Admin Log Browser Improvements (#39130)

Content.Client/Administration/UI/CustomControls/PlayerListControl.xaml.cs

@@ -1,16 +1,15 @@
 using System.Linq;
+using System.Text.RegularExpressions;
 using Content.Client.Administration.Systems;
 using Content.Client.UserInterface.Controls;
 using Content.Client.Verbs.UI;
 using Content.Shared.Administration;
 using Robust.Client.AutoGenerated;
-using Robust.Client.GameObjects;
 using Robust.Client.Graphics;
 using Robust.Client.UserInterface;
 using Robust.Client.UserInterface.Controls;
 using Robust.Client.UserInterface.XAML;
 using Robust.Shared.Input;
-using Robust.Shared.Utility;
 
 namespace Content.Client.Administration.UI.CustomControls;
 
@@ -96,13 +95,26 @@ public sealed partial class PlayerListControl : BoxContainer
     private void FilterList()
     {
         _sortedPlayerList.Clear();
+
+        Regex filterRegex;
+        // There is no neat way to handle invalid regex being submitted other than
+        // catching and ignoring the exception which gets thrown when it's invalid.
+        try
+        {
+            filterRegex = new Regex(FilterLineEdit.Text, RegexOptions.IgnoreCase);
+        }
+        catch (ArgumentException)
+        {
+            return;
+        }
+
         foreach (var info in _playerList)
         {
             var displayName = $"{info.CharacterName} ({info.Username})";
             if (info.IdentityName != info.CharacterName)
                 displayName += $" [{info.IdentityName}]";
             if (!string.IsNullOrEmpty(FilterLineEdit.Text)
-                && !displayName.ToLowerInvariant().Contains(FilterLineEdit.Text.Trim().ToLowerInvariant()))
+                && !filterRegex.IsMatch(displayName))
                 continue;
             _sortedPlayerList.Add(info);
         }