Scene-aware safe area (#193)

Co-authored-by: Ryota matsumoto <ryomatsuya04@gmail.com>

Author: muukii

Sources/FluidCore/SafeAreaFinder.swift

@@ -12,32 +12,32 @@ import UIKit
 public final class SafeAreaFinder: NSObject {
 
   public static let notificationName = Notification.Name(rawValue: "app.muukii.fluid.SafeAreaInsetsManager")
-  
-  @MainActor
-  public static let shared = SafeAreaFinder()
+
+  @available(iOS 13.0, *)
+  public weak var windowScene: UIWindowScene?
 
   private var currentInsets: UIEdgeInsets? = nil
 
-  private var referenceCounter: Int = 0 {
-    didSet {
-      if referenceCounter > 0 {
-        currentDisplayLink.isPaused = false
-      } else {
-        currentDisplayLink.isPaused = true
-      }
-    }
-  }
+  private var isRunning: Bool = false
 
-  private nonisolated(unsafe) var currentDisplayLink: CADisplayLink!
+  private nonisolated(unsafe) var currentDisplayLink: CADisplayLink?
 
-  private override init() {
+  @available(iOS 13.0, *)
+  public init(windowScene: UIWindowScene?) {
+    self.windowScene = windowScene
 
     super.init()
+  }
+
+  private func setUpDisplayLink() {
+    guard currentDisplayLink == nil else {
+      return
+    }
 
     currentDisplayLink = .init(target: self, selector: #selector(handle))
-    currentDisplayLink.preferredFramesPerSecond = 1
-    currentDisplayLink.add(to: .main, forMode: .default)
-    currentDisplayLink.isPaused = true
+    currentDisplayLink?.preferredFramesPerSecond = 1
+    currentDisplayLink?.add(to: .main, forMode: .default)
+    currentDisplayLink?.isPaused = false
   }
 
   public func request() {
@@ -46,23 +46,47 @@ public final class SafeAreaFinder: NSObject {
   }
 
   public func start() {
-    referenceCounter += 1
+    guard isRunning == false else {
+      request()
+      return
+    }
+
+    isRunning = true
+    setUpDisplayLink()
     request()
   }
 
+  /// Stops polling and releases the display link so the finder can deallocate when its owner goes away.
+  public func stop() {
+    guard isRunning || currentDisplayLink != nil else {
+      return
+    }
+
+    isRunning = false
+    currentInsets = nil
+    currentDisplayLink?.invalidate()
+    currentDisplayLink = nil
+  }
+
+  /// Stops polling. Kept as a compatibility alias for older callers that used the reference-counted API.
   public func pause() {
-    referenceCounter -= 1
+    stop()
   }
 
   deinit {
-    currentDisplayLink?.isPaused = true
     currentDisplayLink?.invalidate()
   }
 
   @objc private dynamic func handle() {
-    guard let window = UIApplication.shared.delegate?.window ?? nil else {
+
+    guard let windowScene else {
       return
     }
+
+    guard let window = windowScene.windows.first(where: \.isKeyWindow) ?? windowScene.windows.first else {
+      return
+    }
+
     _handle(in: window)
   }
 
@@ -134,7 +158,7 @@ public final class SafeAreaFinder: NSObject {
 
     if currentInsets != maximumInsets {
       currentInsets = maximumInsets
-      NotificationCenter.default.post(name: Self.notificationName, object: maximumInsets)
+      NotificationCenter.default.post(name: Self.notificationName, object: maximumInsets, userInfo: ["finder": self])
     }
   }
 

Sources/FluidPictureInPicture/FluidPictureInPictureController.swift

@@ -104,6 +104,7 @@ extension FluidPictureInPictureController {
     let containerView: ContainerView = .init()
 
     let sizeForFloating = CGSize(width: 100, height: 140)
+    let safeAreaFinder: SafeAreaFinder
 
     private(set) var state: State = .init() {
       didSet {
@@ -123,6 +124,9 @@ extension FluidPictureInPictureController {
     override init(
       frame: CGRect
     ) {
+
+      self.safeAreaFinder = .init(windowScene: nil)
+
       super.init(frame: frame)
 
       let dragGesture = UIPanGestureRecognizer(target: self, action: #selector(handlePanGesture))
@@ -145,6 +149,7 @@ extension FluidPictureInPictureController {
     }
 
     @objc private func handleInsetsUpdate(notification: Notification) {
+      guard notification.userInfo?["finder"] as? SafeAreaFinder === safeAreaFinder else { return }
       let inset = notification.object as! UIEdgeInsets
       state.inset = inset
       setNeedsLayout()
@@ -229,11 +234,13 @@ extension FluidPictureInPictureController {
 
     override func didMoveToWindow() {
       super.didMoveToWindow()
-      
+
+      safeAreaFinder.windowScene = window?.windowScene
+
       if window != nil {
-        SafeAreaFinder.shared.start()
+        safeAreaFinder.start()
       } else {
-        SafeAreaFinder.shared.pause()
+        safeAreaFinder.pause()
       }
     }
 

