Expert: Doctor Consult using RxAndroid and MVVM with Huawei Kits (Account, Map, Identity) in Android App.

// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
    repositories {
        google()
        jcenter()
        maven {url 'https://developer.huawei.com/repo/'}
    }
    dependencies {
        classpath "com.android.tools.build:gradle:4.0.1"
        classpath 'com.huawei.agconnect:agcp:1.4.2.300'
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        google()
        jcenter()
        maven {url 'https://developer.huawei.com/repo/'}
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

//  implementation 'com.huawei.hms:maps:4.0.0.301'
    implementation 'com.huawei.hms:maps:5.0.1.300'
    //site
    implementation 'com.huawei.hms:site:4.0.0.300'
    //location
    implementation 'com.huawei.hms:location:4.0.3.301'

    implementation 'com.squareup.retrofit2:retrofit:2.5.0'
    implementation 'com.squareup.retrofit2:converter-gson:2.5.0'
    implementation "com.squareup.retrofit2:adapter-rxjava2:2.6.2"

    implementation 'io.reactivex:rxjava:1.3.0'
    implementation 'io.reactivex:rxandroid:1.2.1'
    implementation 'com.android.support:multidex:1.0.3'


    implementation 'com.squareup.okhttp3:logging-interceptor:4.2.2'

    // RxAndroid
    implementation 'io.reactivex.rxjava2:rxjava:2.2.8'
    implementation 'io.reactivex.rxjava2:rxandroid:2.1.1'

            android:name="install_channel"
            android:value="AppGallery" />
        <meta-data
            android:name="com.huawei.hms.client.appid"
            android:value="XXXXXXX" />`
5.Create Activity class with XML UI.
DirectionActivity:

public static final String TAG = "DirectionActivity";
private static final String MAPVIEW_BUNDLE_KEY = "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX";
private HuaweiMap hmap;
private MapView mMapView;
private Marker mMarker;
private List<LatLng> latLngList;

private MapApiViewModel mapApiViewModel;
private CardView cardView;

private LocationCallback mLocationCallback;
private LocationRequest mLocationRequest;
private FusedLocationProviderClient fusedLocationProviderClient;
private SettingsClient settingsClient;


private PolylineBody polylineBody;

private Button btnBooking;

private Map<String, Object> remoteConfigMap;
private AGConnectConfig config;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    init();

    remoteConfigMap = new HashMap<>();
    config = AGConnectConfig.getInstance();
    remoteConfigMap.put("mapstyle", "light");
    config.applyDefault(remoteConfigMap);

    SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.mapView);

    mMapView = findViewById(R.id.mapView);
    Bundle mapViewBundle = null;
    if (savedInstanceState != null) {
        mapViewBundle = savedInstanceState.getBundle(MAPVIEW_BUNDLE_KEY);
    }
    mMapView.onCreate(mapViewBundle);
    mMapView.getMapAsync(DirectionActivity.this);
}


private void init() {
    setContentView(R.layout.activity_direction);
    cardView = findViewById(R.id.card_map);
    btnBooking = findViewById(R.id.btn_book_trip);
    btnBooking.setOnClickListener(view -> {
        Intent intent = new Intent(this, BookAppointmentActivity.class);
       startActivity(intent);
    });
    Toolbar toolbar = findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    getSupportActionBar().setDisplayShowHomeEnabled(true);

    Bundle extras = getIntent().getExtras();
    if (extras != null) {
        String name = extras.getString("name");
        String orgLat = extras.getString("orgLat");
        String orgLong = extras.getString("orgLong");
        String desLat = extras.getString("desLat");
        String desLong = extras.getString("desLong");
        boolean tripDisplay = extras.getBoolean("isTrip");

        if (!tripDisplay) {
            cardView.setVisibility(View.GONE);
        } else {
            cardView.setVisibility(View.VISIBLE);
        }

        setTitle(name);
        setLatLong(orgLat, orgLong, desLat, desLong);
    }


    mapApiViewModel = ViewModelProviders.of(this).get(MapApiViewModel.class);

    fusedLocationProviderClient = LocationServices.getFusedLocationProviderClient(this);
    settingsClient = LocationServices.getSettingsClient(this);
    mLocationRequest = new LocationRequest();
    mLocationRequest.setInterval(10000);
    mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    if (null == mLocationCallback) {
        mLocationCallback = new LocationCallback() {
            @Override
            public void onLocationResult(LocationResult locationResult) {
                if (locationResult != null) {
                    List<Location> locations = locationResult.getLocations();
                    if (!locations.isEmpty()) {
                        for (Location location : locations) {
                            Log.i(TAG,
                                    "onLocationResult location[Longitude,Latitude,Accuracy]:" + location.getLongitude()
                                            + "," + location.getLatitude() + "," + location.getAccuracy());
                        }
                    }
                }
            }

