[ShareLocation] Added background service functionality

Now the sharing of the location should also be working from
the background.

app/build.gradle

@@ -39,6 +39,7 @@ dependencies {
 
     //Google Maps SDK
     implementation 'com.google.android.gms:play-services-maps:19.1.0'
+    implementation 'com.google.android.gms:play-services-location:21.3.0'
 
     // Glide
     implementation 'com.github.bumptech.glide:glide:4.16.0' // Check for the latest version

app/src/main/AndroidManifest.xml

@@ -5,6 +5,7 @@
     <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE_SPECIAL_USE" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_LOCATION" />
     <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
     <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
     <uses-permission android:name="android.permission.ACCESS_BACKGROUND_LOCATION" />
@@ -39,6 +40,9 @@
             android:name=".workers.SleepTimerHelper"
             android:foregroundServiceType="specialUse" />
 
+        <service android:name=".workers.ShareLocationBackgroundWorker"
+            android:foregroundServiceType="location" />
+
         <receiver
             android:name="com.aldo.apps.familyhelpers.DoerflingerHelpersDeviceAdminReceiver"
             android:exported="true"
@@ -51,14 +55,6 @@
                 <action android:name="android.app.action.DEVICE_ADMIN_DISABLED" />
             </intent-filter>
         </receiver>
-
-        <receiver
-            android:name=".utils.CancelLocationSharingReceiver"
-            android:exported="false">
-            <intent-filter>
-                <action android:name="com.aldo.apps.familyhelpers.CANCEL_LOCATION_SHARING" />
-            </intent-filter>
-        </receiver>
     </application>
 
 </manifest>

app/src/main/java/com/aldo/apps/familyhelpers/DoerflingerHelpersDeviceAdminReceiver.java

@@ -8,7 +8,7 @@ import androidx.annotation.NonNull;
 
 public class DoerflingerHelpersDeviceAdminReceiver extends DeviceAdminReceiver {
     @Override
-    public void onEnabled(@NonNull final Context context, @NonNull final  Intent intent) {
+    public void onEnabled(@NonNull final Context context, @NonNull final Intent intent) {
         // Called when the app is enabled as a device administrator.
     }
 

app/src/main/java/com/aldo/apps/familyhelpers/HelperGridActivity.java

@@ -1,7 +1,6 @@
 package com.aldo.apps.familyhelpers;
 
 import static android.Manifest.permission.POST_NOTIFICATIONS;
-
 import static com.aldo.apps.familyhelpers.utils.GlobalConstants.SIGN_IN_PROVIDERS;
 
 import android.content.Intent;
@@ -20,8 +19,8 @@ import androidx.core.content.ContextCompat;
 import com.aldo.apps.familyhelpers.ui.HelperGroupTile;
 import com.aldo.apps.familyhelpers.ui.SleepTimerPopup;
 import com.aldo.apps.familyhelpers.utils.DevicePolicyManagerHelper;
-import com.aldo.apps.familyhelpers.workers.LocationHelper;
 import com.aldo.apps.familyhelpers.workers.DatabaseHelper;
+import com.aldo.apps.familyhelpers.workers.LocationHelper;
 import com.firebase.ui.auth.AuthUI;
 import com.firebase.ui.auth.FirebaseAuthUIActivityResultContract;
 import com.firebase.ui.auth.IdpResponse;
@@ -67,11 +66,10 @@ public class HelperGridActivity extends AppCompatActivity {
     private FirebaseUser mCurrentUser = FirebaseAuth.getInstance().getCurrentUser();
 
     /**
-     * The instance of the {@link DatabaseHelper}.
+     * The {@link ActivityResultLauncher} for the sign in of a firebase user.
      */
-    private DatabaseHelper mDbHelper;
+    private final ActivityResultLauncher<Intent> mSignInLauncher =
-
+            registerForActivityResult(new FirebaseAuthUIActivityResultContract(), this::onSignInResult);    /**
-    /**
      * The {@link ActivityResultLauncher} to ask for the NotificationPermission.
      */
     private final ActivityResultLauncher<String> mRequestPermissionLauncher =
@@ -87,12 +85,6 @@ public class HelperGridActivity extends AppCompatActivity {
                 }
             });
 
-    /**
-     * The {@link ActivityResultLauncher} for the sign in of a firebase user.
-     */
-    private final ActivityResultLauncher<Intent> mSignInLauncher =
-            registerForActivityResult(new FirebaseAuthUIActivityResultContract(), this::onSignInResult);
-
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -108,7 +100,6 @@ public class HelperGridActivity extends AppCompatActivity {
         } else {
             mWelcomeMessageView.setText(String.format(getString(R.string.welcome_message_placeholder),
                     mCurrentUser.getDisplayName()));
-            mDbHelper = new DatabaseHelper();
             mLocationHelper = LocationHelper.getInstance(this);
         }
     }
@@ -159,7 +150,13 @@ public class HelperGridActivity extends AppCompatActivity {
             @Override
             public void launchHelper() {
                 Log.d(TAG, "launchHelper: Clicked ShareLocation");
-                if (mLocationHelper.requestLocationPermissions(HelperGridActivity.this)) {
+                // First check if the notification permission is granted
+                if (!requestNotificationPermission()) {
+                    Log.d(TAG, "launchHelper: Notifications not allowed, return...");
+                    return;
+                }
+                if (mLocationHelper.requestLocationPermissions(HelperGridActivity.this)
+                        && mLocationHelper.requestBackgroundLocationPermission(HelperGridActivity.this)) {
                     Log.d(TAG, "launchHelper: Permission already granted");
                     final Intent intent = new Intent(HelperGridActivity.this, ShareLocationActivity.class);
                     startActivity(intent);
@@ -196,14 +193,13 @@ public class HelperGridActivity extends AppCompatActivity {
      *
      * @param result The result code, used to determine whether is succeeded or not.
      */
-    private void onSignInResult(final FirebaseAuthUIAuthenticationResult  result) {
+    private void onSignInResult(final FirebaseAuthUIAuthenticationResult result) {
         final IdpResponse idpResponse = result.getIdpResponse();
         if (result.getResultCode() == RESULT_OK) {
             mCurrentUser = FirebaseAuth.getInstance().getCurrentUser();
             Log.d(TAG, "onSignInResult: Successfully logged in [" + mCurrentUser.getDisplayName() + "]");
             mWelcomeMessageView.setText(String.format(getString(R.string.welcome_message_placeholder),
                     mCurrentUser.getDisplayName()));
-            mDbHelper = new DatabaseHelper();
             mLocationHelper = LocationHelper.getInstance(this);
         } else {
             Log.w(TAG, "onSignInResult: Sign-In failed");
@@ -213,7 +209,7 @@ public class HelperGridActivity extends AppCompatActivity {
                 Log.w(TAG, "onSignInResult: User canceled, cannot continue");
             } else {
                 Log.e(TAG, "onSignInResult: Login failed with errorCode ["
-                        + idpResponse.getError().getErrorCode() +  "]");
+                        + idpResponse.getError().getErrorCode() + "]");
             }
         }
     }
@@ -223,10 +219,12 @@ public class HelperGridActivity extends AppCompatActivity {
                                            @NonNull final String[] permissions,
                                            @NonNull final int[] grantResults) {
         super.onRequestPermissionsResult(requestCode, permissions, grantResults);
-        if (mLocationHelper.handlePermissionResult(requestCode, grantResults)) {
+        if (mLocationHelper.handlePermissionResult(HelperGridActivity.this, requestCode, grantResults)) {
             final Intent intent = new Intent(HelperGridActivity.this, ShareLocationActivity.class);
             startActivity(intent);
         }
     }
 
