Added randomize/reverse songs logic. Added initial UI-side locking logic.

Harmonia.WinUI/Views/PlaylistDetailView.xaml.cs

@@ -1,5 +1,4 @@
 using CommunityToolkit.WinUI;
-using Harmonia.Core.Imaging;
 using Harmonia.Core.Playlists;
 using Harmonia.WinUI.ViewModels;
 using Microsoft.UI.Dispatching;
@@ -7,14 +6,10 @@ using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;
 using Microsoft.UI.Xaml.Data;
 using Microsoft.UI.Xaml.Input;
-using Microsoft.UI.Xaml.Media;
 using Microsoft.UI.Xaml.Media.Imaging;
 using System;
-using System.Collections.Generic;
 using System.ComponentModel;
 using System.Linq;
-using System.Threading.Tasks;
-using Windows.UI.Popups;
 
 namespace Harmonia.WinUI.Views;
 
@@ -33,24 +28,28 @@ public sealed partial class PlaylistDetailView : UserControl
 
         foreach (MenuFlyoutItemBase item in PlaylistListViewMenuFlyout.Items)
         {
-            item.DataContextChanged += Item_DataContextChanged;
+            HookDataContextChanged(item);
         }
 
+        int currentSortItemIndex = 0;
+
         foreach (SortItem sortItem in _viewModel.SortItems)
         {
-            SortByMenuFlyoutSubItem.Items.Add(new MenuFlyoutItem
+            SortByMenuFlyoutSubItem.Items.Insert(currentSortItemIndex, new MenuFlyoutItem
             {
                 Text = sortItem.Name,
                 Command = _viewModel.SortAllCommand,
                 CommandParameter = sortItem
             });
 
-            SortSelectedByMenuFlyoutSubItem.Items.Add(new MenuFlyoutItem
+            SortSelectedByMenuFlyoutSubItem.Items.Insert(currentSortItemIndex, new MenuFlyoutItem
             {
                 Text = sortItem.Name,
                 Command = _viewModel.SortSelectedCommand,
                 CommandParameter = sortItem
             });
+
+            currentSortItemIndex++;
         }
 
         _viewModel.SortSelectedCommand.CanExecuteChanged += (_, _) =>
@@ -74,15 +73,44 @@ public sealed partial class PlaylistDetailView : UserControl
 
     private void OnViewModelPropertyChanged(object? sender, PropertyChangedEventArgs e)
     {
-        if (e.PropertyName == nameof(_viewModel.PlayingSong))
+        switch (e.PropertyName)
         {
-            ListViewItem listViewItem = (ListViewItem)PlaylistListView.ContainerFromItem(_viewModel.PlayingSong);
-
-            UpdateListViewItemStyle(listViewItem, true);
+            case nameof(_viewModel.PlayingSong):
+                ListViewItem listViewItem = (ListViewItem)PlaylistListView.ContainerFromItem(_viewModel.PlayingSong);
+                UpdateListViewItemStyle(listViewItem, true);
+                break;
+            case nameof(_viewModel.Playlist):
+                ScrollToTop();
+                break;
+            case nameof(_viewModel.SelectedPlaylistSongs):
+                SyncListViewSelection();
+                break;
         }
-        else if (e.PropertyName == nameof(_viewModel.Playlist))
+    }
+
+    private bool _isSyncingSelection;
+
+    private void SyncListViewSelection()
+    {
+        _isSyncingSelection = true;
+
+        try
         {
-            ScrollToTop();
+            PlaylistListView.DeselectAll();
+
+            foreach (PlaylistSong playlistSong in _viewModel.SelectedPlaylistSongs)
+            {
+                int index = PlaylistListView.Items.IndexOf(playlistSong);
+
+                if (index >= 0)
+                {
+                    PlaylistListView.SelectRange(new ItemIndexRange(index, 1));
+                }
+            }
+        }
+        finally
+        {
+            _isSyncingSelection = false;
         }
     }
 
@@ -170,6 +198,19 @@ public sealed partial class PlaylistDetailView : UserControl
         }
     }
 
+    private void HookDataContextChanged(MenuFlyoutItemBase item)
+    {
+        item.DataContextChanged += Item_DataContextChanged;
+
+        if (item is MenuFlyoutSubItem subItem)
+        {
+            foreach (MenuFlyoutItemBase childItem in subItem.Items)
+            {
+                HookDataContextChanged(childItem);
+            }
+        }
+    }
+
     private void Item_DataContextChanged(FrameworkElement sender, DataContextChangedEventArgs args)
     {
         if (sender is not MenuFlyoutItemBase item)
@@ -268,6 +309,9 @@ public sealed partial class PlaylistDetailView : UserControl
 
     private void PlaylistListView_SelectionChanged(object sender, SelectionChangedEventArgs e)
     {
+        if (_isSyncingSelection)
+            return;
+
         if (sender is not ListView listView)
             return;