Code Quality: Remove thumbnail cache to simplify logic and improve performance

src/Files.App/Data/Models/ItemViewModel.cs

@@ -937,117 +937,142 @@ private async Task<BitmapImage> GetShieldIcon()
 			return shieldIcon;
 		}
 
-		private async Task LoadItemThumbnailAsync(ListedItem item)
+		/// <summary>
+		/// Loads basic icon using ReturnIconOnly flag
+		/// </summary>
+		/// <param name="item"></param>
+		/// <returns></returns>
+		private async Task LoadBasicIconAsync(ListedItem item)
 		{
-			var thumbnailSize = folderSettings.GetRoundedIconSize();
-
-			if (item.IsLibrary || item.PrimaryItemAttribute == StorageItemTypes.File || item.IsArchive)
-			{
-				var getIconOnly = UserSettingsService.FoldersSettingsService.ShowThumbnails == false || thumbnailSize < 48;
-				var getThumbnailOnly = !item.IsExecutable && !getIconOnly;
-				var iconInfo = await FileThumbnailHelper.GetIconAsync(
+			// Get icon
+			var icon = await FileThumbnailHelper.GetIconAsync(
 					item.ItemPath,
-					thumbnailSize,
+					folderSettings.GetRoundedIconSize(),
+					item.IsFolder,
 					false,
-					getThumbnailOnly,
-					getIconOnly ? IconOptions.ReturnIconOnly : IconOptions.None);
+					IconOptions.ReturnIconOnly);
 
-				if (!iconInfo.isIconCached)
-				{
-					// Assign a placeholder icon while trying to get a cached thumbnail
-					if (iconInfo.IconData is not null)
-					{
-						await dispatcherQueue.EnqueueOrInvokeAsync(async () =>
-						{
-							item.FileImage = await iconInfo.IconData.ToBitmapAsync();
-						}, Microsoft.UI.Dispatching.DispatcherQueuePriority.Low);
-					}
-
-					// Loop until cached thumbnail is loaded or timeout is reached
-					var cancellationTokenSource = new CancellationTokenSource(3000);
-					while (!iconInfo.isIconCached)
-					{
-						iconInfo = await FileThumbnailHelper.GetIconAsync(
-							item.ItemPath,
-							thumbnailSize,
-							false,
-							getThumbnailOnly,
-							getIconOnly ? IconOptions.ReturnIconOnly : IconOptions.None);
-
-						if (cancellationTokenSource.Token.IsCancellationRequested)
-							break;
-
-						await Task.Delay(500);
-					}
-				}
-
-				if (iconInfo.IconData is not null)
+			if (icon.IconData is not null)
+			{
+				await dispatcherQueue.EnqueueOrInvokeAsync(async () =>
 				{
-					await dispatcherQueue.EnqueueOrInvokeAsync(async () =>
+					var image = await icon.IconData.ToBitmapAsync();
+					if (image is not null)
 					{
-						// Assign the thumbnail/icon to the listed item
-						item.FileImage = await iconInfo.IconData.ToBitmapAsync();
+						// Assign FileImage property
+						item.FileImage = image;
 
-						// Add the file icon to the DefaultIcons list
+						// Add file icon to the DefaultIcons list
 						if
 						(
+							!item.IsFolder &&
 							!DefaultIcons.ContainsKey(item.FileExtension.ToLowerInvariant()) &&
 							!string.IsNullOrEmpty(item.FileExtension) &&
 							!item.IsShortcut &&
 							!item.IsExecutable
 						)
 						{
-							var fileIcon = await FileThumbnailHelper.GetIconAsync(
-								item.ItemPath,
-								thumbnailSize,
-								false,
-								false,
-								IconOptions.ReturnIconOnly);
-
-							var bitmapImage = await fileIcon.IconData.ToBitmapAsync();
-							DefaultIcons.TryAdd(item.FileExtension.ToLowerInvariant(), bitmapImage);
+							DefaultIcons.TryAdd(item.FileExtension.ToLowerInvariant(), image);
 						}
+					}
+				}, Microsoft.UI.Dispatching.DispatcherQueuePriority.Low);
+			}
 
-					}, Microsoft.UI.Dispatching.DispatcherQueuePriority.Low);
-				}
+			// Get icon overlay
+			var iconOverlay = await FileThumbnailHelper.GetIconOverlayAsync(item.ItemPath, true);
+			if (iconOverlay is not null)
+			{
+				await dispatcherQueue.EnqueueOrInvokeAsync(async () =>
+				{
+					item.IconOverlay = await iconOverlay.ToBitmapAsync();
+					item.ShieldIcon = await GetShieldIcon();
+				}, Microsoft.UI.Dispatching.DispatcherQueuePriority.Low);
+			}
+		}
+
+		/// <summary>
+		/// Loads thumbnail without any flags
+		/// Returns early if thumbnails aren't needed for this item (eg. if thumbnails are disabled or size is too small)
+		/// </summary>
+		/// <param name="item"></param>
+		/// <returns></returns>
+		private async Task LoadThumbnailAsync(ListedItem item)
+		{
+			// Cancel if thumbnails aren't enabled
+			var thumbnailSize = folderSettings.GetRoundedIconSize();
+			if (UserSettingsService.FoldersSettingsService.ShowThumbnails == false || thumbnailSize < 48)
+				return;
+
+			// Get thumbnail
+			var icon = await FileThumbnailHelper.GetIconAsync(
+					item.ItemPath,
+					thumbnailSize,
+					item.IsFolder,
+					false,
+					IconOptions.None);
 
