Add a point, line, and polygon | ArcGIS Maps SDK for Flutter

Learn how to display point, line, and polygon graphics A graphic is a visual element composed of a geometry, symbol, and attributes that is displayed on a map or scene. Learn more in a map A map is a collection of layers that are displayed in 2D. It is typically composed of a basemap layer and data layers. Learn more .

add a point line and polygon

You typically use graphics A graphic is a visual element composed of a geometry, symbol, and attributes that is displayed on a map or scene. Learn more to display geographic data that is not connected to a database and that is not persisted, like highlighting a route between two locations, displaying a search buffer around a selected point, or showing the location of map coordinates entered by the user. Graphics are composed of a geometry A geometry is a geometric shape, such as a point, polyline, or polygon, that contains one or more coordinates and a spatial reference. Learn more , symbol A symbol defines the properties used to display a geometry or text. Learn more , and attributes Attributes are fields and values for a single feature or non-spatial record. They are typically stored in a database or service such as a feature service. Learn more .

In this tutorial, you display points, lines, and polygons on a map as graphics A graphic is a visual element composed of a geometry, symbol, and attributes that is displayed on a map or scene. Learn more .

Prerequisites

Before starting this tutorial:

You need an ArcGIS Location Platform or ArcGIS Online account.
Your system meets the system requirements.
You need an IDE for Flutter - we recommend VS Code.

Develop or download

You have two options for completing this tutorial:

Option 1: Develop the code or
Option 2: Download the completed solution

Option 1: Develop the code

To start the tutorial, complete the Display a map tutorial. This creates a map to display the Santa Monica Mountains in California using the topographic basemap from the ArcGIS Basemap Styles service The ArcGIS Basemap Styles service, also referred to as the Basemap Styles service, is a location service that provides basemap styles and data for the world. It returns styles as Mapbox styles and web maps, and data as vector tiles and/or map tiles. It supports all of the styles in the ArcGIS Basemap style and Open Basemap style family. An ArcGIS Location Platform or ArcGIS Online account is required to use the service. Learn more .

Open a Flutter project

Open the project you created by completing the Display a map tutorial.
Continue with the following instructions to display a point, line, and polygon in the map.

Add a graphics overlay

A graphics overlay A graphics overlay is a client-side, temporary container of graphics to display on a map view or scene view. Learn more is a container for graphics A graphic is a visual element composed of a geometry, symbol, and attributes that is displayed on a map or scene. Learn more . It is used with a map view A map view is a user interface that displays map layers and graphics in 2D. It controls the area (extent) of the map that is visible and supports user interactions such as pan and zoom. Learn more to display graphics on a map A map is a collection of layers that are displayed in 2D. It is typically composed of a basemap layer and data layers. Learn more . You can add more than one graphics overlay A graphics overlay is a client-side, temporary container of graphics to display on a map view or scene view. Learn more to a map view A map view is a user interface that displays map layers and graphics in 2D. It controls the area (extent) of the map that is visible and supports user interactions such as pan and zoom. Learn more . Graphics overlays are displayed on top of all the other layers A layer is a reference to a collection of geographic data that is used to access and display data. The data for layers are typically provided by the basemap layer service and data services. Learn more .

Open lib\main.dart.

In onMapViewReady(), create a GraphicsOverlay and add it to the map view controller.

main.dart

  void onMapViewReady() {

    final map = ArcGISMap.withBasemapStyle(BasemapStyle.arcGISTopographic);

    _mapViewController.arcGISMap = map;

    // Create a new graphics overlay object.
    final graphicsOverlay = GraphicsOverlay();

    // Add the graphics overlay to the map view controller.
    _mapViewController.graphicsOverlays.add(graphicsOverlay);

    _mapViewController.setViewpoint(
      Viewpoint.withLatLongScale(
        latitude: 34.02700,
        longitude: -118.80500,
        scale: 72000,
      ),
    );

