Creating OnDragListener for Google Map v2 Fragment

Question

I’m trying to setup an onDrag Listener for a google map fragment, but can’t get the drag event to fire. Since the map doesn\'t support drag events directly, I\'m trying to i

Answer 1

1) Create wrapper class:

public class MapWrapperLayout extends FrameLayout {

    public interface OnDragListener {
        public void onDrag(MotionEvent motionEvent);
    }

    private OnDragListener mOnDragListener;

    public MapWrapperLayout(Context context) {
        super(context);
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        if (mOnDragListener != null) {
            mOnDragListener.onDrag(ev);
        }
        return super.dispatchTouchEvent(ev);
    }

    public void setOnDragListener(OnDragListener mOnDragListener) {
        this.mOnDragListener = mOnDragListener;
    }
}

2) Create subclass of MapFragment class:

public class CustomMapFragment extends SupportMapFragment {

    private View mOriginalView;
    private MapWrapperLayout mMapWrapperLayout;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        mOriginalView = super.onCreateView(inflater, container, savedInstanceState);

        mMapWrapperLayout = new MapWrapperLayout(getActivity());
        mMapWrapperLayout.addView(mOriginalView);

        return mMapWrapperLayout;
}

    @Override
    public View getView() {
        return mOriginalView;
    }

    public void setOnDragListener(MapWrapperLayout.OnDragListener onDragListener) {
        mMapWrapperLayout.setOnDragListener(onDragListener);
    }

3.1) Finally, in your activity:

    // Google map init block
    CustomMapFragment customMapFragment = ((CustomMapFragment) getSupportFragmentManager().findFragmentById(R.id.map));
    customMapFragment.setOnDragListener(new MapWrapperLayout.OnDragListener() {
        @Override
        public void onDrag(MotionEvent motionEvent) {
            Log.d("ON_DRAG", String.format("ME: %s", motionEvent));
            // Handle motion event:
        }
    });
    GoogleMap map = customMapFragment.getMap();

3.2) ... and in your layout:

<fragment android:id="@+id/map"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:name="your.package.CustomMapFragment"/>

Answer 2

To get drag event listener a fragment containing googleMap, one can use below method of google. We can get the target position of map.

googleMap.setOnCameraIdleListener(new GoogleMap.OnCameraIdleListener() {
          @Override
          public void onCameraIdle() {   
              Log.e(TAG,"==camera idle=="+ googleMap.getCameraPosition().target);

          }
      });
googleMap.setOnCameraMoveStartedListener(new GoogleMap.OnCameraMoveStartedListener() {
        @Override
        public void onCameraMoveStarted(int reason) {
            if (reason ==REASON_GESTURE) {
                isMaptouched=true;
                Toast.makeText(getActivity(), "The user gestured on the map.",
                        Toast.LENGTH_SHORT).show();
            } else if (reason ==REASON_API_ANIMATION) {
                Toast.makeText(getActivity(), "The user tapped something on the map.",
                        Toast.LENGTH_SHORT).show();
            } else if (reason ==REASON_DEVELOPER_ANIMATION) {
                Toast.makeText(getActivity(), "The app moved the camera.",
                        Toast.LENGTH_SHORT).show();
            }
        }


    });

Answer 3

I did something like similar using a BehaviorSubject to tell if the map was dirty (moved by user)

    storeMap.setOnCameraMoveStartedListener(new GoogleMap.OnCameraMoveStartedListener() {
        @Override
        public void onCameraMoveStarted(int reason) {
            if (reason == REASON_GESTURE) {
                mapIsDirty.onNext(true);
            }
        }
    });
    storeMap.setOnCameraIdleListener(new OnCameraIdleListener() {
        @Override
        public void onCameraIdle() {
            if(mapIsDirty.getValue()) {
            // Do happy things
            mapIsDirty.onNext(false);
            }
        }
    });

Answer 4

I solved it using the onCameraMoveCancelledListener:

 mMap.setOnMapClickListener(new GoogleMap.OnMapClickListener() {
        @Override
        public void onMapClick(LatLng latLng) {
            stopCamera=true;
        }
    });


    mMap.setOnCameraMoveCanceledListener(new GoogleMap.OnCameraMoveCanceledListener() {
        @Override
        public void onCameraMoveCanceled() {
            stopCamera = true;
        }
    });