            @Override
            public void onLocationAvailability(LocationAvailability locationAvailability) {
                if (locationAvailability != null) {
                    boolean flag = locationAvailability.isLocationAvailable();
                    Log.i(TAG, TAG + flag);
                }
            }
        };
    }

    // check location permisiion
    if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.P) {
        Log.i(TAG, "sdk < 28 Q");
        if (ActivityCompat.checkSelfPermission(this,
                Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED
                && ActivityCompat.checkSelfPermission(this,
                Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            String[] strings =
                    {Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION};
            ActivityCompat.requestPermissions(this, strings, 1);
        }
    } else {
        if (ActivityCompat.checkSelfPermission(this,
                Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED
                && ActivityCompat.checkSelfPermission(this,
                Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED
                && ActivityCompat.checkSelfPermission(this,
                "android.permission.ACCESS_BACKGROUND_LOCATION") != PackageManager.PERMISSION_GRANTED) {
            String[] strings = {Manifest.permission.ACCESS_FINE_LOCATION,
                    Manifest.permission.ACCESS_COARSE_LOCATION,
                    "android.permission.ACCESS_BACKGROUND_LOCATION"};
            ActivityCompat.requestPermissions(this, strings, 2);
        }
    }
}

@Override
protected void onStart() {
    super.onStart();
    mMapView.onStart();
}

@Override
protected void onResume() {
    super.onResume();
    mMapView.onResume();
}

@Override
protected void onPause() {
    super.onPause();
    mMapView.onPause();
}

@Override
protected void onStop() {
    super.onStop();
    mMapView.onStop();
}

@Override
protected void onDestroy() {
    super.onDestroy();
    mMapView.onDestroy();
}

@Override
public void onMapReady(HuaweiMap map) {

    hmap = map;

    hmap.setMyLocationEnabled(true);
    hmap.setTrafficEnabled(true);

    hmap.getUiSettings().setRotateGesturesEnabled(true);
    hmap.getUiSettings().setCompassEnabled(false);

    mapApiViewModel.getPolylineLiveData(getPolylineBody()).observe(this, result -> {
        Log.d(TAG, result.toString());
        getPolylineData(result);
    });

    addHMSRemoteConfigListner();
}

private PolylineBody getPolylineBody() {
    return polylineBody;
}

private void setLatLong(String orgLat, String orgLong, String desLat, String desLong) {
    polylineBody = new PolylineBody();
    Origin origin = new Origin();
    origin.setLat(orgLat);
    origin.setLng(orgLong);

    Destination destination = new Destination();
    destination.setLat(desLat);
    destination.setLng(desLong);

    polylineBody.setDestination(destination);
    polylineBody.setOrigin(origin);
}

public void getPolylineData(PolylineResponse polylineResponse) {
    List<Routes> routesList = polylineResponse.getRoutes();
    List<Paths> paths = new ArrayList<>();
    List<Steps> steps = new ArrayList<>();
    List<Polyline> polylines = new ArrayList<>();
    latLngList = new ArrayList<>();

    for (int x = 0; x < routesList.size(); x++) {
        for (Paths paths1 : routesList.get(x).getPaths()) {
            paths.add(paths1);
        }
        for (int y = 0; y < paths.size(); y++) {
            for (Steps step :
                    paths.get(y).getSteps()) {
                steps.add(step);
            }
        }
        for (int i = 0; i < steps.size(); i++) {
            for (Polyline polyline :
                    steps.get(i).getPolyline()) {
                polylines.add(polyline);
            }
        }
    }

    for (int i = 0; i < polylines.size(); i++) {
        latLngList.add(new LatLng(Double.valueOf(polylines.get(i).getLat())
                , Double.valueOf(polylines.get(i).getLng())));
    }

    hmap.animateCamera(CameraUpdateFactory.newLatLngZoom(latLngList.get(0), 12.0f));
    hmap.addMarker(new MarkerOptions().position(latLngList.get(0)));

    hmap.addPolyline(new PolylineOptions()
            .addAll(latLngList)
            .color(Color.BLUE)
            .width(3));

