[Peek]Clear thumbnails (#26440)

src/modules/peek/Peek.FilePreviewer/Previewers/MediaPreviewer/ImagePreviewer.cs

@@ -11,6 +11,7 @@ using CommunityToolkit.Mvvm.ComponentModel;
 using Microsoft.UI.Dispatching;
 using Microsoft.UI.Xaml.Media;
 using Microsoft.UI.Xaml.Media.Imaging;
+using Peek.Common;
 using Peek.Common.Extensions;
 using Peek.Common.Helpers;
 using Peek.Common.Models;
@@ -59,6 +60,10 @@ namespace Peek.FilePreviewer.Previewers
 
         private bool IsFullImageLoaded => FullQualityImageTask?.Status == TaskStatus.RanToCompletion;
 
+        private IntPtr lowQualityThumbnail;
+
+        private IntPtr highQualityThumbnail;
+
         public static bool IsFileTypeSupported(string fileExt)
         {
             return _supportedFileTypes.Contains(fileExt);
@@ -66,6 +71,7 @@ namespace Peek.FilePreviewer.Previewers
 
         public void Dispose()
         {
+            Clear();
             GC.SuppressFinalize(this);
         }
 
@@ -94,6 +100,7 @@ namespace Peek.FilePreviewer.Previewers
 
         public async Task LoadPreviewAsync(CancellationToken cancellationToken)
         {
+            Clear();
             State = PreviewState.Loading;
 
             LowQualityThumbnailTask = LoadLowQualityThumbnailAsync(cancellationToken);
@@ -157,11 +164,11 @@ namespace Peek.FilePreviewer.Previewers
             {
                 cancellationToken.ThrowIfCancellationRequested();
 
-                var hr = ThumbnailHelper.GetThumbnail(Item.Path, out IntPtr hbitmap, ThumbnailHelper.LowQualityThumbnailSize);
+                var hr = ThumbnailHelper.GetThumbnail(Item.Path, out lowQualityThumbnail, ThumbnailHelper.LowQualityThumbnailSize);
                 if (hr != HResult.Ok)
                 {
                     Logger.LogError("Error loading low quality thumbnail - hresult: " + hr);
-                    throw new ImageLoadingException(nameof(hbitmap));
+                    throw new ImageLoadingException(nameof(lowQualityThumbnail));
                 }
 
                 cancellationToken.ThrowIfCancellationRequested();
@@ -169,9 +176,9 @@ namespace Peek.FilePreviewer.Previewers
                 await Dispatcher.RunOnUiThread(async () =>
                 {
                     cancellationToken.ThrowIfCancellationRequested();
-                    var thumbnailBitmap = await BitmapHelper.GetBitmapFromHBitmapAsync(hbitmap, IsPng(Item), cancellationToken);
                     if (!IsFullImageLoaded && !IsHighQualityThumbnailLoaded)
                     {
+                        var thumbnailBitmap = await BitmapHelper.GetBitmapFromHBitmapAsync(lowQualityThumbnail, IsPng(Item), cancellationToken);
                         Preview = thumbnailBitmap;
                     }
                 });
@@ -184,11 +191,11 @@ namespace Peek.FilePreviewer.Previewers
             {
                 cancellationToken.ThrowIfCancellationRequested();
 
-                var hr = ThumbnailHelper.GetThumbnail(Item.Path, out IntPtr hbitmap, ThumbnailHelper.HighQualityThumbnailSize);
+                var hr = ThumbnailHelper.GetThumbnail(Item.Path, out highQualityThumbnail, ThumbnailHelper.HighQualityThumbnailSize);
                 if (hr != HResult.Ok)
                 {
                     Logger.LogError("Error loading high quality thumbnail - hresult: " + hr);
-                    throw new ImageLoadingException(nameof(hbitmap));
+                    throw new ImageLoadingException(nameof(highQualityThumbnail));
                 }
 
                 cancellationToken.ThrowIfCancellationRequested();
@@ -196,9 +203,9 @@ namespace Peek.FilePreviewer.Previewers
                 await Dispatcher.RunOnUiThread(async () =>
                 {
                     cancellationToken.ThrowIfCancellationRequested();
-                    var thumbnailBitmap = await BitmapHelper.GetBitmapFromHBitmapAsync(hbitmap, IsPng(Item), cancellationToken);
                     if (!IsFullImageLoaded)
                     {
+                        var thumbnailBitmap = await BitmapHelper.GetBitmapFromHBitmapAsync(highQualityThumbnail, IsPng(Item), cancellationToken);
                         Preview = thumbnailBitmap;
                     }
                 });
@@ -211,12 +218,12 @@ namespace Peek.FilePreviewer.Previewers
             {
                 cancellationToken.ThrowIfCancellationRequested();
 
-                using FileStream stream = ReadHelper.OpenReadOnly(Item.Path);
-
                 await Dispatcher.RunOnUiThread(async () =>
                 {
                     cancellationToken.ThrowIfCancellationRequested();
 
+                    using FileStream stream = ReadHelper.OpenReadOnly(Item.Path);
+
                     if (IsSvg(Item))
                     {
                         var source = new SvgImageSource();
@@ -261,6 +268,21 @@ namespace Peek.FilePreviewer.Previewers
             return item.Extension == ".svg";
         }
 
+        private void Clear()
+        {
+            Preview = null;
+
+            if (lowQualityThumbnail != IntPtr.Zero)
+            {
+                NativeMethods.DeleteObject(lowQualityThumbnail);
+            }
+
+            if (highQualityThumbnail != IntPtr.Zero)
+            {
+                NativeMethods.DeleteObject(highQualityThumbnail);
+            }
+        }
+
         private static readonly HashSet<string> _supportedFileTypes = new HashSet<string>
         {
                 // Image types