an API key

If your tile source requires an API key, we recommend directly specifying a source url with the API key included. For example:

https://tiles.example.com/{z}/{x}/{y}.vector.pbf?api_key={your_key}

Documentation

Getting Help

  • Need help with your code?: Check the discussions on this repo or open a new one. Or look for previous questions on the #maplibre tag — or ask a new question.
  • Have a bug to report? Open an issue. If possible, include a full log, code and information which shows the issue.
  • Have a feature request? Open an issue. Tell us what the feature should do and why you want the feature.

Common problems & frequent questions

Loading .mbtiles tile files or sprites/glyphs from the assets shipped with the app

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One approach that has been used successfully to do that is to copy the files from the app's assets directory to another directory, e.g. the app's cache directory, and then reference that location. See e.g. issues https://github.com/maplibre/flutter-maplibre-gl/issues/338 and https://github.com/maplibre/flutter-maplibre-gl/issues/318

Avoid Android UnsatisfiedLinkError

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Update buildTypes in android\app\build.gradle

buildTypes {
    release {
        // other configs
        ndk {
            abiFilters 'armeabi-v7a','arm64-v8a','x86_64', 'x86'
        }
    }
}

iOS app crashes when using location based features

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Please include the NSLocationWhenInUseUsageDescription as described here

Layer is not displayed on IOS, but no error

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Have a look in your LayerProperties object, if you supply a lineColor argument, (or any color argument) the issue might come from here. Android supports the following format : 'rgba(192, 192, 255, 1.0)', but on iOS, this doesn't work!

You have to have the color in the following format : #C0C0FF

iOS crashes with error:

'NSInvalidArgumentException', reason: 'Invalid filter value: filter property must be a string'

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Check if one of your expression is : ["!has", "value"]. Android support this format, but iOS does not. You can replace your expression with : ["!",["has", "value"] ] which works both in Android and iOS.

Note : iOS will display the error : NSPredicate: Use of 'mgl_does:have:' as an NSExpression function is forbidden, but it seems like the expression still works well.

Contributing

Setup melos and run the

melos bootstrap

command in the plugin root directory. Run the example app and familiarize yourself with the plugin directory structure.

Feedback, contributing pull requests and bug reports are very welcome - check the CONTRIBUTING.md guidelines.

Libraries

maplibre_gl
This library contains the MapLibre GL plugin for Flutter.