Refactored the [CurrentSelectionService] to use streams

lib/src/blocs/event_bloc.dart

@@ -2,5 +2,20 @@ import 'dart:async';
 
 import '../resources/firestore_provider.dart';
 import '../resources/firebase_storage_provider.dart';
+import '../services/current_selection_service.dart';
 
-class EventBloc {}
+/// A business logic component that manages the state for an event screen.
+class EventBloc {
+  /// An instance of the current selection service.
+  final CurrentSelectionService _selectionService = currentSelectionService;
+
+  /// The name of the event that's currently selected.
+  ///
+  /// Read only.
+  String get selectedEventName => _selectionService.event.name;
+
+  /// Fetches the tasks for the current user that a part of the currently
+  /// selected event.
+  void fetchTasks() {}
+  void dispose() {}
+}

lib/src/blocs/home_bloc.dart

@@ -17,7 +17,7 @@ class HomeBloc {
   final AuthService _auth = authService;
 
   /// An instance of the firebase repository.
-  final FirestoreProvider _repository = firestoreProvider;
+  final FirestoreProvider _firestore = firestoreProvider;
 
   /// An instance of the current task service.
   final CurrentSelectionService _selectionService = currentSelectionService;
@@ -90,7 +90,7 @@ class HomeBloc {
   /// Fetches the tasks for the current user.
   Future<void> fetchTasks() async {
     final user = await _auth.currentUser;
-    _repository.getUserTasks(user.email).pipe(_tasks);
+    _firestore.getUserTasks(user.email).pipe(_tasks);
   }
 
   /// Returns a future of the avatar url for the current user.
@@ -107,17 +107,24 @@ class HomeBloc {
 
   /// Marks a task as done in the database.
   void markTaskAsDone(TaskModel task) async {
-    _repository.updateTask(
+    _firestore.updateTask(
       task.id,
       done: true,
     );
   }
 
-  /// Sets the global current task.
-  void updateCurrentTask(TaskModel task) {
+  /// Sets the global selected task.
+  void updateSelectedTask(TaskModel task) {
     _selectionService.updateSelectedTask(task);
   }
 
+  /// Updated the global selected event.
+  void updateSelectedEvent(TaskModel task) async {
+    final userModel = await _auth.getCurrentUserModel();
+    final event = await _firestore.getEvent(userModel.id, eventId: task.event);
+    _selectionService.updateSelectedEvent(event);
+  }
+
   /// Updates the serach box text.
   void updateSearchBoxText(String newText) {
     _searchBoxText.add(newText);

lib/src/blocs/task_bloc.dart

@@ -29,11 +29,16 @@ class TaskBloc extends Object with Validators {
   /// A subject of task text.
   final _taskText = BehaviorSubject<String>();
 
+  ///  A subject of the text of the current global task.
+  final _textInitialValue = BehaviorSubject<String>();
+
   /// The priority of the current task.
   TaskPriority priority = TaskPriority.high;
 
-  /// The text of the current global task.
-  String get textInitialValue => _selectionService.task.text;
+  /// The id of the current task.
+  ///
+  /// Only to be used if editing an existing task.
+  String taskId;
 
   //Stream getters.
   /// An observable of the current user model.
@@ -50,6 +55,9 @@ class TaskBloc extends Object with Validators {
   Observable<bool> get submitEnabled =>
       Observable.combineLatest2(eventName, taskText, (a, b) => true);
 
+  /// An observable of the text of the global selected task.
+  Observable<String> get textInitialvalue => _textInitialValue.stream;
+
   //Sinks getters.
   /// Changes the current task event name.
   Function(String) get changeEventName => _eventName.sink.add;
@@ -67,12 +75,13 @@ class TaskBloc extends Object with Validators {
   }
 
   //TODO: Figure out how to update the event and user properties if needed.
+  // as in the number of pending high tasks for example.
 
