Tap handling, object selection, annotation

After having set up our basic environment with the Deep Map™ SDK, we will now look at simple map interaction methods.

To do this, we are first going to create our own MapFragment that extends the SDK MapFragment:

Java

import com.hdm_i.dm.android.mapsdk.HDMFeature;
import com.hdm_i.dm.android.mapsdk.HDMVec3;
import com.hdm_i.dm.android.mapsdk.MapFragment;
import com.hdm_i.dm.android.mapsdk.MapView;

import java.util.List;

public class MyMapFragment extends MapFragment implements MapView.TapDelegate {

    @Override
    public void onSingleTap(List<HDMFeature> features, HDMVec3 tapCoordinateWGS84) {

    }

    @Override
    public void onLongPress(List<HDMFeature> features, HDMVec3 tapCoordinateWGS84) {

    }
}

To use our new MyMapFragment in our demo app, we have to set it in the layout and the Activity:

Java

<fragment android:name="tutorial.hdm_i.com.myapplication.MyMapFragment"
    android:id="@+id/deepmap_fragment"
    android:layout_width="368dp"
    android:layout_height="495dp"
    tools:layout_editor_absoluteY="8dp"
    tools:layout_editor_absoluteX="8dp" />

Java

//MainActivity.java
public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final MyMapFragment mapFragment = (MyMapFragment) getFragmentManager().findFragmentById(R.id.deepmap_fragment);
        mapFragment.loadMap(new MapView.ReadyDelegate() {
            @Override
            public void onReady(MapView mapView) {
                mapView.setTapDelegate(mapFragment);
            }
        });
    }
}

As you can see, our MyMapFragment already implements the MapView.TapDelegate interface. This interface has two methods, onSingleTap and onLongPress. Both methods have the same parameters:

• features: is a list of all features at the tapped location in order from top to bottom

• tapCoordinateWGS84: the coordinate of the tapped point on the map in the WGS84 reference system.

Now let’s implement a simple object selection by using the onSingleTap method:

Java

//MyMapFragment.java
@Override
public void onSingleTap(List<HDMFeature> features, HDMVec3 tapCoordinateWGS84) {
    if(features.size() > 0){
        mapView.selectFeatureWithId(features.get(0).getFeatureId());
    }
}

When you launch the app again, you can now select objects by touching them:

Annotations

For the final part of this tutorial, we will add a simple annotation to our selected feature:

This is done by adding just two lines of code to our onSingleTap method:

Java

//MyMapFragment.java
@Override
public void onSingleTap(List<HDMFeature> features, HDMVec3 tapCoordinateWGS84) {
    if(features.size() > 0){
        mapView.selectFeatureWithId(features.get(0).getFeatureId());
        //Add a new annotation to the map:
        Annotation annotation = new Annotation("Hello World!",features.get(0));
        mapView.addAnnotation(annotation);
    }
}

That’s it! You are now able to select objects and add annotations to the map!