+
+
 }

app/src/main/java/com/aldo/apps/familyhelpers/ShareLocationActivity.java

@@ -2,19 +2,16 @@ package com.aldo.apps.familyhelpers;
 
 import static com.aldo.apps.familyhelpers.utils.GlobalConstants.DEFAULT_HOME_LATITUDE;
 import static com.aldo.apps.familyhelpers.utils.GlobalConstants.DEFAULT_HOME_LONGITUDE;
-import static com.aldo.apps.familyhelpers.utils.GlobalConstants.DEFAULT_MINIMUM_LOCATION_INTERVAL_METERS;
-import static com.aldo.apps.familyhelpers.utils.GlobalConstants.DEFAULT_MINIMUM_LOCATION_INTERVAL_MILLIS;
 import static com.aldo.apps.familyhelpers.utils.GlobalConstants.METER_PER_SECOND_TO_KMH_CONVERTER;
 
+import android.content.Intent;
 import android.content.res.Configuration;
 import android.net.Uri;
 import android.os.Bundle;
 import android.text.TextUtils;
 import android.util.Log;
 import android.view.View;
-import android.widget.CompoundButton;
 import android.widget.ImageView;
-import android.widget.LinearLayout;
 import android.widget.TextView;
 
 import androidx.annotation.NonNull;
@@ -27,6 +24,7 @@ import com.aldo.apps.familyhelpers.model.User;
 import com.aldo.apps.familyhelpers.ui.ActiveShareAdapter;
 import com.aldo.apps.familyhelpers.workers.DatabaseHelper;
 import com.aldo.apps.familyhelpers.workers.LocationHelper;
+import com.aldo.apps.familyhelpers.workers.ShareLocationBackgroundWorker;
 import com.bumptech.glide.Glide;
 import com.google.android.gms.maps.CameraUpdateFactory;
 import com.google.android.gms.maps.GoogleMap;
@@ -40,8 +38,6 @@ import com.google.android.material.materialswitch.MaterialSwitch;
 import com.google.firebase.auth.FirebaseAuth;
 import com.google.firebase.auth.FirebaseUser;
 
-import org.checkerframework.checker.units.qual.A;
-
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Date;
@@ -61,95 +57,77 @@ public class ShareLocationActivity extends AppCompatActivity implements OnMapRea
      * Tag for debugging purpose.
      */
     private static final String TAG = "ShareLocationActivity";
-
+    /**
+     * Map containing all markers and the corresponding ID.
+     */
+    private final Map<String, Marker> mMarkerMap = new HashMap<>();
+    /**
+     * {@link List} of all {@link User}s.
+     */
+    private final List<User> mAllUsers = new ArrayList<>();
     /**
      * The {@link GoogleMap} view.
      */
     private GoogleMap mGmap;
-
     /**
      * The {@link DatabaseHelper} to read and load data from.
      */
     private DatabaseHelper mDbHelper;
-
     /**
      * The currently logged in {@link FirebaseUser}.
      */
     private FirebaseUser mCurrentUser;
-
     /**
      * The ID of the location updates to listen to.
      */
     private String mShareId;
-
     /**
      * The InfoBox {@link ImageView} showing the user icon.
      */
     private ImageView mInfoBoxIcon;
-
     /**
      * The InfoBox {@link TextView} showing the title.
      */
     private TextView mInfoBoxTitle;
-
     /**
      * The InfoBox {@link TextView} showing the Location information.
      */
     private TextView mInfoBoxLocation;
-
     /**
      * The InfoBox {@link TextView} showing the altitude..
      */
     private TextView mInfoBoxAltitude;
-
     /**
      * The InfoBox {@link TextView} showing the last received speed.
      */
     private TextView mInfoBoxSpeed;
-
     /**
      * The InfoBox {@link TextView} showing the timestamp of the last update.
      */
     private TextView mInfoBoxTimeStamp;
-
     /**
      * The {@link Disposable} holding the subscription to the {@link LocationObject}
      * {@link io.reactivex.rxjava3.subjects.BehaviorSubject} in order to have it cancellable.
      */
     private Disposable mLocationUpdateSubscription;
-
     /**
      * The {@link Disposable} holding the subscription to the {@link String}
      * {@link io.reactivex.rxjava3.subjects.BehaviorSubject} in order to know whom to follow.
      */
     private Disposable mCurrentlyFollowingSubscription;
-
     /**
      * The {@link Disposable} holding the subscription to {@link User}
      * {@link io.reactivex.rxjava3.subjects.BehaviorSubject} in order to have it cancellable.
      */
     private Disposable mUserSubscription;
-
     /**
      * Boolean flag indicating whether the system is currently in night mode or not.
      */
     private boolean mIsNightMode;
-
     /**
      * Reference to the Google Maps Marker, to update it's position rather than adding a new one.
      */
     private Marker mGmapsMarker;
-
-    /**
-     * Map containing all markers and the corresponding ID.
-     */
-    private final Map<String, Marker> mMarkerMap = new HashMap<>();
-
-    /**
-     * {@link List} of all {@link User}s.
-     */
-    private final List<User> mAllUsers = new ArrayList<>();
-
     /**
      * The ID of who the user is currently following.
      */
@@ -186,22 +164,6 @@ public class ShareLocationActivity extends AppCompatActivity implements OnMapRea
         mInfoBoxTimeStamp = findViewById(R.id.share_location_info_timestamp);
         mNoActiveShares = findViewById(R.id.tv_no_active_shares);
         mActiveShares = findViewById(R.id.active_share_layout);
-        final MaterialSwitch shareLocationToggle = findViewById(R.id.switch_start_stop_sharing_location);
-        final LocationHelper locationHelper = LocationHelper.getInstance(this);
-        shareLocationToggle.setChecked(locationHelper.isCurrentlySharing());
-        shareLocationToggle.setOnCheckedChangeListener((buttonView, isChecked) -> {
-            if (isChecked) {
-                locationHelper.startLocationUpdates(ShareLocationActivity.this,
-                        DEFAULT_MINIMUM_LOCATION_INTERVAL_MILLIS,
-                        DEFAULT_MINIMUM_LOCATION_INTERVAL_METERS)
-                ;
-            } else {
-                locationHelper.stopLocationUpdates();
-            }
-        });
-
-        locationHelper.getSharingStateSubject().subscribe(isSharing -> shareLocationToggle.setChecked(isSharing),
-                this::handleSubscriptionError);
 
