I have a code that is responsible for building a menu filter. It allows you to filter data by category and then by subcategory.

Initially, subcategories are in a closed state, but when you click on the arrow, they can be opened. Take a look

But my problem is that if I click on the arrow for any category (Country in my case), then all subcategories open at once. Take a look

It's my code

class _FilterDialogUserState extends State<FilterDialogUser> {
  Map<String, List<String>?> filters = {};
  bool needRefresh = false;
  bool isClickedCountry = false;

  @override
  void initState() {
    super.initState();
    filters = widget.initialState;
  }

  List<FilterItem> children = [
    FilterItem('Georgia', subitems: [
      FilterItem('Tbilisi'),
      FilterItem('Batumi'),
    ]),
    FilterItem('Poland', subitems: [
      FilterItem('Warsaw'),
      FilterItem('Krakow'),
      FilterItem('Wroclaw'),
    ]),
    FilterItem('Armenia', subitems: [
      FilterItem('Erevan'),
      FilterItem('Gyumri'),
    ]),
  ];

  // Building a dialog box with filters.
  @override
  Widget build(BuildContext context) {
    return SimpleDialog(
        title: const Text('Filters',
            textAlign: TextAlign.center,
            style: TextStyle(
              fontSize: 25,
              fontFamily: 'SuisseIntl',
            )),
        contentPadding: const EdgeInsets.all(16),

        // Defining parameters for filtering.
        children: [
          Column(
            children: children.map(
              (e) {
                return Column(
                  children: [
                    InkWell(
                      onTap: () async {
                        setState(() {
                          isClickedCountry = !isClickedCountry;
                        });
                      },
                      child: Row(
                        children: [
                          Checkbox(
                            value: e.selected,
                            onChanged: (value) => setState(() {
                              e.subitems.forEach((element) =>
                                  element.selected = value as bool);
                              e.selected = value as bool;
                            }),
                          ),
                          Text(e.text),
                          const Spacer(),
                          isClickedCountry
                              ? const Icon(Icons.arrow_circle_up)
                              : const Icon(Icons.arrow_circle_down)
                        ],
                      ),
                    ),
                    if (e.subitems.isNotEmpty)
                      !isClickedCountry
                          ? Container()
                          : Padding(
                              padding: const EdgeInsets.fromLTRB(30, 0, 0, 0),
                              child: Column(
                                children: e.subitems.map((e) {
                                  return Row(children: [
                                    Checkbox(
                                      value: e.selected,
                                      onChanged: (value) => setState(() {
                                        e.selected = value as bool;
                                      }),
                                    ),
                                    Text(e.text),
                                  ]);
                                }).toList(),
                              ),
                            )
                  ],
                );
              },
            ).toList(),
          ),
        ]);
  }
}

class FilterItem {
  final String text;
  bool selected;
  List<FilterItem> subitems;

  FilterItem(
    this.text, {
    this.selected = false,
    this.subitems = const [],
  });
}

Tell me, is it possible to change my code so that not all subcategories are opened, but only the one that the user clicks on?

CodePudding user response：

The each main filter item must be controlled one by one.

• Define List isClickedCountry variable
• Save and load state from List isClickedCountry variable
  

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

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

class _MyHomePageState extends State<MyHomePage> {
  @override
  void initState() {
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: _buildBody(),
      floatingActionButton: FloatingActionButton(
        onPressed: () {},
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ),
    );
  }

  Widget _buildBody() {
    return FilterDialogUser();
  }
}

class FilterDialogUser extends StatefulWidget {
  FilterDialogUser({Key key}) : super(key: key);

  @override
  State<FilterDialogUser> createState() => _FilterDialogUserState();
}

class _FilterDialogUserState extends State<FilterDialogUser> {
  Map<String, List<String>> filters = {};
  bool needRefresh = false;
  List<bool> isClickedCountry = List.filled(3, false);

  @override
  void initState() {
    super.initState();
    // filters = widget.initialState;
  }

  List<FilterItem> children = [
    FilterItem('Georgia', subitems: [
      FilterItem('Tbilisi'),
      FilterItem('Batumi'),
    ]),
    FilterItem('Poland', subitems: [
      FilterItem('Warsaw'),
      FilterItem('Krakow'),
      FilterItem('Wroclaw'),
    ]),
    FilterItem('Armenia', subitems: [
      FilterItem('Erevan'),
      FilterItem('Gyumri'),
    ]),
  ];

  // Building a dialog box with filters.
  @override
  Widget build(BuildContext context) {
    return SimpleDialog(
        title: const Text('Filters',
            textAlign: TextAlign.center,
            style: TextStyle(
              fontSize: 25,
              fontFamily: 'SuisseIntl',
            )),
        contentPadding: const EdgeInsets.all(16),

        // Defining parameters for filtering.
        children: [
          Column(
            children: children.map(
              (e) {
                final int index = children.indexOf(e);
                return Column(
                  children: [
                    InkWell(
                      onTap: () async {
                        setState(() {
                          isClickedCountry[index] = !isClickedCountry[index];
                        });
                      },
                      child: Row(
                        children: [
                          Checkbox(
                            value: e.selected,
                            onChanged: (value) => setState(() {
                              e.subitems.forEach((element) =>
                                  element.selected = value as bool);
                              e.selected = value as bool;
                            }),
                          ),
                          Text(e.text),
                          const Spacer(),
                          isClickedCountry[index]
                              ? const Icon(Icons.arrow_circle_up)
                              : const Icon(Icons.arrow_circle_down)
                        ],
                      ),
                    ),
                    if (e.subitems.isNotEmpty)
                      !isClickedCountry[index]
                          ? Container()
                          : Padding(
                              padding: const EdgeInsets.fromLTRB(30, 0, 0, 0),
                              child: Column(
                                children: e.subitems.map((e) {
                                  return Row(children: [
                                    Checkbox(
                                      value: e.selected,
                                      onChanged: (value) => setState(() {
                                        e.selected = value as bool;
                                      }),
                                    ),
                                    Text(e.text),
                                  ]);
                                }).toList(),
                              ),
                            )
                  ],
                );
              },
            ).toList(),
          ),
        ]);
  }
}

class FilterItem {
  final String text;
  bool selected;
  List<FilterItem> subitems;

  FilterItem(
    this.text, {
    this.selected = false,
    this.subitems = const [],
  });
}