EpoxySwiftUIHostingController.swift

// Created by eric_horacek on 10/8/21.
// Copyright © 2021 Airbnb Inc. All rights reserved.

import SwiftUI

#if !os(macOS)
// MARK: - EpoxySwiftUIUIHostingController

/// A `UIHostingController` that hosts SwiftUI views within an Epoxy container, e.g. an Epoxy
/// `CollectionView`.
///
/// Exposed publicly to allow consumers to reason about these view controllers, e.g. to opt
/// collection view cells out of automated view controller impression tracking.
///
/// - SeeAlso: `EpoxySwiftUIHostingView`
open class EpoxySwiftUIHostingController<Content: View>: UIHostingController<Content> {

  // MARK: Lifecycle

  /// Creates a `UIHostingController` that optionally ignores the `safeAreaInsets` when laying out
  /// its contained `RootView`.
  public convenience init(rootView: Content, ignoreSafeArea: Bool) {
    self.init(rootView: rootView)

    // We unfortunately need to call a private API to disable the safe area. We can also accomplish
    // this by dynamically subclassing this view controller's view at runtime and overriding its
    // `safeAreaInsets` property and returning `.zero`. An implementation of that logic is
    // available in this file in the `2d28b3181cca50b89618b54836f7a9b6e36ea78e` commit if this API
    // no longer functions in future SwiftUI versions.
    _disableSafeArea = ignoreSafeArea
  }

  // MARK: Open

  open override func viewDidLoad() {
    super.viewDidLoad()

    // A `UIHostingController` has a system background color by default as it's typically used in
    // full-screen use cases. Since we're using this view controller to place SwiftUI views within
    // other view controllers we default the background color to clear so we can see the views
    // below, e.g. to draw highlight states in a `CollectionView`.
    view.backgroundColor = .clear
  }
}
#endif