Map Items

The HERE SDK allows you to add several types of items to the map, such as map polylines and markers. They are explained in detail in the sections below. Currently, the following map items are supported:

• Map polylines: Non-moveable rendered lines.
• Map arrows: A convenient way to show arrow indicators on the map.
• Map polygons: Non-moveable rendered shapes.
• Map circles: Non-moveable rendered circles that can be defined as geo polygons.
• Map markers: Images that can be pinned to 'mark' specific spots on the map.
• Map marker clustering: A group of map markers that can be clustered dependent on zoom level.
• Embedded POIs: Pickable preconfigured and embedded POI objects (carto POIs) on the map such as public transit stations, restaurants, ATMs and other facilities.
• Map markers 3D: 3D shapes rendered on the map at the specified geographic coordinates.
• Location indicator Predefined assets to indicate the current device location on the map.
• Map view pins: A convenient way to show native Android View layouts on the map.

Polylines, polygons and circles, will adjust their size based on the current zoom level, while markers remain and pins unchanged when zooming.

All map items provide a convenient way to pick them from the map.

Add Map Polylines

Polylines can be useful to render, for example, a route geometry on the map. They can be created as shown below:

private MapPolyline createPolyline() {
    ArrayList<GeoCoordinates> coordinates = new ArrayList<>();
    coordinates.add(new GeoCoordinates(52.53032, 13.37409));
    coordinates.add(new GeoCoordinates(52.5309, 13.3946));
    coordinates.add(new GeoCoordinates(52.53894, 13.39194));
    coordinates.add(new GeoCoordinates(52.54014, 13.37958));

    GeoPolyline geoPolyline;
    try {
        geoPolyline = new GeoPolyline(coordinates);
    } catch (InstantiationErrorException e) {
        // Thrown when less than two vertices.
        return null;
    }

    float widthInPixels = 20;
    Color lineColor = Color.valueOf(0, 0.56f, 0.54f, 0.63f)); // RGBA
    MapPolyline mapPolyline = new MapPolyline(geoPolyline, widthInPixels, lineColor);

    return mapPolyline;
}

A MapPolyline consists of three elements:

• A list of two or more geographic coordinates that define where to place the polyline on the map.
• A GeoPolyline that contains this list of coordinates.
• Style parameters such as DashPattern or LineCap to define how to visualize the polyline.

Since a geometric line is defined by two or more points, you need to create an ArrayList, which must contain at least two GeoCoordinates. Otherwise, an exception will be thrown. To change the look of the line, its thickness in pixels and color can be set. See for an example the screenshot.

After you have created one or more map polylines, you can add them to a map scene with:

mapScene = mapView.getMapScene();

mapPolyline = createPolyline();
mapScene.addMapPolyline(mapPolyline);

If a map polyline instance is already attached to a map scene, any further attempt to add it again will be ignored.

Note that a map view allows only one scene and all map items are placed directly on it. If you want to group your map items, you may want to organize them by using an array and add or remove them individually.

You can remove a mapPolyline from the map immediately by calling:

mapScene.removeMapPolyline(mapPolyline);

Note: MapPolyline items are pickable and it is possible to store the Metadata that can be retrieved when picking the item. For an example, see the section below on map markers.

Add Map Arrows

Map arrows behave similar to MapPolyline items, they consist of a polyline with an arbitrary number of points, but show an arrow tip at its end. Map arrows are only visible on zoom levels above 13. They can be useful do indicate directions on the map - for example, when rendered on parts of a route geometry.

private MapArrow createMapArrow() {
    ArrayList<GeoCoordinates> coordinates = new ArrayList<>();
    coordinates.add(new GeoCoordinates(52.53032, 13.37409));
    coordinates.add(new GeoCoordinates(52.5309, 13.3946));
    coordinates.add(new GeoCoordinates(52.53894, 13.39194));
    coordinates.add(new GeoCoordinates(52.54014, 13.37958));

    GeoPolyline geoPolyline;
    try {
        geoPolyline = new GeoPolyline(coordinates);
    } catch (InstantiationErrorException e) {
        // Thrown when less than two vertices.
        return null;
    }

    float widthInPixels = 20;
    Color lineColor = Color.valueOf(0, 0.56f, 0.54f, 0.63f); // RGBA
    MapArrow mapArrow = new MapArrow(geoPolyline, widthInPixels, lineColor);

    return mapArrow;
}

A MapArrow consists of three elements:

• A list of two or more geographic coordinates that define where to place the polyline on the map.
• A GeoPolyline that contains this list of coordinates.
• Style parameters such as color or widthInPixels to define how to visualize the arrow.

