(#86) Load albumart from cache faster in library view

Sources/Stylophone.Common/Services/AlbumArtService.cs

@@ -91,6 +91,7 @@ public void Stop()
         /// <param name="f">MpdFile to check for art</param>
         /// <returns>True if the art is cached, false otherwise.</returns>
         public async Task<bool> IsAlbumArtCachedAsync(IMpdFile f) => await _applicationStorageService.DoesFileExistAsync(Miscellaneous.GetFileIdentifier(f), "AlbumArt");
+        public async Task<bool> IsAlbumArtCachedAsync(string albumName) => await _applicationStorageService.DoesFileExistAsync(albumName, "AlbumArt");
 
         /// <summary>
         /// Queue up an AlbumViewModel for the service to grab its album art.
@@ -224,7 +225,7 @@ private QuantizedColor GetDominantColor(SKBitmap art)
 
         private async Task SaveArtToFileAsync(string fileName, List<byte> data) => await _applicationStorageService.SaveDataToFileAsync(fileName, data.ToArray(), "AlbumArt");
 
-        private async Task<SKBitmap> LoadImageFromFile(string fileName)
+        internal async Task<SKBitmap> LoadImageFromFile(string fileName)
         {
             try
             {

Sources/Stylophone.Common/ViewModels/Items/AlbumViewModel.cs

@@ -9,12 +9,14 @@
 using MpcNET.Tags;
 using MpcNET.Types;
 using SkiaSharp;
+using Stylophone.Common.Helpers;
 using Stylophone.Common.Interfaces;
 using Stylophone.Common.Services;
 using Stylophone.Localization.Strings;
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Runtime.InteropServices.ComTypes;
 using System.Threading.Tasks;
 using System.Windows.Input;
 
@@ -180,6 +182,16 @@ private async Task PlayAlbum()
             }
         }
 
+        public async Task LoadAlbumArtFromCacheAsync()
+        {
+            // Try to show album art early if we have it in cache
+            var cacheName = Miscellaneous.EscapeFilename(Name);
+            if (await _albumArtService.IsAlbumArtCachedAsync(cacheName))
+            {
+                AlbumArt = SKImage.FromBitmap(await _albumArtService.LoadImageFromFile(cacheName));
+            }
+        }
+
         /// <summary>
         /// Load Album Data. You can either provide a MpcConnection object (for batch loading)
         /// or leave as empty to automatically pick up a connection from the datasource.
@@ -196,7 +208,8 @@ public async Task LoadAlbumDataAsync()
         public async Task LoadAlbumDataAsync(MpcConnection c)
         {
             IsDetailLoading = true;
-            AlbumArt = await _interop.GetPlaceholderImageAsync();
+            AlbumArt ??= await _interop.GetPlaceholderImageAsync();
+
             try
             {
                 var findReq = await c.SendAsync(new FindCommand(MpdTags.Album, Name));

Sources/Stylophone.iOS/ViewModels/LibraryViewModel.cs

@@ -73,6 +73,13 @@ internal void LoadItems(IEnumerable<int> indexes, CancellationToken token = defa
             // Albumart loads still use their own connections.
             Task.Run(async () =>
             {
+                // Try to show album artwork early if we have it in cache
+                foreach (var i in indexes)
+                {
+                    var album = BackingCollection[i];
+                    await album.LoadAlbumArtFromCacheAsync();
+                }
+
                 using (var c = await _mpdService.GetConnectionAsync(token))
                     foreach (var i in indexes)
                     {

Sources/Stylophone/ViewModels/LibraryViewModel.cs

@@ -59,6 +59,13 @@ public void RangesChanged(ItemIndexRange visibleRange, IReadOnlyList<ItemIndexRa
                 // Albumart loads still use their own connections.
                 Task.Run(async () =>
                 {
+                    // Try to show album artwork early if we have it in cache
+                    for (var i = visibleRange.FirstIndex; i < visibleRange.LastIndex + 1; i++) // Increment LastIndex by one to properly cover the visible range
+                    {
+                        var album = this[i];
+                        await album.LoadAlbumArtFromCacheAsync();
+                    }
+
                     using (var c = await _mpdService.GetConnectionAsync(token))
                         for (var i = visibleRange.FirstIndex; i < visibleRange.LastIndex + 1; i++) // Increment LastIndex by one to properly cover the visible range
                         {