added pagination

lib/components/utils/debounce.dart

@@ -0,0 +1,20 @@
+import 'dart:async';
+import 'dart:ui';
+
+class Debounce {
+  factory Debounce() => _instance;
+
+  Debounce._();
+
+  static final Debounce _instance = Debounce._();
+
+  static Timer? _timer;
+
+  static void run(
+      VoidCallback action,
+      {Duration delay = const Duration(milliseconds: 500)}
+  ) {
+    _timer?.cancel();
+    _timer = Timer(delay, action);
+  }
+}

lib/components/utils/error_callback.dart

@@ -0,0 +1 @@
+typedef OnErrorCallback = void Function(String? error);

lib/data/dtos/characters_dto.dart

@@ -5,8 +5,9 @@ part 'characters_dto.g.dart';
 @JsonSerializable(createToJson: false)
 class CharactersDto {
   final List<CharacterDataDto>? data;
+  final MetaDto? meta;
 
-  const CharactersDto({this.data});
+  const CharactersDto({this.data, this.meta});
 
   factory CharactersDto.fromJson(Map<String, dynamic> json) => _$CharactersDtoFromJson(json);
 }
@@ -33,3 +34,23 @@ class CharacterAttributesDataDto {
 
   factory CharacterAttributesDataDto.fromJson(Map<String, dynamic> json) => _$CharacterAttributesDataDtoFromJson(json);
 }
+
+@JsonSerializable(createToJson: false)
+class MetaDto {
+  final PaginationDto? pagination;
+
+  const MetaDto({this.pagination});
+
+  factory MetaDto.fromJson(Map<String, dynamic> json) => _$MetaDtoFromJson(json);
+}
+
+@JsonSerializable(createToJson: false)
+class PaginationDto {
+  final int? current;
+  final int? next;
+  final int? last;
+
+  const PaginationDto({this.current, this.next, this.last});
+
+  factory PaginationDto.fromJson(Map<String, dynamic> json) => _$PaginationDtoFromJson(json);
+}

lib/data/dtos/characters_dto.g.dart

@@ -11,6 +11,9 @@ CharactersDto _$CharactersDtoFromJson(Map<String, dynamic> json) =>
       data: (json['data'] as List<dynamic>?)
           ?.map((e) => CharacterDataDto.fromJson(e as Map<String, dynamic>))
           .toList(),
+      meta: json['meta'] == null
+          ? null
+          : MetaDto.fromJson(json['meta'] as Map<String, dynamic>),
     );
 
 CharacterDataDto _$CharacterDataDtoFromJson(Map<String, dynamic> json) =>
@@ -31,3 +34,16 @@ CharacterAttributesDataDto _$CharacterAttributesDataDtoFromJson(
       died: json['died'] as String?,
       image: json['image'] as String?,
     );
+
+MetaDto _$MetaDtoFromJson(Map<String, dynamic> json) => MetaDto(
+      pagination: json['pagination'] == null
+          ? null
+          : PaginationDto.fromJson(json['pagination'] as Map<String, dynamic>),
+    );
+
+PaginationDto _$PaginationDtoFromJson(Map<String, dynamic> json) =>
+    PaginationDto(
+      current: (json['current'] as num?)?.toInt(),
+      next: (json['next'] as num?)?.toInt(),
+      last: (json['last'] as num?)?.toInt(),
+    );

lib/data/mappers/characters_mapper.dart

@@ -1,11 +1,20 @@
 import 'package:flutter_android_app/data/dtos/characters_dto.dart';
 import 'package:flutter_android_app/domain/models/card.dart';
 
+import '../../domain/models/home.dart';
+
 const _imagePlaceholder = 'https://gryazoveckij-r19.gosweb.gosuslugi.ru/netcat_files/460/2008/net_foto_muzh.jpg';
 
+extension CharactersDataDto on CharactersDto {
+  HomeData toDomain() => HomeData(
+    data: data?.map((e) => e.toDomain()).toList(),
+    nextPage: meta?.pagination?.next,
+  );
+}
+
 extension CharacterDataDtoToModel on CharacterDataDto {
   CardData toDomain() => CardData(
-    title: attributes?.name ?? 'UKNOWNN',
+    title: attributes?.name ?? 'UNKNOWN',
     imageUrl: attributes?.image ?? _imagePlaceholder,
     description: _makeDescriptionText(attributes?.born, attributes?.died),
   );

lib/domain/models/home.dart

@@ -0,0 +1,8 @@
+import 'card.dart';
+
+class HomeData {
+  final List<CardData>? data;
+  final int? nextPage;
+
+  HomeData({this.data, this.nextPage});
+}