}

private void requestLocationUpdatesWithCallback() {
    try {
        LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder();
        builder.addLocationRequest(mLocationRequest);
        LocationSettingsRequest locationSettingsRequest = builder.build();
        settingsClient.checkLocationSettings(locationSettingsRequest)
                .addOnSuccessListener(locationSettingsResponse -> {
                    Log.i(TAG, "check location settings success");
                    fusedLocationProviderClient
                            .requestLocationUpdates(mLocationRequest, mLocationCallback, Looper.getMainLooper())
                            .addOnSuccessListener(aVoid -> Log.i(TAG, "requestLocationUpdatesWithCallback onSuccess"))
                            .addOnFailureListener(new OnFailureListener() {
                                @Override
                                public void onFailure(Exception e) {
                                    Log.e(TAG,
                                            "requestLocationUpdatesWithCallback onFailure:" + e.getMessage());
                                }
                            });
                })
                .addOnFailureListener(e -> {
                    Log.e(TAG, "checkLocationSetting onFailure:" + e.getMessage());
                    int statusCode = ((ApiException) e).getStatusCode();
                    switch (statusCode) {
                        case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:
                            try {
                                ResolvableApiException rae = (ResolvableApiException) e;
                                rae.startResolutionForResult(DirectionActivity.this, 0);
                            } catch (IntentSender.SendIntentException sie) {
                                Log.e(TAG, "PendingIntent unable to execute request.");
                            }
                            break;
                    }
                });
    } catch (Exception e) {
        Log.e(TAG, "requestLocationUpdatesWithCallback exception:" + e.getMessage());
    }
}

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    if (requestCode == 1) {
        if (grantResults.length > 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED
                && grantResults[1] == PackageManager.PERMISSION_GRANTED) {
            Log.i(TAG, "onRequestPermissionsResult: apply LOCATION PERMISSION successful");
        } else {
            Log.i(TAG, "onRequestPermissionsResult: apply LOCATION PERMISSSION  failed");
        }
    }

    if (requestCode == 2) {
        if (grantResults.length > 2 && grantResults[2] == PackageManager.PERMISSION_GRANTED
                && grantResults[0] == PackageManager.PERMISSION_GRANTED
                && grantResults[1] == PackageManager.PERMISSION_GRANTED) {
            Log.i(TAG, "onRequestPermissionsResult: apply ACCESS_BACKGROUND_LOCATION successful");
        } else {
            Log.i(TAG, "onRequestPermissionsResult: apply ACCESS_BACKGROUND_LOCATION  failed");
        }
    }
}

private void addHMSRemoteConfigListner() {

    config.fetch(5).addOnSuccessListener(configValues -> {
        config.apply(configValues);
        MapStyleOptions mapStyleOptions;
        String style = config.getValueAsString("mapstyle");
        String colorPrimary = config.getValueAsString("primarycolor");
        Log.d(TAG, "HMS color : " + colorPrimary);

        ActionBar actionBar = getSupportActionBar();
        actionBar.setBackgroundDrawable(new ColorDrawable(Color.parseColor(colorPrimary)));

        if (style.equalsIgnoreCase("dark")) {
            mapStyleOptions = MapStyleOptions.loadRawResourceStyle(DirectionActivity.this, R.raw.mapstyle_night);
            hmap.setMapStyle(mapStyleOptions);
        } else if (style.equalsIgnoreCase("light")) {
            mapStyleOptions = MapStyleOptions.loadRawResourceStyle(DirectionActivity.this, R.raw.mapstyle_day);
            hmap.setMapStyle(mapStyleOptions);
        }
    }).addOnFailureListener((OnFailureListener) e -> {
        Log.d(TAG, e.getMessage());
    });
}

## 
App Build Result

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/wfe3ixmzduj5v0v7831m.png)

## 
Tips and Tricks
Map data of Map Kit does not cover the Chinese mainland. Therefore, the Map SDK for Android, Map SDK (Java) for HarmonyOS, JavaScript API, Static Map API, and Directions API of Map Kit are unavailable in the Chinese mainland. For details about locations where the services are available.
The map zoom icons flash on the map on devices running Android 8 or earlier before the map is loaded. (This issue occurs at a low probability in Android 8, but does not occur in versions later than Android 8.)

Layout file (XML file): Set uiZoomControls to false.
Code file: Set the parameter of the HuaweiMapOptions.zoomControlsEnabled(boolean isZoomControlsEnabled) method to false.

## 
Conclusion
In this article, we have learned how to integrate HMS Core Identity and Map in Android application. After completely read this article user can easily implement Huawei User Address and Map APIs by HMS Core Identity, so that User can consult with doctor using Huawei User Address and redirect to Doctor location.
Thanks for reading this article. Be sure to like and comment to this article, if you found it helpful. It means a lot to me.

## 
References
HMS Identity Docs: https://developer.huawei.com/consumer/en/hms/huawei-identitykit/ 
https://developer.huawei.com/consumer/en/doc/development/HMSCore-Guides/android-sdk-introduction-0000001061991291
HMS Training Videos - 
https://developer.huawei.com/consumer/en/training/