Examples and use cases

Explore practical examples and use cases to effectively utilize indoor maps and venues with the HERE SDK. This section covers a range of topics to help you get the most out of our indoor mapping capabilities.

List all indoor maps

The HERE SDK for Flutter (Navigate) allows you to list all private venues that are accessible for your account and the selected collection. VenueMap contains a list which holds VenueInfo elements containing venue Identifier, venue ID and venue Name.

List<VenueInfo> venueInfo = _venueEngine!.venueMap.getVenueInfoList();
for (int i = 0; i < venueInfo.length; i++) {
  int venueId = venueInfo[i].venueId;
  print("Venue Identifier: " + venueInfo[i].venueIdentifier + " Venue Id: $venueId" + " Venue Name: "+venueInfo[i].venueName);
}

For maps with venue identifier as UUID, venueId would return 0.

Load and show a venue

The HERE SDK for Flutter (Navigate) allows you to load and visualize venues by an identifier. You must know the venue's identifier for the current set of credentials. There are several ways to load and visualize the venues.

VenueMap has two methods to add a venue to the map: selectVenueAsync() and addVenueAsync(). Both methods use getVenueService().addVenueToLoad() to load the venue by an identifier and then add it to the map. The method selectVenueAsync() also selects the venue:

_venueEngine.venueMap.selectVenueAsync(String venueIdentifier);

_venueEngine.venueMap.addVenueAsync(String venueIdentifier);

Note

For legacy maps with an int based venue ID, VenueMap still supports selectVenueAsync(int venueID) and addVenueAsync(int venueID) to load the venue by venue ID.

A venue can also be selected by providing a venue identifier:

Container(
padding: EdgeInsets.only(left: 8, right: 8),
// Widget for opening venue by provided ID.
child: TextField(
    decoration: InputDecoration(
        border: InputBorder.none, hintText: 'Enter a venue identifier'),
    onSubmitted: (text) {
        try {
        // Try to parse a venue identifier.
        String venueIdentifier = text;
        // Select a venue by identifier.
        _venueEngineState.selectVenue(venueIdentifier);
        } on FormatException catch (_) {
        print("Venue identifier should be a number!");
        }
    }),
),

Once the venue is loaded, the VenueService calls the VenueMapListener.onGetVenueCompleted() method:

@override
  onGetVenueCompleted(String venueIdentifier, VenueModel? venueModel, bool online, VenueStyle? venueStyle) {
    if(venueModel == null) {
      print("Failed to load venue Identifier: " + venueIdentifier);
    }
  }

Note

For legacy maps with an int based venue ID, VenueService calls the VenueListener.onGetVenueCompleted(venueID, venueModel, online, venueStyle) method.

Once the venue is loaded successfully, if you are using the addVenueAsync() method, only the VenueLifecycleDelegate.onVenueAdded() method will be triggered. If you are using the selectVenueAsync()method, the VenueSelectionDelegate.onSelectedVenueChanged() method will also be triggered.

// A listener for the venue selection event.
class VenueSelectionListenerImpl extends VenueSelectionListener {
  late VenueEngineState _venueEngineState;

  VenueSelectionListenerImpl(VenueEngineState venueEngineState) {
    _venueEngineState = venueEngineState;
  }

  @override
  onSelectedVenueChanged(Venue? deselectedVenue, Venue? selectedVenue) {
    _venueEngineState.onVenueSelectionChanged(selectedVenue);
    // This functions is used to facilitate the toggling of topology visibility.
    // Setting isTopologyVisible property to true will render the topology on scene and false will lead to hide the topology.
    selectedVenue?.isTopologyVisible = true;
  }
}

A Venue can also be removed from the VenueMap, which triggers the VenueLifecycleListener.onVenueRemoved(veueIdentifier) method:

_venueEngine.venueMap.removeVenue(venue);

Note

For legacy maps with an int based venue ID, if you are using the addVenueAsync() method, the VenueLifecycleListener.onVenueAdded() method will be triggered.
When removing an int based venue ID from VenueMap, the VenueLifecycleListener.onVenueRemoved(venueID) is triggered.

Label text preference

You can override the default label text preference for a venue.

