aman-satu-flutter/lib/views/stocks/stocks_view.dart

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:infinite_scroll_pagination/infinite_scroll_pagination.dart';
import 'package:satu/core/models/inventarization/response/inventarization_response.dart';
import 'package:satu/core/models/stock/stock_response.dart';
import 'package:satu/core/services/dialog_service.dart';
import 'package:satu/core/services/stocks_service.dart';
import 'package:satu/views/inventarization/widget/good_inventarization_list_item.dart';
import 'package:satu/views/stocks/widget/stock_tile.dart';

import '../../../core/entity/goods_entity.dart';
import '../../../core/models/inventarization/good_item/good_item.dart';
import '../../../core/services/dictionary_service.dart';
import '../../../core/services/inventarization_service.dart';
import '../../../core/services/navigator_service.dart';
import '../../../core/utils/locator.dart';
import '../../../routes/route_names.dart';
import '../../../shared/app_colors.dart';
import '../../../shared/shared_styles.dart';
import '../../../shared/ui_helpers.dart';
import '../../../widgets/bar/products_app_bar.dart';
import '../../widgets/fields/input_field.dart';

class StocksView extends StatefulWidget {
  const StocksView({
    Key? key,
  }) : super(key: key);

  @override
  State<StocksView> createState() => _StocksViewState();
}

class _StocksViewState extends State<StocksView> {
  final StockService _service = locator<StockService>();
  late TextEditingController _searchTextController;
  final FocusNode _searchFocusNode = FocusNode();
  String query = '';
  Timer? _debounce;

  static const _pageSize = 20;
  bool _isLastPage = false;

  final PagingController<int, StockResponse> _pagingController =
      PagingController(firstPageKey: 1);

  @override
  void initState() {
    _searchTextController = TextEditingController();
    _searchTextController.addListener(() {
      setState(() {
        query = _searchTextController.text;
      });
      if (_debounce?.isActive ?? false) _debounce?.cancel();
      _debounce = Timer(const Duration(milliseconds: 500), () {
        _pagingController.refresh();
      });
    });

    _pagingController.addPageRequestListener((pageKey) {
      _fetchData(pageKey, _pageSize, query);
    });
    super.initState();
  }

  @override
  void dispose() {
    ;
    _debounce?.cancel();
    _pagingController.dispose();
    _searchTextController.dispose();
    _searchFocusNode.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: const ProductsAppBar(
        title: 'Остатки',
        drawerShow: true,
      ),
      body: Column(
        children: [
          InputField(
            placeholder: 'Поиск по наименованию товара или штрих-код',
            search: true,
            controller: _searchTextController,
            fieldFocusNode: _searchFocusNode,
          ),
          verticalSpaceSmall,
          Padding(
            padding: const EdgeInsets.symmetric(horizontal: 15.0),
            child: SizedBox(
              width: double.infinity,
              child: Row(
                children: [
                  Expanded(
                    flex: 4,
                    child: Text(
                      'Список товара',
                      style: textGray11Style,
                    ),
                  ),
                  Expanded(
                    flex: 2,
                    child: Text(
                      'Количество',
                      style: textGray11Style,
                    ),
                  ),
                  Expanded(
                    flex: 1,
                    child: Text(
                      'Сумма',
                      style: textGray11Style,
                    ),
                  ),
                ],
              ),
            ),
          ),
          verticalSpaceSmall,
          Expanded(
            child: PagedListView<int, StockResponse>.separated(
              //physics: const BouncingScrollPhysics(),
              separatorBuilder: (BuildContext context, int index) {
                return const Divider(
                  height: 1.0,
                  color: disableColor,
                );
              },
              pagingController: _pagingController,
              builderDelegate: PagedChildBuilderDelegate<StockResponse>(
                noItemsFoundIndicatorBuilder: (BuildContext context) {
                  return const Center(
                    child: Text(
                      'В данном списке нет товаров',
                      style: textGray11Style,
                    ),
                  );
                },
                itemBuilder:
                    (BuildContext context, StockResponse item, int index) {
                  return StockTile(
                    key: Key(
                      'good_stock_${item.eaccGoodId}',
                    ),
                    name: item.name,
                    categoryName: item.katName,
                    count: item.cnt,
                    price: item.price,
                    ean: item.ean13,
                  );
                },
              ),
            ),
          ),
        ],
      ),
    );
  }

  Future<void> _fetchData(int pageKey, int perPage, String? query) async {
    final List<StockResponse> newItems = await _service.getList(
      page: pageKey,
      perpage: perPage,
      query: query,
    );
    _isLastPage = newItems.length < _pageSize;

    if (_isLastPage) {
      _pagingController.appendLastPage(newItems);
    } else {
      final nextPageKey = pageKey + 1;
      _pagingController.appendPage(newItems, nextPageKey);
    }
  }
}