I'm working on an application in which I have used custom mapView, and on that mapView if user pinch(two finger gesture), the camera position for map should change accordingly, for eg. if user pinch zoom in, the camera zoom should zoom in for map (only center of the screen) and if user pinch zoom out, the camera zoom should be zoom out for the map(only center of the screen). I've tried for it but for zoom in and zoom out the map is always zooming in. Is there any way to find the distance between two finger that is increasing/decreasing, or gesture is pinch zoom out or pinch zoom in??
UPDATE
MainActivity.java
public class MainActivity extends AppCompatActivity {
private static final String TAG = MainActivity.class.getSimpleName();
private static final int LOCATION_PERMISSION_CONSTANT = 34;
private static final int REQUEST_CHECK_SETTINGS = 12;
//private EnhanchedMapView mapView;
private MapView mapView;
private GoogleMap googleMap;
private FusedLocationProviderClient mFusedLocationClient;
private Location mLastLocation;
LocationManager locationManager;
private TextView tvCoordinates;
private GoogleApiClient googleApiClient;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
bindUI();
mapView.onCreate(savedInstanceState);
fusedLocationMethod(savedInstanceState);
getLocationPermission();
//getLastLocation();
}
private void bindUI() {
mapView = findViewById(R.id.map_view);
tvCoordinates = findViewById(R.id.tv_coordinates);
}
public void fusedLocationMethod(Bundle savedInstanceState) {
mFusedLocationClient = LocationServices.getFusedLocationProviderClient(this);
}
private void getLocationPermission() {
if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION)
!= PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this,
new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION, android.Manifest.permission.ACCESS_COARSE_LOCATION},
LOCATION_PERMISSION_CONSTANT);
return;
}
getLastLocation();
}
@Override
public void onRequestPermissionsResult(int requestCode,
String permissions[], int[] grantResults) {
switch (requestCode) {
case LOCATION_PERMISSION_CONSTANT:
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
if (googleApiClient == null) {
getLocationPermission();
} else {
getLocationPermission();
}
} else {
Toast.makeText(this, "Permission Denied", Toast.LENGTH_SHORT).show();
}
break;
}
}
public void getLastLocation() {
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return;
}
mFusedLocationClient.getLastLocation()
.addOnSuccessListener(this, new OnSuccessListener<Location>() {
@Override
public void onSuccess(Location location) {
if (location == null) {
Log.w(TAG, "onSuccess:null");
return;
}
mLastLocation = location;
preLat = location.getLatitude();
preLong = location.getLongitude();
settingMap(location.getLatitude(), location.getLongitude());
try {
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
} catch (Exception e) {
e.printStackTrace();
Log.d("Error", e.getMessage() + " 203");
}
if (ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return;
}
}
})
.addOnFailureListener(this, new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception e) {
Log.w(TAG, "getLastLocation:onFailure", e);
}
});
}
private double preLat = 0.0;
private double preLong = 0.0;
//setting map
private void settingMap(final double lat, final double longi) {
mapView.getMapAsync(new OnMapReadyCallback() {
@Override
public void onMapReady(GoogleMap gglmap) {
googleMap = gglmap;
googleMap.getUiSettings().setAllGesturesEnabled(false);
googleMap.clear();
CameraPosition cameraPosition = new CameraPosition.Builder().target(new LatLng(lat, longi)).zoom(16).build();
googleMap.moveCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
googleMap.getUiSettings().setMyLocationButtonEnabled(false);
//permission for location
if (ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return;
}
googleMap.setMyLocationEnabled(true);
//googleMap.getUiSettings().setAllGesturesEnabled(false);
googleMap.setOnCameraIdleListener(new GoogleMap.OnCameraIdleListener() {
@Override
public void onCameraIdle() {
int mapViewHeight = mapView.getHeight();
int mapViewWidth = mapView.getWidth();
Projection projection = googleMap.getProjection();
LatLng geographicalPosition = projection.fromScreenLocation(new Point(mapViewWidth / 2, mapViewHeight / 2));
// Toast.makeText(getActivity(),""+geographicalPosition.latitude+" , "+geographicalPosition.longitude,Toast.LENGTH_LONG).show();
tvCoordinates.setText(geographicalPosition.latitude + " , " + geographicalPosition.longitude);
}
});
}
});
}
@Override
public void onResume() {
super.onResume();
mapView.onResume();
}
@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
super.onSaveInstanceState(savedInstanceState);
mapView.onSaveInstanceState(savedInstanceState);
}
@Override