         mActiveShares.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false));
         mActiveShareAdapter = new ActiveShareAdapter(this);
@@ -225,6 +187,8 @@ public class ShareLocationActivity extends AppCompatActivity implements OnMapRea
         if (mLocationUpdateSubscription != null) {
             mLocationUpdateSubscription.dispose();
         }
+
+        initAndSetupShareToggle();
         mUserSubscription = mDbHelper.getAllUsers()
                 .subscribe(this::handleAllUsers, this::handleUserSubscriptionFailed);
         mLocationUpdateSubscription = mDbHelper.subscribeToAllLocationUpdates()
@@ -233,6 +197,28 @@ public class ShareLocationActivity extends AppCompatActivity implements OnMapRea
                 .subscribe(this::handleCurrentlyFollowingChanged, this::handleSubscriptionError);
     }
 
+    /**
+     * Initializes the share switch button.
+     */
+    private void initAndSetupShareToggle() {
+        final MaterialSwitch shareLocationToggle = findViewById(R.id.switch_start_stop_sharing_location);
+
+        final LocationHelper locationHelper = LocationHelper.getInstance(this);
+        shareLocationToggle.setChecked(locationHelper.isCurrentlySharing());
+        shareLocationToggle.setOnCheckedChangeListener((buttonView, isChecked) -> {
+            if (isChecked) {
+                final Intent shareLocationService = new Intent(this, ShareLocationBackgroundWorker.class);
+                startForegroundService(shareLocationService);
+            } else {
+                final Intent stopLocationService = new Intent(this, ShareLocationBackgroundWorker.class);
+                stopService(stopLocationService);
+            }
+        });
+
+        locationHelper.getSharingStateSubject().subscribe(isSharing -> shareLocationToggle.setChecked(isSharing),
+                this::handleSubscriptionError);
+    }
+
     @Override
     protected void onPause() {
         super.onPause();
@@ -291,11 +277,11 @@ public class ShareLocationActivity extends AppCompatActivity implements OnMapRea
     }
 
 
-        /**
+    /**
-         * Removed all markers that became invalid because the sharing was stopped.
+     * Removed all markers that became invalid because the sharing was stopped.
-         *
+     *
-         * @param locationObjectMap The {@link Map} matching shareIds to {@link LocationObject}s.
+     * @param locationObjectMap The {@link Map} matching shareIds to {@link LocationObject}s.
-         */
+     */
     private void removeInvalidExistingMarkers(final Map<String, LocationObject> locationObjectMap) {
         final List<String> toBeRemovedKeys = new ArrayList<>();
         for (Map.Entry<String, Marker> markerEntry : mMarkerMap.entrySet()) {

app/src/main/java/com/aldo/apps/familyhelpers/model/LocationObject.java

@@ -68,6 +68,19 @@ public class LocationObject {
         this.timestamp = timestamp;
     }
 
+    /**
+     * Helper method to create a {@link LocationObject} from a handed in {@link Location}.
+     *
+     * @param location The received {@link Location} from the locationManager.
+     * @return The created {@link LocationObject}.
+     */
+    public static LocationObject fromLocation(final Location location) {
+        final FirebaseUser firebaseUser = FirebaseAuth.getInstance().getCurrentUser();
+        return new LocationObject(firebaseUser.getUid(), location.getLatitude(),
+                location.getLongitude(), location.getAltitude(), location.getSpeed(),
+                location.getTime());
+    }
+
     /**
      * Returns the unique identifier for the shared location.
      *
@@ -122,20 +135,6 @@ public class LocationObject {
         return timestamp;
     }
 
-    /**
-     * Helper method to create a {@link LocationObject} from a handed in {@link Location}.
-     *
-     * @param location The received {@link Location} from the locationManager.
-     *
-     * @return The created {@link LocationObject}.
-     */
-    public static LocationObject fromLocation(final Location location) {
-        final FirebaseUser firebaseUser = FirebaseAuth.getInstance().getCurrentUser();
-        return new LocationObject(firebaseUser.getUid(), location.getLatitude(),
-                location.getLongitude(), location.getAltitude(), location.getSpeed(),
-                location.getTime());
-    }
-
     @NonNull
     @Override
     public String toString() {

app/src/main/java/com/aldo/apps/familyhelpers/model/User.java

@@ -55,6 +55,30 @@ public class User {
         this.creationDate = creationDate;
     }
 
+    /**
+     * Creates a {@link User} from a handed in {@link FirebaseUser}.
+     *
+     * @param firebaseUser The {@link FirebaseUser} to read the fields from.
+     * @return The {@link User} representation of the {@link FirebaseUser}, or null if no
+     * {@link FirebaseUser} is available.
+     */
+    public static User fromFirebaseUser(final FirebaseUser firebaseUser) {
+        if (firebaseUser == null) {
+            return null;
+        }
+        final String uid = firebaseUser.getUid();
+        final String displayName = firebaseUser.getDisplayName();
+        final Uri photoUrl = firebaseUser.getPhotoUrl();
+        final FirebaseUserMetadata metaData = firebaseUser.getMetadata();
+        final long creationDate;
+        if (metaData == null) {
+            creationDate = LocalDateTime.now().toEpochSecond(ZoneOffset.UTC);
+        } else {
+            creationDate = metaData.getCreationTimestamp();
+        }
+        return new User(uid, displayName, photoUrl == null ? null : photoUrl.toString(), creationDate);
+    }
+
     /**
      * Returns the unique Identifies of the user.
      *
@@ -91,31 +115,6 @@ public class User {
         return creationDate;
     }
 