Since a geometric line is defined by two or more points, you need to create an array, which must contain at least two GeoCoordinates. Otherwise, an exception will be thrown. To change the look of the line, its thickness in pixels and color can be set. See for an example the screenshot.

After you have created one or more map arrows, you can add them to a map scene with:

mapScene = mapView.getMapScene();

mapArrow = createMapArrow();
mapScene.addMapArrow(mapArrow);

If a map arrow instance is already attached to a map scene, any further attempt to add it again will be ignored.

Note, a map view allows only one scene and all map items are placed directly on it. If you want to group your map items, you may want to organize them by using an array and add or remove them individually.

You can remove a mapArrow from the map immediately by calling:

mapScene.removeMapArrow(mapArrow);

Note: MapArrow items are pickable and it is possible to store the Metadata that can be retrieved when picking the item. For an example, see the section below on map markers.

Add Map Polygons

A MapPolygon is a shape that consists of at least three coordinates, otherwise it cannot be rendered. Similar to MapPolyline, the coordinates are connected. Polygons can be useful to highlight an area on the map.

Note: The order of the coordinates do matter.

See the example below on how a polygon can be created. The coordinates are connected based on their clockwise order in the list. The resulting shape can be filled with a color:

private MapPolygon createPolygon() {
    ArrayList<GeoCoordinates> coordinates = new ArrayList<>();
    // Note that a polygon requires a clockwise order of the coordinates.
    coordinates.add(new GeoCoordinates(52.54014, 13.37958));
    coordinates.add(new GeoCoordinates(52.53894, 13.39194));
    coordinates.add(new GeoCoordinates(52.5309, 13.3946));
    coordinates.add(new GeoCoordinates(52.53032, 13.37409));

    GeoPolygon geoPolygon;
    try {
        geoPolygon = new GeoPolygon(coordinates);
    } catch (InstantiationErrorException e) {
        // Thrown when less than three vertices.
        return null;
    }

    Color fillColor = Color.valueOf(0, 0.56f, 0.54f, 0.63f)); // RGBA
    MapPolygon mapPolygon = new MapPolygon(geoPolygon, fillColor);

    return mapPolygon;
}

A MapPolygon consists of three elements:

• A list of three or more geographic coordinates that define where to place the polygon on the map.
• A GeoPolygon that contains this list of coordinates.
• A Color to define the fill color of the polygon area.

Since a polygon is defined by three or more points, you need to create an array list, which must contain at least three GeoCoordinates. Otherwise, an exception will be thrown. See for an example the screenshot.

Map polygons can be used to create complex filled or unfilled shapes. However, a self-intersecting polygon can lead to undesired results as the coordinates are connected in the order of the list. As an alternative you can add multiple polygons - or make sure to add the coordinates as they appear on the outline of the desired shape.

Please note that, unlike a map polyline, the outline of a map polygon is connected automatically between the last coordinate and the first coordinate of the list.

After you have created one or more map polygons, you can add them to a map scene with:

MapPolygon mapPolygon = createPolygon();
MapScene mapScene = mapView.getMapScene();
mapScene.addMapPolygon(mapPolygon);

If a map polygon is already attached to a map scene, any further attempt to add it again will be ignored.

Note that a map view allows only one scene and all map items are placed directly on it. If you want to group your map items, you may want to organize them by using an array and add or remove them individually.

A mapPolygon can be removed immediately from the map by calling:

mapScene.removeMapPolygon(mapPolygon);

Note: MapPolygon items are pickable and it is possible to store Metadata that can be retrieved when picking the item. For an example, see the section below on map markers.

Add Map Circles

A circular shape can be useful to highlight areas on the map, draw a location accuracy halo - or to mark a distinct spot on the map. Circles are technically rendered as a sequence of triangular polygon shapes.

