main.dart

import 'package:carousel_slider_plus/carousel_slider_plus.dart';
import 'package:flutter/material.dart';
import 'package:flutter_web_plugins/url_strategy.dart';

final List<String> imgList = [
  'https://images.unsplash.com/photo-1520342868574-5fa3804e551c?ixlib=rb-0.3.5&ixid=eyJhcHBfaWQiOjEyMDd9&s=6ff92caffcdd63681a35134a6770ed3b&auto=format&fit=crop&w=1951&q=80',
  'https://images.unsplash.com/photo-1522205408450-add114ad53fe?ixlib=rb-0.3.5&ixid=eyJhcHBfaWQiOjEyMDd9&s=368f45b0888aeb0b7b08e3a1084d3ede&auto=format&fit=crop&w=1950&q=80',
  'https://images.unsplash.com/photo-1519125323398-675f0ddb6308?ixlib=rb-0.3.5&ixid=eyJhcHBfaWQiOjEyMDd9&s=94a1e718d89ca60a6337a6008341ca50&auto=format&fit=crop&w=1950&q=80',
  'https://images.unsplash.com/photo-1523205771623-e0faa4d2813d?ixlib=rb-0.3.5&ixid=eyJhcHBfaWQiOjEyMDd9&s=89719a0d55dd05e2deae4120227e6efc&auto=format&fit=crop&w=1953&q=80',
  'https://images.unsplash.com/photo-1508704019882-f9cf40e475b4?ixlib=rb-0.3.5&ixid=eyJhcHBfaWQiOjEyMDd9&s=8c6e5e3aba713b17aa1fe71ab4f0ae5b&auto=format&fit=crop&w=1352&q=80',
  'https://images.unsplash.com/photo-1519985176271-adb1088fa94c?ixlib=rb-0.3.5&ixid=eyJhcHBfaWQiOjEyMDd9&s=a0c8d632e977f94e5d312d9893258f59&auto=format&fit=crop&w=1355&q=80'
];

void main() {
  usePathUrlStrategy();
  runApp(const CarouselDemo());
}

final themeMode = ValueNotifier(2);

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

  @override
  Widget build(BuildContext context) {
    return ValueListenableBuilder(
      valueListenable: themeMode,
      builder: (context, value, g) {
        return MaterialApp(
          initialRoute: '/',
          darkTheme: ThemeData.dark(),
          themeMode: ThemeMode.values.toList()[value],
          debugShowCheckedModeBanner: false,
          routes: {
            '/': (ctx) => const CarouselDemoHome(),
            '/basic': (ctx) => const BasicDemo(),
            '/no-center': (ctx) => const NoCenterDemo(),
            '/image': (ctx) => const ImageSliderDemo(),
            '/complicated': (ctx) => const ComplicatedImageDemo(),
            '/enlarge': (ctx) => const EnlargeStrategyDemo(),
            '/manual': (ctx) => const ManuallyControlledSlider(),
            '/no-loop': (ctx) => const NoonLoopingDemo(),
            '/vertical': (ctx) => const VerticalSliderDemo(),
            '/fullscreen': (ctx) => const FullscreenSliderDemo(),
            '/on-demand': (ctx) => const OnDemandCarouselDemo(),
            '/indicator': (ctx) => const CarouselWithIndicatorDemo(),
            '/prefetch': (ctx) => const PrefetchImageDemo(),
            '/reason': (ctx) => const CarouselChangeReasonDemo(),
            '/position': (ctx) => const KeepPageViewPositionDemo(),
            '/multiple': (ctx) => const MultipleItemDemo(),
            '/zoom': (ctx) => const EnlargeStrategyZoomDemo(),
          },
        );
      },
    );
  }
}

class DemoItem extends StatelessWidget {
  final String title;
  final String route;

  const DemoItem(this.title, this.route, {super.key});