-    /**
-     * Creates a {@link User} from a handed in {@link FirebaseUser}.
-     *
-     * @param firebaseUser The {@link FirebaseUser} to read the fields from.
-     *
-     * @return The {@link User} representation of the {@link FirebaseUser}, or null if no
-     *         {@link FirebaseUser} is available.
-     */
-    public static User fromFirebaseUser(final FirebaseUser firebaseUser) {
-        if (firebaseUser == null) {
-            return null;
-        }
-        final String uid = firebaseUser.getUid();
-        final String displayName = firebaseUser.getDisplayName();
-        final Uri photoUrl = firebaseUser.getPhotoUrl();
-        final FirebaseUserMetadata metaData = firebaseUser.getMetadata();
-        final long creationDate;
-        if (metaData == null) {
-            creationDate = LocalDateTime.now().toEpochSecond(ZoneOffset.UTC);
-        } else {
-            creationDate = metaData.getCreationTimestamp();
-        }
-        return new User(uid,displayName, photoUrl == null ? null : photoUrl.toString(), creationDate);
-    }
-
     @Override
     public String toString() {
         return "User{" +

app/src/main/java/com/aldo/apps/familyhelpers/ui/ActiveShareAdapter.java

@@ -1,7 +1,6 @@
 package com.aldo.apps.familyhelpers.ui;
 
 import android.content.Context;
-import android.graphics.PorterDuff;
 import android.net.Uri;
 import android.util.Log;
 import android.view.LayoutInflater;
@@ -10,7 +9,6 @@ import android.view.ViewGroup;
 import android.widget.TextView;
 
 import androidx.annotation.NonNull;
-import androidx.core.content.ContextCompat;
 import androidx.recyclerview.widget.RecyclerView;
 
 import com.aldo.apps.familyhelpers.R;
@@ -20,20 +18,46 @@ import com.bumptech.glide.Glide;
 import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Map;
 
 import de.hdodenhof.circleimageview.CircleImageView;
 import io.reactivex.rxjava3.subjects.BehaviorSubject;
 
+/**
+ * The {@link RecyclerView.Adapter} for the {@link ActiveShareAdapter.ActiveShareViewHolder} to display
+ * which user is currently sharing their location and to offer a selection on whom to follow.
+ */
 public class ActiveShareAdapter extends RecyclerView.Adapter<ActiveShareAdapter.ActiveShareViewHolder> {
+
+    /**
+     * Tag for debugging purposes.
+     */
     private static final String TAG = "ActiveShareAdapter";
 
+    /**
+     * {@link BehaviorSubject} holding the ID of the currently selected user.
+     */
     private final BehaviorSubject<String> mCurrentlySelectedSubject = BehaviorSubject.createDefault("");
 
+    /**
+     * {@link List} of all currently sharing {@link User}s.
+     */
     private final List<User> mSharingUserList = new ArrayList<>();
 
+    /**
+     * A {@link WeakReference} to the calling {@link Context}.
+     */
     private final WeakReference<Context> mContextRef;
 
+    /**
+     * List of all {@link View}s so the focus can be cleared again if another view is touched.
+     */
+    private final List<View> mAllItems = new ArrayList<>();
+
+    /**
+     * C'Tor.
+     *
+     * @param context Calling context.
+     */
     public ActiveShareAdapter(final Context context) {
         mContextRef = new WeakReference<>(context);
     }
@@ -43,6 +67,7 @@ public class ActiveShareAdapter extends RecyclerView.Adapter<ActiveShareAdapter.
     public ActiveShareViewHolder onCreateViewHolder(@NonNull final ViewGroup parent, final int viewType) {
         final View view = LayoutInflater.from(parent.getContext())
                 .inflate(R.layout.active_share_view_holder, parent, false);
+        mAllItems.add(view);
         return new ActiveShareViewHolder(view);
     }
 
@@ -58,24 +83,60 @@ public class ActiveShareAdapter extends RecyclerView.Adapter<ActiveShareAdapter.
         return mSharingUserList.size();
     }
 
+    /**
+     * Helper method to apply a new List of sharing {@link User}s.
+     * TODO: Make it smarter.
+     */
     public void applyNewData(final List<User> newUsers) {
         mSharingUserList.clear();
         mSharingUserList.addAll(newUsers);
+        mAllItems.clear();
         notifyDataSetChanged();
     }
 
+    /**
+     * Returns the {@link BehaviorSubject} holding the ID of the currently selected user.
+     *
+     * @return The {@link BehaviorSubject} holding the ID of the currently selected user.
+     */
     public BehaviorSubject<String> getCurrentlySelectedSubject() {
         return mCurrentlySelectedSubject;
     }
 
+    /**
+     * Helper method to clear the selected state of all views, when a new one is tapped.
+     */
+    private void clearFocusedView() {
+        for (final View view : mAllItems) {
+            view.setSelected(false);
+        }
+    }
+
+    /**
+     * {@link RecyclerView.ViewHolder} implementation for the {@link ActiveShareViewHolder}.
+     */
     public class ActiveShareViewHolder extends RecyclerView.ViewHolder {
 
-        private CircleImageView mProfilePicture;
+        /**
+         * The {@link CircleImageView} holding the profile picture of the user.
+         */
+        private final CircleImageView mProfilePicture;
 
-        private TextView mName;
+        /**
+         * The {@link TextView} showing the name of the user.
+         */
+        private final TextView mName;
 
-        private View mItemView;
+        /**
+         * The overall {@link View}.
+         */
+        private final View mItemView;
 
+        /**
+         * C'Tor.
+         *
+         * @param itemView The already inflated itemView.
+         */
         public ActiveShareViewHolder(@NonNull final View itemView) {
             super(itemView);
             mProfilePicture = itemView.findViewById(R.id.active_share_profile_picture);
@@ -83,6 +144,11 @@ public class ActiveShareAdapter extends RecyclerView.Adapter<ActiveShareAdapter.
             mItemView = itemView;
         }
 