Consequently, circles can be created as a MapPolygon instance using a GeoCircle:

private MapPolygon createMapCircle() {
    float radiusInMeters = 300;
    GeoCircle geoCircle = new GeoCircle(new GeoCoordinates(52.530932, 13.384915), radiusInMeters);

    GeoPolygon geoPolygon = new GeoPolygon(geoCircle);
    Color fillColor = Color.valueOf(0, 0.56f, 0.54f, 0.63f); // RGBA
    MapPolygon mapPolygon = new MapPolygon(geoPolygon, fillColor);

    return mapPolygon;
}

Since a circle is a special shape of a polygon, you can add (or remove) a circle to (or from) a map scene as already shown above in the MapPolygon section.

Add Map Markers

You can use map markers to precisely point to a location on the map. Map markers will always be drawn on top of anything else that is rendered on the map.

The following code will add a map marker to the map:

MapImage mapImage = MapImageFactory.fromResource(context.getResources(), R.drawable.here_car);
MapMarker mapMarker = new MapMarker(geoCoordinates, mapImage);

mapView.getMapScene().addMapMarker(mapMarker);

In this example, we load a PNG ("here_car.png") from the resources and create a MapImage out of it. This MapImage can then be set to a MapMarker instance.

To see the image, we must add the MapMarker to a map scene. Please note that the MapImage will be displayed centered on the provided geoCoordinates.

You can also update the geoCoordinates after the marker is added to the map: It will instantly appear at the new location after mapMarker.setCoordinates() is called.

If you want to remove a MapMarker, simply call:

mapView.getMapScene().removeMapMarker(mapMarker);

You can also remove a list of map markers of type List<MapMarker> at once:

mapView.getMapScene().removeMapMarkers(mapMarkerList);

Likewise, you can add multiple map markers in a batch call via addMapMarkers(mapMarkerList).

Anchored POI Markers

By default, each image is centered on the location provided, and you may want to change this for some types of markers. An example is the POI marker, which usually points to the location with its bottom-middle position.

Therefore, the location of where the image is rendered must be shifted. The default center lies at (0.5, 0.5). If the bottom-right corner of the view should point to the set GeoCoordinates location, then the anchor point must be set to (1, 1).

Anchor points provide a convenient way to specify the location where a marker should be rendered: The top-left corner equals an anchor point of (0, 0) while the bottom-right corner equals an anchor point of (1, 1). Independent of how large the view is, the point that is half the width or height will always be 0.5 - this is similar to the concept of normalized texture UV-coordinates.

If you want to shift the POI to point to the location, you can keep the default middle location (0.5), but you must shift the image upwards by 1. 1 is just as long as the height of the image. Note that you can also specify values greater than 1 or less than 0, so that you can shift the image to any possible location. 2 would represent twice the height of the image and so on.

To add an anchored POI marker to the map, see the example below:

MapImage mapImage = MapImageFactory.fromResource(context.getResources(), R.drawable.poi);

// The bottom, middle position should point to the location.
// By default, the anchor point is set to 0.5, 0.5.
Anchor2D anchor2D = new Anchor2D(0.5F, 1);
MapMarker mapMarker = new MapMarker(geoCoordinates, mapImage, anchor2D);

mapView.getMapScene().addMapMarker(mapMarker);

For the example above, a custom POI image called "poi.png" is added in different resolutions to the project. The Android platform will choose the appropriate image resolution based on the device's display density. See the accompanying example app on how this can be done.

Unlike polylines, each MapImage will keep its size - regardless of how much the map is zoomed in or out.