  @override
  Widget build(BuildContext context) {
    return ListTile(
      title: Text(title),
      onTap: () => Navigator.pushNamed(context, route),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Carousel demo'),
        actions: [
          IconButton(
            icon: const Icon(Icons.nightlight_round),
            onPressed: () => themeMode.value = themeMode.value == 1 ? 2 : 1,
          )
        ],
      ),
      body: ListView(
        children: const <Widget>[
          DemoItem('Basic demo', '/basic'),
          DemoItem('No center mode demo', '/no-center'),
          DemoItem('Image carousel slider', '/image'),
          DemoItem('More complicated image slider', '/complicated'),
          DemoItem('Enlarge strategy demo slider', '/enlarge'),
          DemoItem('Manually controlled slider', '/manual'),
          DemoItem('Noon-looping carousel slider', '/no-loop'),
          DemoItem('Vertical carousel slider', '/vertical'),
          DemoItem('Fullscreen carousel slider', '/fullscreen'),
          DemoItem('Carousel with indicator controller demo', '/indicator'),
          DemoItem('On-demand carousel slider', '/on-demand'),
          DemoItem('Image carousel slider with prefetch demo', '/prefetch'),
          DemoItem('Carousel change reason demo', '/reason'),
          DemoItem('Keep Page View position demo', '/position'),
          DemoItem('Multiple item in one screen demo', '/multiple'),
          DemoItem('Enlarge strategy: zoom demo', '/zoom'),
        ],
      ),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Basic demo')),
      body: CarouselSlider(
        items: List.generate(5, (i) => i + 1).map((item) {
          return Container(
            color: Colors.green,
            child: Center(child: Text(item.toString())),
          );
        }).toList(),
      ),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Basic demo')),
      body: CarouselSlider(
        options: CarouselOptions(disableCenter: true),
        items: List.generate(5, (i) => i + 1).map((item) {
          return Container(
            color: Colors.green,
            child: Text(item.toString()),
          );
        }).toList(),
      ),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Image slider demo')),
      body: CarouselSlider(
        items: imgList.map((item) {
          return Center(
            child: Image.network(
              item,
              fit: BoxFit.cover,
              width: 1000,
            ),
          );
        }).toList(),
      ),
    );
  }
}

final List<Widget> imageSliders = imgList.map((item) {
  return Container(
    margin: const EdgeInsets.all(5.0),
    child: ClipRRect(
      borderRadius: const BorderRadius.all(Radius.circular(5.0)),
      child: Stack(
        children: <Widget>[
          Image.network(item, fit: BoxFit.cover, width: double.infinity),
          Positioned(
            bottom: 0.0,
            left: 0.0,
            right: 0.0,
            child: Container(
              decoration: const BoxDecoration(
                gradient: LinearGradient(
                  colors: [
                    Color.fromARGB(200, 0, 0, 0),
                    Color.fromARGB(0, 0, 0, 0),
                  ],
                  begin: Alignment.bottomCenter,
                  end: Alignment.topCenter,
                ),
              ),
              padding:
                  const EdgeInsets.symmetric(vertical: 10.0, horizontal: 20.0),
              child: Text(
                'No. ${imgList.indexOf(item)} image',
                style: const TextStyle(
                  color: Colors.white,
                  fontSize: 20.0,
                  fontWeight: FontWeight.bold,
                ),
              ),
            ),
          ),
        ],
      ),
    ),
  );
}).toList();

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Complicated image slider demo')),
      body: CarouselSlider(
        options: CarouselOptions(
          autoPlay: true,
          aspectRatio: 2.0,
          enlargeCenterPage: true,
        ),
        items: imageSliders,
      ),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Enlarge strategy demo')),
      body: CarouselSlider(
        options: CarouselOptions(
          autoPlay: true,
          aspectRatio: 2.0,
          enlargeCenterPage: true,
          enlargeStrategy: CenterPageEnlargeStrategy.height,
        ),
        items: imageSliders,
      ),
    );
  }
}

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

  @override
  State<StatefulWidget> createState() {
    return _ManuallyControlledSliderState();
  }
}

class _ManuallyControlledSliderState extends State<ManuallyControlledSlider> {
  final CarouselSliderController _controller = CarouselSliderController();