   /// Saves or updates the current task in the database.
   Future<void> submit(isEdit) {
     if (isEdit) {
       return _firestore.updateTask(
-        _selectionService.task.id,
+        taskId,
         text: _taskText.value,
         priority: TaskModel.ecodedPriority(priority),
       );
@@ -97,14 +106,20 @@ class TaskBloc extends Object with Validators {
   /// Grabs the data from the current global task and pipes it to the local
   /// streams.
   void populateWithCurrentTask() {
-    TaskModel currentTask = _selectionService.task;
-    if (currentTask != null) {
-      changeEventName(currentTask.event);
-      changeTaskText(currentTask.text);
-    }
+    // We only want the task that was just selected and stop listening
+    // after receiving it.
+    _selectionService.task.take(1).listen(
+      (TaskModel task) {
+        _textInitialValue.sink.add(task.text);
+        changeEventName(task.event);
+        changeTaskText(task.text);
+        taskId = task.id;
+      },
+    );
   }
 
   void dispose() {
+    _textInitialValue.close();
     _taskText.close();
     _user.close();
     _eventName.close();

lib/src/screens/event_screen.dart

@@ -1,5 +1,24 @@
 import 'package:flutter/material.dart';
 
-class EventScreen extends StatelessWidget {
-  Widget build(BuildContext context) {}
+import '../blocs/event_bloc.dart';
+import '../widgets/custom_app_bar.dart';
+
+class EventScreen extends StatefulWidget {
+  _EventScreenState createState() => _EventScreenState();
+}
+
+class _EventScreenState extends State<EventScreen> {
+  final EventBloc bloc = EventBloc();
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: CustomAppBar(
+        title: '',
+      ),
+    );
+  }
+
+  void dispose() {
+    bloc.dispose();
+    super.dispose();
+  }
 }

lib/src/screens/home_screen.dart

@@ -92,8 +92,11 @@ class _HomeScreenState extends State<HomeScreen> {
                 child: TaskListTile(
                   task: task,
                   onDone: () => bloc.markTaskAsDone(task),
-                  onEdit: () {
-                    bloc.updateCurrentTask(task);
+                  onEventPressed: () {
+                    bloc.updateSelectedEvent(task);
+                  },
+                  onEditPressed: () {
+                    bloc.updateSelectedTask(task);
                     Navigator.of(context).pushNamed('editTask/');
                   },
                 ),

lib/src/screens/task_screen.dart

@@ -26,16 +26,10 @@ class _TaskScreenState extends State<TaskScreen> {
   /// An instance of this screen's bloc.
   final TaskBloc bloc = TaskBloc();
 
-  /// The initial value for the text field.
-  ///
-  /// This only gets used whent the screen is set to edit.
-  String textFieldInitialValue;
-
   initState() {
     if (widget.isEdit) {
       bloc.populateWithCurrentTask();
     }
-    textFieldInitialValue = bloc.textInitialValue;
     super.initState();
   }
 
@@ -50,11 +44,21 @@ class _TaskScreenState extends State<TaskScreen> {
             padding: const EdgeInsets.only(top: 15.0, left: 20.0, right: 20.0),
             child: Column(
               children: <Widget>[
-                BigTextInput(
-                  initialValue: widget.isEdit ? textFieldInitialValue : '',
-                  height: 95,
-                  onChanged: bloc.changeTaskText,
-                ),
+                StreamBuilder(
+                    stream: bloc.textInitialvalue,
+                    builder:
+                        (BuildContext context, AsyncSnapshot<String> snapshot) {
+                      String textFieldInitialValue = '';
+                      if (snapshot.hasData) {
+                        textFieldInitialValue = snapshot.data;
+                      }
+                      return BigTextInput(
+                        initialValue:
+                            widget.isEdit ? textFieldInitialValue : '',
+                        height: 95,
+                        onChanged: bloc.changeTaskText,
+                      );
+                    }),
                 SizedBox(
                   height: 15,
                 ),

lib/src/services/auth_service.dart

@@ -63,6 +63,15 @@ class AuthService {
     return _googleSignInProvider.signOut();
   }
 