Pick Map Markers

After you have added the map markers onto the map, you can use a tap gesture listener to find out if a user tapped on a map marker:

private void setTapGestureHandler() {
    mapView.getGestures().setTapListener(new TapListener() {
        @Override
        public void onTap(@NonNull Point2D touchPoint) {
            pickMapMarker(touchPoint);
        }
    });
}

private void pickMapMarker(final Point2D touchPoint) {
    float radiusInPixel = 2;
    mapView.pickMapItems(touchPoint, radiusInPixel, new MapViewBase.PickMapItemsCallback() {
        @Override
        public void onPickMapItems(@Nullable PickMapItemsResult pickMapItemsResult) {
            if (pickMapItemsResult == null) {
                // An error occurred while performing the pick operation.
                return;
            }
            List<MapMarker> mapMarkerList = pickMapItemsResult.getMarkers();
            if (mapMarkerList.size() == 0) {
                return;
            }
            MapMarker topmostMapMarker = mapMarkerList.get(0);

            showDialog("Map marker picked:", "Location: " +
                    topmostMapMarker.getCoordinates().latitude + ", " +
                    topmostMapMarker.getCoordinates().longitude);
        }
    });
}

As soon as the tap gesture is detected, we can use the view coordinates of the tapped location on the screen to ask the map view for any map markers around that location. In most cases, specifying a radius of two pixels is adequate. Then the PickMapItemsCallback provides access to the map items found, such as a MapPolygon or a MapMarker.

Adding Metadata

In many cases, users may want to interact with the shown markers - for example, by tapping on a search result to see more details about a restaurant. For this purpose, a MapMarker can hold an instance of the Metadata class, so it is possible to attach various types of data to it - even custom types are supported.

Metadata can hold several key/value pairs. Below, we create a new key named "key_poi" and set a String as the value containing the information about the type of the marker:

Metadata metadata = new Metadata();
metadata.setString("key_poi", "This is a POI.");
mapMarker.setMetadata(metadata);

Certainly, you can set any information you may need. The moment we want to read the contents of a Metadata instance, we simply ask for the data stored for a key, which is "key_poi" in our example:

Metadata metadata = topmostMapMarker.getMetadata();
if (metadata != null) {
    String message = "No message found.";
    String string = metadata.getString("key_poi");
    if (string != null) {
        message = string;
    }
    showDialog("Map Marker picked", message);
    return;
}

A MapMarker instance, by default, does not contain Metadata and mapMarker.getMetadata() may return null. The data accessed by a key can be null as well, if the Metadata object does not contain such information.

If it does, we look for the String stored for our key "key_poi" and call a helper method to present the contained String to the user. You can choose any string as a key based on your preference, but use a unique key, or you will otherwise overwrite the content stored for a different data item. To see the full example's source code, please check the MapMarker example app.

Add Map Marker Cluster

Depending on zoom level, multiple MapMarker items can overlap. With the MapMarkerCluster class you can group multiple MapMarker items to a group that can reduce the visual clutter. Markers that are overlapping will be replaced by a single image representation. Such a cluster image can be picked and contains only the markers that are contained within.

The code below shows how a cluster containing multiple MapMarker items can be created:

public void showMapMarkerCluster() {
    MapImage clusterMapImage = MapImageFactory.fromResource(context.getResources(), R.drawable.blue_square);
    MapMarkerCluster mapMarkerCluster = new MapMarkerCluster(new MapMarkerCluster.ImageStyle(clusterMapImage));
    mapView.getMapScene().addMapMarkerCluster(mapMarkerCluster);

    for (int i = 0; i < 10; i++) {
        mapMarkerCluster.addMapMarker(createRandomMapMarkerInViewport());
    }
}

You can set a MapImage that should be used to represent a cluster of two or more overlapping map markers.

Note that MapMarker items can be added or removed to a MapMarkerCluster that is already shown on the map. If you want the remove the cluster including all markers call:

mapView.getMapScene().removeMapMarkerCluster(mapMarkerCluster);

Note that MapMarker items contained in a cluster are not part of pickMapItemsResult.getMarkers(). Therefore, we can pick them separately with the code as shown below - after we have received the pick result from our pickMapItems() call (see MapMarker section):

private void handlePickedMapMarkerClusters(PickMapItemsResult pickMapItemsResult) {
    List<MapMarkerCluster.Grouping> groupingList = pickMapItemsResult.getClusteredMarkers();
    if (groupingList.size() == 0) {
        return;
    }

    MapMarkerCluster.Grouping topmostGrouping = groupingList.get(0);
    int clusterSize = topmostGrouping.markers.size();
    if (clusterSize == 0) {
        // This cluster does not contain any MapMarker items.
        return;
    }
    if (clusterSize == 1) {
        showDialog("Map marker picked",
                "This MapMarker belongs to a cluster.");
    } else {
        showDialog("Map marker cluster picked",
                "Number of contained markers in this cluster: " + clusterSize + ". " +
                        "Total number of markers in this MapMarkerCluster: " + topmostGrouping.parent.getMarkers().size());
    }
}

With this code you can detect if a cluster was picked and inform the user of the contained markers. You can also identify a single MapMarker instance if the markers list is containing only one item.

