Using Google Maps to add maps in Flutter applications

Editor’s note: This post was updated on 23 September 2022.

I can’t imagine what life would be like without Google Maps. We use it for everything from finding directions to a destination, to searching for a nearby restaurant or gas station, to just zooming in and out of the map to see the street view of any location on the planet.

Adding Google Maps to your mobile app can open up a whole new world to your users — literally. In this tutorial, we’ll show you how to use the official plugin for integrating Google Maps in your Flutter app.

Here’s what we’ll cover:

• Creating a project in Google Cloud Platform
• Enabling the Maps API
• Generating and restricting API keys
• Adding Google Maps in Flutter (Android)
• Adding Google Maps in Flutter (iOS)
• Adding the GoogleMap widget
• Styling maps in Flutter
• Modifying your maps with the GoogleMap widget
• Showing a list of maps
• Taking a snapshot of your location

Creating a project in Google Cloud Platform

The very first step is to create a project at Google Developers Console. This is required because you’ll need APIs to integrate Google Maps in your app.

Head to the Google Developers Console and click the already-selected project.

Click NEW PROJECT and enter the details.

Click on the current project name again and you should see your new project created in the list.

Enabling the Maps API

Once the project is created, you’ll have to enable the Maps API SDK for both Android and iOS.

1. Click the Library menu on the left
2. Search for “Maps SDK”
3. Click Maps SDK for iOS and then click Enable
4. Click Maps SDK for Android and then click Enable

Generating and restricting API keys

It is important to note that the access to the Google Map APIs is not free. Therefore, you must create a set of API keys for it and restrict its permissions to reduce the chances of unauthorized usage. Here’s how you can generate the keys.

1. Click on the Credentials menu on the left
2. Click the + CREATE CREDENTIALS button
3. Select the API key option

If you’re targeting both platforms, you should obtain two API keys so that you can track them better.

After creating the API keys, I would highly recommend implementing some restrictions. For example, if you’re willing to use the API keys just for a map, then you should allow it to be used by the Maps service only.

There are two types of restrictions:

1. Application restrictions enable you to define which type of app should have access to this key (i.e., Android or iOS). You can select the appropriate option to make sure the key you created works only for that specific platform
2. API restrictions enable you to select which services are accessible using this key. If it were just for the map, you’d select Maps API from the list

Adding Google Maps in Flutter app (Android)

To be able to use the Google Maps inside the app via the API key you created in the previous section, you’ll have to copy and paste as per the instructions below.

First, open your Flutter project and navigate to the file at this location: android/app/src/main/AndroidManifest.xml.

Next, paste in the code below:

<application ...
    <meta-data android:name="com.google.android.geo.API_KEY"
               android:value="YOUR KEY HERE"/>

Replace the value "YOUR KEY HERE" with an API key you created. Then, add the location permission.

Now the AndroidManifest.xml file should look like this:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.pinkesh.google_maps_flutter">

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

    <application
        android:label="google_maps_flutter"
        android:icon="@mipmap/ic_launcher">

       <!-- TODO: Add your API key here -->
       <meta-data android:name="com.google.android.geo.API_KEY"
           android:value="YOUR KEY HERE"/>

        <activity>...</activity>
    </application>
</manifest>

Adding Google Maps in Flutter (iOS)

The steps for running Google Maps in a Flutter app for iOS devices are similar to the procedure for Android.

First, specify your API key in the application delegate ios/Runner/AppDelegate.swift

Then, write the import GoogleMaps statement at the top to avoid iOS build issues.

The file should look like this:

import UIKit
import Flutter
import GoogleMaps
@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
override func application(
_ application: UIApplication,
didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
) -> Bool {
GeneratedPluginRegistrant.register(with: self)
GMSServices.provideAPIKey("YOUR-KEY")
return super.application(application, didFinishLaunchingWithOptions: launchOptions)
}
}

Next, open the Xcode and add the location permission in the info.plist file:

<key>NSLocationWhenInUseUsageDescription</key>
<string>The app needs location permission</string>

Adding the GoogleMap widget

After completing the steps outlined below, you’ll be able to see Google Maps on the screen in your Flutter app.

First, add the google_maps_flutter plugin to the pubspec.yaml file.

dependencies:
  flutter:
    sdk: flutter
  cupertino_icons: 1.0.0
  google_maps_flutter: ^2.0.1

Next, place the GoogleMap widget in your Dart file.

