Rideau

Rideau is a UIKit drawer / bottom sheet library for iOS, inspired by the sheet interfaces used in apps like Maps and Shortcuts.

Current Scope

• UIKit-first API for iOS bottom sheets
• Inline embedding with RideauView
• Modal presentation with RideauViewController
• Multiple snap points such as .hidden, .pointsFromBottom, and .fraction
• Automatic coordination with UIScrollView content inside the sheet
• Self-sizing content via RideauContentType
• Interruptible alongside animations powered by UIViewPropertyAnimator
• Optional helper views for rounded corners and a thumb handle

The current public scroll-view API supports automatic detection or noTracking.

Requirements

• iOS 13.0+
• Xcode 16+
• Swift Package Manager

Build Rideau from Xcode or with an iOS destination. The package and its dependencies are UIKit-based.

Installation

Rideau is currently distributed via Swift Package Manager.

dependencies: [
  .package(url: "https://github.com/FluidGroup/Rideau.git", from: "1.0.0")
]

Then add Rideau to your target dependencies.

Quick Start

Inline sheet

import Rideau
import UIKit

let rideauView = RideauView(
  configuration: .init { config in
    config.snapPoints = [.hidden, .fraction(0.5), .full]
    config.scrollViewOption.scrollViewDetection = .automatic
  }
)

rideauView.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(rideauView)

NSLayoutConstraint.activate([
  rideauView.topAnchor.constraint(equalTo: view.topAnchor),
  rideauView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
  rideauView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
  rideauView.bottomAnchor.constraint(equalTo: view.bottomAnchor),
])

let contentView: UIView = ...

rideauView.containerView.set(
  bodyView: contentView,
  resizingOption: .resizeToVisibleArea
)

Modal presentation

import Rideau
import UIKit

let sheet = RideauViewController(
  bodyViewController: YourViewController(),
  configuration: .init { config in
    config.snapPoints = [.hidden, .fraction(0.5), .full]
  },
  initialSnapPoint: .fraction(0.5),
  resizingOption: .resizeToVisibleArea,
  backdropColor: UIColor(white: 0, alpha: 0.5)
)

present(sheet, animated: true)

If your content starts as a UIView, wrap it with RideauWrapperViewController(view:).

API Highlights

Snap points

RideauSnapPoint supports the following cases:

• .hidden
• .fraction(CGFloat)
• .pointsFromTop(CGFloat)
• .pointsFromBottom(CGFloat)
• .autoPointsFromBottom
• .full

config.snapPoints = [
  .hidden,
  .pointsFromBottom(120),
  .fraction(0.6),
  .full,
]

Scroll-view coordination

config.scrollViewOption.scrollViewDetection = .automatic
config.scrollViewOption.scrollViewDetection = .noTracking

Adaptive width and safe areas

Keep a sheet bottom-aligned while limiting its width on larger windows:

config.horizontalLayout = .adaptive(maximumWidth: 653)

The sheet is centered within its available region with an 8-point inset on either side. Pass edgeInset to customize the spacing. The default .fullWidth preserves existing layouts, and modal dimming always covers the full window. On iOS 27.1 and later, when built with Xcode 27.1 or later, an active vertical division moves the sheet into the leading region, respecting the reserved-region margins. Earlier systems still support the width limit and centering.

Resizing preserves the content and selected snap point. .autoPointsFromBottom measures content at the resolved sheet width. Use the content's safeAreaLayoutGuide or containerView.accessibleAreaLayoutGuide to keep controls inside the safe area.

Self-sizing content

Conform a UIView or UIViewController to RideauContentType, update your layout, then call requestRideauSelfSizingUpdate(animator:).

final class SheetContentView: UIView, RideauContentType {
  private var heightConstraint: NSLayoutConstraint!

  func expand() {
    heightConstraint.constant = 300
    requestRideauSelfSizingUpdate(
      animator: UIViewPropertyAnimator(duration: 0.4, dampingRatio: 1, animations: nil)
    )
  }
}

Movement and callbacks

rideauView.handlers.willMoveTo = { snapPoint in
  print("Will move to:", snapPoint)
}

rideauView.handlers.didMoveTo = { snapPoint in
  print("Did move to:", snapPoint)
}

rideauView.move(to: .full, animated: true) {
  print("Finished")
}

Use handlers.animatorsAlongsideMoving or RideauViewDelegate when you want additional UIViewPropertyAnimator instances to track sheet movement.

Optional Helpers

• RideauMaskedCornerRoundedViewController
• RideauMaskedCornerRoundedView
• RideauThumbView

SwiftUI

Rideau does not expose a native SwiftUI sheet API. If you want to use SwiftUI content, host it inside a UIHostingController and embed that view in Rideau.

The demo app includes a small wrapper example in RideauDemo/DemoContents.swift.

Demo

The demo uses Storybook 3.2.2 and requires iOS 17 or later with a Swift 6.3 or later toolchain. Open Adaptive width / Safe area to see the content safe area in green, the excluded region in orange, and live window/content right-inset readings. The height button and device folding demonstrate how the values change. Adaptive width / Scrollable sheet and Adaptive width / Self-sizing sheet cover scrolling and intrinsic sizing with the same width policy.

The app accepts source-qualified Storybook launch arguments:

--storybook "Adaptive width / Safe area" --storybook-file RideauDemo/DemoPreviews.swift

Open the RideauDemo scheme for working examples of:

• Inline presentation
• Modal presentation
• Self-sizing content
• UIKit-backed sheet content
• SwiftUI content hosted inside UIKit

License

Rideau is released under the MIT license.