step-26

lib/helpers/loading/loading_screen.dart

@@ -0,0 +1,104 @@
+import 'dart:async';
+
+import 'package:flutter/material.dart';
+import 'package:mynotes/helpers/loading/loading_screen_controller.dart';
+
+class LoadingScreen {
+  factory LoadingScreen() => _shared;
+  static final LoadingScreen _shared = LoadingScreen._sharedInstance();
+  LoadingScreen._sharedInstance();
+
+  LoadingScreenController? controller;
+
+  void show({
+    required BuildContext context,
+    required String text,
+  }) {
+    if (controller?.update(text) ?? false) {
+      return;
+    } else {
+      controller = showOverlay(
+        context: context,
+        text: text,
+      );
+    }
+  }
+
+  void hide() {
+    controller?.close();
+    controller = null;
+  }
+
+  LoadingScreenController showOverlay({
+    required BuildContext context,
+    required String text,
+  }) {
+    final _text = StreamController<String>();
+    _text.add(text);
+
+    final state = Overlay.of(context);
+    final renderBox = context.findRenderObject() as RenderBox;
+    final size = renderBox.size;
+
+    final overlay = OverlayEntry(
+      builder: (context) {
+        return Material(
+          color: Colors.black.withAlpha(150),
+          child: Center(
+            child: Container(
+                constraints: BoxConstraints(
+                  maxWidth: size.width * 0.8,
+                  maxHeight: size.height * 0.8,
+                  minWidth: size.width * 0.5,
+                ),
+                decoration: BoxDecoration(
+                  color: Colors.white,
+                  borderRadius: BorderRadius.circular(10.0),
+                ),
+                child: Padding(
+                  padding: const EdgeInsets.all(16.0),
+                  child: SingleChildScrollView(
+                    child: Column(
+                      mainAxisSize: MainAxisSize.min,
+                      mainAxisAlignment: MainAxisAlignment.center,
+                      children: [
+                        const SizedBox(height: 10),
+                        const CircularProgressIndicator(),
+                        const SizedBox(height: 20),
+                        StreamBuilder(
+                          stream: _text.stream,
+                          builder: (context, snapshot) {
+                            if (snapshot.hasData) {
+                              return Text(
+                                snapshot.data as String,
+                                textAlign: TextAlign.center,
+                              );
+                            } else {
+                              return Container();
+                            }
+                          },
+                        ),
+                      ],
+                    ),
+                  ),
+                )),
+          ),
+        );
+      },
+    );
+
+    state?.insert(overlay);
+
+    return LoadingScreenController(
+      close: () {
+        _text.close();
+        overlay.remove();
+        return true;
+      },
+      update: (text) {
+        _text.add(text);
+        return true;
+      },
+    );
+  }
+}

lib/helpers/loading/loading_screen_controller.dart

@@ -0,0 +1,15 @@
+import 'package:flutter/foundation.dart' show immutable;
+
+typedef CloseLoadingScreen = bool Function();
+typedef UpdateLoadingScreen = bool Function(String text);
+
+@immutable
+class LoadingScreenController {
+  final CloseLoadingScreen close;
+  final UpdateLoadingScreen update;
+
+  const LoadingScreenController({
+    required this.close,
+    required this.update,
+  });
+}

lib/main.dart

@@ -1,6 +1,7 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:mynotes/constants/routes.dart';
+import 'package:mynotes/helpers/loading/loading_screen.dart';
 import 'package:mynotes/services/auth/bloc/auth_bloc.dart';
 import 'package:mynotes/services/auth/bloc/auth_event.dart';
 import 'package:mynotes/services/auth/bloc/auth_state.dart';
@@ -36,7 +37,17 @@ class HomePage extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     context.read<AuthBloc>().add(const AuthEventInitialize());
-    return BlocBuilder<AuthBloc, AuthState>(
+    return BlocConsumer<AuthBloc, AuthState>(
+      listener: (context, state) {
+        if (state.isLoading) {
+          LoadingScreen().show(
+            context: context,
+            text: state.loadingText ?? 'Please wait a moment',
+          );
+        } else {
+          LoadingScreen().hide();
+        }
+      },
       builder: (context, state) {
         if (state is AuthStateLoggedIn) {
           return const NotesView();

lib/services/auth/bloc/auth_bloc.dart

@@ -4,7 +4,8 @@ import 'package:mynotes/services/auth/bloc/auth_event.dart';
 import 'package:mynotes/services/auth/bloc/auth_state.dart';
 