+        /**
+         * Helper method to apply userData to a View.
+         *
+         * @param user The  {@link User} to be attached.
+         */
         public void setUserData(final User user) {
             if (user == null) {
                 Log.w(TAG, "setUserData: Skip update, no valid update yet");
@@ -90,7 +156,15 @@ public class ActiveShareAdapter extends RecyclerView.Adapter<ActiveShareAdapter.
             }
             mItemView.setOnClickListener(v -> {
                 Log.d(TAG, "setUserData: Clicked on [" + user + "]");
-                mCurrentlySelectedSubject.onNext(user.getuId());
+                if (mItemView.isSelected()) {
+                    mCurrentlySelectedSubject.onNext("");
+                    clearFocusedView();
+                    mItemView.setSelected(false);
+                } else {
+                    mCurrentlySelectedSubject.onNext(user.getuId());
+                    clearFocusedView();
+                    mItemView.setSelected(true);
+                }
             });
             mName.setText(user.getDisplayName());
             final Context context = mContextRef.get();

app/src/main/java/com/aldo/apps/familyhelpers/utils/CancelLocationSharingReceiver.java

@@ -1,38 +0,0 @@
-package com.aldo.apps.familyhelpers.utils;
-
-import static com.aldo.apps.familyhelpers.utils.GlobalConstants.SHARE_LOCATION_CANCEL_ACTION;
-
-import android.content.BroadcastReceiver;
-import android.content.Context;
-import android.content.Intent;
-import android.util.Log;
-
-import com.aldo.apps.familyhelpers.workers.LocationHelper;
-
-/**
- * Broadcast received to cancel an ongoing sharing of location.
- */
-public class CancelLocationSharingReceiver extends BroadcastReceiver {
-
-    /**
-     * Tag for debugging purpose.
-     */
-    private static final String TAG = "CancelLocationSharingRe";
-
-    /**
-     * Empty C'tor.
-     */
-    public CancelLocationSharingReceiver() {
-        // Empty C'tor.
-    }
-
-
-    @Override
-    public void onReceive(final Context context, final Intent intent) {
-        if (intent != null && SHARE_LOCATION_CANCEL_ACTION.equalsIgnoreCase(intent.getAction())) {
-            Log.d(TAG, "onReceive: Notification cancelled, cancel location sharing");
-            final LocationHelper locationHelper = LocationHelper.getInstance(context);
-            locationHelper.stopLocationUpdates();
-        }
-    }
-}

app/src/main/java/com/aldo/apps/familyhelpers/utils/DevicePolicyManagerHelper.java

@@ -54,7 +54,6 @@ public final class DevicePolicyManagerHelper {
      * Returns the singleton instance of the {@link DevicePolicyManagerHelper}.
      *
      * @param context The {@link Context} from where this was called.
-     *
      * @return the singleton instance of the {@link DevicePolicyManagerHelper}.
      */
     public static DevicePolicyManagerHelper getInstance(final Context context) {

app/src/main/java/com/aldo/apps/familyhelpers/utils/GlobalConstants.java

@@ -3,6 +3,7 @@ package com.aldo.apps.familyhelpers.utils;
 import com.firebase.ui.auth.AuthUI;
 
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 
 /**
@@ -10,88 +11,75 @@ import java.util.List;
  */
 public final class GlobalConstants {
 
-    /**
-     * Private C'tor to prevent instantiation.
-     */
-    private GlobalConstants() {}
-
     /**
      * ID of the NotificationChannel for the SleepTimer Notification.
      */
     public static final String SLEEP_TIMER_CHANNEL_ID = "CountdownChannel";
-
     /**
      * ID of the NotificationChannel for the ShareLocation Notification.
      */
     public static final String SHARE_LOCATION_CHANNEL_ID = "LocationShareChannel";
-
     /**
      * Factor to calculate seconds from milliseconds and vice versa.
      */
     public static final int ONE_SECOND_IN_MILLIS = 1000;
-
     /**
      * Factor to calculate hours from minutes and vice versa.
      */
     public static final int ONE_HOUR_IN_MINUTES = 60;
-
     /**
      * The NotificationID of the SleepTimer notification.
      */
     public static final int SLEEP_TIMER_NOTIFICATION_ID = 1;
-
     /**
      * The NotificationID of the ShareLocation notification.
      */
     public static final int SHARE_LOCATION_NOTIFICATION_ID = 2;
-
     /**
      * The action to be invoked when the sharing of location should be cancelled.
      */
     public static final String SHARE_LOCATION_CANCEL_ACTION = "com.aldo.apps.familyhelpers.CANCEL_LOCATION_SHARING";
-
     /**
      * The key of the extra to be applied to the starting intent of the sleepTimer service,
      * holding the initial duration in millis.
      */
     public static final String SLEEP_TIMER_DURATION_MILLIS_EXTRA = "sleep_timer_duration";
-
     /**
      * Action to cancel an ongoing sleep timer.
      */
     public static final String SLEEP_TIMER_CANCEL_ACTION = "SLEEP_TIMER_CANCEL";
-
     /**
      * Default minimum time interval between two location updates.
      * Currently set to 5 Seconds.
      */
     public static final int DEFAULT_MINIMUM_LOCATION_INTERVAL_MILLIS = 5000;
-
     /**
      * Default minimum distance interval between two location updates.
      * Currently set to 5 Meters.
      */
     public static final int DEFAULT_MINIMUM_LOCATION_INTERVAL_METERS = 5;
-
     /**
      * Conversion constants to convert m/s into km/h
      */
     public static final double METER_PER_SECOND_TO_KMH_CONVERTER = 3.6;
-
     /**
      * Latitude of the default home (== Blaustein)
      */
     public static final double DEFAULT_HOME_LATITUDE = 48.41965746149261;
-
     /**
      * Longitude of the default home (== Blaustein)
      */
     public static final double DEFAULT_HOME_LONGITUDE = 9.909289365473684;
-
     /**
      * List of available Firebase signIn/Login providers.
      */
-    public static final List<AuthUI.IdpConfig> SIGN_IN_PROVIDERS = Arrays.asList(
+    public static final List<AuthUI.IdpConfig> SIGN_IN_PROVIDERS = Collections.singletonList(
             new AuthUI.IdpConfig.GoogleBuilder().build()
     );
+
+    /**
+     * Private C'tor to prevent instantiation.
+     */
+    private GlobalConstants() {
+    }
 }

app/src/main/java/com/aldo/apps/familyhelpers/workers/DatabaseHelper.java

@@ -2,22 +2,16 @@ package com.aldo.apps.familyhelpers.workers;
 
 import static com.aldo.apps.familyhelpers.utils.DatabaseConstants.DB_COLL_LOCATION;
 import static com.aldo.apps.familyhelpers.utils.DatabaseConstants.DB_COLL_USERS;
-import static com.aldo.apps.familyhelpers.utils.DatabaseConstants.DB_DOC_USER_ID;
 
 import android.util.Log;
 
