Objective-C to Swift - FLEX

flex.swift

// Rewrite from FLEX
import RxCocoa
import RxGesture
import RxSwift

// https://github.com/Flipboard/FLEX/blob/master/Classes/ExplorerInterface/FLEXExplorerViewController.m#L611

var overlay: UIWindow?
func findViews(at point: CGPoint, ignoreHidden: Bool = true) -> [UIView] {
  return UIApplication.shared.windows
    .filter { $0 != overlay && $0.point(inside: point, with: nil) }
    .flatMap {
      [$0] + $0.recursiveSubviews(at: point, ignoreHidden: ignoreHidden)
    }
}

extension UIView {
  func recursiveSubviews(at point: CGPoint, ignoreHidden: Bool = true) -> [UIView] {
    return subviews.filter {
      // filter out non-visible view if ignoreHidden == true
      ignoreHidden && !$0.isHidden && $0.alpha > 0.01
    }.flatMap { view -> [UIView] in
      if view.frame.contains(point) {
        // subview contains point
        return [view] + view.recursiveSubviews(at: convert(point, to: view))
      } else if !view.clipsToBounds {
        // no contain but subview clipsToBounds == false keep looking subviews
        return view.recursiveSubviews(at: convert(point, to: view))
      } else {
        // nothing happens
        return []
      }
    }
  }
}

class Explorer: UIViewController {
  let bag = DisposeBag()
  override func viewDidLoad() {
    super.viewDidLoad()
    view.backgroundColor = UIColor(white: 0, alpha: 0.2)
    view.rx.tapGesture()
      .when(.recognized)
      .asLocation(in: .view)
      .debug()
      .map {
        findViews(at: $0).last!
      }
      .debug()
      .subscribe()
      .disposed(by: bag)

    view.rx
      .swipeGesture(.down)
      .when(.recognized)
      .subscribe(onNext: { _ in
        overlay?.isHidden = true
      }).disposed(by: bag)
  }
}