Usually, only a single MapMarkerCluster instance is needed and above we handle only the topmost cluster.

Depending on the distance of the markers, multiple cluster images can appear for the same MapMarkerCluster instance - each containing a subset of the total number of clustered markers.

See the MapItems app for an example on GitHub.

Pick Embedded POIs

Embedded POIs are carto POI marker that are already preconfigured and shown on the MapView, by default. Unlike MapMarker items, their content and visual appearance cannot be changed. However, it is possible to tap on such an icon and retrieve information such as location, PlaceCategory and the name of the POI.

Embedded POIs can be picked in parallel to other MapMarker items shown on the map, unless they are currently hidden by another map item.

private void setTapGestureHandler() {
    mapView.getGestures().setTapListener(new TapListener() {
        @Override
        public void onTap(@NonNull Point2D touchPoint) {
            pickMapMarker(touchPoint);
        }
    });
}

private void pickMapMarker(final Point2D touchPoint) {
    // You can also use a larger area to include multiple carto POIs.
    Rectangle2D rectangle2D = new Rectangle2D(touchPoint, new Size2D(1, 1));
    mapView.pickMapFeatures(rectangle2D, new MapViewBase.PickMapFeaturesCallback() {
        @Override
        public void onPickMapFeature(@Nullable PickMapFeaturesResult pickMapFeaturesResult) {
            if (pickMapFeaturesResult == null) {
                // An error occurred while performing the pick operation.
                return;
            }

            List<PickMapFeaturesResult.PoiResult> cartoPOIList = pickMapFeaturesResult.getPois();
            int listSize = cartoPOIList.size();
            if (listSize == 0) {
                return;
            }

            PickMapFeaturesResult.PoiResult topmostCartoPOI = cartoPOIList.get(0);
            showDialog("Carto POI picked:", topmostCartoPOI.name + ", Location: " +
                    topmostCartoPOI.coordinates.latitude + ", " +
                    topmostCartoPOI.coordinates.longitude + ". ");
        }
    });
}

Each picked embedded POI contains an offlineSearchId that can be used to fetch more Place details with the OfflineSearchEngine. Note that this information is already part of the map data and the provided ID cannot be used for the online SearchEngine.

The visibility of embedded POIs on the map can be controlled with MapScene.setPoiVisibility() that allows to set a VisibilityState for a list of POI categories.

See the CartoPOIPicking app for an example on GitHub.

Add 3D Map Markers

The HERE SDK allows to add custom 3D models onto the map. Optionally, these models can be textured together with a blend Color. The common .obj file format is used to specify the geometry of the 3D model. You can generate it with common 3D modeling software - for example, with the free Three.js online editor.

The obj file format specifies the vertices, normals, texture coordinates and faces to define how the model will be rendered. The resulting model can be moved around the map by updating its coordinates. Its orientation can be changed by updating its bearing, pitch and roll.

Note that the HERE SDK does not support material files (*.mtl) and multi texturing.

Once you have a model defined in the obj format and a texture to wrap around the model, add both files to an assets directory in your project. For example': app/src/main/assets/....

Below we added one obj file and a PNG texture:

• app/src/main/assets/obstacle.obj
• app/src/main/assets/obstacle_texture.png

As a tip, use Android's AssetManager to verify that the files exist, like so:

private void checkIfFileExistsInAssetsFolder(String fileName) {
    AssetManager assetManager = context.getAssets();
    try {
        assetManager.open(fileName);
    } catch (IOException e) {
        Log.e("MapMarkerExample", "Error: File not found!");
    }
}

With this you will get an exception when the file does not exist at the expected file location.

