Move all logic from SubFloorHideComponent to SubFloorHideSystem. (#3824)

Content.Shared/GameObjects/Components/SubFloorHideComponent.cs

@@ -1,6 +1,6 @@
 #nullable enable
+using Content.Shared.GameObjects.EntitySystems;
 using Robust.Shared.GameObjects;
-using Robust.Shared.Log;
 
 namespace Content.Shared.GameObjects.Components
 {
@@ -13,60 +13,7 @@ namespace Content.Shared.GameObjects.Components
     [RegisterComponent]
     public sealed class SubFloorHideComponent : Component
     {
-        [ComponentDependency(nameof(OnAddSnapGrid))]
-        private SnapGridComponent? _snapGridComponent;
-
         /// <inheritdoc />
         public override string Name => "SubFloorHide";
-
-        /// <inheritdoc />
-        protected override void Startup()
-        {
-            base.Startup();
-
-            Owner.EntityManager.EventBus.RaiseEvent(EventSource.Local, new SubFloorHideDirtyEvent(Owner));
-        }
-
-        /// <inheritdoc />
-        protected override void Shutdown()
-        {
-            base.Shutdown();
-
-            if (Owner.Transform.Running == false)
-                return;
-
-            if (_snapGridComponent != null)
-            {
-                _snapGridComponent.OnPositionChanged -= SnapGridOnPositionChanged;
-            }
-
-            Owner.EntityManager.EventBus.RaiseEvent(EventSource.Local, new SubFloorHideDirtyEvent(Owner));
-        }
-
-        private void OnAddSnapGrid()
-        {
-            if (_snapGridComponent == null)
-            {
-                // Shouldn't happen but allows us to use nullables. OnPositionChanged needs to be componentbus anyway.
-                Logger.Error("Snapgrid was null for subfloor {Owner}");
-                return;
-            }
-            _snapGridComponent.OnPositionChanged += SnapGridOnPositionChanged;
-        }
-
-        private void SnapGridOnPositionChanged()
-        {
-            Owner.EntityManager.EventBus.RaiseEvent(EventSource.Local, new SubFloorHideDirtyEvent(Owner));
-        }
-    }
-
-    internal sealed class SubFloorHideDirtyEvent : EntityEventArgs
-    {
-        public IEntity Sender { get; }
-
-        public SubFloorHideDirtyEvent(IEntity sender)
-        {
-            Sender = sender;
-        }
     }
 }

Content.Shared/GameObjects/EntitySystems/SubFloorHideSystem.cs

@@ -1,6 +1,7 @@
 #nullable enable
 using Content.Shared.GameObjects.Components;
 using Content.Shared.Maps;
+using JetBrains.Annotations;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Map;
@@ -12,6 +13,7 @@ namespace Content.Shared.GameObjects.EntitySystems
     /// <summary>
     ///     Entity system backing <see cref="SubFloorHideComponent"/>.
     /// </summary>
+    [UsedImplicitly]
     public class SubFloorHideSystem : EntitySystem
     {
         [Dependency] private readonly IMapManager _mapManager = default!;
@@ -52,18 +54,44 @@ namespace Content.Shared.GameObjects.EntitySystems
             _mapManager.GridChanged += MapManagerOnGridChanged;
             _mapManager.TileChanged += MapManagerOnTileChanged;
 
-            SubscribeLocalEvent<SubFloorHideDirtyEvent>(HandleDirtyEvent);
+            // TODO: Make this sane when EntityStarted becomes a directed event.
+            EntityManager.EntityStarted += OnEntityStarted;
+
+            SubscribeLocalEvent<SubFloorHideComponent, EntityTerminatingEvent>(OnSubFloorTerminating);
+            SubscribeLocalEvent<SubFloorHideComponent, SnapGridPositionChangedEvent>(OnSnapGridPositionChanged);
         }
 
-        private void HandleDirtyEvent(SubFloorHideDirtyEvent ev)
+        public override void Shutdown()
         {
-            if (!_mapManager.TryGetGrid(ev.Sender.Transform.GridID, out var grid))
+            base.Shutdown();
-            {
-                return;
-            }
 
-            var indices = grid.WorldToTile(ev.Sender.Transform.WorldPosition);
+            _mapManager.GridChanged -= MapManagerOnGridChanged;
-            UpdateTile(grid, indices);
+            _mapManager.TileChanged -= MapManagerOnTileChanged;
+
+            EntityManager.EntityStarted -= OnEntityStarted;
+
+            UnsubscribeLocalEvent<SubFloorHideComponent, EntityTerminatingEvent>(OnSubFloorTerminating);
+            UnsubscribeLocalEvent<SubFloorHideComponent, SnapGridPositionChangedEvent>(OnSnapGridPositionChanged);
+        }
+
+        private void OnEntityStarted(object? sender, EntityUid uid)
+        {
+            if (ComponentManager.HasComponent<SubFloorHideComponent>(uid))
+            {
+                UpdateEntity(uid);
+            }
+        }
+
+        private void OnSubFloorTerminating(EntityUid uid, SubFloorHideComponent component, EntityTerminatingEvent args)
+        {
+            UpdateEntity(uid);
+        }
+
+        private void OnSnapGridPositionChanged(EntityUid uid, SubFloorHideComponent component, SnapGridPositionChangedEvent ev)
+        {
+            // We do this directly instead of calling UpdateEntity.
+            if(_mapManager.TryGetGrid(ev.NewGrid, out var grid))
+                UpdateTile(grid, ev.Position);
         }
 
         private void MapManagerOnTileChanged(object? sender, TileChangedEventArgs e)
@@ -79,6 +107,14 @@ namespace Content.Shared.GameObjects.EntitySystems
             }
         }
 
+        private void UpdateEntity(EntityUid uid)
+        {
+            if (!ComponentManager.TryGetComponent(uid, out ITransformComponent? transform) ||
+                !_mapManager.TryGetGrid(transform.GridID, out var grid)) return;
+
+            UpdateTile(grid, grid.WorldToTile(transform.WorldPosition));
+        }
+
         private void UpdateTile(IMapGrid grid, Vector2i position)
         {
             var tile = grid.GetTileRef(position);