  }

Add a point graphic

A point graphic A graphic is a visual element composed of a geometry, symbol, and attributes that is displayed on a map or scene. Learn more is created using a point A geometry is a geometric shape, such as a point, polyline, or polygon, that contains one or more coordinates and a spatial reference. Learn more and a marker symbol A symbol defines the properties used to display a geometry or text. Learn more . A point is defined with x and y coordinates, and a spatial reference A spatial reference is a set of parameters, typically defined by a WKID, that define the coordinate system and spatial properties for geographic data. Applications use a spatial reference to correctly display the position of geographic data in a map or scene. Learn more . For latitude and longitude coordinates, the spatial reference is WGS84.

Create an ArcGISPoint and a SimpleMarkerSymbol. To create the ArcGISPoint, provide longitude (x) and latitude (y) coordinates, and a SpatialReference. Use the SpatialReference.wgs84 convenience property. Create and style a SimpleMarkerSymbol.

Point graphics support a number of symbol types such as SimpleMarkerSymbol, PictureMarkerSymbol and TextSymbol. Learn more about the Symbol class in the API documentation.

main.dart

    _mapViewController.setViewpoint(
      Viewpoint.withLatLongScale(
        latitude: 34.02700,
        longitude: -118.80500,
        scale: 72000,
      ),
    );

    // Create an ArcGIS point with long and lat
    // and set the spatial reference.
    final point = ArcGISPoint(
      x: -118.80657463861,
      y: 34.0005930608889,
      spatialReference: SpatialReference.wgs84,
    );

    // Create a new orange circle with a solid blue outline symbol.
    final pointSymbol =
        SimpleMarkerSymbol(
            style: SimpleMarkerSymbolStyle.circle,
            color: Colors.orange,
            size: 10,
          )
          ..outline = SimpleLineSymbol(
            style: SimpleLineSymbolStyle.solid,
            color: Colors.blue,
            width: 2,
          );

Create a Graphic with the point and pointSymbol. Display the Graphic by adding it to the graphicOverlay’s list of graphics.

main.dart

    // Create an ArcGIS point with long and lat
    // and set the spatial reference.
    final point = ArcGISPoint(
      x: -118.80657463861,
      y: 34.0005930608889,
      spatialReference: SpatialReference.wgs84,
    );

    // Create a new orange circle with a solid blue outline symbol.
    final pointSymbol =
        SimpleMarkerSymbol(
            style: SimpleMarkerSymbolStyle.circle,
            color: Colors.orange,
            size: 10,
          )
          ..outline = SimpleLineSymbol(
            style: SimpleLineSymbolStyle.solid,
            color: Colors.blue,
            width: 2,
          );

    // Create a graphic using the point and point symbol defined earlier.
    final pointGraphic = Graphic(geometry: point, symbol: pointSymbol);

    // Add the graphic to the graphics overlay to display it.
    graphicsOverlay.graphics.add(pointGraphic);

Run the app

Make sure you have an Android emulator, iOS simulator or physical device configured and running.
In VS Code, select Run > Run Without Debugging.

You should see a point graphic in Point Dume State Beach.

Add a line graphic

A line graphic A graphic is a visual element composed of a geometry, symbol, and attributes that is displayed on a map or scene. Learn more is created using a polyline A geometry is a geometric shape, such as a point, polyline, or polygon, that contains one or more coordinates and a spatial reference. Learn more and a line symbol A symbol defines the properties used to display a geometry or text. Learn more . A polyline is defined as a sequence of points.

Polylines have one or more distinct parts. Each part is a sequence of points. For a continuous line, you can use the Polyline constructor to create a polyline with just one part. To create a polyline with more than one part, use a PolylineBuilder.

Create a Polyline and a SimpleLineSymbol. To create the Polyline, call the addPointXY() method on PolylineBuilder for each (x, y) coordinate pair that defines a point along the polyline’s path. Create and style a SimpleLineSymbol.

