Fix showing loading, when it doesn't have to

Ruben2776 · Jan 31, 2025 · c335561 · c335561
1 parent 92fbb40
commit c335561
Show file tree

Hide file tree

Showing 2 changed files with 41 additions and 20 deletions.
diff --git a/src/PicView.Avalonia/Navigation/ImageIterator.cs b/src/PicView.Avalonia/Navigation/ImageIterator.cs
@@ -492,14 +492,20 @@ public async Task NextIteration(NavigateTo navigateTo, CancellationTokenSource c
         }
     }
 
+    /// <summary>
+    ///     Iterates to the given index in the image list, shows the corresponding image and preloads the next/previous images.
+    /// </summary>
+    /// <param name="index">The index to iterate to.</param>
+    /// <param name="cts">The cancellation token source.</param>
+    /// <returns>A <see cref="Task" /> that represents the asynchronous operation.</returns>
     public async Task IterateToIndex(int index, CancellationTokenSource cts)
     {
         if (index < 0 || index >= ImagePaths.Count)
         {
             ErrorHandling.ShowStartUpMenu(_vm);
             return;
         }
-        
+
         try
         {
             CurrentIndex = index;
@@ -508,20 +514,21 @@ public async Task IterateToIndex(int index, CancellationTokenSource cts)
             var preloadValue = PreLoader.Get(index, ImagePaths);
             if (preloadValue is not null)
             {
-                if (preloadValue.IsLoading)
+                // Wait for image to load
+                if (preloadValue is { IsLoading: true, ImageModel.Image: not null })
                 {
                     TryShowPreview();
-                }
 
-                while (preloadValue.IsLoading)
-                {
-                    await Task.Delay(20, cts.Token).ConfigureAwait(false);
-                    if (CurrentIndex != index)
+                    do
                     {
-                        // Skip loading if user went to next value
-                        await cts.CancelAsync();
-                        return;
-                    }
+                        await Task.Delay(20, cts.Token).ConfigureAwait(false);
+                        if (CurrentIndex != index)
+                        {
+                            // Skip loading if user went to next value
+                            await cts.CancelAsync();
+                            return;
+                        }
+                    } while (preloadValue.IsLoading);
                 }
             }
             else
@@ -555,7 +562,8 @@ public async Task IterateToIndex(int index, CancellationTokenSource cts)
 
                 if (!cts.IsCancellationRequested)
                 {
-                    await UpdateImage.UpdateSource(_vm, index, ImagePaths, IsReversed, preloadValue, nextPreloadValue)
+                    await UpdateImage.UpdateSource(_vm, index, ImagePaths, IsReversed, preloadValue,
+                            nextPreloadValue)
                         .ConfigureAwait(false);
                 }
             }
@@ -594,7 +602,7 @@ await PreLoader.PreLoadAsync(CurrentIndex, IsReversed, ImagePaths)
         {
             // Ignore
 #if DEBUG
-            Trace.WriteLine($"{nameof(IterateToIndex)} canceled");
+            Trace.WriteLine($"\n{nameof(IterateToIndex)} canceled\n");
 #endif
         }
         catch (Exception e)
@@ -622,6 +630,7 @@ void TryShowPreview()
 
     private static Timer? _timer;
 
+
     private async Task TimerIteration(int index, CancellationTokenSource cts)
     {
         if (_timer is null)
@@ -687,4 +696,4 @@ private void Dispose(bool disposing)
     }
 
     #endregion
-}
+}
diff --git a/src/PicView.Avalonia/Navigation/NavigationHelper.cs b/src/PicView.Avalonia/Navigation/NavigationHelper.cs
@@ -610,32 +610,44 @@ public static async Task LoadPicFromDirectoryAsync(string file, MainViewModel vm
 
     #region Private helpers
 
+    /// <summary>
+    /// Checks if the previous iteration has been cancelled and starts the next iteration in a new task.
+    /// </summary>
+    /// <param name="navigateTo">The direction to navigate.</param>
+    /// <param name="vm">The main view model instance.</param>
+    /// <returns>A task representing the asynchronous operation.</returns>
     private static async Task CheckCancellationAndStartNextIteration(NavigateTo navigateTo, MainViewModel vm)
     {
-        await Task.Run(async () =>
+        await Task.Run(() =>
         {
             if (_cancellationTokenSource is not null)
             {
-                await _cancellationTokenSource.CancelAsync().ConfigureAwait(false);
+                _ = _cancellationTokenSource.CancelAsync().ConfigureAwait(false);
             }
 
             _cancellationTokenSource = new CancellationTokenSource();
-            await vm.ImageIterator.NextIteration(navigateTo, _cancellationTokenSource).ConfigureAwait(false);
+            _ = vm.ImageIterator.NextIteration(navigateTo, _cancellationTokenSource).ConfigureAwait(false);
             _cancellationTokenSource.CancelAfter(TimeSpan.FromMinutes(5));
         }).ConfigureAwait(false);
     }
 
+    /// <summary>
+    /// Checks if the previous iteration has been cancelled and starts the iteration at the given index in a new task.
+    /// </summary>
+    /// <param name="index">The index to iterate to.</param>
+    /// <param name="vm">The main view model instance.</param>
+    /// <returns>A task representing the asynchronous operation.</returns>
     private static async Task CheckCancellationAndStartIterateToIndex(int index, MainViewModel vm)
     {
-        await Task.Run(async () =>
+        await Task.Run(() =>
         {
             if (_cancellationTokenSource is not null)
             {
-                await _cancellationTokenSource.CancelAsync().ConfigureAwait(false);
+                _ = _cancellationTokenSource.CancelAsync().ConfigureAwait(false);
             }
 
             _cancellationTokenSource = new CancellationTokenSource();
-            await vm.ImageIterator.IterateToIndex(index, _cancellationTokenSource).ConfigureAwait(false);
+            _ = vm.ImageIterator.IterateToIndex(index, _cancellationTokenSource).ConfigureAwait(false);
             _cancellationTokenSource.CancelAfter(TimeSpan.FromMinutes(5));
         }).ConfigureAwait(false);
     }