Action Sheet Presentation Controller

README.md

Action Sheet Presentation Controller

Use any view controller in an action sheet. This is not worthy of a dedicated pod or a framework. Please don't make it one.

Usage

Return an ActionSheetPresentationController from presentationController(forPresented:presenting:) and make sure the presented view controller's view has a measurable Auto Layout size.

To-Dos

• Respect preferredContentSize instead of only Auto Layout size
• Adapt to regular width by switching to a popover presentation
• Switch to a normal UIButton instead of a custom dismiss button.

ActionSheetPresentationController.swift

//  Created by Caleb Davenport on 7/14/17.

import UIKit

final class ActionSheetPresentationController: UIPresentationController {

    // MARK: - Properties

    private var dimmingView: UIView!

    private var customPresentedView: UIView!

    override var presentedView: UIView? {
        return customPresentedView
    }

    override var frameOfPresentedViewInContainerView: CGRect {
        let size = customPresentedView.systemLayoutSizeFitting(
            containerView!.bounds.size,
            withHorizontalFittingPriority: UILayoutPriorityRequired,
            verticalFittingPriority: UILayoutPriorityFittingSizeLevel)

        let (slice, _) = containerView!.bounds.divided(atDistance: size.height, from: .maxYEdge)

        return slice
    }


    // MARK: - UIPresentationController

    override func presentationTransitionWillBegin() {
        super.presentationTransitionWillBegin()

        if dimmingView == nil {
            dimmingView = UIView()
            dimmingView.backgroundColor = UIColor(white: 0, alpha: 0.4)

            let cancelGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(cancel))
            dimmingView.addGestureRecognizer(cancelGestureRecognizer)

            dimmingView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
            dimmingView.frame = containerView!.bounds
            containerView!.addSubview(dimmingView)
        }

        if customPresentedView == nil {
            let dismissButton = ActionSheetPresentationControllerDismissButton()
            dismissButton.addTarget(self, action: #selector(cancel), for: .touchUpInside)
            dismissButton.setContentHuggingPriority(UILayoutPriorityDefaultHigh, for: .vertical)

            let dismissButtonSectionView = ActionSheetPresentationControllerSectionView()
            dismissButton.translatesAutoresizingMaskIntoConstraints = false
            dismissButtonSectionView.addSubview(dismissButton)

            let presentedViewControllerSectionView = ActionSheetPresentationControllerSectionView()
            presentedViewController.view.translatesAutoresizingMaskIntoConstraints = false
            presentedViewControllerSectionView.addSubview(presentedViewController.view)

            NSLayoutConstraint.activate([
                dismissButton.leadingAnchor.constraint(equalTo: dismissButtonSectionView.leadingAnchor),
                dismissButton.trailingAnchor.constraint(equalTo: dismissButtonSectionView.trailingAnchor),
                dismissButton.topAnchor.constraint(equalTo: dismissButtonSectionView.topAnchor),
                dismissButton.bottomAnchor.constraint(equalTo: dismissButtonSectionView.bottomAnchor),

                presentedViewController.view.leadingAnchor.constraint(equalTo: presentedViewControllerSectionView.leadingAnchor),
                presentedViewController.view.trailingAnchor.constraint(equalTo: presentedViewControllerSectionView.trailingAnchor),
                presentedViewController.view.topAnchor.constraint(equalTo: presentedViewControllerSectionView.topAnchor),
                presentedViewController.view.bottomAnchor.constraint(equalTo: presentedViewControllerSectionView.bottomAnchor)])

            let stackView = UIStackView(arrangedSubviews: [presentedViewControllerSectionView, dismissButtonSectionView])
            stackView.autoresizingMask = [.flexibleWidth, .flexibleTopMargin]
            stackView.axis = .vertical
            stackView.isLayoutMarginsRelativeArrangement = true
            stackView.spacing = 10
            stackView.layoutMargins = UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10)

            customPresentedView = stackView
        }

        dimmingView.alpha = 0

        presentedViewController.transitionCoordinator?.animate(alongsideTransition: { _ in
            self.dimmingView.alpha = 1
        })
    }

    override func dismissalTransitionWillBegin() {
        presentedViewController.transitionCoordinator?.animate(alongsideTransition: { _ in
            self.dimmingView.alpha = 0
        })
    }

    override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
        super.viewWillTransition(to: size, with: coordinator)

        coordinator.animate(alongsideTransition: { _ in
            self.customPresentedView.frame = self.frameOfPresentedViewInContainerView
        })
    }