Once the VenueEngine is initialized, a callback is called. From this point on, there is access to the VenueService. The optional method setLabeltextPreference() can be called to set the label text preference during rendering. Overriding the default style label text preference provides an opportunity to set the following options as a list where the order defines the preference:

"OCCUPANT_NAMES"
"SPACE_NAME"
"INTERNAL_ADDRESS"
"SPACE_TYPE_NAME"
"SPACE_CATEGORY_NAME"

These can be set in any desired order. For example, if the label text preference does not contain "OCCUPANT_NAMES" then it will switch to "SPACE_NAME" and so on, based on the order of the list. Nothing is displayed if no preference is found.

class VenueEngineWidget extends StatefulWidget {
  final VenueEngineState state;

  VenueEngineWidget({required this.state});

  @override
  VenueEngineState createState() => state;
}

// The VenueEngineState listens to different venue events and helps another
// widgets react on changes.
class VenueEngineState extends State<VenueEngineWidget> {
  late VenueServiceListener _serviceListener;

  void onVenueEngineCreated() {
    var venueMap = venueEngine!.venueMap;
    // Add needed listeners.
    _serviceListener = VenueServiceListenerImpl();
    _venueEngine!.venueService.addServiceListener(_serviceListener);

    // Start VenueEngine. Once authentication is done, the authentication
    // callback will be triggered. Afterwards, VenueEngine will start
    // VenueService. Once VenueService is initialized,
    // VenueServiceListener.onInitializationCompleted method will be called.
    venueEngine!.start(_onAuthCallback);

    if(HRN != "") {
      // Set platform catalog HRN
      venueEngine!.venueService.setHrn(HRN);
    }

    // Set label text preference
    venueEngine!.venueService.setLabeltextPreference(LabelPref);
  }
}

Select venue drawings and levels

A Venue object allows you to control the state of the venue.

The property selectedDrawing allows to get and set a drawing which will be visible on the map. When a new drawing is selected, the VenueDrawingSelectionListener.onDrawingSelected() method is triggered.

The following provides an example of how to select a drawing when an item is clicked in a ListView:

  // Create a list view item from the drawing.
  Widget _drawingItemBuilder(BuildContext context, VenueDrawing drawing) {
    bool isSelectedDrawing = drawing.identifier == _selectedDrawing!.identifier;
    Property? nameProp = drawing.properties["name"];
    return TextButton(
      style: TextButton.styleFrom(
          foregroundColor: isSelectedDrawing ? Colors.blue : Colors.white,
          padding: EdgeInsets.zero
      ),
      child: Text(
        nameProp != null ? nameProp.asString : "",
        textAlign: TextAlign.center,
        style: TextStyle(
          color: isSelectedDrawing ? Colors.white : Colors.black,
          fontWeight: isSelectedDrawing ? FontWeight.bold : FontWeight.normal,
        ),
      ),
      onPressed: () {
        // Hide the list with drawings.
        _isOpen = false;
        // Select a drawing, if the user clicks on the item.
        _selectedVenue!.selectedDrawing = drawing;
      },
    );
  }

The properties selectedLevel and selectedLevelIndex allow you to get and set a selected level. If a new level is selected, the VenueLevelSelectionListener.onLevelSelected() method is triggered.

The following provides an example of how to select a level when an item is clicked in a ListView:

  // Create a list view item from the level.
  Widget _levelItemBuilder(BuildContext context, VenueLevel level) {
    bool isSelectedLevel = level.identifier == _selectedLevel!.identifier;
    return TextButton(
      style: TextButton.styleFrom(
          foregroundColor: isSelectedLevel ? Colors.blue : Colors.white,
          padding: EdgeInsets.zero
      ),
      child: Text(
        level.shortName,
        textAlign: TextAlign.center,
        style: TextStyle(
          color: isSelectedLevel ? Colors.white : Colors.black,
          fontWeight: isSelectedLevel ? FontWeight.bold : FontWeight.normal,
        ),
      ),
      onPressed: () {
        // Select a level, if the user clicks on the item.
        _selectedVenue!.selectedLevel = level;
      },
    );
  }

A full example of the UI switchers to control drawings and levels is available in the "indoor_map_app" example app, available on GitHub.