lib/main.dart

@@ -1,5 +1,8 @@
 import 'package:flutter/material.dart';
+import 'package:flutter_android_app/presentation/home_page/bloc/bloc.dart';
 import 'package:flutter_android_app/presentation/home_page/home_page.dart';
+import 'package:flutter_android_app/repositories/potter_repository.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
 
 void main() {
   runApp(const MyApp());
@@ -16,7 +19,15 @@ class MyApp extends StatelessWidget {
         colorScheme: ColorScheme.fromSeed(seedColor: Colors.green),
         useMaterial3: true,
       ),
-      home: const MyHomePage(title: 'Harry Potter characters'),
+      home: RepositoryProvider<PotterRepository>(
+        lazy: true,
+        create: (_) => PotterRepository(),
+        child: BlocProvider<HomeBloc>(
+          lazy: false,
+          create: (context) => HomeBloc(context.read<PotterRepository>()),
+          child: const MyHomePage(title: 'Harry Potter characters'),
+        ),
+      ),
     );
   }
 }

lib/presentation/home_page/bloc/bloc.dart

@@ -0,0 +1,39 @@
+import 'package:flutter_android_app/presentation/home_page/bloc/events.dart';
+import 'package:flutter_android_app/presentation/home_page/bloc/state.dart';
+import 'package:flutter_android_app/repositories/potter_repository.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
+
+class HomeBloc extends Bloc<HomeEvent, HomeState> {
+  final PotterRepository repo;
+
+  HomeBloc(this.repo) : super(const HomeState()) {
+    on<HomeLoadDataEvent>(_onLoadData);
+  }
+
+  Future<void> _onLoadData(HomeLoadDataEvent event, Emitter<HomeState> emit) async {
+    if (event.nextPage == null) {
+      emit(state.copyWith(isLoading: true));
+    } else {
+      emit(state.copyWith(isPaginationLoading: true));
+    }
+
+    String? error;
+
+    final data = await repo.loadData(
+        q: event.search,
+        page: event.nextPage ?? 1,
+        onError: (e) => error = e,
+    );
+
+    if (event.nextPage != null) {
+      data?.data?.insertAll(0, state.data?.data ?? []);
+    }
+
+    emit(state.copyWith(
+        isLoading: false,
+        isPaginationLoading: false,
+        data: data,
+        error: error,
+    ));
+  }
+}

lib/presentation/home_page/bloc/events.dart

@@ -0,0 +1,10 @@
+abstract class HomeEvent {
+  const HomeEvent();
+}
+
+class HomeLoadDataEvent extends HomeEvent {
+  final String? search;
+  final int? nextPage;
+
+  const HomeLoadDataEvent({this.search, this.nextPage});
+}

lib/presentation/home_page/bloc/state.dart

@@ -0,0 +1,36 @@
+import 'package:equatable/equatable.dart';
+import '../../../domain/models/home.dart';
+
+class HomeState extends Equatable {
+  final HomeData? data;
+  final bool isLoading;
+  final bool isPaginationLoading;
+  final String? error;
+
+  const HomeState({
+    this.data,
+    this.isLoading = false,
+    this.isPaginationLoading = false,
+    this.error,
+  });
+
+  HomeState copyWith({
+    HomeData? data,
+    bool? isLoading,
+    bool? isPaginationLoading,
+    String? error,
+  }) => HomeState(
+      data: data ?? this.data,
+      isLoading: isLoading ?? this.isLoading,
+      isPaginationLoading: isPaginationLoading ?? this.isPaginationLoading,
+      error: error ?? this.error,
+  );
+
+  @override
+  List<Object?> get props => [
+    data,
+    isLoading,
+    isPaginationLoading,
+    error,
+  ];
+}

lib/presentation/home_page/home_page.dart

@@ -1,8 +1,12 @@
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter_android_app/components/utils/debounce.dart';
 import 'package:flutter_android_app/domain/models/card.dart';
 import 'package:flutter_android_app/presentation/details_page/details_page.dart';
-import 'package:flutter_android_app/repositories/potter_repository.dart';
+import 'package:flutter_android_app/presentation/home_page/bloc/bloc.dart';
+import 'package:flutter_android_app/presentation/home_page/bloc/events.dart';
+import 'package:flutter_android_app/presentation/home_page/bloc/state.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
 
 part 'card.dart';
 