  @override
  void initState() {
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Manually controlled slider')),
      body: SingleChildScrollView(
        child: Column(
          children: <Widget>[
            CarouselSlider(
              items: imageSliders,
              options: CarouselOptions(enlargeCenterPage: true, height: 200),
              controller: _controller,
            ),
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: <Widget>[
                Flexible(
                  child: ElevatedButton(
                    onPressed: () => _controller.previousPage(),
                    child: const Text('←'),
                  ),
                ),
                Flexible(
                  child: ElevatedButton(
                    onPressed: () => _controller.nextPage(),
                    child: const Text('→'),
                  ),
                ),
                ...Iterable<int>.generate(imgList.length).map(
                  (int pageIndex) => Flexible(
                    child: ElevatedButton(
                      onPressed: () => _controller.animateToPage(pageIndex),
                      child: Text("$pageIndex"),
                    ),
                  ),
                ),
              ],
            )
          ],
        ),
      ),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Noon-looping carousel demo')),
      body: CarouselSlider(
        options: CarouselOptions(
          aspectRatio: 2.0,
          enlargeCenterPage: true,
          enableInfiniteScroll: false,
          initialPage: 2,
          autoPlay: true,
        ),
        items: imageSliders,
      ),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Vertical sliding carousel demo')),
      body: CarouselSlider(
        options: CarouselOptions(
          aspectRatio: 2.0,
          enlargeCenterPage: true,
          scrollDirection: Axis.vertical,
          autoPlay: true,
        ),
        items: imageSliders,
      ),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    final double height = MediaQuery.sizeOf(context).height;
    return Scaffold(
      appBar: AppBar(title: const Text('Fullscreen sliding carousel demo')),
      body: CarouselSlider(
        options: CarouselOptions(
          height: height,
          viewportFraction: 1.0,
          enlargeCenterPage: false,
        ),
        items: imgList.map((item) {
          return Center(
            child: Image.network(
              item,
              fit: BoxFit.cover,
              height: height,
            ),
          );
        }).toList(),
      ),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('On-demand carousel demo')),
      body: CarouselSlider.builder(
        itemCount: 100,
        options: CarouselOptions(
          aspectRatio: 2.0,
          enlargeCenterPage: true,
          autoPlay: true,
        ),
        itemBuilder: (ctx, index, realIdx) {
          return Text(index.toString());
        },
      ),
    );
  }
}

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

  @override
  State<StatefulWidget> createState() {
    return _CarouselWithIndicatorState();
  }
}

class _CarouselWithIndicatorState extends State<CarouselWithIndicatorDemo> {
  int _current = 0;
  final CarouselSliderController _controller = CarouselSliderController();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Carousel with indicator controller demo'),
      ),
      body: SafeArea(
        child: Column(children: [
          Expanded(
            child: CarouselSlider(
              items: imageSliders,
              controller: _controller,
              options: CarouselOptions(
                autoPlay: true,
                enlargeCenterPage: true,
                aspectRatio: 2.0,
                onPageChanged: (index, reason) {
                  setState(() => _current = index);
                },
              ),
            ),
          ),
          Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: imgList.asMap().entries.map((entry) {
              return GestureDetector(
                onTap: () => _controller.animateToPage(entry.key),
                child: Container(
                  width: 12.0,
                  height: 12.0,
                  margin: const EdgeInsets.symmetric(
                    vertical: 8.0,
                    horizontal: 4.0,
                  ),
                  decoration: BoxDecoration(
                    shape: BoxShape.circle,
                    color: (Theme.of(context).brightness == Brightness.dark
                            ? Colors.white
                            : Colors.black)
                        .withValues(
                      alpha: _current == entry.key ? 0.9 : 0.4,
                    ),
                  ),
                ),
              );
            }).toList(),
          ),
        ]),
      ),
    );
  }
}

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

  @override
  State<StatefulWidget> createState() {
    return _PrefetchImageDemoState();
  }
}

class _PrefetchImageDemoState extends State<PrefetchImageDemo> {
  final List<String> images = [
    'https://images.unsplash.com/photo-1586882829491-b81178aa622e?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=2850&q=80',
    'https://images.unsplash.com/photo-1586871608370-4adee64d1794?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=2862&q=80',
    'https://images.unsplash.com/photo-1586901533048-0e856dff2c0d?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=1650&q=80',
    'https://images.unsplash.com/photo-1586902279476-3244d8d18285?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=2850&q=80',
    'https://images.unsplash.com/photo-1586943101559-4cdcf86a6f87?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=1556&q=80',
    'https://images.unsplash.com/photo-1586951144438-26d4e072b891?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=1650&q=80',
    'https://images.unsplash.com/photo-1586953983027-d7508a64f4bb?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=1650&q=80',
  ];

