180911(화) - Google Maps (Location data)

Google Maps

Location data

- My Location layer

・ map 에 device's location을 표시하는 simple way를 제공

・ not provide data

- Google Play services Location API

・ recommended all programmatic request for location data

- LocationSource 

・ provide custom location provider

Location permissions

- ACCESS_COARSE_LOCATION and ACCESS_FINE_LOCATION

-android.permission.ACCESS_COARSE_LOCATION 

・ use WiFi or mobile cell data (or both)가 device's location 을 결정

・ 대략 equivalent city block으로 return

- android.permission.ACCESS_FINE_LOCATION

・ location provider로부터 precise location as possible

・ GPS + WiFi + cell data

Add the permissions to manifest

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.myapp" >
  ...
  <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
  ...
</manifest>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.myapp" >
  ...
  <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
  ...
</manifest>

if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
                == PackageManager.PERMISSION_GRANTED) {
    mMap.setMyLocationEnabled(true);
} else {
    // Show rationale and request permission.
}

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    if (requestCode == MY_LOCATION_REQUEST_CODE) {
      if (permissions.length == 1 &&
          permissions[0] == Manifest.permission.ACCESS_FINE_LOCATION &&
          grantResults[0] == PackageManager.PERMISSION_GRANTED) {
        mMap.setMyLocationEnabled(true);
    } else {
      // Permission was denied. Display an error message.
    }
}

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    if (requestCode == MY_LOCATION_REQUEST_CODE) {
      if (permissions.length == 1 &&
          permissions[0] == Manifest.permission.ACCESS_FINE_LOCATION &&
          grantResults[0] == PackageManager.PERMISSION_GRANTED) {
        mMap.setMyLocationEnabled(true);
    } else {
      // Permission was denied. Display an error message.
    }
}

The My Location layer

ublic class MyLocationDemoActivity extends FragmentActivity
    implements OnMyLocationButtonClickListener,
        OnMyLocationClickListener,
        OnMapReadyCallback {

  private GoogleMap mMap;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.my_location_demo);

    SupportMapFragment mapFragment =
        (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
    mapFragment.getMapAsync(this);
  }

  @Override
  public void onMapReady(GoogleMap map) {
    mMap = map;
    // TODO: Before enabling the My Location layer, you must request
    // location permission from the user. This sample does not include
    // a request for location permission.
    mMap.setMyLocationEnabled(true);
    mMap.setOnMyLocationButtonClickListener(this);
    mMap.setOnMyLocationClickListener(this);
  }

  @Override
  public void onMyLocationClick(@NonNull Location location) {
    Toast.makeText(this, "Current location:\n" + location, Toast.LENGTH_LONG).show();
  }

  @Override
  public boolean onMyLocationButtonClick() {
    Toast.makeText(this, "MyLocation button clicked", Toast.LENGTH_SHORT).show();
    // Return false so that we don't consume the event and the default behavior still occurs
    // (the camera animates to the user's current position).
    return false;
  }
}




Google Play Services Location API

- Location API