Now you can use the following code to add a MapMarker3D to the map:

String geometryFile = "obstacle.obj";
String textureFile = "obstacle_texture.png";
checkIfFileExistsInAssetsFolder(geometryFile);
checkIfFileExistsInAssetsFolder(textureFile);

MapMarker3DModel mapMarker3DModel = new MapMarker3DModel(geometryFile, textureFile);
MapMarker3D mapMarker3D = new MapMarker3D(geoCoordinates, mapMarker3DModel);
mapMarker3D.setScale(6);

mapView.getMapScene().addMapMarker3d(mapMarker3D);

Above, we pass both asset files to the MapMarker3DModel constructor that defines the model. Similarly, like we have already seen for MapImage elements, you can pass the model to one of the available MapMarker3D constructors. Note that we also set a scale factor to let the model appear 6x bigger. Since the obj model is defined in a 3D coordinate space, it does not contain length units.

You can add and remove MapMarker3D items like other map items via MapScene.

Below you can see an example of how it may appear. The model will be centered on the provided geographic coordinates. The center of the model is defined by the origin of its coordinate system.

MapMarker3D items are always rendered on top of anything else that is visible on the map. Note that you cannot pick MapMarker3D items yet.

Like 2D MapMarker items, a MapMarker3D will not change its size when the map is zoomed in or out, but it will rotate together with map.

Add Flat Map Markers

By default, map markers do not rotate with the map - nor get tilted when the map is tilted. This can be changed by using a MapMarker3D to become flat. In fact, flat map markers are a special case of MapMarker3D items that contain a 0 length on the z-axis in 3D space. So, basically, the model represents a 2D plane, you can create with any 3D editor.

Below you see a 2D example for a plane, that is 2 units large on the x- and y-axis. Since 3D objects can be easily scaled, the size of the model is not important. The origin of the coordinate system in our example lies at the bottom of the plane. This way we can wrap a POI marker asset as texture that points to the provided geographic coordinates.

# A 2 x 2 square, centered upon origin.

v -1 2 0
v 1 2 0
v -1 0 0
v 1 0 0
# 4 vertices

vt 0 1
vt 1 1
vt 0 0
vt 1 0
# 4 texture vertices

vn 0 0 1
vn 0 0 1
vn 0 0 1
vn 0 0 1
# 4 vertex normals

f 1/1/1 3/3/3 2/2/2
f 3/3/3 4/4/4 2/2/2
# 2 faces

For this example, we store the above model definition of a plane into a text file called "plane.obj".

Since the plane is a square, we extend the size of the POI image on the left and right side with a transparent area, so that the image becomes a square. As our original image is a rectangle and not a square it would get distorted when it would be wrapped onto the plane.

Once you have a model defined in the obj format and a texture to wrap around the model, add both files to an assets directory in your project. For example': app/src/main/assets/....

Below we added one obj file and a PNG texture:

• app/src/main/assets/plane.obj
• app/src/main/assets/poi_texture.png

Use the following code to add a flat marker to the map:

String geometryFile = "plane.obj";
String textureFile = "poi_texture.png";
checkIfFileExistsInAssetsFolder(geometryFile);
checkIfFileExistsInAssetsFolder(textureFile);

MapMarker3DModel mapMarker3DModel = new MapMarker3DModel(geometryFile, textureFile);
MapMarker3D mapMarker3D = new MapMarker3D(geoCoordinates, mapMarker3DModel);
mapMarker3D.setScale(60);

mapView.getMapScene().addMapMarker3d(mapMarker3D);

The code for the checkIfFileExistsInAssetsFolder() method can be seen in the previous section.

Note that we used a normalized length of 2 units in 3D space, therefore we scale the model to be 60x bigger. The result can be seen in the screenshot below.

We have added a red circle to indicate the location to which the flat marker is pointing to.

Flat map markers rotate along with the map - and the map marker will also be tilted when the map is tilted, allowing for a 3D-like effect, although its 2D model is flat. Please note that, by default, flat map markers will not change their scale value together with the zoom level of the map: For example, when zooming out the map, a map marker will still be visible - same as for an unflattened MapMarker.

Add a Location Indicator

Another type of 3D map items is the LocationIndicator. Usually, only one instance is added to the map to indicate the current location of the user's device on the map - including a heading direction.

