sdd_anim_stateful.dart

class SlidableDrawerDelegateDemo extends StatefulWidget {
  @override
  _SlidableDrawerDelegateDemoState createState() =>
      new _SlidableDrawerDelegateDemoState();
}

class _SlidableDrawerDelegateDemoState extends State<SlidableDrawerDelegateDemo>
    with TickerProviderStateMixin {
  AnimationController _controller;

  @override
  void initState() {
    super.initState();
    _controller = AnimationController(duration: _kDuration, vsync: this);
  }

  Future<Null> _playAnimation() async {
    try {
      await _controller.forward().orCancel;
      await _controller.reverse().orCancel;
    } on TickerCanceled {
      // the animation got canceled, probably because we were disposed
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Slidable Drawer Delegate Animation'),
      ),
      body: GestureDetector(
        behavior: HitTestBehavior.opaque,
        onTap: () => _playAnimation(),
        child: Padding(
          padding: const EdgeInsets.all(8.0),
          child: Center(
            child: SlidableDrawerDelegateAnimation(
              controller: _controller.view,
            ),
          ),
        ),
      ),
    );
  }
}