Customize the style of a venue

You can change the visual style of VenueGeometry objects. Geometry style and/or label style objects must be created and provided to the Venue.setCustomStyle() method:

// Create geometry and label styles for the selected geometry.
final VenueGeometryStyle _geometryStyle =
  VenueGeometryStyle(Color.fromARGB(255, 72, 187, 245), Color.fromARGB(255, 30, 170, 235), 1);
final VenueLabelStyle _labelStyle =
  VenueLabelStyle(Color.fromARGB(255, 255, 255, 255), Color.fromARGB(255, 0, 130, 195), 1, 28);

_selectedVenue.setCustomStyle([geometry], _geometryStyle, _labelStyle);

Select space by identifier

The ID of spaces, levels and drawings can be extracted using getIdentifier(), e.g. for spaces call: spaces.getIdentifier(). Then, for using those id values, a specific space can be searched in a level or a drawing with getGeometryById(String id).

List<String> geometriesID = [];
List<VenueGeometry> geometries = [];
geometriesID.forEach((id) {
VenueGeometry? geometry = venue.selectedDrawing.getGeometryByIdentifier(id);
geometries.add(geometry!);
});
final VenueGeometryStyle _geometryStyle =
VenueGeometryStyle(Color.fromARGB(255, 72, 187, 245), Color.fromARGB(255, 30, 170, 235), 1);
final VenueLabelStyle _labelStyle =
VenueLabelStyle(Color.fromARGB(255, 255, 255, 255), Color.fromARGB(255, 0, 130, 195), 1, 28);
_selectedVenue.setCustomStyle(geometries, _geometryStyle, _labelStyle);

Handle tap gestures on a venue

You can select a venue object by tapping it. First, create a tap listener subclass which will put a MapMarker on top of the selected geometry:

class VenueTapController extends TapListener {
  final HereMapController hereMapController;
  final VenueMap venueMap;

  MapImage? _markerImage;
  MapMarker? _marker;

  VenueTapController(
      {required this.hereMapController,
      required this.venueMap}) {
    // Set a tap listener.
    hereMapController.gestures.tapListener = this;
    // Get an image for MapMarker.
    _loadFileAsUint8List('poi.png').then((imagePixelData) => _markerImage =
        MapImage.withPixelDataAndImageFormat(imagePixelData, ImageFormat.png));
  }

  Future<Uint8List> _loadFileAsUint8List(String fileName) async {
    // The path refers to the assets directory as specified in pubspec.yaml.
    ByteData fileData = await rootBundle.load('assets/' + fileName);
    return Uint8List.view(fileData.buffer);
  }
}

Inside the tap listener, you can use the tapped geographic coordinates as parameter for the VenueMap.getGeometry() and VenueMap.getVenue() methods:

  @override
  onTap(Point2D origin) {
    deselectGeometry();

    // Get geo coordinates of the tapped point.
    GeoCoordinates? position = hereMapController!.viewToGeoCoordinates(origin);
    if (position == null) {
      return;
    }

    // Get a VenueGeometry under the tapped position.
    VenueGeometry? geometry = venueMap.getGeometry(position);
    if (geometry != null) {
      // If there is a geometry, put a marker on top of it.
      _addPOIMapMarker(position);
    } else {
      // If no geometry was tapped, check if there is a not-selected venue under
      // the tapped position. If there is one, select it.
      Venue? venue = venueMap.getVenue(position);
      if (venue != null) {
        venueMap.selectedVenue = venue;
      }
    }
  }

  void deselectGeometry() {
    // If the map marker is already on the screen, remove it.
    if (_marker != null) {
      hereMapController!.mapScene.removeMapMarker(_marker!);
      _marker = null;
    }
  }

  void _addPOIMapMarker(GeoCoordinates geoCoordinates) {
    if (_markerImage == null) {
      return;
    }

    // By default, the anchor point is set to 0.5, 0.5 (= centered).
    // Here the bottom, middle position should point to the location.
    Anchor2D anchor2D = Anchor2D.withHorizontalAndVertical(0.5, 1);
    _marker = MapMarker.withAnchor(geoCoordinates, _markerImage!, anchor2D);
    hereMapController!.mapScene.addMapMarker(_marker!);
  }

A full example of the usage of the map tap event with venues is available in the "indoor_map_app" example app, available on GitHub.