move updating the time to PlayerModel

this makes the chapter view much much smoother

Model/Player/PlayerModel.swift

@@ -131,7 +131,7 @@ final class PlayerModel: ObservableObject {
         @Default(.rotateToLandscapeOnEnterFullScreen) private var rotateToLandscapeOnEnterFullScreen
     #endif
 
-    @Published var currentChapter: Int?
+    @Published var currentChapterIndex: Int?
 
     var accounts: AccountsModel { .shared }
     var comments: CommentsModel { .shared }
@@ -1114,4 +1114,36 @@ final class PlayerModel: ObservableObject {
         onPlayStream.forEach { $0(stream) }
         onPlayStream.removeAll()
     }
+
+    func updateTime(_ cmTime: CMTime) {
+        let time = CMTimeGetSeconds(cmTime)
+        let newChapterIndex = chapterForTime(time)
+        if currentChapterIndex != newChapterIndex {
+            DispatchQueue.main.async {
+                self.currentChapterIndex = newChapterIndex
+            }
+        }
+    }
+
+    private func chapterForTime(_ time: Double) -> Int? {
+        guard let chapters = self.videoForDisplay?.chapters else {
+            return nil
+        }
+
+        for (index, chapter) in chapters.enumerated() {
+            let nextChapterStartTime = index < (chapters.count - 1) ? chapters[index + 1].start : nil
+
+            if let nextChapterStart = nextChapterStartTime {
+                if time >= chapter.start, time < nextChapterStart {
+                    return index
+                }
+            } else {
+                if time >= chapter.start {
+                    return index
+                }
+            }
+        }
+
+        return nil
+    }
 }

Shared/Player/Video Details/ChapterView.swift

@@ -6,13 +6,12 @@ import SwiftUI
 #if !os(tvOS)
     struct ChapterView: View {
         var chapter: Chapter
-        var nextChapterStart: Double?
 
         var chapterIndex: Int
         @ObservedObject private var player = PlayerModel.shared
 
         var isCurrentChapter: Bool {
-            player.currentChapter == chapterIndex
+            player.currentChapterIndex == chapterIndex
         }
 
         var body: some View {
@@ -31,7 +30,7 @@ import SwiftUI
                     .receive(on: DispatchQueue.main)
             ) { notification in
                 if let cmTime = notification.object as? CMTime {
-                    self.handleTimeUpdate(cmTime)
+                    player.updateTime(cmTime)
                 }
             }
         }
@@ -74,13 +73,6 @@ import SwiftUI
         static var thumbnailHeight: Double {
             thumbnailWidth / 1.7777
         }
-
-        private func handleTimeUpdate(_ cmTime: CMTime) {
-            let time = CMTimeGetSeconds(cmTime)
-            if time >= chapter.start, nextChapterStart == nil || time < nextChapterStart! {
-                player.currentChapter = chapterIndex
-            }
-        }
     }
 
 #else
@@ -144,7 +136,7 @@ struct ChapterView_Preview: PreviewProvider {
             ChapterViewTVOS(chapter: .init(title: "Chapter", start: 30))
                 .injectFixtureEnvironmentObjects()
         #else
-            ChapterView(chapter: .init(title: "Chapter", start: 30), nextChapterStart: nil, chapterIndex: 0)
+            ChapterView(chapter: .init(title: "Chapter", start: 30), chapterIndex: 0)
                 .injectFixtureEnvironmentObjects()
         #endif
     }

Shared/Player/Video Details/ChaptersView.swift

@@ -70,8 +70,7 @@ struct ChaptersView: View {
         private func chapterViews(for chaptersToShow: ArraySlice<Chapter>, opacity: Double = 1.0, clickable: Bool = true) -> some View {
             ForEach(Array(chaptersToShow.indices), id: \.self) { index in
                 let chapter = chaptersToShow[index]
-                let nextChapterStart: Double? = index < chaptersToShow.count - 1 ? chaptersToShow[index + 1].start : nil
-                ChapterView(chapter: chapter, nextChapterStart: nextChapterStart, chapterIndex: index)
+                ChapterView(chapter: chapter, chapterIndex: index)
                     .opacity(index == 0 ? 1.0 : opacity)
                     .allowsHitTesting(clickable)
             }