Unlike other map items, a LocationIndicator implements the MapViewLifecycleListener interface, as it's lifecycle is managed by the MapView once it is added.

The HERE SDK provides predefined 3D assets for various use cases. If desired, these can be replaced by setting your own customized MapMarker3DModel for each of the predefined styles.

As all map markers, also a LocationIndicator will not be scaled when the zoom level of the map view will change. However, if the map is tilted, the LocationIndicator will get smaller when it is moved farther to the horizon.

Let's see an example how to add a LocationIndicator onto the map:

private void addLocationIndicator(GeoCoordinates geoCoordinates,
                                  LocationIndicator.IndicatorStyle indicatorStyle) {
    LocationIndicator locationIndicator = new LocationIndicator();
    locationIndicator.setLocationIndicatorStyle(indicatorStyle);

    // A LocationIndicator is intended to mark the user's current location,
    // including a bearing direction.
    // For testing purposes, we create a Location object. Usually, you may want to get this from
    // a GPS sensor instead.
    Location location = new Location.Builder()
        .setCoordinates(geoCoordinates)
        .setTimestamp(new Date())
        .setBearingInDegrees(getRandom(0, 360))
        .build();

    locationIndicator.updateLocation(location);

    // A LocationIndicator listens to the lifecycle of the map view,
    // therefore, for example, it will get destroyed when the map view gets destroyed.
    mapView.addLifecycleListener(locationIndicator);
}

As you can see above, no asset is required. Instead an IndicatorStyle is set:

• LocationIndicator.IndicatorStyle.NAVIGATION: An asset designed for navigational use cases.
• LocationIndicator.IndicatorStyle.PEDESTRIAN: An asset designed for handheld usage, ie. while sitting or walking.

Both styles indicate the current bearing - which represents the direction the user is heading to. In the example, we set a random bearing value between 0° and 360° degrees. A bearing of 0° degress is indicating North-up, and thus, the arrow is pointing up - as the map is also pointing North-up, by default.

During navigation, a common UX approach is to rotate the map into the direction the user is driving, so that the direction arrow keeps pointing up, although the bearing may change. Usually, during navigation the arrow is expected to point into the direction of the road the user is traveling on.

For a pedestrian use case, the focus lies on the current location of the user. Therefore, the direction is indicated by a much smaller arrow.

It depends on the application how the bearing value is utilized. Note that the bearing value as derived from the Location object indicates the direction of movement, while alternatively an application may choose to set the bearing in relation to true north (compass mode). If you want the arrow to point to true North, then instead change the bearing value to 0°. Note that such adaptions must be done each time when you receive a new Location update from a location source (see below).

Usually, only one instance of a LocationIndicator is set to the map. By calling updateLocation() its location can be updated and by calling setLocationIndicatorStyle() its style can be updated on-the-fly.

Each style has several associated MarkerType values that define different states, such as a gray state when the GPS signal is lost. When a LocationIndicator is customized, it is important to set all types, otherwise changing a state will have no effect.

The following code snippet shows how to switch between a predefined gray type - indicating an inactive state - and the default state:

boolean isActive = locationIndicator.isActive();
// Toggle between active / inactive state.
locationIndicator.setActive(!isActive);

A LocationIndicator implements the MapViewLifecycleListener interface, therefore it's coupled with the lifecyle of the MapView.

As a benefit - to support the most common use case - you can add the LocationIndicator to the map once and then its lifecycle will be automatically managed by the MapView. However, if you want to remove the LocationIndicator on your own, call:

mapView.removeLifecycleListener(locationIndicator);

For most uses cases, the LocationIndicator should get updated based on frequent Location updates. You can see an isolated usage example as part of the MapItems example app.

Check the Get Locations section to see how to acquire real Location updates from the GPS chip of your device. The Positioning example app shows how the LocationIndicator can be used for that.