+  /// Returns the model that represents the current logged in user.
+  Future<UserModel> getCurrentUserModel() async {
+    final user = await _googleSignInProvider.getCurrentUser();
+    if (user != null) {
+      return _firestoreProvider.getUser(username: user.email);
+    }
+    return null;
+  }
+
   void dispose() {
     _user.close();
   }

lib/src/services/current_selection_service.dart

@@ -1,3 +1,5 @@
+import 'package:rxdart/rxdart.dart';
+
 import '../models/event_model.dart';
 import '../models/task_model.dart';
 
@@ -7,25 +9,26 @@ import '../models/task_model.dart';
 /// can grab the user selection for this service.
 class CurrentSelectionService {
   /// The current selected task.
-  TaskModel _selectedTask;
+  final _selectedTask = BehaviorSubject<TaskModel>();
 
   /// The current selected event.
-  EventModel _selectedEvent;
+  final _selectedEvent = BehaviorSubject<EventModel>();
 
-  /// The current selected task.
-  TaskModel get task => _selectedTask;
+  /// An observable of the current selected event.
+  Observable<TaskModel> get task => _selectedTask.stream;
 
   /// The current selected event.
-  EventModel get event => _selectedEvent;
+  Observable<EventModel> get event => _selectedEvent.stream;
 
   /// Updates the current selected task.
-  void updateSelectedTask(TaskModel newTask) {
-    _selectedTask = newTask;
-  }
+  Function(TaskModel) get updateSelectedTask => _selectedTask.sink.add;
 
   // Updates the current selected event.
-  void updateSelectedEvent(EventModel newEvent) {
-    _selectedEvent = newEvent;
+  Function(EventModel) get updateSelectedEvent => _selectedEvent.sink.add;
+
+  dispose() {
+    _selectedEvent.close();
+    _selectedTask.close();
   }
 }
 

lib/src/widgets/big_text_input.dart

@@ -22,7 +22,7 @@ class BigTextInput extends StatefulWidget {
     this.height,
     this.width,
     this.elevated = true,
-    this.initialValue,
+    this.initialValue = '',
   });
 
   @override
@@ -33,6 +33,13 @@ class _BigTextInputState extends State<BigTextInput> {
   /// Custom controller for the text input.
   TextEditingController _controller;
 
+  /// Flag to indicate if the initial value has been set or not.
+  ///
+  /// Without this flag the text property of the controller will be set
+  /// continuously and the cursor inside the text field will return to the
+  /// origin when tapped.
+  bool initialValueWasSet = false;
+
   /// Setus up the controller.
   void initState() {
     _controller = TextEditingController(text: widget.initialValue);
@@ -40,6 +47,17 @@ class _BigTextInputState extends State<BigTextInput> {
     super.initState();
   }
 
+  // Set the text property of the controller if the newly rendered widget
+  // contains a non empty initial value. It should only be done once, otherwise
+  // the cursor will continuously return to the start of the input when tapped.
+  void didUpdateWidget(oldWidget) {
+    if (widget.initialValue != '' && !initialValueWasSet) {
+      _controller.text = widget.initialValue;
+      initialValueWasSet = true;
+    }
+    super.didUpdateWidget(oldWidget);
+  }
+
   /// Calls [onChanged] when updates are sent by the controller.
   void controllerListener() {
     widget.onChanged(_controller.text);

lib/src/widgets/task_list_tile.dart

@@ -14,7 +14,7 @@ class TaskListTile extends StatelessWidget {
   final VoidCallback onDone;
 
   /// Function to be called when the "edit" button is pressed.
-  final VoidCallback onEdit;
+  final VoidCallback onEditPressed;
 
   /// Function to be called when the "event" button is pressed.
   final VoidCallback onEventPressed;
@@ -31,7 +31,7 @@ class TaskListTile extends StatelessWidget {
   TaskListTile({
     @required this.task,
     this.onDone,
-    this.onEdit,
+    this.onEditPressed,
     this.onEventPressed,
   }) : assert(task != null);
 
@@ -115,7 +115,7 @@ class TaskListTile extends StatelessWidget {
             mainAxisAlignment: MainAxisAlignment.end,
             children: <Widget>[
               ActionButton(
-                onPressed: onEdit,
+                onPressed: onEditPressed,
                 text: 'Edit',
                 leadingIconData: Icons.edit,
               ),