public void onPause() {
super.onPause();
mapView.onPause();
}
@Override
public void onStop() {
super.onStop();
mapView.onStop();
}
@Override
public void onLowMemory() {
super.onLowMemory();
mapView.onLowMemory();
}
@Override
public void onDestroy() {
super.onDestroy();
mapView.onDestroy();
}
@Override
public void onStart() {
super.onStart();
mapView.onStart();
}
}
EnhancedMapView.java
public class EnhanchedMapView extends MapView implements OnMapReadyCallback {
private long mLastTouchTime = -1;
private static final int INVALID_POINTER_ID = -1;
private OnMapReadyCallback mMapReadyCallback;
private GoogleMap mGoogleMap;
private float mPosX;
private float mPosY;
private float mLastTouchX;
private float mLastTouchY;
private int mActivePointerId = INVALID_POINTER_ID;
private void init() {
}
@Override
public void getMapAsync(OnMapReadyCallback callback) {
mMapReadyCallback = callback;
super.getMapAsync(this);
}
@Override
public void onMapReady(GoogleMap googleMap) {
mGoogleMap = googleMap;
}
LatLng geographicalPosition;
boolean isPinch = false;
@Override
public boolean dispatchTouchEvent(MotionEvent event) {
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
mGoogleMap.getUiSettings().setScrollGesturesEnabled(true);
long thisTime = System.currentTimeMillis();
if (thisTime - mLastTouchTime < ViewConfiguration.getDoubleTapTimeout()) {
if (mGoogleMap != null) {
LatLng zoomCenter = mGoogleMap.getProjection().fromScreenLocation(new Point((int) event.getX(), (int) event.getY()));
float currentZoom = mGoogleMap.getCameraPosition().zoom;
int mapViewHeight = getHeight();
int mapViewWidth = getWidth();
Projection projection = mGoogleMap.getProjection();
geographicalPosition = projection.fromScreenLocation(new Point(mapViewWidth / 2, mapViewHeight / 2));
MarkerOptions markerOptions = new MarkerOptions();
markerOptions.position(geographicalPosition);
mGoogleMap.addMarker(markerOptions);
mGoogleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(geographicalPosition.latitude, geographicalPosition.longitude), currentZoom + 1));
}
mLastTouchTime = -1;
} else {
mLastTouchTime = thisTime;
mGoogleMap.getUiSettings().setZoomGesturesEnabled(false);
}
break;
case MotionEvent.ACTION_POINTER_DOWN:
mGoogleMap.getUiSettings().setZoomGesturesEnabled(false);
mGoogleMap.getUiSettings().setScrollGesturesEnabled(false);
Log.d("Nirmal", "ACTION_POINTER_DOWN");
isPinch = true;
int mapViewHeight = getHeight();
int mapViewWidth = getWidth();
Projection projection = mGoogleMap.getProjection();
geographicalPosition = projection.fromScreenLocation(new Point(mapViewWidth / 2, mapViewHeight / 2));
break;
case MotionEvent.ACTION_POINTER_UP:
mGoogleMap.getUiSettings().setScrollGesturesEnabled(true);
isPinch = false;
break;
case MotionEvent.ACTION_UP:
mGoogleMap.getUiSettings().setScrollGesturesEnabled(true);
break;
case MotionEvent.ACTION_MOVE:
if (isPinch) {
if (mGoogleMap == null || geographicalPosition == null)
break;
//Log.d("Nirmal", "ACTION_MOVE");
Log.d("Nirmal", "" + event.getX() + " , " + event.getY());
float currentZoom = mGoogleMap.getCameraPosition().zoom;
mGoogleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(geographicalPosition.latitude, geographicalPosition.longitude), currentZoom + 0.05f));
}
break;
}
return super.dispatchTouchEvent(event);
}
}
As pskink recommended, you need ScaleGestureDetector
object, which determines zoom "direction". Something like that:
ScaleGestureDetector mScaleDetector = new ScaleGestureDetector(getContext(),
new ScaleGestureDetector.SimpleOnScaleGestureListener() {
private float scaleFactor = 1f;
@Override
public boolean onScale(ScaleGestureDetector detector) {
// store scale factor for detect zoom "direction" on end
scaleFactor = detector.getScaleFactor();
return true;
}
@Override
public void onScaleEnd(ScaleGestureDetector detector) {
float currentZoom = mGoogleMap.getCameraPosition().zoom;
if (scaleFactor > 1) {
// zoom in detected
mGoogleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(mZoomCenter, currentZoom + 1));
} else if (scaleFactor < 1) {
// zoom out detected
mGoogleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(mZoomCenter, currentZoom - 1));
}
super.onScaleEnd(detector);
}
});
And you can use it in your EnhanchedMapView.dispatchTouchEvent()
easily:
...
@Override
public boolean dispatchTouchEvent(MotionEvent event) {
// just call .onTouchEvent() on your ScaleGestureDetector object
mScaleDetector.onTouchEvent(event);
switch (event.getAction() & MotionEvent.ACTION_MASK) {
...
NB! You need to disable GoogleMap
zoom gesture
@Override
public void onMapReady(GoogleMap googleMap) {
mGoogleMap = googleMap;
mGoogleMap.getUiSettings().setZoomGesturesEnabled(false);
...
}
and never enable it.
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