main.dart

// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

// Mimicking the behavior of VSyncProvider through a global variable
TickerProvider vsync;

class VSyncProvider extends StatefulWidget {
  const VSyncProvider({Key key, this.child}) : super(key: key);
  final Widget child;

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

class _VSyncProviderState extends State<VSyncProvider>
    with SingleTickerProviderStateMixin {
  @override
  Widget build(BuildContext context) {
    TickerMode.of(context);
    vsync = this;
    return widget.child;
  }
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return VSyncProvider(
      child: TickerMode(
        // Voluntarily mute the animation, as a descendant of VSyncProvider
        enabled: false,
        child: MaterialApp(
          home: MyHomePage(),
        ),
      ),
    );
  }
}

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

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

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

  initState() {
    super.initState();
    animationController = AnimationController(
      // replace with `this` and the animation would pause
      vsync: vsync,
      duration: Duration(seconds: 10),
    )..repeat();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Example'),
      ),
      body: Center(
        child: AnimatedBuilder(
          animation: animationController,
          builder: (_, __) {
            // The animation should not play and stay at 0
            return Text((animationController.value * 100).floor().toString());
          },
        ),
      ),
    );
  }
}