Add indicator showing amount of ghost roles available (#5150)

* Add indicator showing amount of ghost roles available

* Make the indicator turn red if ghost roles are available

Content.Client/Ghost/GhostSystem.cs

@@ -16,6 +16,10 @@ namespace Content.Client.Ghost
         [Dependency] private readonly IPlayerManager _playerManager = default!;
         [Dependency] private readonly IGameHud _gameHud = default!;
 
+        // Changes to this value are manually propagated.
+        // No good way to get an event into the UI.
+        public int AvailableGhostRoleCount { get; private set; } = 0;
+
         private bool _ghostVisibility;
 
         private bool GhostVisibility
@@ -51,6 +55,7 @@ namespace Content.Client.Ghost
             SubscribeLocalEvent<GhostComponent, PlayerDetachedEvent>(OnGhostPlayerDetach);
 
             SubscribeNetworkEvent<GhostWarpsResponseEvent>(OnGhostWarpsResponse);
+            SubscribeNetworkEvent<GhostUpdateGhostRoleCountEvent>(OnUpdateGhostRoleCount);
         }
 
         private void OnGhostInit(EntityUid uid, GhostComponent component, ComponentInit args)
@@ -78,7 +83,7 @@ namespace Content.Client.Ghost
             // I hate UI I hate UI I Hate UI
             if (component.Gui == null)
             {
-                component.Gui = new GhostGui(component, EntityManager.EntityNetManager!);
+                component.Gui = new GhostGui(component, this, EntityManager.EntityNetManager!);
                 component.Gui.Update();
             }
 
@@ -113,5 +118,12 @@ namespace Content.Client.Ghost
                 window.Populate();
             }
         }
+
+        private void OnUpdateGhostRoleCount(GhostUpdateGhostRoleCountEvent msg)
+        {
+            AvailableGhostRoleCount = msg.AvailableGhostRoles;
+            foreach (var ghost in EntityManager.EntityQuery<GhostComponent>(true))
+                ghost.Gui?.Update();
+        }
     }
 }

Content.Client/Ghost/UI/GhostGui.cs

@@ -1,3 +1,4 @@
+using Content.Client.Stylesheets;
 using Content.Shared.Ghost;
 using Robust.Client.Console;
 using Robust.Client.UserInterface;
@@ -13,16 +14,18 @@ namespace Content.Client.Ghost.UI
     {
         private readonly Button _returnToBody = new() {Text = Loc.GetString("ghost-gui-return-to-body-button") };
         private readonly Button _ghostWarp = new() {Text = Loc.GetString("ghost-gui-ghost-warp-button") };
-        private readonly Button _ghostRoles = new() {Text = Loc.GetString("ghost-gui-ghost-roles-button") };
+        private readonly Button _ghostRoles = new();
         private readonly GhostComponent _owner;
+        private readonly GhostSystem _system;
 
         public GhostTargetWindow? TargetWindow { get; }
 
-        public GhostGui(GhostComponent owner, IEntityNetworkManager eventBus)
+        public GhostGui(GhostComponent owner, GhostSystem system, IEntityNetworkManager eventBus)
         {
             IoCManager.InjectDependencies(this);
 
             _owner = owner;
+            _system = system;
 
             TargetWindow = new GhostTargetWindow(eventBus);
 
@@ -57,6 +60,15 @@ namespace Content.Client.Ghost.UI
         public void Update()
         {
             _returnToBody.Disabled = !_owner.CanReturnToBody;
+            _ghostRoles.Text = Loc.GetString("ghost-gui-ghost-roles-button", ("count", _system.AvailableGhostRoleCount));
+            if (_system.AvailableGhostRoleCount != 0)
+            {
+                _ghostRoles.StyleClasses.Add(StyleBase.ButtonCaution);
+            }
+            else
+            {
+                _ghostRoles.StyleClasses.Remove(StyleBase.ButtonCaution);
+            }
             TargetWindow?.Populate();
         }