Added a programmatic method to switch Firebase tracking on/off (OneSignal#349)

* Added a programmatic method to switch Firebase tracking on/off

* Added javadoc for tracking enable method

Author: Alamgir

OneSignalSDK/onesignal/src/main/java/com/onesignal/OneSignal.java

@@ -956,7 +956,7 @@ static void onAppFocus() {
 
       getCurrentPermissionState(appContext).refreshAsTo();
 
-      if(trackFirebaseAnalytics != null)
+      if(trackFirebaseAnalytics != null && getFirebaseAnalyticsEnabled(appContext))
          trackFirebaseAnalytics.trackInfluenceOpenEvent();
    }
 
@@ -1487,7 +1487,7 @@ public void run() {
          }
       });
 
-      if(trackFirebaseAnalytics != null)
+      if(trackFirebaseAnalytics != null && getFirebaseAnalyticsEnabled(appContext))
          trackFirebaseAnalytics.trackOpenedEvent(openedResult);
    }
 
@@ -1501,7 +1501,7 @@ static void handleNotificationReceived(JSONArray data, boolean displayed, boolea
       OSNotificationOpenResult openResult = generateOsNotificationOpenResult(data, displayed, fromAlert);
       mInitBuilder.mNotificationReceivedHandler.notificationReceived(openResult.notification);
 
-      if(trackFirebaseAnalytics != null)
+      if(trackFirebaseAnalytics != null && getFirebaseAnalyticsEnabled(appContext))
          trackFirebaseAnalytics.trackReceivedEvent(openResult);
 
    }
@@ -1634,6 +1634,26 @@ static void updateUserIdDependents(String userId) {
       OneSignalChromeTab.setup(appContext, appId, userId, AdvertisingIdProviderGPS.getLastValue());
    }
 
+   /**
+    * By default, OneSignal does not auto-track notification events through Firebase.
+    * Call this method with {@code true} to start tracking.
+    *
+    * @see <a href="https://documentation.onesignal.com/docs/firebase-analytics">Firebase Analytics | OneSignal Docs</a>
+    * @param enable whether to enable Firebase tracking
+    */
+   public static void enableFirebaseAnalytics(boolean enable) {
+      if (appContext == null)
+         return;
+
+      OneSignalPrefs.saveBool(OneSignalPrefs.PREFS_ONESIGNAL,
+              OneSignalPrefs.PREFS_GT_FIREBASE_TRACKING_ENABLED, enable);
+   }
+
+   static boolean getFirebaseAnalyticsEnabled(Context context) {
+      return OneSignalPrefs.getBool(OneSignalPrefs.PREFS_ONESIGNAL,
+              OneSignalPrefs.PREFS_GT_FIREBASE_TRACKING_ENABLED,false);
+   }
+
    // If true(default) - Device will always vibrate unless the device is in silent mode.
    // If false - Device will only vibrate when the device is set on it's vibrate only mode.
    /**

OneSignalSDK/onesignal/src/main/java/com/onesignal/OneSignalPrefs.java

@@ -25,6 +25,7 @@ class OneSignalPrefs {
     static final String PREFS_GT_SOUND_ENABLED = "GT_SOUND_ENABLED";
     static final String PREFS_OS_LAST_SESSION_TIME = "OS_LAST_SESSION_TIME";
     static final String PREFS_GT_VIBRATE_ENABLED = "GT_VIBRATE_ENABLED";
+    static final String PREFS_GT_FIREBASE_TRACKING_ENABLED = "GT_FIREBASE_TRACKING_ENABLED";
     static final String PREFS_OS_FILTER_OTHER_GCM_RECEIVERS = "OS_FILTER_OTHER_GCM_RECEIVERS";
     static final String PREFS_GT_APP_ID = "GT_APP_ID";
     static final String PREFS_GT_PLAYER_ID = "GT_PLAYER_ID";