Line graphics support a number of symbol types such as SimpleLineSymbol and TextSymbol. Learn more about the Symbol class in the API documentation.

main.dart

    // Add the graphic to the graphics overlay to display it.
    graphicsOverlay.graphics.add(pointGraphic);

    // Create a polyline builder and set its spatial reference.
    // Use the `addPointXY()` method to add (x,y) coordinates one at a time
    // that define the polyline's geometry.
    final polylineBuilder =
        PolylineBuilder(spatialReference: SpatialReference.wgs84)
          ..addPointXY(x: -118.82152, y: 34.01395)
          ..addPointXY(x: -118.81489, y: 34.00806)
          ..addPointXY(x: -118.80887, y: 34.00166);

    // Retrieve the polyline's geometry that the builder constructed.
    final polyline = polylineBuilder.toGeometry();

    // Create a solid blue line simple line symbol.
    final polylineSymbol = SimpleLineSymbol(
      style: SimpleLineSymbolStyle.solid,
      color: Colors.blue,
      width: 3,
    );

Create a Graphic with the polyline and polylineSymbol. Display the Graphic by adding it to the list of graphics.

main.dart

    // Retrieve the polyline's geometry that the builder constructed.
    final polyline = polylineBuilder.toGeometry();

    // Create a solid blue line simple line symbol.
    final polylineSymbol = SimpleLineSymbol(
      style: SimpleLineSymbolStyle.solid,
      color: Colors.blue,
      width: 3,
    );

    // Create a graphic using the polyline and polyline symbol defined earlier.
    final polylineGraphic = Graphic(geometry: polyline, symbol: polylineSymbol);

    // Add the graphic to the graphics overlay to display it.
    graphicsOverlay.graphics.add(polylineGraphic);

Use Flutter’s hot restart to load your code changes and restart the app.

You should see a point and line graphic along Westward Beach.

Add a polygon graphic

A polygon graphic A graphic is a visual element composed of a geometry, symbol, and attributes that is displayed on a map or scene. Learn more is created using a polygon A geometry is a geometric shape, such as a point, polyline, or polygon, that contains one or more coordinates and a spatial reference. Learn more and a fill symbol A symbol defines the properties used to display a geometry or text. Learn more . A polygon is defined as a sequence of points that describe a closed boundary.

Polygons have one or more distinct parts. Each part is a sequence of points describing a closed boundary. For a single area with no holes, you can use the Polygon constructor to create a polygon with just one part. To create a polygon with more than one part, use a PolygonBuilder.

Create a Polygon and a SimpleFillSymbol. To create the Polygon, call the addPointXY() method on PolygonBuilder for each (x,y) coordinate pair that defines a point on the closed boundary. Create and style a SimpleFillSymbol.

Polygon graphics support a number of symbol types such as SimpleFillSymbol, PictureFillSymbol, SimpleMarkerSymbol and TextSymbol. Learn more about the Symbol class in the API documentation.

main.dart

    // Add the graphic to the graphics overlay to display it.
    graphicsOverlay.graphics.add(polylineGraphic);

    // Create a polygon builder and set its spatial reference.
    // Use the `addPointXY()` method to add (x,y) coordinates one at a time
    // that define the polygon's geometry.
    final polygonBuilder =
        PolygonBuilder(spatialReference: SpatialReference.wgs84)
          ..addPointXY(x: -118.81898, y: 34.01375)
          ..addPointXY(x: -118.80679, y: 34.02158)
          ..addPointXY(x: -118.79143, y: 34.01638)
          ..addPointXY(x: -118.79596, y: 34.00856)
          ..addPointXY(x: -118.80855, y: 34.00350);

    // Retrieve the polygon's geometry that the builder constructed.
    final polygon = polygonBuilder.toGeometry();

