Revert "Remove some BUI boilerplate" (#30214)

Revert "Remove some BUI boilerplate (#28399)"

This reverts commit cbf329a82d.

Content.Client/MachineLinking/UI/SignalTimerBoundUserInterface.cs

@@ -1,6 +1,5 @@
 using Content.Shared.MachineLinking;
 using Robust.Client.GameObjects;
-using Robust.Client.UserInterface;
 using Robust.Shared.Timing;
 
 namespace Content.Client.MachineLinking.UI;
@@ -20,14 +19,19 @@ public sealed class SignalTimerBoundUserInterface : BoundUserInterface
     {
         base.Open();
 
-        _window = this.CreateWindow<SignalTimerWindow>();
-        _window.OnStartTimer += StartTimer;
+        _window = new SignalTimerWindow(this);
+
+        if (State != null)
+            UpdateState(State);
+
+        _window.OpenCentered();
+        _window.OnClose += Close;
         _window.OnCurrentTextChanged += OnTextChanged;
         _window.OnCurrentDelayMinutesChanged += OnDelayChanged;
         _window.OnCurrentDelaySecondsChanged += OnDelayChanged;
     }
 
-    public void StartTimer()
+    public void OnStartTimer()
     {
         SendMessage(new SignalTimerStartMessage());
     }
@@ -44,6 +48,11 @@ public sealed class SignalTimerBoundUserInterface : BoundUserInterface
         SendMessage(new SignalTimerDelayChangedMessage(_window.GetDelay()));
     }
 
+    public TimeSpan GetCurrentTime()
+    {
+        return _gameTiming.CurTime;
+    }
+
     /// <summary>
     /// Update the UI state based on server-sent info
     /// </summary>
@@ -63,4 +72,11 @@ public sealed class SignalTimerBoundUserInterface : BoundUserInterface
         _window.SetTimerStarted(cast.TimerStarted);
         _window.SetHasAccess(cast.HasAccess);
     }
+
+    protected override void Dispose(bool disposing)
+    {
+        base.Dispose(disposing);
+        if (!disposing) return;
+        _window?.Dispose();
+    }
 }