 class AuthBloc extends Bloc<AuthEvent, AuthState> {
-  AuthBloc(AuthProvider provider) : super(const AuthStateUninitialized()) {
+  AuthBloc(AuthProvider provider)
+      : super(const AuthStateUninitialized(isLoading: true)) {
     // send email verification
     on<AuthEventSendEmailVerification>((event, emit) async {
       await provider.sendEmailVerification();
@@ -19,9 +20,12 @@ class AuthBloc extends Bloc<AuthEvent, AuthState> {
           password: password,
         );
         await provider.sendEmailVerification();
-        emit(const AuthStateNeedsVerification());
+        emit(const AuthStateNeedsVerification(isLoading: false));
       } on Exception catch (e) {
-        emit(AuthStateRegistering(e));
+        emit(AuthStateRegistering(
+          exception: e,
+          isLoading: false,
+        ));
       }
     });
     // initialize
@@ -36,9 +40,12 @@ class AuthBloc extends Bloc<AuthEvent, AuthState> {
           ),
         );
       } else if (!user.isEmailVerified) {
-        emit(const AuthStateNeedsVerification());
+        emit(const AuthStateNeedsVerification(isLoading: false));
       } else {
-        emit(AuthStateLoggedIn(user));
+        emit(AuthStateLoggedIn(
+          user: user,
+          isLoading: false,
+        ));
       }
     });
     // log in
@@ -47,6 +54,7 @@ class AuthBloc extends Bloc<AuthEvent, AuthState> {
         const AuthStateLoggedOut(
           exception: null,
           isLoading: true,
+          loadingText: 'Please wait while I log you in',
         ),
       );
       final email = event.email;
@@ -64,7 +72,7 @@ class AuthBloc extends Bloc<AuthEvent, AuthState> {
               isLoading: false,
             ),
           );
-          emit(const AuthStateNeedsVerification());
+          emit(const AuthStateNeedsVerification(isLoading: false));
         } else {
           emit(
             const AuthStateLoggedOut(
@@ -72,7 +80,10 @@ class AuthBloc extends Bloc<AuthEvent, AuthState> {
               isLoading: false,
             ),
           );
-          emit(AuthStateLoggedIn(user));
+          emit(AuthStateLoggedIn(
+            user: user,
+            isLoading: false,
+          ));
         }
       } on Exception catch (e) {
         emit(

lib/services/auth/bloc/auth_state.dart

@@ -4,34 +4,50 @@ import 'package:equatable/equatable.dart';
 
 @immutable
 abstract class AuthState {
-  const AuthState();
+  final bool isLoading;
+  final String? loadingText;
+  const AuthState({
+    required this.isLoading,
+    this.loadingText = 'Please wait a moment',
+  });
 }
 
 class AuthStateUninitialized extends AuthState {
-  const AuthStateUninitialized();
+  const AuthStateUninitialized({required bool isLoading})
+      : super(isLoading: isLoading);
 }
 
 class AuthStateRegistering extends AuthState {
   final Exception? exception;
-  const AuthStateRegistering(this.exception);
+  const AuthStateRegistering({
+    required this.exception,
+    required isLoading,
+  }) : super(isLoading: isLoading);
 }
 
 class AuthStateLoggedIn extends AuthState {
   final AuthUser user;
-  const AuthStateLoggedIn(this.user);
+  const AuthStateLoggedIn({
+    required this.user,
+    required bool isLoading,
+  }) : super(isLoading: isLoading);
 }
 
 class AuthStateNeedsVerification extends AuthState {
-  const AuthStateNeedsVerification();
+  const AuthStateNeedsVerification({required bool isLoading})
+      : super(isLoading: isLoading);
 }
 
 class AuthStateLoggedOut extends AuthState with EquatableMixin {
   final Exception? exception;
-  final bool isLoading;
   const AuthStateLoggedOut({
     required this.exception,
-    required this.isLoading,
-  });
+    required bool isLoading,
+    String? loadingText,
+  }) : super(
+          isLoading: isLoading,
+          loadingText: loadingText,
+        );
 
   @override
   List<Object?> get props => [exception, isLoading];

lib/views/login_view.dart

@@ -18,7 +18,6 @@ class LoginView extends StatefulWidget {
 class _LoginViewState extends State<LoginView> {
   late final TextEditingController _email;
   late final TextEditingController _password;
-  CloseDialog? _closeDialogHandle;
 
   @override
   void initState() {
@@ -39,17 +38,6 @@ class _LoginViewState extends State<LoginView> {
     return BlocListener<AuthBloc, AuthState>(
       listener: (context, state) async {
         if (state is AuthStateLoggedOut) {
-          final closeDialog = _closeDialogHandle;
-
-          if (!state.isLoading && closeDialog != null) {
-            closeDialog();
-            _closeDialogHandle = null;
-          } else if (state.isLoading && closeDialog == null) {
-            _closeDialogHandle = showLoadingDialog(
-              context: context,
-              text: 'Loading...',
-            );
-          }
           if (state.exception is UserNotFoundAuthException) {
             await showErrorDialog(context, 'User not found');
           } else if (state.exception is WrongPasswordAuthException) {