WhatsApp Like Swipe to Reply animation

main.dart

import 'package:flutter/material.dart';

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

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

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage>
    with SingleTickerProviderStateMixin {
  AnimationController _controller;
  Animation<Offset> animation;

  @override
  initState() {
    super.initState();
    _controller = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 200),
    );
    animation = Tween(
      begin: const Offset(0.0, 0.0),
      end: const Offset(0.3, 0.0),
    ).animate(
      CurvedAnimation(
        curve: Curves.decelerate,
        parent: _controller,
      ),
    );
  }

  @override
  dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: GestureDetector(
          onHorizontalDragUpdate: (details) {
            if (details.delta.dx > 1) {
              _controller.forward().whenComplete(() => _controller.reverse());
            }
          },
          child: SlideTransition(
            position: animation,
            child: Container(
              color: Colors.red.shade200,
              margin: const EdgeInsets.symmetric(horizontal: 16.0),
              padding:
                  const EdgeInsets.symmetric(vertical: 4.0, horizontal: 8.0),
              child: Text('Hello There! How are you?'),
            ),
          ),
        ),
      ),
    );
  }
}