thing_sheet 0.2.0

A Flutter modal bottom sheet driven by spring physics (not a static curve/tween), with a ready-made Material Expressive visual style included.

thing_sheet

A Flutter modal bottom sheet driven by spring physics (not a static curve/tween), with a ready-made Material Expressive visual style included. Built on top of the motor package for its spring simulation.

Features

• Spring-based animation – the sheet enters with an expressive spatial spring and exits with a fast standard spring, instead of a static Curves value.
• Drag merges with the animation – when the sheet is dragged and released, the drag velocity is carried directly into the open/close spring simulation, so it feels like a natural fling similar to modern iOS/Android sheets.
• Overdrag resistance – dragging the sheet past its fully-open position feels resisted, then settles back smoothly.
• Automatic dismiss threshold – the sheet closes automatically if the drag velocity or final resting position crosses a certain threshold.
• isDismissable – control whether the sheet can be closed via drag, scrim tap, or the back button (Android).
• Keyboard-safe – automatically pushed up when the keyboard appears.
• Accessibility – route labels and semantics hints for screen readers are handled automatically (following the same conventions as Flutter's built-in showModalBottomSheet).
• ThingExpressiveSheet – a ready-to-use wrapper widget with a rounded card, an optional drag indicator (grabber), and Material 3 Expressive-style max width/height constraints.

Getting started

Add the dependency to your pubspec.yaml:

dependencies:
  thing_sheet: ^0.0.1

Then run:

flutter pub get

Usage

A plain sheet with spring animation

import 'package:thing_sheet/thing_sheet.dart';

final result = await showSpringBottomSheet<String>(
  context: context,
  builder: (context) => YourSheetContent(),
);

A sheet with the Material Expressive style (card, drag indicator)

final result = await ThingExpressiveSheet.show<String>(
  context,
  showIndicator: true,
  isDismissable: true,
  builder: (context) {
    return Column(
      mainAxisSize: MainAxisSize.min,
      children: [
        Text('Sheet title'),
        // other content
      ],
    );
  },
);

A sheet that can't be dismissed casually

Use isDismissable: false to prevent the sheet from closing via drag, scrim tap, or the back button — useful for flows that require the user to press a specific confirmation button.

await showSpringBottomSheet(
  context: context,
  isDismissable: false,
  builder: (context) => ConfirmationContent(),
);

A more complete example is available in the /example folder.

Additional information

• This package depends on motor for its spring curves/simulations (MaterialSpringMotion).
• Contributions, bug reports, and feature requests can be submitted through this package's repository/issue tracker.
• License: see the LICENSE file.