    // Create an orange fill with solid blue line outline simple fill symbol.
    final polygonSymbol = SimpleFillSymbol(
      style: SimpleFillSymbolStyle.solid,
      color: Colors.orange,
      outline: SimpleLineSymbol(
        style: SimpleLineSymbolStyle.solid,
        color: Colors.blue,
        width: 2,
      ),
    );

Create a Graphic with the polygon and polygonSymbol. Display the Graphic by adding it to the list of graphics.

main.dart

    // Retrieve the polygon's geometry that the builder constructed.
    final polygon = polygonBuilder.toGeometry();

    // Create an orange fill with solid blue line outline simple fill symbol.
    final polygonSymbol = SimpleFillSymbol(
      style: SimpleFillSymbolStyle.solid,
      color: Colors.orange,
      outline: SimpleLineSymbol(
        style: SimpleLineSymbolStyle.solid,
        color: Colors.blue,
        width: 2,
      ),
    );

    // Create a graphic using the polygon and polygon symbol defined earlier.
    final polygonGraphic = Graphic(geometry: polygon, symbol: polygonSymbol);

    // Add the graphic to the graphics overlay to display it.
    graphicsOverlay.graphics.add(polygonGraphic);

Hot restart your app.

You should see a point, line, and polygon graphic around Mahou Riviera in the Santa Monica Mountains.

Alternatively, you can download the tutorial solution, as follows.

Option 2: Download the solution

Click the Download solution link under Solution and unzip the file to a location on your machine.
Open the project in VS code.

Since the downloaded solution does not contain authentication code, you must first set up authentication to create credentials, then add authentication code and set the developer credentials to the solution.

Set up authentication

To access the secure ArcGIS location services ArcGIS Location Services, also referred to as Location Services, are services hosted by Esri that provide geospatial functionality for developing mapping applications. They include the ArcGIS Basemap Styles service, ArcGIS Static Basemap Tiles service, ArcGIS Places service, ArcGIS Geocoding service, ArcGIS Routing service, ArcGIS GeoEnrichment service, and ArcGIS Elevation service. An ArcGIS Location Platform or ArcGIS Online account is required to use the services. Learn more used in this tutorial, you must implement API key authentication API key authentication is a type of authentication that uses an API key to authenticate requests to ArcGIS services and secure portal items. Learn more or user authentication User authentication is a type of authentication that allows users with an ArcGIS account to sign into an application and allow it to access ArcGIS content, services, and resources on their behalf. The typical authorization protocol used is OAuth2.0. Learn more using an ArcGIS Location Platform An ArcGIS Location Platform account, formerly known as an ArcGIS Developer account, is an identity associated with an ArcGIS Location Platform subscription. Learn more or an ArcGIS Online An ArcGIS Online account, also known as an ArcGIS Organization account, is an identity associated with an ArcGIS Online subscription. It can be used to access ArcGIS tools and develop applications with ArcGIS location services for an organization. Learn more account.

You can implement API key authentication or user authentication in this tutorial. Compare the differences below:

API key authentication API key authentication is a type of authentication that uses an API key to authenticate requests to ArcGIS services and secure portal items. Learn more

Users are not required to sign in.
Requires creating an API key credential API key credentials are an item that contains the parameters used to create and manage long-lived access tokens for API key authentication. They are a type of developer credential. Learn more with the correct privileges.
API keys An API key is a long-lived access token created using API key credentials. They are valid for up to one year and are typically embedded directly into client applications. Learn more are long-lived access tokens.
Service usage is billed to the API key owner/developer.
Simplest authentication method to implement.
Recommended approach for new ArcGIS developers.

Learn more in API key authentication.

