holy_sheet 0.0.3

  • Readme
  • Changelog
  • Example
  • Installing
  • 53

holy_sheet #

A Flutter sheet & panel widget that's good as hell.

Use it to build something like:

  • Spotify's currently playing sheet
  • Material Bottom Sheet, but from the top of the screen
  • Apple's NFC / Apple Pay modals
  • Google Maps' scrollable detail views

HolySheet respects the following conventions:

  1. The sheet is always modal.
  2. The sheet is always draggable.
  3. The sheet passes its constraints to its child, which it then (by default) translates with a custom layout.
  4. The sheet expects that all scrollable areas within itself respect the gesture arena and declare defeat when reasonable.


  • simple methods for controlling the sheet using a non-sibling gesture recognizer
    • i.e., making the background of the modal draggable
  • make sure it handles google maps-style cascading

Install #

  holy_sheet: ^0.0.1

Usage #

import 'package:holy_sheet/holy_sheet.dart';

// see exampe/lib/main.dart for details

class _MyHomePageState extends State<MyHomePage> with SingleTickerProviderStateMixin {
  AnimationController _controller;
  Animation<double> _opacity;

  void initState() {
    _controller = Harusaki.controller(
      value: 1.0,
      vsync: this,
    _opacity = Tween<double>(begin: 0, end: 1).animate(_controller);

  Widget build(BuildContext context) {
    final padding = MediaQuery.of(context).padding.top;
    final headerHeight = padding + kToolbarHeight;
    final contentHeight = MediaQuery.of(context).size.height - kToolbarHeight - headerHeight;
    final _height = Tween<double>(
      begin: headerHeight,
      end: headerHeight + contentHeight,

    return Stack(
      children: <Widget>[
        // the background
          color: Colors.yellow,
        // the darkening background
          opacity: _opacity,
          child: Container(
            color: Colors.black45,
        // the sheet layer
          // use the `.normal` SpringDescription
          description: Harusaki.normal,
          // descend from the top
          riseFrom: RiseFrom.Heaven,
          animationController: _controller,
          // a custom animation for entrance/exit
          animationBuilder: (context, child) {
            return Align(
              alignment: Alignment.topCenter,
              child: SizedBox(
                height: _height.transform(_controller.value).clamp(0.0, double.infinity),
                child: child,
          // the contents of the sheet
          builder: (context) {
            // a simple layout for showing the different layers
            // it uses a Material as the primary background
            return Material(
              elevation: 1,
              color: Theme.of(context).bottomSheetTheme.backgroundColor,
              // then clips the content within an overflow box
              child: ClipRect(
                child: OverflowBox(
                  minHeight: headerHeight,
                  maxHeight: headerHeight + contentHeight,
                  alignment: Alignment.topCenter,
                  // which is a purple back layer
                  child: Container(
                    color: Colors.purple,
                    child: Column(
                      // and some simple containers that illustrate the dimensions of the device
                      children: <Widget>[
                        Container(color: Colors.red, height: padding),
                        Container(color: Colors.blue, height: kToolbarHeight),


  • fix: handle case where child height is 0, breaking math


  • add travelDistance prop, clarify onDrag calculations


  • initial implementation, see README.md


example #

A new Flutter project.

Getting Started #

This project is a starting point for a Flutter application.

A few resources to get you started if this is your first Flutter project:

For help getting started with Flutter, view our online documentation, which offers tutorials, samples, guidance on mobile development, and a full API reference.

Use this package as a library

1. Depend on it

Add this to your package's pubspec.yaml file:

  holy_sheet: ^0.0.3

2. Install it

You can install packages from the command line:

with Flutter:

$ flutter pub get

Alternatively, your editor might support flutter pub get. Check the docs for your editor to learn more.

3. Import it

Now in your Dart code, you can use:

import 'package:holy_sheet/holy_sheet.dart';
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Learn more about scoring.

We analyzed this package on Jan 25, 2020, and provided a score, details, and suggestions below. Analysis was completed with status completed using:

  • Dart: 2.7.0
  • pana: 0.13.4
  • Flutter: 1.12.13+hotfix.5

Health suggestions

Format lib/holy_sheet.dart.

Run flutter format to format lib/holy_sheet.dart.

Maintenance suggestions

Package is pre-v0.1 release. (-10 points)

While nothing is inherently wrong with versions of 0.0.*, it might mean that the author is still experimenting with the general direction of the API.

The package description is too short. (-9 points)

Add more detail to the description field of pubspec.yaml. Use 60 to 180 characters to describe the package, what it does, and its target use case.


Package Constraint Resolved Available
Direct dependencies
Dart SDK >=2.1.0 <3.0.0
flutter 0.0.0
Transitive dependencies
collection 1.14.11 1.14.12
meta 1.1.8
sky_engine 0.0.99
typed_data 1.1.6
vector_math 2.0.8
Dev dependencies