-import androidx.annotation.Nullable;
-
 import com.aldo.apps.familyhelpers.model.LocationObject;
 import com.aldo.apps.familyhelpers.model.User;
 import com.google.firebase.auth.FirebaseAuth;
 import com.google.firebase.auth.FirebaseUser;
 import com.google.firebase.firestore.DocumentSnapshot;
-import com.google.firebase.firestore.EventListener;
 import com.google.firebase.firestore.FirebaseFirestore;
-import com.google.firebase.firestore.FirebaseFirestoreException;
 import com.google.firebase.firestore.ListenerRegistration;
-import com.google.firebase.firestore.QuerySnapshot;
 
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -64,7 +58,7 @@ public class DatabaseHelper {
     /**
      * {@link Map} containing all users.
      */
-    private Map<String, User> mAllUserMap = new HashMap<>();
+    private final Map<String, User> mAllUserMap = new HashMap<>();
 
     /**
      * C'tor.
@@ -119,6 +113,13 @@ public class DatabaseHelper {
         return mAllUsers;
     }
 
+    /**
+     * Returns a {@link User} object for the given ID.
+     *
+     * @param userId The identifier of the wanted user.
+     *
+     * @return The identified user or null of not existing.
+     */
     public User getUserForId(final String userId) {
         Log.d(TAG, "getUserForId() called with: userId = [" + userId + "]");
         if (mAllUserMap.containsKey(userId)) {
@@ -162,25 +163,25 @@ public class DatabaseHelper {
         mLocationUpdateListener = mDatabase.collection(DB_COLL_LOCATION)
                 .document(shareId)
                 .addSnapshotListener((value, error) -> {
-            if (value == null) {
+                    if (value == null) {
-                Log.d(TAG, "onEvent: Location was deleted");
+                        Log.d(TAG, "onEvent: Location was deleted");
-                mObservedLocation.onComplete();
+                        mObservedLocation.onComplete();
-                return;
+                        return;
-            }
+                    }
-            final LocationObject updatedLocation = value.toObject(LocationObject.class);
+                    final LocationObject updatedLocation = value.toObject(LocationObject.class);
-            if (updatedLocation == null) {
+                    if (updatedLocation == null) {
-                Log.w(TAG, "onEvent: Error while parsing, ignore");
+                        Log.w(TAG, "onEvent: Error while parsing, ignore");
-                return;
+                        return;
-            }
+                    }
-            mObservedLocation.onNext(updatedLocation);
+                    mObservedLocation.onNext(updatedLocation);
-        });
+                });
     }
 
     /**
      * Helper method to start listening for all available location sharings in progress.
      *
      * @return The {@link BehaviorSubject} containing a {@link Map} of all {@link LocationObject} matched
-     *         to the sharing ID.
+     * to the sharing ID.
      */
     public BehaviorSubject<Map<String, LocationObject>> subscribeToAllLocationUpdates() {
         final Map<String, LocationObject> locationMap = new HashMap<>();
@@ -191,18 +192,18 @@ public class DatabaseHelper {
         }
         mLocationUpdateListener = mDatabase.collection(DB_COLL_LOCATION)
                 .addSnapshotListener((value, error) -> {
-            if (value == null || value.isEmpty()) {
+                    if (value == null || value.isEmpty()) {
-                Log.d(TAG, "onEvent: No ongoing location shares, return empty map.");
+                        Log.d(TAG, "onEvent: No ongoing location shares, return empty map.");
-                behaviorSubject.onNext(new HashMap<>());
+                        behaviorSubject.onNext(new HashMap<>());
-                return;
+                        return;
-            }
+                    }
-            final List<DocumentSnapshot> allDocs = value.getDocuments();
+                    final List<DocumentSnapshot> allDocs = value.getDocuments();
-            locationMap.clear();
+                    locationMap.clear();
-            for (final DocumentSnapshot documentSnapshot : allDocs) {
+                    for (final DocumentSnapshot documentSnapshot : allDocs) {
-                locationMap.put(documentSnapshot.getId(), documentSnapshot.toObject(LocationObject.class));
+                        locationMap.put(documentSnapshot.getId(), documentSnapshot.toObject(LocationObject.class));
-            }
+                    }
-            behaviorSubject.onNext(locationMap);
+                    behaviorSubject.onNext(locationMap);
-        });
+                });
 
         return behaviorSubject;
     }

app/src/main/java/com/aldo/apps/familyhelpers/workers/LocationHelper.java

@@ -1,8 +1,7 @@
 package com.aldo.apps.familyhelpers.workers;
 
+import static android.Manifest.permission.ACCESS_BACKGROUND_LOCATION;
 import static android.Manifest.permission.ACCESS_FINE_LOCATION;
-import static com.aldo.apps.familyhelpers.utils.GlobalConstants.DEFAULT_MINIMUM_LOCATION_INTERVAL_METERS;
-import static com.aldo.apps.familyhelpers.utils.GlobalConstants.DEFAULT_MINIMUM_LOCATION_INTERVAL_MILLIS;
 import static com.aldo.apps.familyhelpers.utils.GlobalConstants.SHARE_LOCATION_CANCEL_ACTION;
 import static com.aldo.apps.familyhelpers.utils.GlobalConstants.SHARE_LOCATION_CHANNEL_ID;
 import static com.aldo.apps.familyhelpers.utils.GlobalConstants.SHARE_LOCATION_NOTIFICATION_ID;
@@ -18,6 +17,7 @@ import android.location.LocationListener;
 import android.location.LocationManager;
 import android.os.Looper;
 import android.util.Log;
+import android.widget.Toast;
 
 import androidx.annotation.NonNull;
 import androidx.core.app.ActivityCompat;
@@ -25,9 +25,9 @@ import androidx.core.app.NotificationCompat;
 import androidx.core.content.ContextCompat;
 
 import com.aldo.apps.familyhelpers.R;
+import com.aldo.apps.familyhelpers.ShareLocationActivity;
 import com.aldo.apps.familyhelpers.model.LocationObject;
 import com.aldo.apps.familyhelpers.ui.NotificationHelper;
-import com.aldo.apps.familyhelpers.utils.CancelLocationSharingReceiver;
 
 import java.lang.ref.WeakReference;
 import java.util.List;
@@ -36,6 +36,7 @@ import io.reactivex.rxjava3.subjects.BehaviorSubject;
 