User authentication User authentication is a type of authentication that allows users with an ArcGIS account to sign into an application and allow it to access ArcGIS content, services, and resources on their behalf. The typical authorization protocol used is OAuth2.0. Learn more

Users are required to sign in with an ArcGIS account An ArcGIS account is an identity with a user type and set of privileges that can access specific ArcGIS products, tools, APIs, services, and resources. The main account types that can be used for development are an ArcGIS Location Platform account, ArcGIS Online account, and ArcGIS Enterprise account. ArcGIS Location Platform and ArcGIS Online accounts are also associated with a subscription. Learn more .
User accounts must have privilege Privileges are a set of permissions assigned to ArcGIS accounts, developer credentials, and applications that grant access to secure resources and functionality in ArcGIS. Learn more to access the ArcGIS services A service, also known as an ArcGIS service, is software that supports an ArcGIS REST API and provides geospatial functionality or data. A service can be hosted by Esri or in ArcGIS Enterprise. Learn more used in application.
Requires creating OAuth credentials OAuth credentials are an item that contains parameters required to implement user authentication or app authentication, including a client_id, client_secret, and redirect URIs. They are a type of developer credential. Learn more .
Application uses a redirect URL and client ID.
Service usage is billed to the organization of the user signed into the application.

Learn more in User authentication.

To complete this tutorial, click on the tab in the switcher below for your authentication type of choice, either API key authentication or User authentication.

Create a new API key access token An access token is an authorization string that provides access to secure ArcGIS content, data, and services. Its capabilities are determined by the privileges it supports. It is obtained by implementing API key authentication, User authentication, or App authentication. Learn more with privileges Privileges are a set of permissions assigned to ArcGIS accounts, developer credentials, and applications that grant access to secure resources and functionality in ArcGIS. Learn more to access the secure resources used in this tutorial.

Complete the Create an API key tutorial and create an API key with the following privilege(s) Privileges are a set of permissions assigned to ArcGIS accounts, developer credentials, and applications that grant access to secure resources and functionality in ArcGIS. Learn more :
- Privileges
  - Location services > Basemaps
Copy and paste the API key access token into a safe location. It will be used in a later step.

Create new OAuth credentials to access the secure resources used in this tutorial.

Complete the Create OAuth credentials for user authentication tutorial to obtain a Client ID and Redirect URL.

A Client ID uniquely identifies your app on the authenticating server. If the server cannot find an app with the provided Client ID, it will not proceed with authentication.
The Redirect URL (also referred to as a callback url) is used to identify a response from the authenticating server when the system returns control back to your app after an OAuth login. Since it does not necessarily represent a valid endpoint that a user could navigate to, the redirect URL can use a custom scheme, such as my-app://auth. It is important to make sure the redirect URL used in your app’s code matches a redirect URL configured on the authenticating server.
Copy and paste the Client ID and Redirect URL into a safe location. They will be used in a later step.

All users that access this application need account privileges Privileges are a set of permissions assigned to ArcGIS accounts, developer credentials, and applications that grant access to secure resources and functionality in ArcGIS. Learn more to access the ArcGIS Basemap Styles service The ArcGIS Basemap Styles service, also referred to as the Basemap Styles service, is a location service that provides basemap styles and data for the world. It returns styles as Mapbox styles and web maps, and data as vector tiles and/or map tiles. It supports all of the styles in the ArcGIS Basemap style and Open Basemap style family. An ArcGIS Location Platform or ArcGIS Online account is required to use the service. Learn more .

Add authentication code and set developer credentials

To allow your app users to access ArcGIS location services ArcGIS Location Services, also referred to as Location Services, are services hosted by Esri that provide geospatial functionality for developing mapping applications. They include the ArcGIS Basemap Styles service, ArcGIS Static Basemap Tiles service, ArcGIS Places service, ArcGIS Geocoding service, ArcGIS Routing service, ArcGIS GeoEnrichment service, and ArcGIS Elevation service. An ArcGIS Location Platform or ArcGIS Online account is required to use the services. Learn more , you will add authentication code and use the developer credentials that you created in the Set up authentication step to authenticate requests for resources.