Sources/FluidSnackbar/FloatingDisplayController.swift

@@ -33,8 +33,15 @@ open class FloatingDisplayController {
 
   // MARK: - Initializers
 
-  public init(edgeTargetSafeArea: FloatingDisplayTarget.EdgeTargetSafeArea) {
-    self.displayTarget = .init(edgeTargetSafeArea: edgeTargetSafeArea)
+  @available(iOS 13.0, *)
+  public init(
+    edgeTargetSafeArea: FloatingDisplayTarget.EdgeTargetSafeArea,
+    windowScene: UIWindowScene
+  ) {
+    self.displayTarget = .init(
+      edgeTargetSafeArea: edgeTargetSafeArea,
+      windowScene: windowScene
+    )
   }
 
 // MARK: - Functions

Sources/FluidSnackbar/FloatingDisplayTarget.swift

@@ -40,14 +40,22 @@ public final class FloatingDisplayTarget {
         left: .activeWindow
       )
     }
+
+    fileprivate var containsActiveWindowEdge: Bool {
+      top == .activeWindow
+        || right == .activeWindow
+        || bottom == .activeWindow
+        || left == .activeWindow
+    }
   }
 
-  public enum TargetSafeArea {
+  public enum TargetSafeArea: Equatable {
     case notificationWindow
     case activeWindow
   }
 
   private let notificationWindow: NotificationWindow
+  private let safeAreaFinder: SafeAreaFinder
   private let notificationViewController: NotificationViewController
 
   public var additionalSafeAreaInsets: UIEdgeInsets {
@@ -69,35 +77,31 @@ public final class FloatingDisplayTarget {
   }
 
   public func makeWindowVisible() {
+    _ = notificationViewController.view
     notificationWindow.isHidden = false
+
+    if notificationViewController.needsActiveWindowSafeArea {
+      safeAreaFinder.start()
+    }
   }
 
   public func hideWindow() {
     notificationWindow.isHidden = true
+    safeAreaFinder.stop()
   }
 
-  public init(edgeTargetSafeArea: EdgeTargetSafeArea) {
-
-    self.notificationViewController = .init(edgeTargetSafeArea: edgeTargetSafeArea)
-
-    if #available(iOS 13, *) {
-
-      let windowScene = UIApplication.shared
-        .connectedScenes
-        .lazy
-        .filter { $0.activationState == .foregroundActive }
-        .compactMap { $0 as? UIWindowScene }
-        .first
+  @available(iOS 13.0, *)
+  public init(
+    edgeTargetSafeArea: EdgeTargetSafeArea,
+    windowScene: UIWindowScene
+  ) {
 
-      if let windowScene = windowScene {
-        notificationWindow = .init(windowScene: windowScene)
-      } else {
-        notificationWindow = .init(frame: .zero)
-      }
-
-    } else {
-      notificationWindow = .init(frame: .zero)
-    }
+    self.safeAreaFinder = .init(windowScene: windowScene)
+    self.notificationViewController = .init(
+      edgeTargetSafeArea: edgeTargetSafeArea,
+      safeAreaFinder: safeAreaFinder
+    )
+    self.notificationWindow = .init(windowScene: windowScene)
 
     notificationWindow.windowLevel = UIWindow.Level(rawValue: 5)
     notificationWindow.isHidden = true
@@ -108,11 +112,11 @@ public final class FloatingDisplayTarget {
     notificationViewController.endAppearanceTransition()
   }
 
-  deinit {      
-    Task { @MainActor [notificationWindow] in      
+  deinit {
+    Task { @MainActor [safeAreaFinder, notificationWindow] in
+      safeAreaFinder.stop()
       notificationWindow.isHidden = false
     }
-    
   }
 
 }
@@ -149,9 +153,18 @@ extension FloatingDisplayTarget {
   fileprivate final class NotificationViewController: UIViewController {
 
     private let edgeTargetSafeArea: EdgeTargetSafeArea
+    private let safeAreaFinder: SafeAreaFinder
 
-    init(edgeTargetSafeArea: EdgeTargetSafeArea) {
+    fileprivate var needsActiveWindowSafeArea: Bool {
+      edgeTargetSafeArea.containsActiveWindowEdge
+    }
+
+    init(
+      edgeTargetSafeArea: EdgeTargetSafeArea,
+      safeAreaFinder: SafeAreaFinder
+    ) {
       self.edgeTargetSafeArea = edgeTargetSafeArea
+      self.safeAreaFinder = safeAreaFinder
       super.init(nibName: nil, bundle: nil)
     }
 
