Add Open in PiP option (fix #137)

Model/Player/PiPDelegate.swift

@@ -37,6 +37,9 @@ final class PiPDelegate: NSObject, AVPictureInPictureControllerDelegate {
         _: AVPictureInPictureController,
         restoreUserInterfaceForPictureInPictureStopWithCompletionHandler completionHandler: @escaping (Bool) -> Void
     ) {
-        completionHandler(true)
+        player?.show()
+        DispatchQueue.main.asyncAfter(deadline: .now() + 0.3) {
+            completionHandler(true)
+        }
     }
 }

Model/Player/PlayerControlsModel.swift

@@ -109,6 +109,29 @@ final class PlayerControlsModel: ObservableObject {
         }
     }
 
+    func startPiP(startImmediately: Bool = true) {
+        if player.activeBackend == .mpv {
+            player.avPlayerBackend.switchToMPVOnPipClose = true
+        }
+
+        #if !os(macOS)
+            player.exitFullScreen()
+        #endif
+
+        if player.activeBackend != PlayerBackendType.appleAVPlayer {
+            player.saveTime { [weak player] in
+                player?.changeActiveBackend(from: .mpv, to: .appleAVPlayer)
+            }
+        }
+
+        DispatchQueue.main.asyncAfter(deadline: .now() + 0.2) { [weak player] in
+            player?.avPlayerBackend.startPictureInPictureOnPlay = true
+            if startImmediately {
+                player?.pipController?.startPictureInPicture()
+            }
+        }
+    }
+
     func removeTimer() {
         timer?.invalidate()
         timer = nil

Model/Player/PlayerModel.swift

@@ -205,7 +205,7 @@ final class PlayerModel: ObservableObject {
         backend.pause()
     }
 
-    func play(_ video: Video, at time: CMTime? = nil) {
+    func play(_ video: Video, at time: CMTime? = nil, showingPlayer: Bool = true) {
         var delay = 0.0
         #if !os(macOS)
             delay = 0.3
@@ -223,7 +223,9 @@ final class PlayerModel: ObservableObject {
             return
         }
 
-        show()
+        if showingPlayer {
+            show()
+        }
     }
 
     func playStream(
@@ -268,6 +270,7 @@ final class PlayerModel: ObservableObject {
 
     func saveTime(completionHandler: @escaping () -> Void = {}) {
         guard let currentTime = backend.currentTime, currentTime.seconds > 0 else {
+            completionHandler()
             return
         }
 
@@ -341,6 +344,10 @@ final class PlayerModel: ObservableObject {
     }
 
     func changeActiveBackend(from: PlayerBackendType, to: PlayerBackendType) {
+        guard activeBackend != to else {
+            return
+        }
+
         Defaults[.activeBackend] = to
         self.activeBackend = to