Snappy UI - Offloading non UI task to background threads

This gives a huge increase in perceived performance. The UI is now much more responsive since some tasks are run in the background and don't block the UI anymore.

Model/Player/Backends/MPVBackend.swift

@@ -10,7 +10,7 @@ import SwiftUI
 
 final class MPVBackend: PlayerBackend {
     static var timeUpdateInterval = 0.5
-    static var networkStateUpdateInterval = 1.0
+    static var networkStateUpdateInterval = 0.1
 
     private var logger = Logger(label: "mpv-backend")
 

Shared/Home/FavoriteItemView.swift

@@ -89,6 +89,9 @@ struct FavoriteItemView: View {
                         loadCacheAndResource()
                     }
                 }
+                .onDisappear {
+                    resource?.removeObservers(ownedBy: store)
+                }
                 .onChange(of: player.currentVideo) { _ in reloadVisibleWatches() }
                 .onChange(of: hideShorts) { _ in reloadVisibleWatches() }
                 .onChange(of: hideWatched) { _ in reloadVisibleWatches() }
@@ -96,15 +99,14 @@ struct FavoriteItemView: View {
         }
         .id(watchModel.historyToken)
         .onChange(of: accounts.current) { _ in
+            resource?.removeObservers(ownedBy: store)
             resource?.addObserver(store)
             loadCacheAndResource(force: true)
         }
         .onChange(of: watchModel.historyToken) { _ in
-            Delay.by(0.5) {
             reloadVisibleWatches()
         }
     }
-    }
 
     var emptyItemsText: String {
         var filterText = ""
@@ -164,15 +166,18 @@ struct FavoriteItemView: View {
                 .prefix(favoritesModel.limit(item))
         )
         let last = watches.last
+
         for watch in watches {
             player.loadHistoryVideoDetails(watch) {
                 guard let video = player.historyVideo(watch.videoID), itemVisible(.init(video: video)) else { return }
                 visibleWatches.append(watch)
-                guard watch == last else { return }
+
+                if watch == last {
                     visibleWatches.sort { $0.watchedAt ?? Date() > $1.watchedAt ?? Date() }
                 }
             }
         }
+    }
 
     var limitedItems: [ContentItem] {
         var items: [ContentItem]

Shared/Home/FavoriteResourceObserver.swift

@@ -5,18 +5,52 @@ final class FavoriteResourceObserver: ObservableObject, ResourceObserver {
     @Published var contentItems = [ContentItem]()
 
     func resourceChanged(_ resource: Resource, event _: ResourceEvent) {
+        // swiftlint:disable discouraged_optional_collection
+        var newVideos: [Video]?
+        var newItems: [ContentItem]?
+        // swiftlint:enable discouraged_optional_collection
+
+        var newChannel: Channel?
+        var newChannelPlaylist: ChannelPlaylist?
+        var newPlaylist: Playlist?
+        var newPage: SearchPage?
+
         if let videos: [Video] = resource.typedContent() {
-            contentItems = videos.map { ContentItem(video: $0) }
+            newVideos = videos
         } else if let channel: Channel = resource.typedContent() {
-            contentItems = channel.videos.map { ContentItem(video: $0) }
+            newChannel = channel
         } else if let playlist: ChannelPlaylist = resource.typedContent() {
-            contentItems = playlist.videos.map { ContentItem(video: $0) }
+            newChannelPlaylist = playlist
         } else if let playlist: Playlist = resource.typedContent() {
-            contentItems = playlist.videos.map { ContentItem(video: $0) }
+            newPlaylist = playlist
         } else if let page: SearchPage = resource.typedContent() {
-            contentItems = page.results
+            newPage = page
         } else if let items: [ContentItem] = resource.typedContent() {
-            contentItems = items
+            newItems = items
+        }
+
+        DispatchQueue.global(qos: .userInitiated).async {
+            var newContentItems: [ContentItem] = []
+
+            if let videos = newVideos {
+                newContentItems = videos.map { ContentItem(video: $0) }
+            } else if let channel = newChannel {
+                newContentItems = channel.videos.map { ContentItem(video: $0) }
+            } else if let playlist = newChannelPlaylist {
+                newContentItems = playlist.videos.map { ContentItem(video: $0) }
+            } else if let playlist = newPlaylist {
+                newContentItems = playlist.videos.map { ContentItem(video: $0) }
+            } else if let page = newPage {
+                newContentItems = page.results
+            } else if let items = newItems {
+                newContentItems = items
+            }
+
+            DispatchQueue.main.async {
+                if !newContentItems.isEmpty {
+                    self.contentItems = newContentItems
+                }
+            }
         }
     }
 }

Shared/YatteeApp.swift

@@ -150,6 +150,7 @@ struct YatteeApp: App {
         }
         configured = true
 
+        DispatchQueue.main.async {
             #if DEBUG
                 SiestaLog.Category.enabled = .common
             #endif
@@ -168,9 +169,11 @@ struct YatteeApp: App {
                 player.restoreQueue()
             }
 
+            DispatchQueue.global(qos: .userInitiated).async {
                 if !Defaults[.saveRecents] {
                     recents.clear()
                 }
+            }
 
             let startupSection = Defaults[.startupSection]
             var section: TabSelection? = startupSection.tabSelection
@@ -183,7 +186,9 @@ struct YatteeApp: App {
 
             NavigationModel.shared.tabSelection = section ?? .search
 
+            DispatchQueue.global(qos: .userInitiated).async {
                 playlists.load()
+            }
 
             #if !os(macOS)
                 player.updateRemoteCommandCenter()
@@ -196,15 +201,23 @@ struct YatteeApp: App {
             #if os(iOS)
                 DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
                     if Defaults[.lockPortraitWhenBrowsing] {
-                    Orientation.lockOrientation(.portrait, andRotateTo: .portrait)
+                        Orientation.lockOrientation(.all, andRotateTo: .portrait)
                     }
                 }
             #endif
 
+            DispatchQueue.global(qos: .userInitiated).async {
                 URLBookmarkModel.shared.refreshAll()
+            }
 
-        migrateHomeHistoryItems()
+            DispatchQueue.global(qos: .userInitiated).async {
-        migrateQualityProfiles()
+                self.migrateHomeHistoryItems()
+            }
+
+            DispatchQueue.global(qos: .userInitiated).async {
+                self.migrateQualityProfiles()
+            }
+        }
     }
 
     func migrateHomeHistoryItems() {