Stop loading icons when the conflict dialog is closed (#8042)

Author: gave92

src/Files/Dialogs/FilesystemOperationDialog.xaml

@@ -11,6 +11,7 @@
     xmlns:vc="using:Files.Converters"
     x:Name="RootDialog"
     Title="{x:Bind ViewModel.Title, Mode=OneWay}"
+    Closing="RootDialog_Closing"
     CornerRadius="{StaticResource OverlayCornerRadius}"
     DefaultButton="Primary"
     IsPrimaryButtonEnabled="{x:Bind ViewModel.PrimaryButtonEnabled, Mode=OneWay}"

src/Files/Dialogs/FilesystemOperationDialog.xaml.cs

@@ -107,6 +107,11 @@ private void Grid_Loaded(object sender, Windows.UI.Xaml.RoutedEventArgs e)
                 (sender as Grid).FindAscendant<ListViewItem>().ContextFlyout = ItemContextFlyout;
             }
         }
+
+        private void RootDialog_Closing(ContentDialog sender, ContentDialogClosingEventArgs args)
+        {
+            ViewModel.ClosingCommand.Execute(null);
+        }
     }
 
     public interface IFilesystemOperationDialogView

src/Files/ViewModels/Dialogs/FilesystemOperationDialogViewModel.cs

@@ -1,6 +1,7 @@
 using Files.DataModels;
 using Files.Dialogs;
 using Files.Enums;
+using Files.Extensions;
 using Files.Helpers;
 using Microsoft.Toolkit.Mvvm.ComponentModel;
 using Microsoft.Toolkit.Mvvm.Input;
@@ -9,6 +10,7 @@
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Linq;
+using System.Threading;
 using System.Threading.Tasks;
 using System.Windows.Input;
 using Windows.UI.Xaml.Controls;
@@ -106,16 +108,28 @@ public bool MustResolveConflicts
 
         public ICommand ApplyToAllCommand { get; private set; }
 
+        public ICommand ClosingCommand { get; private set; }
+
+        private CancellationTokenSource ClosingCts { get; }
+
         public FilesystemOperationDialogViewModel()
         {
+            ClosingCts = new CancellationTokenSource();
+
             // Create commands
             PrimaryButtonCommand = new RelayCommand(PrimaryButton);
             SecondaryButtonCommand = new RelayCommand(SecondaryButton);
+
             LoadedCommand = new RelayCommand(() =>
             {
                 UpdatePrimaryButtonEnabled();
             });
 
+            ClosingCommand = new RelayCommand(() =>
+            {
+                ClosingCts.Cancel();
+            });
+
             ApplyToAllCommand = new RelayCommand<string>(s =>
             {
                 ApplyConflictOptionToAll((FileNameConflictResolveOptionType)int.Parse(s));
@@ -284,29 +298,30 @@ public static FilesystemOperationDialog GetDialog(FilesystemItemsOperationDataMo
             };
             viewModel.Items = new ObservableCollection<FilesystemOperationItemViewModel>(itemsData.ToItems(
                 viewModel.UpdatePrimaryButtonEnabled, viewModel.OptionGenerateNewName, viewModel.OptionReplaceExisting, viewModel.OptionSkip));
-            _ = LoadItemsIcon(viewModel.Items);
+            _ = LoadItemsIcon(viewModel.Items, viewModel.ClosingCts.Token);
             FilesystemOperationDialog dialog = new FilesystemOperationDialog(viewModel);
 
             return dialog;
         }
 
-        private static async Task LoadItemsIcon(IEnumerable<FilesystemOperationItemViewModel> items)
+        private static async Task LoadItemsIcon(IEnumerable<FilesystemOperationItemViewModel> items, CancellationToken token)
         {
-            await Task.Run(() => Task.WhenAll(items.ToList().Select(async (item) =>
+            await items.ParallelForEach(async (item) =>
             {
                 try
                 {
                     var iconData = await FileThumbnailHelper.LoadIconFromPathAsync(item.SourcePath, 64u, Windows.Storage.FileProperties.ThumbnailMode.ListView);
                     if (iconData != null)
                     {
+                        if (token.IsCancellationRequested) return;
                         await Windows.ApplicationModel.Core.CoreApplication.MainView.Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Low, async () =>
                         {
                             item.ItemIcon = await iconData.ToBitmapAsync();
                         });
                     }
                 }
                 catch { }
-            })));
+            }, 10, token);
         }
     }
 }