Remove some BUI boilerplate (#28399)

* Remove some BUI boilerplate

- The disposals overrides got removed due to the helper method handling it.
- Replace window creation with CreateWindow helper.
- Fixed some stinky code which would cause exceptions.

* More

* moar

* weh

* done

* More BUIs

* More updates

* weh

* moar

* look who it is

* weh

* merge

* weh

* fixes

Content.Client/Gateway/UI/GatewayBoundUserInterface.cs

@@ -1,6 +1,7 @@
 using Content.Shared.Gateway;
 using JetBrains.Annotations;
 using Robust.Client.GameObjects;
+using Robust.Client.UserInterface;
 
 namespace Content.Client.Gateway.UI;
 
@@ -17,24 +18,13 @@ public sealed class GatewayBoundUserInterface : BoundUserInterface
     {
         base.Open();
 
-        _window = new GatewayWindow(EntMan.GetNetEntity(Owner));
+        _window = this.CreateWindow<GatewayWindow>();
+        _window.SetEntity(EntMan.GetNetEntity(Owner));
 
         _window.OpenPortal += destination =>
         {
             SendMessage(new GatewayOpenPortalMessage(destination));
         };
-        _window.OnClose += Close;
-        _window?.OpenCentered();
-    }
-
-    protected override void Dispose(bool disposing)
-    {
-        base.Dispose(disposing);
-        if (disposing)
-        {
-            _window?.Dispose();
-            _window = null;
-        }
     }
 
     protected override void UpdateState(BoundUserInterfaceState state)

Content.Client/Gateway/UI/GatewayWindow.xaml.cs

@@ -22,7 +22,7 @@ public sealed partial class GatewayWindow : FancyWindow,
     public event Action<NetEntity>? OpenPortal;
     private List<GatewayDestinationData> _destinations = new();
 
-    public readonly NetEntity Owner;
+    public NetEntity Owner;
 
     private NetEntity? _current;
     private TimeSpan _nextReady;
@@ -46,16 +46,20 @@ public sealed partial class GatewayWindow : FancyWindow,
     /// </summary>
     private bool _isCooldownPending = true;
 
-    public GatewayWindow(NetEntity netEntity)
+    public GatewayWindow()
     {
         RobustXamlLoader.Load(this);
         var dependencies = IoCManager.Instance!;
         _timing = dependencies.Resolve<IGameTiming>();
-        Owner = netEntity;
 
         NextUnlockBar.ForegroundStyleBoxOverride = new StyleBoxFlat(Color.FromHex("#C74EBD"));
     }
 
+    public void SetEntity(NetEntity entity)
+    {
+
+    }
+
     public void UpdateState(GatewayBoundUserInterfaceState state)
     {
         _destinations = state.Destinations;