timeline.dart

class Timeline extends StatefulWidget {
  PageController pageController;
  Timeline({Key key, this.pageController}) : super(key: key);

  @override
  _HomeState createState() => _HomeState();
}

class _HomeState extends State<Timeline>
    with AutomaticKeepAliveClientMixin<Timeline> {
  // final AsyncMemoizer _memoizer = AsyncMemoizer();
  bool get wantKeepAlive => true; //flutter lib method
  bool isAuthorized = false;
  final LocalStorageService storageService = locator<LocalStorageService>();
  final logger = locator<CustomLoggerService>();

  final BrandRepository _brandRepository = BrandRepository();
  // final CategoryRepository _categoryRepository = CategoryRepository();

  @override
  void initState() {
    super.initState();
  }


  bool themeSwitch = false;
  dynamic themeColors() {
    if (themeSwitch) return Colors.black;
    return Colors.greenAccent;
  }

  @override
  Widget build(BuildContext context) {

    super.build(context);

    return DefaultTabController(
      length: 4,
      child: Scaffold(
        backgroundColor: Colors.white,
        appBar: _builAppBarWithTabs(),
        body: Center(
          child: ConstrainedBox(
            constraints: BoxConstraints(maxWidth: 1200),
            child: ListView(
              scrollDirection: Axis.vertical,
              children: <Widget>[
                Padding(
                  padding: const EdgeInsets.only(bottom: 150),
                  child: Container(
                    height: 800,
                    child: CustomScrollView(
                      scrollDirection: Axis.vertical,
                      slivers: <Widget>[
                        SliverToBoxAdapter(
                          child: MasonryGrid(
                            column: getResponsiveColumnNumber(context, 1, 2, 6),
                            children: <Widget>[
                              // First Bloc
                              BlocProvider(
                                create: (context) {
                                  BrandBloc(repository: _brandRepository);
                                },
                                child: Container(
                                  width: 200,
                                  alignment: Alignment.center,
                                  height: 80,
                                  child: BrandScreen(
                                    brandBloc: context.bloc(),
                                  ),
                                ),
                              ),
                              CategoryScreen(
                                // Second Bloc
                                categoryBloc: CategoryBloc(
                                  repository: context.repository(),
                                ),
                              ),
                              Container(
                                width: 200,
                                alignment: Alignment.center,
                                height: 330,
                                child: _buildFeaturedItemsList(),
                              ),
                              Placeholder(
                                strokeWidth: 0,
                                color: Colors.white,
                              )
                            ],
                          ),
                        ),
                      ],
                    ),
                  ),
                ),


              ],
            ),
          ),
        ),
      ),
    );
  }

  Widget _buildFeaturedItemsList() {
    return ListView.separated(
      primary: true,
      addAutomaticKeepAlives: true,
      // addSemanticIndexes: true,
      // addRepaintBoundaries: true,
      shrinkWrap: true,
      padding: EdgeInsets.only(left: 15, right: 15, bottom: 0),
      scrollDirection: Axis.horizontal,
      itemCount: 10,
      itemBuilder: (context, index) {
        return ProductsListItem(
          name: "3 David Klin",
          currentPrice: 249,
          originalPrice: 499,
          discount: 50,
          imageUrl:
              "https://images-na.ssl-images-amazon.com/images/I/71O0zS0DT0L._UX342_.jpg",
          productRate: 3,
        );
      },
      separatorBuilder: (context, index) => const SizedBox(width: 2),
    );
  }

  AppBar _builAppBarWithTabs() {
    return AppBar(
      actionsIconTheme: IconThemeData(
        color: Colors.black,
      ),
      elevation: 0,
      backgroundColor: Colors.white,
      actions: <Widget>[
        Badge(
          showBadge: false,
          position: BadgePosition.topRight(),
          badgeContent: Text('3'),
          child: IconButton(
            icon: FaIcon(FontAwesomeIcons.bell),
            onPressed: () {
              Navigator.of(context).push(
                PageRouteBuilder(
                  opaque: false, // set to false
                  pageBuilder: (_, __, ___) {
                    return Scaffold(
                      backgroundColor: Color.fromRGBO(255, 255, 255, 0.9),
                      body: Container(
                        decoration: BoxDecoration(
                          border: Border.all(
                              width: 40,
                              color: Colors
                                  .transparent), //color is transparent so that it does not blend with the actual color specified
                          borderRadius: const BorderRadius.all(
                              const Radius.circular(30.0)),
                          // color: Color.fromRGBO(255, 0, 0,
                          //     0.5) // Specifies the background color and the opacity
                        ),
                        child: CustomListView(
                          separatorBuilder: (context, index) => Divider(
                            thickness: 3,
                            height: 10,
                          ),
                          loadingBuilder: CustomListLoading.defaultBuilder,
                          itemBuilder: (context, index, item) {
                            return ListTile(
                              title: Text(item['title']),
                              subtitle: Text(item['body']),
                            );
                          },
                          adapter: NetworkListAdapter(
                            url: 'https://jsonplaceholder.typicode.com/posts',
                            limitParam: '_limit',
                            offsetParam: '_start',
                          ),
                          empty: Text(
                            'No Notifications !\n Buy something!',
                            style: subtitleStyle,
                          ),
                          header: Center(
                            child: Text(
                              'Notifications',
                              style: subtitleStyle,
                            ),
                          ),

                          // Item provider adapter (default: null)
                          // adapter: ListAdapter (

                          //   fetchItems: (int offset, int limit) {
                          //     return ListItems([
                          //       ListTile(),
                          //      ]);
                          //   },
                          // ),

                          // Callback function to build widget if exception occurs during fetching items
                          errorBuilder: (BuildContext context, _,
                              CustomListViewState state) {
                            return Column(
                              children: <Widget>[
                                Text('details.error.toString()'),
                                RaisedButton(
                                  onPressed: () => state.loadMore(),
                                  child: Text('Retry'),
                                ),
                              ],
                            );
                          },
                        ),
                      ),
                    );
                  },
                ),
              );
            },
          ),
        ),
        IconButton(
            icon: FaIcon(FontAwesomeIcons.search),
            onPressed: () {
              widget.pageController.animateToPage(1,
                  duration: Duration(milliseconds: 500),
                  curve: Curves.easeInOut);
            }),
      ],
      bottom: TabBar(
        labelPadding: EdgeInsets.symmetric(horizontal: 20),
        indicatorColor: kDarkColor,
        labelColor: kDarkColor,
        indicatorWeight: 2,
        unselectedLabelColor: Colors.black,
        isScrollable: true,
        tabs: [
          Tab(child: Text('Timeline.mostPopularTab'.tr())),
          Tab(child: Text('Timeline.menTab'.tr())),
          Tab(child: Text('Timeline.womenTab'.tr())),
          Tab(child: Text('Timeline.kidsTab'.tr())),
        ],
      ),
      title: logoImage,
    );
  }
}