GoogleMap(
      initialCameraPosition: _kInitialPosition,
    ),

GoogleMap is given a _kInitialPosition, which holds the default location to show on the map when it’s loaded.

static final LatLng _kMapCenter =
    LatLng(19.018255973653343, 72.84793849278007);

static final CameraPosition _kInitialPosition =
    CameraPosition(target: _kMapCenter, zoom: 11.0, tilt: 0, bearing: 0);

Here is the bare minimum code to show the map:

import 'package:flutter/material.dart';
import 'package:google_maps_flutter/google_maps_flutter.dart';

class SimpleMap extends StatefulWidget {
  @override
  _SimpleMapState createState() => _SimpleMapState();
}

class _SimpleMapState extends State<SimpleMap> {
  static final LatLng _kMapCenter =
      LatLng(19.018255973653343, 72.84793849278007);

  static final CameraPosition _kInitialPosition =
      CameraPosition(target: _kMapCenter, zoom: 11.0, tilt: 0, bearing: 0);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Google Maps Demo'),
      ),
      body: GoogleMap(
        initialCameraPosition: _kInitialPosition,
      ),
    );
  }
}

If you do not see the map correctly and/or receive an error that looks like: Cannot enable mylocation layer as location permissions are not granted, you can try doing one of the following:

1. Ensure you have requested the appropriate permissions for accessing the location of the device. The following permissions need to be added to the manifest file:

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

2. Write logic to request for permission again if the user denies it. If they choose the “don’t ask again” option on the permissions dialog, write the logic to notify them that the app will not work without the location permissions
3. Check if the Map SDK is enabled on the Google Cloud console

Styling maps in Flutter

If you’re working on a particularly stylish product and you want your map to reflect the look and feel of your branding, you can customize the map.

For this example, we’ll try to create a map style that is similar to that of Uber by following these steps:

1. Go to this website
2. Select the silver theme
3. Click to adjust Landmark and Labels
4. Restore Park colors
5. Click Finish
6. Click the COPY JSON button

Now with the map style in hand, you’ll be able to put it inside the app and have the plugin consume it.

First, create an assets folder at the root of the app.

Next, create a map_style.json file inside it, and paste the code snippet you copied.

Add a reference in the pubspec.yaml file:

assets:
 - map_style.json

Load the new style in a map via GoogleMapController. The updated code should look like this:

import 'package:flutter/material.dart';
import 'package:google_maps_flutter/google_maps_flutter.dart';

class SimpleMap extends StatefulWidget {
  @override
  _SimpleMapState createState() => _SimpleMapState();
}

class _SimpleMapState extends State<SimpleMap> {
  static final LatLng _kMapCenter =
      LatLng(19.018255973653343, 72.84793849278007);

  static final CameraPosition _kInitialPosition =
      CameraPosition(target: _kMapCenter, zoom: 11.0, tilt: 0, bearing: 0);

  GoogleMapController _controller;

  Future<void> onMapCreated(GoogleMapController controller) async {
    _controller = controller;
    String value = await DefaultAssetBundle.of(context)
        .loadString('assets/map_style.json');
    _controller.setMapStyle(value);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Google Maps Demo'),
      ),
      body: GoogleMap(
        initialCameraPosition: _kInitialPosition,
        onMapCreated: onMapCreated,
      ),
    );
  }
}
onMapCreated is a callback that’s called when the map is ready to use. It provides the GoogleMapController, which is really helpful for performing certain actions on the map. For this example, we used it to set the map style via the _controller.setMapStyle(value); method.

Here is the output:

Modifying maps with the GoogleMap widget

The GoogleMap widget gives you a lot of flexibility to modify the map. Let’s explore some ways to do that.

Changing the map type

There are various types of maps available, including satellite, terrain, and hybrid. You can simply set the desired type to the mapType property of the widget:

GoogleMap(
  initialCameraPosition: _kInitialPosition,
  onMapCreated: onMapCreated,
  mapType: MapType.satellite,
);

Enabling my location button

By default, the map will show the location provided in the initialCameraPosition parameter of the widget (or any other location that you provide to the map programmatically). If the user wants to return to their location, setting myLocationEnabled to true will do the job.

A small blue dot will appear on the screen when the device is stationary and a chevron if the device is moving.