@@ -16,18 +20,6 @@ class MyHomePage extends StatefulWidget {
 }
 
 class _MyHomePageState extends State<MyHomePage> {
-  @override
-  void initState() {
-    WidgetsBinding.instance.addPostFrameCallback((_) {
-      ScaffoldMessenger.of(context).showSnackBar(SnackBar(
-        content: Text('Hello', style: Theme.of(context).textTheme.bodyLarge),
-        backgroundColor: Colors.deepPurple.shade200,
-        duration: const Duration(seconds: 4),
-      ));
-    });
-    super.initState();
-  }
-
   @override
   Widget build(BuildContext context) {
     return Scaffold(
@@ -49,8 +41,18 @@ class Body extends StatefulWidget {
 
 class _BodyState extends State<Body> {
   final TextEditingController searchController = TextEditingController();
-  final repository = PotterRepository();
+  final ScrollController scrollController = ScrollController();
-  Future<List<CardData>?> data = PotterRepository().loadData();
+
+  @override
+  void initState() {
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      context.read<HomeBloc>().add(const HomeLoadDataEvent());
+    });
+
+    scrollController.addListener(_onNextPageListener);
+
+    super.initState();
+  }
 
   @override
   Widget build(BuildContext context) {
@@ -63,38 +65,57 @@ class _BodyState extends State<Body> {
               child: CupertinoSearchTextField(
                 controller: searchController,
                 onChanged: (search) {
-                  setState(() {
+                  Debounce.run(() => context.read<HomeBloc>().add(HomeLoadDataEvent(search: search)));
-                    data = repository.loadData(q: search);
-                  });
                 },
               ),
             ),
-            Expanded(
+            BlocBuilder<HomeBloc, HomeState>(
-              child: Center(
+              builder: (context, state) => state.error != null
-                child: FutureBuilder<List<CardData>?>(
+                ? Text(
-                  future: data,
+                  state.error ?? '',
-                  builder: (context, snapshot) => SingleChildScrollView(
+                  style: Theme.of(context).textTheme.headlineSmall?.copyWith(color: Colors.red),
-                    child: snapshot.hasData
-                        ? Column(
-                      mainAxisAlignment: MainAxisAlignment.center,
-                      children: snapshot.data?.map((data) {
-                        return _Card.fromData(
-                          data,
-                          onLike: (String title, bool isLiked) => _showSnackBar(context, title, isLiked),
-                          onTap: () => _navToDetails(context, data),
-                        );
-                      }).toList() ?? [],
-                    )
-                        : const CircularProgressIndicator(),
-                  ),
                 )
-              )
+                : state.isLoading
+                  ? const CircularProgressIndicator()
+                  : Expanded(
+                    child: RefreshIndicator(
+                      onRefresh: _onRefresh,
+                      child: ListView.builder(
+                        controller: scrollController,
+                        padding: EdgeInsets.zero,
+                        itemCount: state.data?.data?.length ?? 0,
+                        itemBuilder: (context, index) {
+                          final data = state.data?.data?[index];
+                          return data != null
+                              ? _Card.fromData(
+                                data,
+                                onLike: (title, isLiked) => _showSnackBar(context, title, isLiked),
+                                onTap: () => _navToDetails(context, data),
+                              )
+                              : const SizedBox.shrink();
+                        },
+                      ),
+                    ),
+                  )
+            ),
+            BlocBuilder<HomeBloc, HomeState>(
+              builder: (context, state) => state.isPaginationLoading
+                  ? const CircularProgressIndicator()
+                  : const SizedBox.shrink(),
             ),
           ],
         )
     );
   }
 
+  @override
+  void dispose() {
+    searchController.dispose();
+    scrollController.dispose();
+
+    super.dispose();
+  }
+
   void _showSnackBar(BuildContext context, String title, bool isLiked) {
     WidgetsBinding.instance.addPostFrameCallback((_) {
       ScaffoldMessenger.of(context).showSnackBar(SnackBar(
@@ -111,4 +132,21 @@ class _BodyState extends State<Body> {
   void _navToDetails(BuildContext context, CardData data) {
     Navigator.push(context, CupertinoPageRoute(builder: (context) => DetailsPage(data)));
   }
+
+  Future<void> _onRefresh() {
+    context.read<HomeBloc>().add(HomeLoadDataEvent(search: searchController.text));
+    return Future.value(null);
+  }
+
+  void _onNextPageListener() {
+    if (scrollController.offset >= scrollController.position.maxScrollExtent) {
+      final bloc = context.read<HomeBloc>();
+      if (!bloc.state.isPaginationLoading) {
+        bloc.add(HomeLoadDataEvent(
+            search: searchController.text,
+            nextPage: bloc.state.data?.nextPage,
+        ));
+      }
+    }
+  }
 }

lib/repositories/api_interface.dart

@@ -1,5 +1,7 @@
-import 'package:flutter_android_app/domain/models/card.dart';
+import 'package:flutter_android_app/domain/models/home.dart';
+
+import '../components/utils/error_callback.dart';
 
 abstract class ApiInterface {
-  Future<List<CardData>?> loadData({String? q});
+  Future<HomeData?> loadData({OnErrorCallback? onError});
 }

lib/repositories/mock_repository.dart

@@ -2,10 +2,13 @@ import 'package:flutter/material.dart';
 import 'package:flutter_android_app/domain/models/card.dart';
 import 'package:flutter_android_app/repositories/api_interface.dart';
 
