fix pip screen bug

iosApp/iosApp/SceneDelegate.swift

@@ -30,12 +30,6 @@ class SceneDelegate: UIResponder, UIWindowSceneDelegate {
     func sceneWillResignActive(_ scene: UIScene) {
         // 键盘还在时，系统会把键盘场景挂到画中画上；连接一旦被拆掉就会报 scene 不存在。
         window?.endEditing(true)
-        let defaults = UserDefaults(suiteName: "group.com.zhushenwudi.lovelivemusicplayer")
-        let playing = defaults?.bool(forKey: "pipIsPlaying") ?? false
-        let enabled = defaults?.bool(forKey: "desktopLyricEnabled") ?? false
-        if playing && enabled {
-            pipManager.manualChangePicInPic(needStart: true)
-        }
     }
 
     func sceneDidBecomeActive(_ scene: UIScene) {
@@ -44,9 +38,8 @@ class SceneDelegate: UIResponder, UIWindowSceneDelegate {
         let defaults = UserDefaults(suiteName: "group.com.zhushenwudi.lovelivemusicplayer")
         let playing = defaults?.bool(forKey: "pipIsPlaying") ?? false
         let enabled = defaults?.bool(forKey: "desktopLyricEnabled") ?? false
-        if playing && enabled {
-            pipManager.picInPicAutoOpen(nil)
-        }
+        pipManager.picInPicAutoOpen(enabled)
+        pipManager.setPlaying(playing)
     }
 
     func scene(_ scene: UIScene, openURLContexts URLContexts: Set<UIOpenURLContext>) {
@@ -72,7 +65,10 @@ class SceneDelegate: UIResponder, UIWindowSceneDelegate {
         pipManager.addScreenView(on: window)
         let enabled = UserDefaults(suiteName: "group.com.zhushenwudi.lovelivemusicplayer")?
             .bool(forKey: "desktopLyricEnabled") ?? false
+        let playing = UserDefaults(suiteName: "group.com.zhushenwudi.lovelivemusicplayer")?
+            .bool(forKey: "pipIsPlaying") ?? false
         pipManager.picInPicAutoOpen(enabled)
+        pipManager.setPlaying(playing)
         didSetupPip = true
     }
 
@@ -91,13 +87,10 @@ class SceneDelegate: UIResponder, UIWindowSceneDelegate {
                 self.pipManager.picInPicAutoOpen(enabled)
             case "playing":
                 let playing = (notification.userInfo?["playing"] as? String) == "true"
-                if playing {
-                    self.pipManager.picInPicAutoOpen(nil)
-                } else {
-                    self.pipManager.manualChangePicInPic(needStart: false)
-                }
+                self.pipManager.setPlaying(playing)
             case "show":
-                self.pipManager.manualChangePicInPic(needStart: true)
+                // PiP 需要在前台时就准备好，由系统在真正转入后台时自动启动。
+                self.pipManager.picInPicAutoOpen(nil)
             case "hide":
                 self.pipManager.stopPictureInPictureOnly()
             case "foreground":

iosApp/iosApp/pip/PipScreenManager.swift

@@ -13,8 +13,8 @@ class PipScreenManager: NSObject, @preconcurrency AVPictureInPictureControllerDe
     private let sampleHost = SampleBufferHostView()
     private var didPrepare = false
     private var wantsPip = false
-    private var isOpenPicInPic = false
-    private var isStartingPip = false
+    private var isAutoOpenEnabled = false
+    private var isPlaying = false
     private var timebase: CMTimebase?
     private var line1 = ""
     private var line2 = ""
@@ -54,8 +54,14 @@ class PipScreenManager: NSObject, @preconcurrency AVPictureInPictureControllerDe
     }
 
     func picInPicAutoOpen(_ isOpen: Bool?) {
-        if let isOpen { isOpenPicInPic = isOpen }
-        if isOpenPicInPic { enqueueCurrentFrame() }
+        if let isOpen { isAutoOpenEnabled = isOpen }
+        refreshAutomaticStartEligibility()
+        if isAutoOpenEnabled { enqueueCurrentFrame() }
+    }
+
+    func setPlaying(_ playing: Bool) {
+        isPlaying = playing
+        refreshAutomaticStartEligibility()
     }
 