GoogleMap(
  initialCameraPosition: _kInitialPosition,
  onMapCreated: onMapCreated,
  myLocationEnabled: true,
);

People often wonder “How do I change my location on Google Maps in Flutter?” The answer to that question is that you can’t change your location on Google Maps in Flutter. Your location is determined by your geographical location on Earth via GPS calculations and it cannot be modified unless your device is moved to a new location.

In case you want to change the position of the “my location” button, you can create a FloatingActionButton (FAB) to replace the stock “my location” button and place it anywhere you want on the screen. You will only need to write the logic for centering the map’s camera on your location when the button is clicked. Here’s what the logic might look like:

void _currentLocation() async {

    // Create a map controller
    final GoogleMapController controller = await _controller.future;
    LocationData currentLocation;
    var location = new Location();
    try {
        // Find and store your location in a variable
        currentLocation = await location.getLocation();
    } on Exception {
        currentLocation = null;
    }

    // Move the map camera to the found location using the controller
    controller.animateCamera(CameraUpdate.newCameraPosition(
        CameraPosition(
            bearing: 0,
            target: LatLng(currentLocation.latitude, currentLocation.longitude),
            zoom: 17.0,
        ),
    ));
}

Creating markers on the map

Markers are a great way to show a particular location.

To see how to create markers on your map, refer to the code below:

Set<Marker> _createMarker() {
  return {
    Marker(
        markerId: MarkerId("marker_1"),
        position: _kMapCenter,
        infoWindow: InfoWindow(title: 'Marker 1'),
        rotation: 90),
    Marker(
      markerId: MarkerId("marker_2"),
      position: LatLng(18.997962200185533, 72.8379758747611),
    ),
  };
}

Each marker in the set expects some parameters, which are useful to convey the information. The first marker is given the infowindow, which shows its ID (you can write anything here to describe the place) and a rotation of 90 degrees. The rotation param is very useful when you have multiple markers at the same place — for example, multiple cell antennae on a single tower.

GoogleMap(
  initialCameraPosition: _kInitialPosition,
  onMapCreated: onMapCreated,
  markers: _createMarker(),
);

Enabling traffic mode

You can turn on traffic mode by simply setting the value of trafficEnabled to true.

GoogleMap(
  initialCameraPosition: _kInitialPosition,
  onMapCreated: onMapCreated,
  trafficEnabled: true,
);

Showing a list of maps

Let’s say you want to show a list of maps by displaying markers to help users locate satellite offices, other hospitals, etc.

First, create a GridView to show a list of Google Maps widgets. You can set the initialCameraPosition. Set liteModeEnabled to true. This creates the image of a map that you can’t interact with:

GridView.count(
  crossAxisCount: 2,
  crossAxisSpacing: 8,
  mainAxisSpacing: 8,
  // Generate 100 widgets that display their index in the List.
  children: List.generate(10, (index) {
    return Center(
      child: GoogleMap(
        initialCameraPosition: _kInitialPosition,
        markers: _createMarker(),
        liteModeEnabled: true,
      ),
    );
  }),
)

Create a set of markers and make sure you have a different position assigned to it.

Set<Marker> _createMarker() {
  return {
    Marker(
        markerId: MarkerId("marker_1"),
        position: _kMapCenter),
    Marker(
      markerId: MarkerId("marker_2"),
      position: LatLng(18.997962200185533, 72.8379758747611),
    ),
  };
}

At the time of writing, this feature is only available for Android.

Taking a snapshot of your location

The ability to take a snapshot of your location and quickly share your journey with others is a really cool feature.

First, create a button somewhere in your app. The _controller.takeSnapshot() method will do the rest of the magic for you with the click of a button.

FloatingActionButton(
  onPressed: () async {
    final imageBytes = await _controller.takeSnapshot();
    setState(() {
      _imageBytes = imageBytes;
    });
  },
  child: Icon(Icons.fullscreen),
)

Next, create a widget to show the snapshot:

Container(
  decoration: BoxDecoration(color: Colors.blueGrey[50]),
  height: 150,
  width: 120,
  child: _imageBytes != null ? Image.memory(_imageBytes) : null,
)

That’s it! The full code can be found on GitHub.

Conclusion

In this tutorial, we showed how to integrate Google Maps in your Flutter app and explored some ways to customize your map’s look and feel. We walked through how to enable the Maps API, generate and restrict API keys, and set up, style, and modify maps in a Flutter application.

Adding Google Maps capabilities to your app opens up a world of possibilities. With the basics under your belt, you’re ready to start building location-based features and interactive maps into your Flutter app.