 /**
  * Helper class to encapsulate all Location specific calls into one utility class.
+ * TODO: Change logic to make use of the FusedLocationProvider.
  */
 public final class LocationHelper implements LocationListener {
 
@@ -47,42 +48,42 @@ public final class LocationHelper implements LocationListener {
     /**
      * The request code of the for the location permission request.
      */
-    private static final int LOCATION_PERMISSION_REQUEST_CODE = 1;
+    private static final int LOCATION_PERMISSION_REQUEST_CODE = 100;
+
+    /**
+     * The request code of the for the background location permission request.
+     */
+    private static final int BACKGROUND_LOCATION_REQUEST_CODE = 101;
     /**
      * The singleton instance of this {@link LocationHelper}.
      */
     private static LocationHelper sInstance;
-    private final WeakReference<Context> mContextRef;
+
     /**
      * The {@link LocationManager} object to listen to location updates.
      */
     private final LocationManager mLocationManager;
-
-    /**
-     * Boolean flag to check whether a subscription for location updates is already running or not.
-     */
-    private boolean mIsSubscribed;
-
     /**
      * The {@link BehaviorSubject} for the {@link LocationObject} for clients to subscribe to.
      * TODO: Check if needed.
      */
-    private final  BehaviorSubject<LocationObject> mLocationSubject = BehaviorSubject.create();
+    private final BehaviorSubject<LocationObject> mLocationSubject = BehaviorSubject.create();
-
     /**
      * The {@link DatabaseHelper} for db access.
      */
     private final DatabaseHelper mDbHelper;
-
     /**
      * The {@link NotificationHelper} to show and update {@link Notification}s.
      */
     private final NotificationHelper mNotificationHelper;
-
     /**
      * The {@link BehaviorSubject} holding the state of current subscription.
      */
     private final BehaviorSubject<Boolean> mSharingStateSubject = BehaviorSubject.createDefault(false);
+    /**
+     * Boolean flag to check whether a subscription for location updates is already running or not.
+     */
+    private boolean mIsSubscribed;
 
     /**
      * Private C'Tor for singleton instance.
@@ -91,7 +92,6 @@ public final class LocationHelper implements LocationListener {
      */
     private LocationHelper(final Context context) {
         mLocationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
-        mContextRef = new WeakReference<>(context);
         mNotificationHelper = new NotificationHelper(context);
         mDbHelper = new DatabaseHelper();
         mNotificationHelper.createAndRegisterNotificationChannel(
@@ -135,16 +135,41 @@ public final class LocationHelper implements LocationListener {
         return true;
     }
 
+    /**
+     * Request the permission for {@link android.Manifest.permission#ACCESS_BACKGROUND_LOCATION} if not
+     * yet granted before.
+     *
+     * @param activity The {@link Activity} from where this was called.
+     * @return true if permission was already granted before, false otherwise.
+     */
+    public boolean requestBackgroundLocationPermission(final Activity activity) {
+        if (ContextCompat.checkSelfPermission(activity, ACCESS_BACKGROUND_LOCATION) != PackageManager.PERMISSION_GRANTED) {
+            // Provide a justification to the user.
+            Toast.makeText(activity, R.string.share_location_background_permission_rationale,
+                    Toast.LENGTH_LONG).show();
+            ActivityCompat.requestPermissions(activity, new String[]{ACCESS_BACKGROUND_LOCATION},
+                    BACKGROUND_LOCATION_REQUEST_CODE);
+            return false;
+        }
+        return true;
+    }
+
     /**
      * Helper method to handle the result of the permission request dialog.
      *
+     * @param activity     The calling {@link Activity}.
      * @param requestCode  The code of the permission request.
      * @param grantResults The result codes.
      * @return true if permission was granted, false otherwise.
      */
-    public boolean handlePermissionResult(final int requestCode, final int[] grantResults) {
+    public boolean handlePermissionResult(final Activity activity, final int requestCode, final int[] grantResults) {
         if (requestCode == LOCATION_PERMISSION_REQUEST_CODE) {
-            // Permission granted, proceed with location updates
+            // Permission granted, ask for background permission.
+            requestBackgroundLocationPermission(activity);
+            return false;
+        }
+        if (requestCode == BACKGROUND_LOCATION_REQUEST_CODE) {
+            // Permission granted, continue with updates.
             return grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED;
         }
         return false;
@@ -153,17 +178,17 @@ public final class LocationHelper implements LocationListener {
     /**
      * Helper method to start listening for updates.
      *
-     * @param activity          The {@link Activity} from where this was called.
+     * @param context           The {@link Context} from where this was called.
      * @param minIntervalMillis The minimum time interval in millisecond
      * @param minDistance       The minimum distance for an update to be received.
      * @return true if subscription started, false otherwise.
      */
-    public boolean startLocationUpdates(final Activity activity, final int minIntervalMillis, final int minDistance) {
+    public boolean startLocationUpdates(final Context context, final int minIntervalMillis, final int minDistance) {
         if (mIsSubscribed) {
             Log.d(TAG, "startLocationUpdates: Already subscribed, no need to update");
             return true;
         }
-        if (ContextCompat.checkSelfPermission(activity, ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
+        if (ContextCompat.checkSelfPermission(context, ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
             mLocationManager.requestLocationUpdates(
                     LocationManager.FUSED_PROVIDER,
                     minIntervalMillis,
@@ -200,6 +225,7 @@ public final class LocationHelper implements LocationListener {
      * @return true if location sharing is active, false otherwise.
      */
     public boolean isCurrentlySharing() {
+        Log.d(TAG, "isCurrentlySharing: Called with currently sharing = [" + mIsSubscribed + "]");
         return mIsSubscribed;
     }
 
