Use LRU cache for icons to improve performance when changing back and forth between frequently used apps, and reduce possibility of an icon randomly not loading

src/FocusVolumeControl/AudioSessions/ActiveAudioSessionWrapper.cs

@@ -5,45 +5,58 @@ using BarRaider.SdTools;
 using System.Drawing;
 using System.Runtime.InteropServices;
 using FocusVolumeControl.UI;
+using BitFaster.Caching.Lru;
 
 namespace FocusVolumeControl.AudioSessions;
 
 public sealed class ActiveAudioSessionWrapper : IAudioSession
 {
+	static ConcurrentLru<string, string> _iconCache = new ConcurrentLru<string, string>(10);
+
 	public string DisplayName { get; set; }
 	public string ExecutablePath { get; set; }
 	public string IconPath { get; set; }
 	private List<IAudioSessionControl2> Sessions { get; } = new List<IAudioSessionControl2>();
 	private IEnumerable<ISimpleAudioVolume> Volume => Sessions.Cast<ISimpleAudioVolume>();
 
-	string _icon;
+	string GetIconFromIconPath()
+	{
+		return _iconCache.GetOrAdd(IconPath, (key) =>
+		{
+			var tmp = (Bitmap)Bitmap.FromFile(IconPath);
+			tmp.MakeTransparent();
+			return Tools.ImageToBase64(tmp, true);
+		});
+	}
+
+	string GetIconFromExecutablePath()
+	{
+		return _iconCache.GetOrAdd(ExecutablePath, (key) =>
+		{
+			var tmp = IconExtraction.GetIcon(ExecutablePath);
+			//var tmp = Icon.ExtractAssociatedIcon(ExecutablePath);
+			return Tools.ImageToBase64(tmp, true);
+		});
+	}
 
 	public string GetIcon()
-	{
-		if (string.IsNullOrEmpty(_icon))
 	{
 		try
 		{
 			if (!string.IsNullOrEmpty(IconPath))
 			{
-					var tmp = (Bitmap)Bitmap.FromFile(IconPath);
-					tmp.MakeTransparent();
-					_icon = Tools.ImageToBase64(tmp, true);
+				return GetIconFromIconPath();
 			}
 			else
 			{
-					var tmp = IconExtraction.GetIcon(ExecutablePath);
-					//var tmp = Icon.ExtractAssociatedIcon(ExecutablePath);
-					_icon = Tools.ImageToBase64(tmp, true);
+				return GetIconFromExecutablePath();
 			}
 		}
 		catch
 		{
-				_icon = "Images/encoderIcon";
+			return "Images/encoderIcon";
 		}
 	}
-		return _icon;
-	}
 
 	public bool Any()
 	{

src/FocusVolumeControl/FocusVolumeControl.csproj

@@ -97,6 +97,9 @@
     </Content>
   </ItemGroup>
   <ItemGroup>
+    <PackageReference Include="BitFaster.Caching">
+      <Version>2.2.1</Version>
+    </PackageReference>
     <PackageReference Include="IsExternalInit">
       <Version>1.0.3</Version>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>

src/FocusVolumeControl/WindowChangedEventLoop.cs

@@ -39,12 +39,24 @@ namespace FocusVolumeControl
 
 		public event Action WindowChanged;
 
-		private void WinEventProc(IntPtr hWinEventHook, uint eventType, IntPtr hwnd, int idObject, int idChild, uint dwEventThread, uint dwmsEventTime)
+		CancellationTokenSource? _cancellationTokenSource = null;
+
+		private async void WinEventProc(IntPtr hWinEventHook, uint eventType, IntPtr hwnd, int idObject, int idChild, uint dwEventThread, uint dwmsEventTime)
 		{
 			try
 			{
+				//debounce the window changed events by 100 ms because if you click mouse over an application on the start bar
+				//and then click on the preview window, it will quickly go from current -> fallback -> new app
+				//which can often result in it getting stuck on the fallback app
+				_cancellationTokenSource?.Cancel();
+				_cancellationTokenSource = new CancellationTokenSource();
+				await Task.Delay(100, _cancellationTokenSource.Token);
 				WindowChanged?.Invoke();
 			}
+			catch (TaskCanceledException)
+			{
+				//ignored
+			}
 			catch (Exception ex)
 			{
 				Logger.Instance.LogMessage(TracingLevel.ERROR, $"Unexpected Error in EventHandler:\n {ex}");