Added playing song view. Adding styling to playing song. Fixed caching cancellation issue.

Harmonia.WinUI/Views/PlaylistView.xaml.cs

@@ -6,9 +6,13 @@ 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 Windows.UI.Popups;
 
 namespace Harmonia.WinUI.Views;
 
@@ -21,6 +25,8 @@ public sealed partial class PlaylistView : UserControl
         InitializeComponent();
 
         _viewModel = (PlaylistViewModel)DataContext;
+        _viewModel.PropertyChanging += OnViewModelPropertyChanging;
+        _viewModel.PropertyChanged += OnViewModelPropertyChanged;
         _viewModel.PlayingSongChangedAutomatically += OnPlayingSongChangedAutomatically;
 
         foreach (MenuFlyoutItemBase item in PlaylistListViewMenuFlyout.Items)
@@ -29,6 +35,75 @@ public sealed partial class PlaylistView : UserControl
         }
     }
 
+    private void OnViewModelPropertyChanging(object? sender, PropertyChangingEventArgs e)
+    {
+        if (e.PropertyName == nameof(_viewModel.PlayingSong))
+        {
+            ListViewItem listViewItem = (ListViewItem)PlaylistListView.ContainerFromItem(_viewModel.PlayingSong);
+
+            if (listViewItem != null)
+            {
+                UpdateListViewItemStyle(listViewItem, false);
+            }
+        }
+    }
+
+    private void OnViewModelPropertyChanged(object? sender, PropertyChangedEventArgs e)
+    {
+        if (e.PropertyName == nameof(_viewModel.PlayingSong))
+        {
+            ListViewItem listViewItem = (ListViewItem)PlaylistListView.ContainerFromItem(_viewModel.PlayingSong);
+
+            UpdateListViewItemStyle(listViewItem, true);
+        }
+    }
+
+    private void UpdateListViewItemStyle(FrameworkElement listViewItem, bool isPlaying)
+    {
+        if (listViewItem == null)
+            return;
+
+        FrameworkElement? frameworkElement;
+
+        if (listViewItem.Name == "PlaylistSongListViewItem")
+        {
+            frameworkElement = listViewItem;
+        }
+        else
+        {
+            if (listViewItem.FindDescendant("PlaylistSongListViewItem") is not FrameworkElement frameworkElement2)
+                return;
+
+            frameworkElement = frameworkElement2;
+        }
+
+        if (frameworkElement == null)
+            return;
+
+        string songItemTitleBrushName = isPlaying ? "PlayingSongTitleTextBlock" : "SongTitleTextBlock";
+        string songItemSubtitleBrushName = isPlaying ? "PlayingSongSubtitleTextBlock" : "SongSubtitleTextBlock";
+
+        UpdateElementStyle(frameworkElement, "SongTitleTextBlock", songItemTitleBrushName);
+        UpdateElementStyle(frameworkElement, "SongArtistsTextBlock", songItemSubtitleBrushName);
+        UpdateElementStyle(frameworkElement, "SongAlbumTextBlock", songItemSubtitleBrushName);
+    }
+
+    private void UpdateElementStyle(FrameworkElement dependencyObject, string elementName, string resourceName)
+    {
+        if (dependencyObject.FindDescendant(elementName) is not FrameworkElement frameworkElement)
+            return;
+
+        Resources.TryGetValue(resourceName, out object? resource);
+
+        if (resource == null)
+            Application.Current.Resources.TryGetValue(resourceName, out resource);
+
+        if (resource is not Style style)
+            return;
+
+        frameworkElement.Style = style;
+    }
+
     private void OnPlayingSongChangedAutomatically(object? sender, EventArgs e)
     {
         BringPlayingSongIntoView();
@@ -112,6 +187,16 @@ public sealed partial class PlaylistView : UserControl
         });
     }
 
+    private void PlaylistSongListViewItem_DataContextChanged(FrameworkElement sender, DataContextChangedEventArgs args)
+    {
+        if (args.NewValue is not PlaylistSong playlistSong)
+            return;
+
+        bool isPlaying = playlistSong == _viewModel.PlayingSong;
+        
+        UpdateListViewItemStyle(sender, isPlaying);
+    }
+
     private async void PlaylistListViewItem_DoubleTapped(object sender, DoubleTappedRoutedEventArgs e)
     {
         if (sender is not FrameworkElement element)