@@ -160,7 +173,10 @@ extension FloatingDisplayTarget {
     }
 
     override fileprivate func loadView() {
-      view = View(edgeTargetSafeArea: edgeTargetSafeArea)
+      view = View(
+        edgeTargetSafeArea: edgeTargetSafeArea,
+        safeAreaFinder: safeAreaFinder
+      )
     }
 
     override fileprivate func viewDidLoad() {
@@ -172,6 +188,7 @@ extension FloatingDisplayTarget {
     fileprivate class View: UIView {
 
       private let edgeTargetSafeArea: EdgeTargetSafeArea
+      private let safeAreaFinder: SafeAreaFinder
 
       private var _safeAreaLayoutGuide: UILayoutGuide = .init()
       private var activeWindowSafeAreaLayoutGuideConstraintLeft: NSLayoutConstraint?
@@ -181,15 +198,19 @@ extension FloatingDisplayTarget {
 
       private var hasSafeAreaFinderActivated: Bool = false
 
-      init(edgeTargetSafeArea: EdgeTargetSafeArea) {
+      init(
+        edgeTargetSafeArea: EdgeTargetSafeArea,
+        safeAreaFinder: SafeAreaFinder
+      ) {
 
         self.edgeTargetSafeArea = edgeTargetSafeArea
+        self.safeAreaFinder = safeAreaFinder
 
         super.init(frame: .zero)
 
         addLayoutGuide(_safeAreaLayoutGuide)
 
-        var containsActievWindowSafeAreaEdge: Bool = false
+        var containsActiveWindowSafeAreaEdge: Bool = false
 
         switch edgeTargetSafeArea.top {
         case .notificationWindow:
@@ -198,7 +219,7 @@ extension FloatingDisplayTarget {
         case .activeWindow:
           activeWindowSafeAreaLayoutGuideConstraintTop = topAnchor.constraint(
             equalTo: _safeAreaLayoutGuide.topAnchor)
-          containsActievWindowSafeAreaEdge = true
+          containsActiveWindowSafeAreaEdge = true
         }
 
         switch edgeTargetSafeArea.right {
@@ -209,7 +230,7 @@ extension FloatingDisplayTarget {
         case .activeWindow:
           activeWindowSafeAreaLayoutGuideConstraintRight = rightAnchor.constraint(
             equalTo: _safeAreaLayoutGuide.rightAnchor)
-          containsActievWindowSafeAreaEdge = true
+          containsActiveWindowSafeAreaEdge = true
         }
 
         switch edgeTargetSafeArea.bottom {
@@ -220,7 +241,7 @@ extension FloatingDisplayTarget {
         case .activeWindow:
           activeWindowSafeAreaLayoutGuideConstraintBottom = bottomAnchor.constraint(
             equalTo: _safeAreaLayoutGuide.bottomAnchor)
-          containsActievWindowSafeAreaEdge = true
+          containsActiveWindowSafeAreaEdge = true
         }
 
         switch edgeTargetSafeArea.left {
@@ -230,10 +251,10 @@ extension FloatingDisplayTarget {
         case .activeWindow:
           activeWindowSafeAreaLayoutGuideConstraintLeft = leftAnchor.constraint(
             equalTo: _safeAreaLayoutGuide.leftAnchor)
-          containsActievWindowSafeAreaEdge = true
+          containsActiveWindowSafeAreaEdge = true
         }
 
-        if containsActievWindowSafeAreaEdge {
+        if containsActiveWindowSafeAreaEdge {
 
           NSLayoutConstraint.activate(
             [
@@ -248,13 +269,13 @@ extension FloatingDisplayTarget {
           NotificationCenter.default.addObserver(
             self, selector: #selector(handleInsetsUpdate), name: SafeAreaFinder.notificationName,
             object: nil)
-          SafeAreaFinder.shared.start()
         }
       }
 
       @objc private func handleInsetsUpdate(notification: Notification) {
 
         guard hasSafeAreaFinderActivated else { return }
+        guard notification.userInfo?["finder"] as? SafeAreaFinder === safeAreaFinder else { return }
 
         let insets = notification.object as! UIEdgeInsets
         self.activeWindowSafeAreaLayoutGuideConstraintLeft?.constant = insets.left
@@ -287,10 +308,9 @@ extension FloatingDisplayTarget {
       }
 
       deinit {
-        Task { @MainActor [hasSafeAreaFinderActivated] in 
-          if hasSafeAreaFinderActivated {
-            SafeAreaFinder.shared.pause()
-          }
+        NotificationCenter.default.removeObserver(self)
+        Task { @MainActor [safeAreaFinder] in
+          safeAreaFinder.stop()
         }
       }
     }