Allow Analytics collection and Crash report collection to be disabled

As the developer I really don't want users to disable these, but as
a User, I always want the option, so I should include it.

lib/app.dart

@@ -19,15 +19,15 @@ import 'screens/githostsetup_screens.dart';
 import 'screens/onboarding_screens.dart';
 
 class JournalApp extends StatelessWidget {
-  static Future main() async {
+  static Future main(SharedPreferences pref) async {
     Fimber.plantTree(DebugTree.elapsed(useColors: true));
 
-    var pref = await SharedPreferences.getInstance();
     var appState = AppState(pref);
-
     appState.dumpToLog();
 
-    _enableAnalyticsIfPossible();
+    if (Settings.instance.collectUsageStatistics) {
+      _enableAnalyticsIfPossible();
+    }
 
     if (appState.localGitRepoConfigured == false) {
       // FIXME: What about exceptions!
@@ -41,8 +41,6 @@ class JournalApp extends StatelessWidget {
     var dir = await getGitBaseDirectory();
     appState.gitBaseDirectory = dir.path;
 
-    Settings.instance.load(pref);
-
     runApp(StateContainer(
       appState: appState,
       child: JournalApp(),

lib/main.dart

@@ -2,23 +2,32 @@ import 'dart:async';
 
 import 'package:flutter/material.dart';
 import 'package:flutter_crashlytics/flutter_crashlytics.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
 import 'package:journal/app.dart';
+import 'package:journal/settings.dart';
 
 void main() async {
+  var pref = await SharedPreferences.getInstance();
+  Settings.instance.load(pref);
+
+  var reportCrashes =
+      !JournalApp.isInDebugMode && Settings.instance.collectCrashReports;
+
   FlutterError.onError = (FlutterErrorDetails details) {
-    if (JournalApp.isInDebugMode) {
+    if (!reportCrashes) {
       FlutterError.dumpErrorToConsole(details);
     } else {
       Zone.current.handleUncaughtError(details.exception, details.stack);
     }
   };
 
-  if (!JournalApp.isInDebugMode) {
+  if (reportCrashes) {
     await FlutterCrashlytics().initialize();
   }
 
   runZoned<Future<void>>(() async {
-    await JournalApp.main();
+    await JournalApp.main(pref);
   }, onError: (Object error, StackTrace stackTrace) async {
     print("Uncaught Exception: " + error.toString());
     print(stackTrace);

lib/screens/settings_screen.dart

@@ -197,6 +197,34 @@ class SettingsListState extends State<SettingsList> {
           Settings.instance.save();
         },
       ),
+      SizedBox(height: 16.0),
+      PreferenceTitle("Analytics"),
+      CheckboxPreference(
+        "Collect Anonymous Usage Statistics",
+        "usage_stats",
+        defaultVal: Settings.instance.collectUsageStatistics,
+        onEnable: () {
+          Settings.instance.collectUsageStatistics = true;
+          Settings.instance.save();
+        },
+        onDisable: () {
+          Settings.instance.collectUsageStatistics = false;
+          Settings.instance.save();
+        },
+      ),
+      CheckboxPreference(
+        "Collect Anonymous Crash Reports",
+        "crash_reports",
+        defaultVal: Settings.instance.collectCrashReports,
+        onEnable: () {
+          Settings.instance.collectCrashReports = true;
+          Settings.instance.save();
+        },
+        onDisable: () {
+          Settings.instance.collectCrashReports = false;
+          Settings.instance.save();
+        },
+      ),
       VersionNumberTile(),
     ]);
   }

lib/settings.dart

@@ -24,6 +24,9 @@ class Settings {
 
   NoteViewerFontSize noteViewerFontSize = NoteViewerFontSize.Normal;
 
+  bool collectUsageStatistics = true;
+  bool collectCrashReports = true;
+
   void load(SharedPreferences pref) {
     gitAuthor = pref.getString("gitAuthor") ?? gitAuthor;
     gitAuthorEmail = pref.getString("gitAuthorEmail") ?? gitAuthorEmail;
@@ -36,6 +39,11 @@ class Settings {
     str = pref.getString("noteFileNameFormat") ?? noteFileNameFormat.toString();
     noteFileNameFormat =
         NoteFileNameFormat.values.firstWhere((e) => e.toString() == str);
+
+    collectUsageStatistics =
+        pref.getBool("collectCrashReports") ?? collectUsageStatistics;
+    collectCrashReports =
+        pref.getBool("collectCrashReports") ?? collectCrashReports;
   }
 
   Future save() async {
@@ -44,6 +52,8 @@ class Settings {
     pref.setString("gitAuthorEmail", gitAuthorEmail);
     pref.setString("noteViewerFontSize", noteViewerFontSize.toString());
     pref.setString("noteFileNameFormat", noteFileNameFormat.toString());
+    pref.setBool("collectUsageStatistics", collectUsageStatistics);
+    pref.setBool("collectCrashReports", collectCrashReports);
 
     // Shouldn't we check if something has actually changed?
     for (var f in changeObservers) {