Open lib/main.dart.
In the main() function, set the ArcGISEnvironment.apiKey value to your access token An access token is an authorization string that provides access to secure ArcGIS content, data, and services. Its capabilities are determined by the privileges it supports. It is obtained by implementing API key authentication, User authentication, or App authentication. Learn more .
main.dart
void main () { ArcGISEnvironment.apiKey = 'YOUR_ACCESS_TOKEN'; runApp( const MaterialApp(home: MainApp()) ); }

Best Practice: The access token is stored directly in the code as a convenience for this tutorial. Do not store credentials directly in source code in a production environment.

Add the Authenticator toolkit component to manage your OAuth credentials.

Add the ArcGIS Maps SDK for Flutter Toolkit package to your app by following these instructions

Add the following code to main.dart:

Define a final class member inside _MainAppState class, _oAuthUserConfiguration, and initialize it with OAuthUserConfiguration passing in the portalUri, clientId, and redirectUri values.
Add code to revoke all tokens, Authenticator.revokeOAuthTokens(), and clear all credentials, Authenticator.clearCredentials(), from the authenticator’s credential store during application sign-out.
Add the Authenticator widget as a parent of the ArcGISMapView widget in the existing widget tree found in the build(). Set the value of the named parameter, oAuthUserConfigurations to a list containing the new member variable _oAuthUserConfiguration.

main.dart

class _MainAppState extends State<MainApp> {

  final _mapViewController = ArcGISMapView.createController();

  final _oAuthUserConfiguration = OAuthUserConfiguration(
    portalUri: Uri.parse('https://www.arcgis.com'),
    clientId: 'YOUR_CLIENT_ID',
    redirectUri: Uri.parse('YOUR_REDIRECT_URL'),
  );

  @override
  void dispose() {
    Authenticator.revokeOAuthTokens().whenComplete(
      Authenticator.clearCredentials,
    );

    super.dispose();
  }

  @override
  Widget build(BuildContext context) {

    return Scaffold(
      body: Column(
        children: [
          Expanded(
            child: Authenticator(
              oAuthUserConfigurations: [_oAuthUserConfiguration],
              child: ArcGISMapView(
                controllerProvider: () => _mapViewController,
                onMapViewReady: onMapViewReady,
              ),
            ),
          ),
        ],
      ),
    );

  }
}

Best Practice: The OAuth credentials are stored directly in the code as a convenience for this tutorial. Do not store credentials directly in source code in a production environment.

For Android only, a system browser is required for user authentication User authentication is a type of authentication that allows users with an ArcGIS account to sign into an application and allow it to access ArcGIS content, services, and resources on their behalf. The typical authorization protocol used is OAuth2.0. Learn more . Add the following activity to the Android manifest in your project:
android/app/src/main/AndroidManifest.xml
 <activity android:name="com.linusu.flutter_web_auth_2.CallbackActivity" android:exported="true"> <intent-filter android:label="flutter_web_auth_2"> <action android:name="android.intent.action.VIEW" /> <category android:name="android.intent.category.DEFAULT" /> <category android:name="android.intent.category.BROWSABLE" /> <data android:scheme="YOUR_CALLBACK_URL_SCHEME_HERE" /> </intent-filter> </activity> 
Replace YOUR_CALLBACK_URL_SCHEME_HERE with the scheme of the redirect URL used when you set up authentication earlier. This is necessary so that the browser can communicate back to your app after the login workflow completes.

For example, if you have a redirect URL, such as: my-app://auth, the value of the scheme would be: my-app. This value would replace YOUR_CALLBACK_URL_SCHEME_HERE in the activity.

Run the application

Follow these steps to run the application.

In VS Code’s terminal, run:
flutter pub upgrade
Run:
dart run arcgis_maps install
Make sure you have an Android emulator, iOS simulator or physical device configured and running.
In VS Code, select Run > Run Without Debugging.

You should see a point, line, and polygon graphic around Mahou Riviera in the Santa Monica Mountains.

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