zhiying_base_widget/lib/pages/custom_page/custom_item_page.dart

import 'package:flutter/material.dart';
import 'package:pull_to_refresh/pull_to_refresh.dart';
import 'package:provider/provider.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:zhiying_base_widget/pages/main_page/notifier/main_page_notifier.dart';
import 'package:zhiying_base_widget/widgets/refresh/refresh_footer/refresh_footer.dart';
import 'package:zhiying_base_widget/widgets/refresh/refresh_header/refresh_header.dart';
import 'package:zhiying_comm/zhiying_comm.dart';
import 'bloc/custom_item_page_bloc.dart';
import 'bloc/custom_item_page_state.dart';
import 'bloc/custom_item_page_event.dart';
import 'bloc/custom_item_page_repository.dart';

///
/// 通用模块的分类导航下的子模块
///
///
class CustomItemPage extends StatelessWidget {
  final Map<String, dynamic> data;
  final int tabIndex;
  final String modPid;
  final String modId;

  CustomItemPage(this.data, this.tabIndex, this.modId, this.modPid);

  @override
  Widget build(BuildContext context) {
    return MultiProvider(
      providers: [
        ChangeNotifierProvider.value(value: MainPageNotifier()),
      ],
      child: BlocProvider<CustomItemPageBloc>(
        create: (_) => CustomItemPageBloc(CustomItemPageRepository(this.data, this.tabIndex, this.modId, this.modPid)),
        child: _CustomItemPageContainer(
          this.data,
          this.tabIndex,
          this.modId,
          this.modPid,
          key: UniqueKey(),
        ),
      ),
    );
  }
}

class _CustomItemPageContainer extends StatefulWidget {
  final Map<String, dynamic> data;
  final int tabIndex;
  final String modPid;
  final String modId;

  const _CustomItemPageContainer(this.data, this.tabIndex, this.modId, this.modPid, {Key key}) : super(key: key);

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

class __CustomItemPageContainerState extends State<_CustomItemPageContainer> with AutomaticKeepAliveClientMixin {
  @override
  bool get wantKeepAlive => true;

  ScrollController _controller;
  RefreshController _refreshController;

  /// 回到顶点
  void _scrollTop() {
    // _controller.jumpTo(0);
    _controller.animateTo(0, duration: Duration(milliseconds: 200), curve: Curves.linear);
  }

  /// 初始化
  void _initEvent() {
    BlocProvider.of<CustomItemPageBloc>(context).add(CustomItemPageInitEvent());
  }

  /// 刷新
  void _refreshEvent() {
    BlocProvider.of<CustomItemPageBloc>(context).add(CustomItemPageRefreshEvent());
  }

  /// 下拉更多
  void _loadEvent() {
    // BlocProvider.of<CustomItemPageBloc>(context).add(CustomItemPageLoadEvent());
    Provider.of<MainPageNotifier>(context, listen: false).loadMore();
    Future.delayed(Duration(seconds: 1),()=> _refreshController?.loadComplete());
  }

  @override
  void initState() {
    _controller = ScrollController();
    _refreshController = RefreshController(initialRefresh: false);
    _initEvent();
    super.initState();
  }

  @override
  void dispose() {
    _controller?.dispose();
    _refreshController?.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return BlocConsumer<CustomItemPageBloc, CustomItemPageState>(
      listener: (context, state) {},
      buildWhen: (prev, current) {
        if (current is CustomItemPageRefreshSuccessState) {
          _refreshController?.refreshCompleted(resetFooterState: true);
          return false;
        }
        if (current is CustomItemPageRefreshErrorState) {
          _refreshController?.refreshFailed();
          return false;
        }
        if (current is CustomItemPageLoadSuccessState) {
          _refreshController?.loadComplete();
          return false;
        }
        if (current is CustomItemPageLoadErrorState) {
          _refreshController?.loadNoData();
          return false;
        }
        if (current is CustomItemPageErrorState) {
          return false;
        }
        return true;
      },
      builder: (context, state) {
        if (state is CustomItemPageLoadedState) {
          if (EmptyUtil.isEmpty(state.model))
            return _buildEmptyWidget();
          else
            return _buildMainWidget(state.model);
        }
        if (state is CustomItemPageInitErrorState) {
          return _buildEmptyWidget();
        }
        return _buildSkeletonWidget();
      },
    );
  }

  /// 有数据
  Widget _buildMainWidget(final List<Map<String, dynamic>> model) {
    return MediaQuery.removePadding(
      context: context,
      removeTop: true,
      child: SmartRefresher(
        controller: _refreshController,
        enablePullDown: true,
        enablePullUp: true,
        onRefresh: _refreshEvent,
        onLoading: _loadEvent,
        header: RefreshHeader(),
        footer: RefreshFooter(),
        child: CustomScrollView(
          controller: _controller,
          slivers: _buildContentWidgets(model),
        ),
      ),
    );
  }

  /// 根据widget的modName生成视图
  List<Widget> _buildContentWidgets(final List<Map<String, dynamic>> datas) {
    List<Widget> result = [];
    for (int i = 0; i < datas.length; i++) {
      WidgetModel item = WidgetModel.fromJson(Map<String, dynamic>.from(datas[i]));
      result.addAll(WidgetFactory.create(
        item.modName,
        isSliver: true,
        model: datas[i],
      ));
    }
    return result;
  }

  /// 空数据
  Widget _buildEmptyWidget() {
    return Container();
  }

  /// 骨架图
  Widget _buildSkeletonWidget() {
    return Container();
  }
}