samples/gallery/lib/studies/shrine/scrim.dart

// Copyright 2019 The Flutter team. 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';

class Scrim extends StatelessWidget {
  const Scrim({this.controller});

  final AnimationController controller;

  @override
  Widget build(BuildContext context) {
    final Size deviceSize = MediaQuery.of(context).size;
    return ExcludeSemantics(
      child: AnimatedBuilder(
        animation: controller,
        builder: (context, child) {
          final Color color =
              Color(0xFFF0EA).withOpacity(controller.value * 0.87);

          final Widget scrimRectangle = Container(
              width: deviceSize.width, height: deviceSize.height, color: color);

          final bool ignorePointer =
              (controller.status == AnimationStatus.dismissed);
          final bool tapToRevert =
              (controller.status == AnimationStatus.completed);

          if (tapToRevert) {
            return GestureDetector(
              onTap: () {
                controller.reverse();
              },
              child: scrimRectangle,
            );
          } else if (ignorePointer) {
            return IgnorePointer(child: scrimRectangle);
          } else {
            return scrimRectangle;
          }
        },
      ),
    );
  }
}