@@ -218,8 +244,12 @@ public final class LocationHelper implements LocationListener {
      * @param context The {@link Context} from where this is called.
      * @return The {@link Notification} to be shown.
      */
-    private Notification buildNotification(final Context context) {
+    public Notification buildNotification(final Context context) {
-        final Intent deleteIntent = new Intent(context, CancelLocationSharingReceiver.class);
+        final Intent notificationIntent = new Intent(context, ShareLocationActivity.class);
+        final PendingIntent pendingIntent = PendingIntent.getActivity(context, 0,
+                notificationIntent, PendingIntent.FLAG_IMMUTABLE);
+
+        final Intent deleteIntent = new Intent(context, ShareLocationBackgroundWorker.class);
         deleteIntent.setAction(SHARE_LOCATION_CANCEL_ACTION);
         final PendingIntent pendingDeleteIntent = PendingIntent.getBroadcast(context, 0,
                 deleteIntent, PendingIntent.FLAG_IMMUTABLE);
@@ -227,6 +257,7 @@ public final class LocationHelper implements LocationListener {
         return new NotificationCompat.Builder(context, SHARE_LOCATION_CHANNEL_ID)
                 .setContentTitle(context.getString(R.string.title_share_location))
                 .setContentText(context.getString(R.string.share_location_notification_content))
+                .setContentIntent(pendingIntent)
                 .setSmallIcon(R.drawable.ic_location_helper)
                 .setDeleteIntent(pendingDeleteIntent)
                 .addAction(android.R.drawable.ic_menu_close_clear_cancel,
@@ -238,14 +269,9 @@ public final class LocationHelper implements LocationListener {
     @Override
     public void onLocationChanged(@NonNull final Location location) {
         final LocationObject locationObject = LocationObject.fromLocation(location);
+        Log.d(TAG, "onLocationChanged: Received update with " + locationObject);
         mLocationSubject.onNext(locationObject);
         mDbHelper.insertOrUpdateLocation(locationObject);
-        final Context context = mContextRef.get();
-        if (context != null) {
-            mNotificationHelper.updateNotification(SHARE_LOCATION_NOTIFICATION_ID, buildNotification(context));
-        }
-
-        Log.d(TAG, "onLocationChanged: Received update with " + locationObject);
     }
 
     @Override

app/src/main/java/com/aldo/apps/familyhelpers/workers/ShareLocationBackgroundWorker.java

@@ -0,0 +1,76 @@
+package com.aldo.apps.familyhelpers.workers;
+
+import static com.aldo.apps.familyhelpers.utils.GlobalConstants.SHARE_LOCATION_CANCEL_ACTION;
+import static com.aldo.apps.familyhelpers.utils.GlobalConstants.SLEEP_TIMER_NOTIFICATION_ID;
+
+import android.app.Service;
+import android.content.Intent;
+import android.os.Handler;
+import android.os.IBinder;
+import android.os.Looper;
+import android.util.Log;
+
+import androidx.annotation.Nullable;
+
+/**
+ * Service implementation to keep location updates running also in the background.
+ */
+public class ShareLocationBackgroundWorker extends Service {
+
+    /**
+     * Tag for debugging purpose.
+     */
+    private static final String TAG = "ShareLocationBackground";
+
+    /**
+     * {@link Handler} on the MainThread in order to perform the location update.
+     */
+    private final Handler mHandler = new Handler(Looper.getMainLooper());
+
+    /**
+     * The {@link LocationHelper} to update the location in the database.
+     */
+    private LocationHelper mLocationHelper;
+
+    /**
+     * The {@link Runnable} to execute the task in.
+     */
+    private Runnable mShareLocationRunnable;
+
+    @Override
+    public void onCreate() {
+        super.onCreate();
+        mLocationHelper = LocationHelper.getInstance(this);
+    }
+
+    @Override
+    public int onStartCommand(final Intent intent, final int flags, int startId) {
+        if (intent == null) {
+            Log.e(TAG, "onStartCommand: Invalid intent intent received, do nothing");
+            return START_REDELIVER_INTENT;
+        }
+        if (intent.getAction() != null && intent.getAction().equals(SHARE_LOCATION_CANCEL_ACTION)) {
+            stopSelf();
+            mLocationHelper.stopLocationUpdates();
+            return START_NOT_STICKY;
+        }
+        mShareLocationRunnable = () ->
+                mLocationHelper.startLocationUpdates(ShareLocationBackgroundWorker.this,
+                        1000, 0);
+        mHandler.post(mShareLocationRunnable);
+        startForeground(SLEEP_TIMER_NOTIFICATION_ID, mLocationHelper.buildNotification(this));
+        return super.onStartCommand(intent, flags, startId);
+    }
+
+    @Nullable
+    @Override
+    public IBinder onBind(final Intent intent) {
+        return null;
+    }
+
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+        mHandler.removeCallbacks(mShareLocationRunnable);
+    }
+}

app/src/main/java/com/aldo/apps/familyhelpers/workers/SleepTimerHelper.java

@@ -36,6 +36,7 @@ public class SleepTimerHelper extends Service {
      * Tag for debugging purpose.
      */
     private static final String TAG = "SleepTimerHelper";
+
     /**
      * {@link Handler} on the MainThread in order to perform the actual locking.
      */
@@ -87,7 +88,7 @@ public class SleepTimerHelper extends Service {
 
     @Nullable
     @Override
-    public IBinder onBind(Intent intent) {
+    public IBinder onBind(final Intent intent) {
         return null;
     }
 
@@ -144,7 +145,6 @@ public class SleepTimerHelper extends Service {
      * Formats the provided time in milliseconds in a human readable format.
      *
      * @param millis The remaining time in milliseconds.
-     *
      * @return The String representation of the milliseconds.
      */
     private String formatTime(long millis) {

app/src/main/res/drawable/currently_followed_user_selector.xml

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="utf-8"?>
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:state_selected="true">
+        <shape android:layout_height="match_parent">
+            <solid android:color="@color/md_theme_secondaryContainer_mediumContrast" />
+
+            <corners
+                android:bottomLeftRadius="4dp"
+                android:bottomRightRadius="4dp"
+                android:topLeftRadius="4dp"
+                android:topRightRadius="4dp" />
+        </shape>
+    </item>
+    <item android:state_selected="false">
+    <shape>
+        <solid android:color="@color/md_theme_background" />
+        <corners
+            android:bottomLeftRadius="4dp"
+            android:bottomRightRadius="4dp"
+            android:topLeftRadius="4dp"
+            android:topRightRadius="4dp" />
+    </shape>
+</item>
+</selector>

app/src/main/res/layout/active_share_view_holder.xml

@@ -2,6 +2,7 @@
 <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="75dp"
     android:layout_height="75dp"
+    android:background="@drawable/currently_followed_user_selector"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools">
 

app/src/main/res/values/strings.xml

@@ -31,5 +31,6 @@
     <string name="share_location_info_speed">The last received velocity was %.2f m/s (%.1f km/h)</string>
     <string name="share_location_info_timestamp">This update was received at: %s</string>
     <string name="share_location_toggle_button">Share your location</string>
+    <string name="share_location_background_permission_rationale">In order to share your position also while in the background, please grant the always permission</string>
 
 </resources>