    // MARK: - Private

    @objc private func cancel() {
        presentedViewController.dismiss(animated: true, completion: nil)
    }
}

ActionSheetPresentationControllerDismissButton.swift

//  Created by Caleb Davenport on 7/14/17.

import UIKit

final class ActionSheetPresentationControllerDismissButton: UIControl {

    // MARK: - Properties

    private let textLabel: UILabel = {
        let view = UILabel()
        view.font = UIFont.systemFont(ofSize: 20, weight: UIFontWeightSemibold)
        view.text = L10n.General.done.localizedCapitalized
        view.textAlignment = .center
        return view
    }()

    override var intrinsicContentSize: CGSize {
        return CGSize(width: UIViewNoIntrinsicMetric, height: 57)
    }


    // MARK: - Initializers

    override init(frame: CGRect) {
        super.init(frame: frame)
        setup()
    }

    required init?(coder: NSCoder) {
        super.init(coder: coder)
        setup()
    }


    // MARK: - UIView

    override func layoutSubviews() {
        super.layoutSubviews()
        textLabel.frame = bounds
    }

    override func tintColorDidChange() {
        super.tintColorDidChange()
        textLabel.textColor = tintColor
    }


    // MARK: - Private

    private func setup() {
        textLabel.textColor = tintColor
        addSubview(textLabel)
    }
}

ActionSheetPresentationControllerSectionView.swift

//  Created by Caleb Davenport on 7/14/17.

import UIKit

final class ActionSheetPresentationControllerSectionView: UIView {

    // MARK: - Properties

    private let visualEffectView = UIVisualEffectView(effect: UIBlurEffect(style: .extraLight))


    // MARK: - Initializers

    override init(frame: CGRect) {
        super.init(frame: frame)
        setup()
    }

    required init?(coder: NSCoder) {
        super.init(coder: coder)
        setup()
    }


    override func layoutSubviews() {
        super.layoutSubviews()
        visualEffectView.frame = bounds
    }


    // MARK: - Private

    private func setup() {
        layer.masksToBounds = true
        layer.cornerRadius = 14

        visualEffectView.isUserInteractionEnabled = false

        addSubview(visualEffectView)
    }
}

DatePickerViewController.swift

//  Created by Caleb Davenport on 7/14/17.

import UIKit

final class DatePickerViewController: UIViewController {

    // MARK: - Properties

    let datePicker = UIDatePicker()


    // MARK: - Initializers

    init() {
        super.init(nibName: nil, bundle: nil)
        modalPresentationStyle = .custom
        transitioningDelegate = self
    }

    @available(*, unavailable)
    required init?(coder: NSCoder) {
        unimplemented()
    }


    // MARK: - UIViewController

    override func viewDidLoad() {
        super.viewDidLoad()

        datePicker.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(datePicker)

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

extension DatePickerViewController: UIViewControllerTransitioningDelegate {
    func presentationController(forPresented presented: UIViewController, presenting: UIViewController?, source: UIViewController) -> UIPresentationController? {
        return ActionSheetPresentationController(presentedViewController: presented, presenting: presenting)
    }
}

Thank you so much, this has been super helpful to me as I was having the same problem.
Two questions though.

1. When comparing with UIAlertController, I noticed that the sheet's width stays the same in portrait and landscape, and seems to be equal to the layout margin frame in portrait orientation. In order to compute this value in frameOfPresentedViewInContainerView, is there a way I can get the layout margin frame of the portrait orientation even when the phone is actually in landscape?

2. Originally I was trying to use auto layout constraints to size and place the presented view in the container, but never managed to get it work. Is that the actual recommended way to use frame calculation in frameOfPresentedViewInContainerView instead?

Thanks a lot!