QinGang_interested/lib/pages/main_tab.dart

import 'package:flutter/material.dart';
import 'package:qhd_prevention/pages/badge_manager.dart';
import 'package:qhd_prevention/pages/home/home_page.dart';
import 'package:qhd_prevention/pages/mine/mine_page.dart';
import 'package:qhd_prevention/pages/my_appbar.dart';
import 'package:qhd_prevention/pages/notif/notif_page.dart';
import 'package:qhd_prevention/services/heartbeat_service.dart';

/// 用于向子树公布当前 tab 索引
class CurrentTabNotifier extends InheritedWidget {
  final int currentIndex;

  const CurrentTabNotifier({
    required this.currentIndex,
    required Widget child,
    Key? key,
  }) : super(key: key, child: child);

  static CurrentTabNotifier? of(BuildContext context) {
    return context.dependOnInheritedWidgetOfExactType<CurrentTabNotifier>();
  }

  @override
  bool updateShouldNotify(covariant CurrentTabNotifier oldWidget) {
    return oldWidget.currentIndex != currentIndex;
  }
}

class MainPage extends StatefulWidget {
  const MainPage({Key? key, required this.isChooseFirm}) : super(key: key);
  final bool isChooseFirm;

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

class _MainPageState extends State<MainPage> with WidgetsBindingObserver {
  int _currentIndex = 0;
  final GlobalKey<HomePageState> _homeKey = GlobalKey<HomePageState>();
  final GlobalKey<NotifPageState> _notifKey = GlobalKey<NotifPageState>();
  // final GlobalKey<ApplicationPageTwoState> _appKey = GlobalKey<ApplicationPageTwoState>();
  final GlobalKey<MinePageState> _mineKey = GlobalKey<MinePageState>();
  late List<Widget> _pages;
  late List<bool> _tabVisibility; // 存储每个Tab的显示状态

  // 添加 BadgeManager 实例
  late final BadgeManager _badgeManager;

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

    // 初始化 BadgeManager
    _badgeManager = BadgeManager();
    _badgeManager.initAllModules();

    // 监听 BadgeManager 的变化
    _badgeManager.addListener(_onBadgeChanged);

    // 注册生命周期监听
    WidgetsBinding.instance.addObserver(this);
    // 初始化所有Tab
    _tabVisibility = [true, true, true];
    _pages = <Widget>[
      HomePage(key: _homeKey, isChooseFirm: widget.isChooseFirm),
      NotifPage(key: _notifKey),
      MinePage(key: _mineKey, isChooseFirm: widget.isChooseFirm),
    ];
    // 启动心跳服务
    HeartbeatService().start();
  }

  @override
  void dispose() {
    _badgeManager.removeListener(_onBadgeChanged);
    // 移除生命周期监听
    WidgetsBinding.instance.removeObserver(this);

    // 停止心跳服务
    HeartbeatService().stop();

    super.dispose();
  }

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    super.didChangeAppLifecycleState(state);

    switch (state) {
      case AppLifecycleState.resumed:
        // 应用回到前台，恢复心跳
        HeartbeatService().resume();
        break;
      case AppLifecycleState.paused:
      case AppLifecycleState.inactive:
      case AppLifecycleState.detached:
      case AppLifecycleState.hidden:
        // 应用进入后台，暂停心跳
        HeartbeatService().pause();
        break;
    }
  }

  Widget _buildIconWithBadge({required Widget icon, required int badgeCount}) {
    if (badgeCount <= 0) return icon;
    return Stack(
      clipBehavior: Clip.none,
      children: [
        icon,
        Positioned(
          right: -12,
          top: -4,
          child: Container(
            padding: const EdgeInsets.symmetric(horizontal: 5, vertical: 1),
            decoration: BoxDecoration(
              color: Colors.red,
              borderRadius: BorderRadius.circular(8),
            ),
            constraints: const BoxConstraints(minWidth: 16, minHeight: 16),
            child: Center(
              child: Text(
                '$badgeCount',
                style: const TextStyle(
                  color: Colors.white,
                  fontSize: 11,
                  height: 1,
                ),
                textAlign: TextAlign.center,
              ),
            ),
          ),
        ),
      ],
    );
  }

  @override
  Widget build(BuildContext context) {
    final bm = _badgeManager;

    // 构建可见的底部导航项
    final List<BottomNavigationBarItem> visibleItems = [];
    final List<Widget> visiblePages = [];

    for (int i = 0; i < _tabVisibility.length; i++) {
      if (_tabVisibility[i]) {
        switch (i) {
          case 0:
            visibleItems.add(
              BottomNavigationBarItem(
                icon: Image.asset(
                  'assets/tabbar/basics.png',
                  width: 24,
                  height: 24,
                ),
                activeIcon: Image.asset(
                  'assets/tabbar/basics_cur.png',
                  width: 24,
                  height: 24,
                ),
                label: '首页',
              ),
            );
            visiblePages.add(_pages[i]);
            break;
          case 1:
            visibleItems.add(BottomNavigationBarItem(
              icon: _buildIconWithBadge(
                icon: Image.asset('assets/tabbar/works.png', width: 24, height: 24),
                badgeCount: bm.notifCount,
              ),
              activeIcon: _buildIconWithBadge(
                icon: Image.asset('assets/tabbar/works_cur.png', width: 24, height: 24),
                badgeCount: bm.notifCount,
              ),
              label: '通知',
            ));
            visiblePages.add(_pages[i]);
            break;
          case 2:
            visibleItems.add(
              BottomNavigationBarItem(
                icon: Image.asset(
                  'assets/tabbar/my.png',
                  width: 24,
                  height: 24,
                ),
                activeIcon: Image.asset(
                  'assets/tabbar/my_cur.png',
                  width: 24,
                  height: 24,
                ),
                label: '我的',
              ),
            );
            visiblePages.add(_pages[i]);
            break;
        }
      }
    }

    // 将当前索引映射到可见Tab的索引
    int getVisibleIndex(int originalIndex) {
      int visibleIndex = 0;
      for (int i = 0; i <= originalIndex; i++) {
        if (_tabVisibility[i]) {
          if (i == originalIndex) return visibleIndex;
          visibleIndex++;
        }
      }
      return 0; // 默认返回第一个可见Tab
    }

    final visibleCurrentIndex = getVisibleIndex(_currentIndex);

    return CurrentTabNotifier(
      currentIndex: _currentIndex,
      child: Scaffold(
        appBar: null,
        body: IndexedStack(index: visibleCurrentIndex, children: visiblePages),
        bottomNavigationBar:
            visibleItems.length >= 2
                ? BottomNavigationBar(
                  currentIndex: visibleCurrentIndex,
                  type: BottomNavigationBarType.fixed,
                  selectedItemColor: Colors.blue,
                  unselectedItemColor: Colors.grey,
                  onTap: (visibleIndex) {
                    int originalIndex = 0;
                    int count = 0;
                    for (int i = 0; i < _tabVisibility.length; i++) {
                      if (_tabVisibility[i]) {
                        if (count == visibleIndex) {
                          originalIndex = i;
                          break;
                        }
                        count++;
                      }
                    }
                    setState(() => _currentIndex = originalIndex);
                  },
                  items: visibleItems,
                )
                : null, // 如果没有可见的Tab，隐藏底部导航栏
      ),
    );
  }


  void _onBadgeChanged() {
    // 当角标数据变化时，只更新需要重建的部分
    // 但这里我们只需要触发 build 来更新底部导航栏的角标
    if (mounted) {
      setState(() {
        // 只触发重建，不改变数据
      });
    }
  }

}