  @override
  void initState() {
    WidgetsBinding.instance.addPostFrameCallback((_) {
      for (var imageUrl in images) {
        precacheImage(NetworkImage(imageUrl), context);
      }
    });
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Prefetch image slider demo')),
      body: CarouselSlider.builder(
        itemCount: images.length,
        options: CarouselOptions(
          autoPlay: true,
          aspectRatio: 2.0,
          enlargeCenterPage: true,
        ),
        itemBuilder: (context, index, realIdx) {
          return Center(
            child: Image.network(
              images[index],
              fit: BoxFit.cover,
              width: 1000,
            ),
          );
        },
      ),
    );
  }
}

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

  @override
  State<StatefulWidget> createState() {
    return _CarouselChangeReasonDemoState();
  }
}

class _CarouselChangeReasonDemoState extends State<CarouselChangeReasonDemo> {
  String reason = '';
  final CarouselSliderController _controller = CarouselSliderController();

  void onPageChange(int index, CarouselPageChangedReason changeReason) {
    setState(() {
      reason = changeReason.toString();
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Change reason demo')),
      body: SafeArea(
        child: Column(
          children: <Widget>[
            Expanded(
              child: CarouselSlider(
                items: imageSliders,
                options: CarouselOptions(
                  enlargeCenterPage: true,
                  aspectRatio: 16 / 9,
                  onPageChanged: onPageChange,
                  autoPlay: true,
                ),
                controller: _controller,
              ),
            ),
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: <Widget>[
                Flexible(
                  child: ElevatedButton(
                    onPressed: () => _controller.previousPage(),
                    child: const Text('←'),
                  ),
                ),
                Flexible(
                  child: ElevatedButton(
                    onPressed: () => _controller.nextPage(),
                    child: const Text('→'),
                  ),
                ),
                ...Iterable<int>.generate(imgList.length).map(
                  (int pageIndex) => Flexible(
                    child: ElevatedButton(
                      onPressed: () => _controller.animateToPage(pageIndex),
                      child: Text("$pageIndex"),
                    ),
                  ),
                ),
              ],
            ),
            Center(
              child: Column(
                children: [
                  const Text('page change reason: '),
                  Text(reason),
                ],
              ),
            )
          ],
        ),
      ),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Keep Page View position demo')),
      body: ListView.builder(itemBuilder: (ctx, index) {
        if (index == 3) {
          return CarouselSlider(
            options: CarouselOptions(
              aspectRatio: 2.0,
              enlargeCenterPage: true,
              pageViewKey: const PageStorageKey<String>('carousel_slider_plus'),
            ),
            items: imageSliders,
          );
        } else {
          return Container(
            margin: const EdgeInsets.symmetric(vertical: 20),
            color: Colors.blue,
            height: 200,
            child: const Center(
              child: Text('other content'),
            ),
          );
        }
      }),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Multiple item in one slide demo')),
      body: CarouselSlider.builder(
        options: CarouselOptions(
          aspectRatio: 2.0,
          enlargeCenterPage: false,
          viewportFraction: 1,
        ),
        itemCount: (imgList.length / 2).round(),
        itemBuilder: (context, index, realIdx) {
          final int first = index * 2;
          final int second = first + 1;
          return Row(
            children: [first, second].map((idx) {
              return Expanded(
                flex: 1,
                child: Container(
                  margin: const EdgeInsets.symmetric(horizontal: 10),
                  child: Image.network(imgList[idx], fit: BoxFit.cover),
                ),
              );
            }).toList(),
          );
        },
      ),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('enlarge strategy: zoom demo')),
      body: CarouselSlider(
        options: CarouselOptions(
          aspectRatio: 2.0,
          enlargeCenterPage: true,
          enlargeStrategy: CenterPageEnlargeStrategy.zoom,
          enlargeFactor: 0.4,
        ),
        items: imageSliders,
      ),
    );
  }
}