How to use the MapViewLifecycleListener

The MapViewLifecycleListener can be implemented by any class that wants to listen to the lifecycle of the MapView. As an example, for the LocationIndicator, this interface is already implemented. The implementation takes care to react on the following events:

• onAttach(MapViewBase mapView): Called when adding the implementing object to the map view.
• onPause(): Called when the map view to which the implementing object is attached gets paused (usually, when the app goes into background).
• onResume(): Called when the map view to which the implementing object is attached gets resumed (usually, when the app goes into foreground).
• onDetach(MapViewBase mapView): Called when removing the implementing object from the map view.
• onDestroy(): Called when the map view to which the implementing object is attached to is destroyed.

You can attach and remove the implementing object like so:

• Attach an object to the MapView lifecycle: mapView.addLifecycleListener(myObject);
• Remove an object from the MapView lifecycle: mapView.removeLifecycleListener(myObject);

Add Map View Pins

While map markers offer a seamless way to place items on the map, map pins can be used to pin a native View to the map. This can be useful to show information pop-up bubbles (or animated info bubbles), annotations, or customized controls. For example, when tapping on a map marker, you can show a map pin with additional information about the marker location.

Map pins can be composed out of multiple Views, and each of them can be used just like any other View, allowing you to add nested layouts of your choice, attach click handlers, or apply animations, for example.

As is the custom, you can define your views in a XML layout file and inflate them programmatically - or generate the desired view content programmatically. For example:

TextView textView = new TextView(context);
textView.setTextColor(Color.parseColor("#FFFFFF"));
textView.setText("Centered ViewPin");

LinearLayout linearLayout = new LinearLayout(context);
linearLayout.setBackgroundResource(R.color.colorAccent);
linearLayout.setPadding(10, 10, 10, 10);
linearLayout.addView(textView);

This creates a LinearLayout (which is derived from View) holding a TextView. You can also directly add a TextView, without adding it to an intermediate layout. Any combination of views - or single views - can be added.

Now, all we need to do is to add our little view composition to the map. Note that pins can be added directly to the map - unlike other map items such as polygons or markers:

ViewPin viewPin = mapView.pinView(linearLayout, geoCoordinates);

Note that this method returns a proxy object that can be used to control the pinning, for example, to specify an anchor point.

It is also possible to apply animations to the view or attach some other interaction listeners. After a View is attached to the map view, it will behave like any other Android View - except that it stays fixed on the map and moves along with it when panning or zooming. Note, the ViewPin does not rotate when you rotate the map - similar to map polylines and map markers.

You can add as many map pins as you like, but you should take performance into consideration. For example, if you want to indicate multiple search results on the map, then map pins are less performant than map markers.

To remove a pin from the map, simply call:

mapView.unpinView(view);

If you have added multiple ViewPin instances, you can access all pins from the mapView object by calling:

List<ViewPin> viewPins = mapView.getViewPins();

Usually, map pins are the best choice for showing additional dynamic content for a specific location on the map.

Anchored Map View Pins

By default, the map pin will be centered on the provided location. But if you want to use a pin without covering the area underneath, what can you do?

For this purpose, you can specify an anchor point, which influences the view's position on the screen in the same way as we have already seen for map markers above:

viewPin.setAnchorPoint(new Anchor2D(0.5F, 1));

This will place the view centered horizontally on the location, while the bottom of the view is matching the provided coordinate. As visualized in the screenshot below, the map pin sits on a map circle object that indicates the provided center location of the map pin.

Anchor points provide a convenient way to specify the location where the view should be rendered: The top-left corner equals an anchor point of (0, 0) while the bottom-right corner equals an anchor point of (1, 1). Independent of how large the view is, the point that is half the width or height will always be 0.5 - this is similar to the concept of normalized texture UV-coordinates. For an illustration, please see the map markers section above.

By default, the anchor point is (0.5, 0.5), which will render the view centered on the location. If the bottom-right corner of the view should point to the set GeoCoordinates location, then the anchor point must be set to (1, 1).

Since a view can be of any size, the maximum width and height will have a value of 1. The dimension of the view is calculated after it is fully inflated. If you know the exact dimensions of your view, you can easily calculate a specific point inside the view in relation to the maximum value of 1.

Note: While offsets allows you to specify the translation along the x- and y-axis, an anchor point defines the relative position of the top-left corner of a rectangle such as a view. In relation to the view's boundaries, it defines the point where the view is centered on the provided GeoCoordinates location.