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() }
@@ -96,13 +99,12 @@ 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()
-            }
+            reloadVisibleWatches()
         }
     }
 
@@ -164,12 +166,15 @@ 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 }
-                visibleWatches.sort { $0.watchedAt ?? Date() > $1.watchedAt ?? Date() }
+
+                if watch == last {
+                    visibleWatches.sort { $0.watchedAt ?? Date() > $1.watchedAt ?? Date() }
+                }
             }
         }
     }

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

@@ -150,61 +150,74 @@ struct YatteeApp: App {
         }
         configured = true
 
-        #if DEBUG
-            SiestaLog.Category.enabled = .common
-        #endif
-        SDImageCodersManager.shared.addCoder(SDImageAWebPCoder.shared)
-        SDWebImageManager.defaultImageCache = PINCache(name: "stream.yattee.app")
+        DispatchQueue.main.async {
+            #if DEBUG
+                SiestaLog.Category.enabled = .common
+            #endif
+            SDImageCodersManager.shared.addCoder(SDImageAWebPCoder.shared)
+            SDWebImageManager.defaultImageCache = PINCache(name: "stream.yattee.app")
 
-        if !Defaults[.lastAccountIsPublic] {
-            AccountsModel.shared.configureAccount()
-        }
-
-        if let countryOfPublicInstances = Defaults[.countryOfPublicInstances] {
-            InstancesManifest.shared.setPublicAccount(countryOfPublicInstances, asCurrent: AccountsModel.shared.current.isNil)
-        }
-
-        if !AccountsModel.shared.current.isNil {
-            player.restoreQueue()
-        }
-
-        if !Defaults[.saveRecents] {
-            recents.clear()
-        }
-
-        let startupSection = Defaults[.startupSection]
-        var section: TabSelection? = startupSection.tabSelection
-
-        #if os(macOS)
-            if section == .playlists {
-                section = .search
+            if !Defaults[.lastAccountIsPublic] {
+                AccountsModel.shared.configureAccount()
             }
-        #endif
 
-        NavigationModel.shared.tabSelection = section ?? .search
+            if let countryOfPublicInstances = Defaults[.countryOfPublicInstances] {
+                InstancesManifest.shared.setPublicAccount(countryOfPublicInstances, asCurrent: AccountsModel.shared.current.isNil)
+            }
 
-        playlists.load()
+            if !AccountsModel.shared.current.isNil {
+                player.restoreQueue()
+            }
 
-        #if !os(macOS)
-            player.updateRemoteCommandCenter()
-        #endif
-
-        if player.presentingPlayer {
-            player.presentingPlayer = false
-        }
-
-        #if os(iOS)
-            DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
-                if Defaults[.lockPortraitWhenBrowsing] {
-                    Orientation.lockOrientation(.portrait, andRotateTo: .portrait)
+            DispatchQueue.global(qos: .userInitiated).async {
+                if !Defaults[.saveRecents] {
+                    recents.clear()
                 }
             }
-        #endif
 
-        URLBookmarkModel.shared.refreshAll()
+            let startupSection = Defaults[.startupSection]
+            var section: TabSelection? = startupSection.tabSelection
 
-        migrateHomeHistoryItems()
-        migrateQualityProfiles()
+            #if os(macOS)
+                if section == .playlists {
+                    section = .search
+                }
+            #endif
+
+            NavigationModel.shared.tabSelection = section ?? .search
+
+            DispatchQueue.global(qos: .userInitiated).async {
+                playlists.load()
+            }
+
+            #if !os(macOS)
+                player.updateRemoteCommandCenter()
+            #endif
+
+            if player.presentingPlayer {
+                player.presentingPlayer = false
+            }
+
+            #if os(iOS)
+                DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
+                    if Defaults[.lockPortraitWhenBrowsing] {
+                        Orientation.lockOrientation(.all, andRotateTo: .portrait)
+                    }
+                }
+            #endif
+
+            DispatchQueue.global(qos: .userInitiated).async {
+                URLBookmarkModel.shared.refreshAll()
+            }
+
+            DispatchQueue.global(qos: .userInitiated).async {
+                self.migrateHomeHistoryItems()
+            }
+
+            DispatchQueue.global(qos: .userInitiated).async {
+                self.migrateQualityProfiles()
+            }
+        }
     }
 
     func migrateHomeHistoryItems() {