-				var iconOverlay = await FileThumbnailHelper.GetIconOverlayAsync(item.ItemPath, false);
-				if (iconOverlay is not null)
+			if (icon.IconData is not null)
+			{
+				await dispatcherQueue.EnqueueOrInvokeAsync(async () =>
 				{
-					// Assign the icon overlay to the listed item
-					await dispatcherQueue.EnqueueOrInvokeAsync(async () =>
-					{
-						item.IconOverlay = await iconOverlay.ToBitmapAsync();
-						item.ShieldIcon = await GetShieldIcon();
-					}, Microsoft.UI.Dispatching.DispatcherQueuePriority.Low);
-				}
+					// Assign FileImage property
+					var image = await icon.IconData.ToBitmapAsync();
+					if (image is not null)
+						item.FileImage = image;
+				}, Microsoft.UI.Dispatching.DispatcherQueuePriority.Low);
 			}
-			else
+		}
+
+		/// <summary>
+		/// Tries getting a cached thumbnail from the system. This is usually only needed for cloud locations, otherwise LoadThumbnailAsync does the job.
+		/// </summary>
+		/// <param name="item"></param>
+		/// <returns></returns>
+		private async Task LoadCachedThumbnailAsync(ListedItem item)
+		{
+			// Cancel for exe files which don't need thumbnails
+			if (item.IsExecutable)
+				return;
+
+			// Cancel if thumbnails aren't enabled
+			var thumbnailSize = folderSettings.GetRoundedIconSize();
+			if (UserSettingsService.FoldersSettingsService.ShowThumbnails == false || thumbnailSize < 48)
+				return;
+
+			// Get icon
+			var icon = await FileThumbnailHelper.GetIconAsync(
+					item.ItemPath,
+					thumbnailSize,
+					item.IsFolder,
+					true,
+					IconOptions.None);
+
+			// Loop until cached thumbnail is loaded or timeout is reached
+			var cancellationTokenSource = new CancellationTokenSource(3000);
+			while (true)
 			{
-				var getIconOnly = UserSettingsService.FoldersSettingsService.ShowThumbnails == false || thumbnailSize < 48;
-				var iconInfo = await FileThumbnailHelper.GetIconAsync(
+				icon = await FileThumbnailHelper.GetIconAsync(
 					item.ItemPath,
 					thumbnailSize,
+					item.IsFolder,
 					true,
-					false, getIconOnly ? IconOptions.ReturnIconOnly : IconOptions.None);
+					IconOptions.None);
 
-				if (iconInfo.IconData is not null)
-				{
-					await dispatcherQueue.EnqueueOrInvokeAsync(async () =>
-					{
-						item.FileImage = await iconInfo.IconData.ToBitmapAsync();
-					}, Microsoft.UI.Dispatching.DispatcherQueuePriority.Low);
-				}
+				if (icon.isIconCached || cancellationTokenSource.Token.IsCancellationRequested)
+					break;
+
+				await Task.Delay(500);
+			}
 
-				var iconOverlay = await FileThumbnailHelper.GetIconOverlayAsync(item.ItemPath, true);
-				if (iconOverlay is not null)
+			// Update FileImage property if icon is cached
+			if (icon.isIconCached)
+			{
+				await dispatcherQueue.EnqueueOrInvokeAsync(async () =>
 				{
-					await dispatcherQueue.EnqueueOrInvokeAsync(async () =>
-					{
-						item.IconOverlay = await iconOverlay.ToBitmapAsync();
-						item.ShieldIcon = await GetShieldIcon();
-					}, Microsoft.UI.Dispatching.DispatcherQueuePriority.Low);
-				}
+					var image = await icon.IconData.ToBitmapAsync();
+					if (image is not null)
+						item.FileImage = image;
+				}, Microsoft.UI.Dispatching.DispatcherQueuePriority.Low);
 			}
 		}
 
@@ -1092,7 +1117,7 @@ await Task.Run(async () =>
 						}
 
 						cts.Token.ThrowIfCancellationRequested();
-						_ = LoadItemThumbnailAsync(item);
+						await LoadBasicIconAsync(item);
 
 						if (item.IsLibrary || item.PrimaryItemAttribute == StorageItemTypes.File || item.IsArchive)
 						{
@@ -1198,6 +1223,14 @@ await dispatcherQueue.EnqueueOrInvokeAsync(() =>
 								SetFileTag(item);
 							});
 						}
+						else
+						{
+							// Load cached thumbnail for cloud files
+							if (item.SyncStatusUI.SyncStatus != CloudDriveSyncStatus.NotSynced && item.SyncStatusUI.SyncStatus != CloudDriveSyncStatus.Unknown)
+								_ = LoadCachedThumbnailAsync(item);
+							else
+								_ = LoadThumbnailAsync(item);
+						}
 
 						if (loadGroupHeaderInfo)
 						{