main.dart

import 'package:flutter/material.dart';
import 'package:flutter/widgets.dart';

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

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

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

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

class _MyHomePageState extends State<MyHomePage> {
  late PageController _pageController;
  double page = 0.0;

  List<String> images = [
    'https://flutter4fun.com/wp-content/uploads/2021/06/1-1.jpg',
    'https://flutter4fun.com/wp-content/uploads/2021/06/2-1.jpg',
    'https://flutter4fun.com/wp-content/uploads/2021/06/3-1.jpg',
    'https://flutter4fun.com/wp-content/uploads/2021/06/4-1.jpg',
    'https://flutter4fun.com/wp-content/uploads/2021/06/5-1.jpg',
    'https://flutter4fun.com/wp-content/uploads/2021/06/6-1.jpg',
    'https://flutter4fun.com/wp-content/uploads/2021/06/7-1.jpg',
    'https://flutter4fun.com/wp-content/uploads/2021/06/8-1.jpg',
    'https://flutter4fun.com/wp-content/uploads/2021/06/9-1.jpg',
    'https://flutter4fun.com/wp-content/uploads/2021/06/10-1.jpg',
  ];

  @override
  void initState() {
    _pageController = PageController(
      initialPage: 1,
      viewportFraction: 0.7,
    );

    _pageController.addListener(_onScroll);
    super.initState();
  }

  void _onScroll() {
    setState(() {
      page = _pageController.page!;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: AspectRatio(
          aspectRatio: 2,
          child: PageView.builder(
            controller: _pageController,
            itemBuilder: (context, index) {
              return Padding(
                padding: const EdgeInsets.all(16.0),
                child: ParallaxImage(
                  url: images[index],
                  horizontalSlide: (index - page).clamp(-1, 1).toDouble(),
                ),
              );
            },
            itemCount: images.length,
          ),
        ),
      ),
    );
  }

  @override
  void dispose() {
    _pageController.removeListener(_onScroll);
    _pageController.dispose();
    super.dispose();
  }
}

class ParallaxImage extends StatelessWidget {
  final String url;
  final double horizontalSlide;

  const ParallaxImage({
    Key? key,
    required this.url,
    required this.horizontalSlide,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Image.network(
      url,
      alignment: Alignment(horizontalSlide, 1),
      fit: BoxFit.cover,
    );
  }
}