     @objc func updatePipScreenView(lyricLine1: String?, lyricLine2: String?, currentLine: Int) {
@@ -65,19 +71,7 @@ class PipScreenManager: NSObject, @preconcurrency AVPictureInPictureControllerDe
         enqueueCurrentFrame()
     }
 
-    func manualChangePicInPic(needStart: Bool) {
-        if needStart {
-            wantsPip = true
-            isOpenPicInPic = true
-            pipController?.invalidatePlaybackState()
-            startPipIfPossible(retries: 8)
-        } else {
-            stopPictureInPictureOnly()
-        }
-    }
-
     func stopPictureInPictureOnly() {
-        wantsPip = false
         if pipController?.isPictureInPictureActive == true {
             pipController?.stopPictureInPicture()
         }
@@ -86,7 +80,6 @@ class PipScreenManager: NSObject, @preconcurrency AVPictureInPictureControllerDe
     func pictureInPictureControllerDidStartPictureInPicture(
         _ pictureInPictureController: AVPictureInPictureController
     ) {
-        isStartingPip = false
         if !wantsPip {
             pictureInPictureController.stopPictureInPicture()
             return
@@ -98,7 +91,6 @@ class PipScreenManager: NSObject, @preconcurrency AVPictureInPictureControllerDe
         _ pictureInPictureController: AVPictureInPictureController,
         failedToStartPictureInPictureWithError error: Error
     ) {
-        isStartingPip = false
         print("PiP failed to start: \(error)")
     }
 
@@ -118,7 +110,7 @@ class PipScreenManager: NSObject, @preconcurrency AVPictureInPictureControllerDe
     func pictureInPictureControllerIsPlaybackPaused(
         _ pictureInPictureController: AVPictureInPictureController
     ) -> Bool {
-        !isOpenPicInPic
+        !wantsPip
     }
 
     func pictureInPictureController(
@@ -153,33 +145,23 @@ class PipScreenManager: NSObject, @preconcurrency AVPictureInPictureControllerDe
         controller.requiresLinearPlayback = true
         controller.setValue(1, forKey: "controlsStyle")
         controller.delegate = self
-        // 自动开启会和 sceneWillResignActive 里的手动开启抢同一次系统连接，快速上滑时连接会被拆掉。
-        controller.canStartPictureInPictureAutomaticallyFromInline = false
+        // 系统只会在 App 真正转入后台时自动开启；临时 inactive
+        // （下拉系统界面、未完成的任务切换手势）不会误弹出桌面歌词。
+        controller.canStartPictureInPictureAutomaticallyFromInline = true
         pipController = controller
         didPrepare = true
+        refreshAutomaticStartEligibility()
     }
 
-    /// 必须在还没进后台时同步调用。启动过程中再调一次会拆掉系统连接。
-    private func startPipIfPossible(retries: Int) {
-        guard wantsPip, let pip = pipController else { return }
-        if pip.isPictureInPictureActive || isStartingPip { return }
-        guard UIApplication.shared.applicationState != .background else { return }
-        guard pip.isPictureInPicturePossible else {
-            if retries > 0 {
-                DispatchQueue.main.async { [weak self] in
-                    self?.startPipIfPossible(retries: retries - 1)
-                }
-            } else {
-                print("PiP not possible after retries")
-            }
-            return
+    private func refreshAutomaticStartEligibility() {
+        wantsPip = isAutoOpenEnabled && isPlaying
+        pipController?.invalidatePlaybackState()
+        if !wantsPip {
+            stopPictureInPictureOnly()
         }
-        isStartingPip = true
-        pip.startPictureInPicture()
     }
 
     private func enqueueCurrentFrame() {
-        if isStartingPip { return }
         guard didPrepare || sampleHost.superview != nil else { return }
         guard let pixelBuffer = makePixelBuffer(size: Self.renderSize) else { return }
         CVPixelBufferLockBaseAddress(pixelBuffer, [])