+import '../components/utils/error_callback.dart';
+import '../domain/models/home.dart';
+
 class MockRepository extends ApiInterface {
   @override
-  Future<List<CardData>?> loadData({String? q}) async {
+  Future<HomeData?> loadData({OnErrorCallback? onError}) async {
-    return [
+    return HomeData(data: [
       CardData(
         title: 'Title 1',
         description: 'Lorem ipsum dolor sit amet, consectetur adipiscing elit',
@@ -22,6 +25,6 @@ class MockRepository extends ApiInterface {
         description: 'Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor',
         imageUrl: 'https://i.imgur.com/m2FhVAK.png',
       ),
-    ];
+    ]);
   }
 }

lib/repositories/potter_repository.dart

@@ -1,10 +1,12 @@
 import 'package:dio/dio.dart';
 import 'package:flutter_android_app/data/dtos/characters_dto.dart';
 import 'package:flutter_android_app/data/mappers/characters_mapper.dart';
-import 'package:flutter_android_app/domain/models/card.dart';
+import 'package:flutter_android_app/domain/models/home.dart';
 import 'package:flutter_android_app/repositories/api_interface.dart';
 import 'package:pretty_dio_logger/pretty_dio_logger.dart';
 
+import '../components/utils/error_callback.dart';
+
 class PotterRepository extends ApiInterface {
   static final Dio _dio = Dio()
     ..interceptors.add(PrettyDioLogger(
@@ -15,19 +17,28 @@ class PotterRepository extends ApiInterface {
   static const String _baseUrl = 'https://api.potterdb.com';
 
   @override
-  Future<List<CardData>?> loadData({String? q}) async {
+  Future<HomeData?> loadData({
+      OnErrorCallback? onError,
+      String? q, int page = 1,
+      int pageSize = 20,
+  }) async {
     try {
       const String url = '$_baseUrl/v1/characters';
 
       final Response<dynamic> response = await _dio.get<Map<dynamic, dynamic>>(
         url,
-        queryParameters: q != null ? {'filter[name_cont]': q} : null,
+        queryParameters: {
+          'filter[name_cont]': q,
+          'page[number]': page,
+          'page[size]': pageSize,
+        },
       );
 
       final CharactersDto dto = CharactersDto.fromJson(response.data as Map<String, dynamic>);
-      final List<CardData>? data = dto.data?.map((e) => e.toDomain()).toList();
+      final HomeData data = dto.toDomain();
       return data;
     } on DioException catch (e) {
+      onError?.call(e.error?.toString());
       return null;
     }
   }

pubspec.lock

@@ -38,6 +38,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.11.0"
+  bloc:
+    dependency: transitive
+    description:
+      name: bloc
+      sha256: "106842ad6569f0b60297619e9e0b1885c2fb9bf84812935490e6c5275777804e"
+      url: "https://pub.dev"
+    source: hosted
+    version: "8.1.4"
   boolean_selector:
     dependency: transitive
     description:
@@ -198,6 +206,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.0.0"
+  equatable:
+    dependency: "direct main"
+    description:
+      name: equatable
+      sha256: "567c64b3cb4cf82397aac55f4f0cbd3ca20d77c6c03bedbc4ceaddc08904aef7"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.0.7"
   fake_async:
     dependency: transitive
     description:
@@ -227,6 +243,14 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
+  flutter_bloc:
+    dependency: "direct main"
+    description:
+      name: flutter_bloc
+      sha256: b594505eac31a0518bdcb4b5b79573b8d9117b193cc80cc12e17d639b10aa27a
+      url: "https://pub.dev"
+    source: hosted
+    version: "8.1.6"
   flutter_lints:
     dependency: "direct dev"
     description:
@@ -392,6 +416,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.0.0"
+  nested:
+    dependency: transitive
+    description:
+      name: nested
+      sha256: "03bac4c528c64c95c722ec99280375a6f2fc708eec17c7b3f07253b626cd2a20"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.0.0"
   package_config:
     dependency: transitive
     description:
@@ -424,6 +456,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.4.0"
+  provider:
+    dependency: transitive
+    description:
+      name: provider
+      sha256: c8a055ee5ce3fd98d6fc872478b03823ffdb448699c6ebdbbc71d59b596fd48c
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.1.2"
   pub_semver:
     dependency: transitive
     description:

pubspec.yaml

@@ -39,6 +39,8 @@ dependencies:
   json_annotation: ^4.9.0
   dio: ^5.7.0
   pretty_dio_logger: ^1.4.0
+  flutter_bloc: ^8.1.6
+  equatable: ^2.0.7
 
 dev_dependencies:
   flutter_test: