liangchengyou / wow_english

  import 'package:flutter/material.dart';
  import 'package:flutter_bloc/flutter_bloc.dart';

  import 'package:wow_english/pages/module/course_module_page.dart';

  import '../unit/view.dart';

  import 'blocs/tab_bloc.dart';

  
  class TabPage extends StatelessWidget {
    const TabPage({super.key});
  
    final _pages =const <Widget>[

      UnitPage(),

      CourseModulePage()

    ];
  
    final _tabIcons = const <Icon>[
      Icon(Icons.ac_unit),
      Icon(Icons.ac_unit_outlined)
    ];
  
    final  _tabTexts = const <String>[
      '页面1',
      '页面2'
    ];
  
    @override
    Widget build(BuildContext context) {
      return Scaffold(
        body: _buildIndexedStack(),
        bottomNavigationBar: _buildBottomNavBars(),
      );
    }
  
    Widget _buildIndexedStack() => BlocBuilder<TabBloc,TabState>(
        builder: (context, state) => IndexedStack(
          index: state.index,
          children: _pages,
        )
    );
  
    Widget _buildBottomNavBars() => BlocBuilder<TabBloc,TabState>(
        builder: (context, state) => Container(
          decoration: BoxDecoration(
              boxShadow: <BoxShadow>[
                BoxShadow(
                    color: Theme.of(context).dividerColor,
                    blurRadius: .1
                )
              ]
          ),
          child: BottomNavigationBar(
            currentIndex: state.index,
            items: _buildBottomNavBarItems(context),
            onTap: (value) => context.read<TabBloc>().add(UpdateTabIndexEvent(value)),
          ),
        )
    );
  
    List<BottomNavigationBarItem> _buildBottomNavBarItems(BuildContext context) => _tabIcons.map((e) {
      final index = _tabIcons.indexOf(e);
      return BottomNavigationBarItem(
          label: _tabTexts[index],
          activeIcon: _tabIcons[index],
          icon: _tabIcons[index]
      );}).toList();
  }