main_example.dart

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

import 'common.dart';

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

const actions = [
  SlideAction(
    color: Color(0xFFFE4A49),
    icon: Icons.delete,
    label: 'Delete',
  ),
  SlideAction(
    color: Color(0xFF21B7CA),
    icon: Icons.share,
    label: 'Share',
  ),
];

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

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

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

class _MyHomePageState extends State<MyHomePage>
    with SingleTickerProviderStateMixin {
  AnimationController? controller;

  @override
  void initState() {
    super.initState();
    controller = AnimationController(
      vsync: this,
      upperBound: 0.5,
      duration: const Duration(milliseconds: 2000),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Flutter Slidable'),
      ),
      body: SlidablePlayer(
        animation: controller,
        child: ListView(
          children: const [
            SizedBox(height: 20),
            MySlidable(motion: BehindMotion()),
            MySlidable(motion: StretchMotion()),
            MySlidable(motion: ScrollMotion()),
            MySlidable(motion: DrawerMotion()),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          if (controller!.isCompleted) {
            controller!.reverse();
          } else if (controller!.isDismissed) {
            controller!.forward();
          }
        },
        child: const Icon(Icons.play_arrow),
      ),
    );
  }
}

class SlidablePlayer extends StatefulWidget {
  const SlidablePlayer({
    Key? key,
    required this.animation,
    required this.child,
  }) : super(key: key);

  final Animation<double>? animation;
  final Widget child;

  @override
  _SlidablePlayerState createState() => _SlidablePlayerState();

  static _SlidablePlayerState? of(BuildContext context) {
    return context.findAncestorStateOfType<_SlidablePlayerState>();
  }
}

class _SlidablePlayerState extends State<SlidablePlayer> {
  final Set<SlidableController?> controllers = <SlidableController?>{};

  @override
  void initState() {
    super.initState();
    widget.animation!.addListener(handleAnimationChanged);
  }

  @override
  void dispose() {
    widget.animation!.removeListener(handleAnimationChanged);
    super.dispose();
  }

  void handleAnimationChanged() {
    final value = widget.animation!.value;
    controllers.forEach((controller) {
      controller!.ratio = value;
    });
  }

  @override
  Widget build(BuildContext context) {
    return widget.child;
  }
}

class SlidableControllerSender extends StatefulWidget {
  const SlidableControllerSender({
    Key? key,
    this.child,
  }) : super(key: key);

  final Widget? child;

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

class _SlidableControllerSenderState extends State<SlidableControllerSender> {
  SlidableController? controller;
  _SlidablePlayerState? playerState;

  @override
  void initState() {
    super.initState();
    controller = Slidable.of(context);
    playerState = SlidablePlayer.of(context);
    playerState!.controllers.add(controller);
  }

  @override
  void dispose() {
    playerState!.controllers.remove(controller);
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return widget.child!;
  }
}

class MySlidable extends StatelessWidget {
  const MySlidable({
    Key? key,
    required this.motion,
  }) : super(key: key);

  final Widget motion;

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.all(8),
      child: Slidable(
        startActionPane: ActionPane(
          motion: motion,
          children: actions,
        ),
        child: SlidableControllerSender(
          child: Tile(text: motion.runtimeType.toString()),
        ),
      ),
    );
  }
}

class SlideAction extends StatelessWidget {
  const SlideAction({
    Key? key,
    required this.color,
    required this.icon,
    required this.label,
    this.flex = 1,
  }) : super(key: key);

  final Color color;
  final IconData icon;
  final int flex;
  final String label;

  @override
  Widget build(BuildContext context) {
    return SlidableAction(
      flex: flex,
      backgroundColor: color,
      foregroundColor: Colors.white,
      onPressed: (_) {},
      icon: Icon(icon),
      label: label,
    );
  }
}