carouSel Example

carouSel.dart

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({
    super.key,
  });

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  final ScrollController _c = ScrollController();
  final List<int> _itemList = [];
  final _displayCount = 4;
  final _itemCount = 30;
  var _carouSelCount = 0;
  var _carouSelFlg = true;
  var _pixels = 0.0;
  @override
  void initState() {
    super.initState();
    for (var i = 0; i < _itemCount; i++) {
      _itemList.add(i);
    }
    _c.addListener(() {
      setState(() {
        var value = (MediaQuery.of(context).size.width / _displayCount) / 2;

        _carouSelCheck(value);
      });
    });
  }

  void _carouSelCheck(double value) {
    if (_carouSelFlg) {
      if (_c.position.pixels > _pixels) {
        _carouSelFlg = false;
        _carouSelCount += 2;
      } else {
        _carouSelFlg = false;
        _carouSelCount -= 2;
      }

      _c
          .animateTo((_carouSelCount * value * 2),
              duration: const Duration(milliseconds: 500), curve: Curves.easeIn)
          .then((value) => _carouSelFlg = true);
    }
    _pixels = _c.position.pixels;
  }

  @override
  Widget build(BuildContext context) {
    var value = MediaQuery.of(context).size.width / _displayCount;
    return Scaffold(
      appBar: AppBar(
        title: const Text('ListView.builder'),
        centerTitle: true,
      ),
      body: Center(
        child: SizedBox(
          height: 200,
          child: GestureDetector(
            child: ListView.builder(
              controller: _c,
              scrollDirection: Axis.horizontal,
              itemCount: _itemList.length,
              itemBuilder: (BuildContext context, int index) {
                return Container(
                  alignment: Alignment.center,
                  margin:
                      EdgeInsets.only(left: index == 0 ? (value) * 1.5 : value),
                  height: value,
                  width: value,
                  color: index.isOdd ? Colors.white : Colors.red,
                  child: TextButton.icon(
                    onPressed: () {},
                    icon: const Icon(Icons.add),
                    label: Text('${_itemList[index]}'),
                  ),
                );
              },
            ),
          ),
        ),
      ),
    );
  }
}

exam.mov