Multiple selection List Flutter

main.dart

/// Flutter code sample for ListTile.selected

// Here is an example of using a [StatefulWidget] to keep track of the
// selected index, and using that to set the `selected` property on the
// corresponding [ListTile].

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

/// This is the main application widget.
class MyApp extends StatelessWidget {
  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: _title,
      home: Scaffold(
        appBar: AppBar(title: const Text(_title)),
        body: MyStatefulWidget(),
      ),
    );
  }
}

/// This is the stateful widget that the main application instantiates.
class MyStatefulWidget extends StatefulWidget {
  MyStatefulWidget({Key key}) : super(key: key);

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

/// This is the private State class that goes with MyStatefulWidget.
class _MyStatefulWidgetState extends State<MyStatefulWidget> {
  List<int> _selectedIndexList = [];
  bool _selectionMode = false;
  
  _isSelected(index) => _selectedIndexList.contains(index);

  _toggleSelection(index) {
    setState(() {
      if (_isSelected(index)) {
        _selectedIndexList.remove(index);
      } else {
        _selectedIndexList.add(index);
      }
    
      _selectionMode = _selectedIndexList.length > 0;
    });
  }
  
  _onTap(index) {
    if (_selectionMode) {
      _toggleSelection(index);
      return;
    }
    
    print('opening item at index $index');
  }

  @override
  Widget build(BuildContext context) {
    return ListView.builder(
      itemCount: 10,
      itemBuilder: (BuildContext context, int index) {
        bool selected = _isSelected(index);
        return ListTile(
          leading: Wrap(
            children: [
              GestureDetector(
                child: Icon(selected ? Icons.check_box : Icons.check_box_outline_blank),
                onTap: () => _toggleSelection(index),
              ),
              SizedBox(width: 8),
              Icon(Icons.settings),
            ],
          ),
          title: Text('Item $index'),
          selected: selected,
          onTap: () {
            _onTap(index);
          },
          onLongPress: () => _toggleSelection(index),
          trailing: _selectionMode ? SizedBox(width: 8) : Icon(Icons.chevron_right),
        );
      },
    );
  }
}