security HUD now shows a job icon on entities with a body (#18054)

Content.Client/Overlays/EquipmentHudSystem.cs

@@ -0,0 +1,117 @@
+using Content.Shared.GameTicking;
+using Content.Shared.Inventory;
+using Content.Shared.Inventory.Events;
+using Robust.Client.GameObjects;
+using Robust.Client.Player;
+
+namespace Content.Client.Overlays;
+
+/// <summary>
+/// This is a base system to make it easier to enable or disabling UI elements based on whether or not the player has
+/// some component, either on their controlled entity on some worn piece of equipment.
+/// </summary>
+public abstract class EquipmentHudSystem<T> : EntitySystem where T : IComponent
+{
+    [Dependency] private readonly IPlayerManager _player = default!;
+
+    protected bool IsActive;
+    protected virtual SlotFlags TargetSlots => ~SlotFlags.POCKET;
+
+    public override void Initialize()
+    {
+        base.Initialize();
+
+        SubscribeLocalEvent<T, ComponentStartup>(OnStartup);
+        SubscribeLocalEvent<T, ComponentRemove>(OnRemove);
+
+        SubscribeLocalEvent<PlayerAttachedEvent>(OnPlayerAttached);
+        SubscribeLocalEvent<PlayerDetachedEvent>(OnPlayerDetached);
+
+        SubscribeLocalEvent<T, GotEquippedEvent>(OnCompEquip);
+        SubscribeLocalEvent<T, GotUnequippedEvent>(OnCompUnequip);
+
+        SubscribeLocalEvent<T, RefreshEquipmentHudEvent<T>>(OnRefreshComponentHud);
+        SubscribeLocalEvent<T, InventoryRelayedEvent<RefreshEquipmentHudEvent<T>>>(OnRefreshEquipmentHud);
+
+        SubscribeLocalEvent<RoundRestartCleanupEvent>(OnRoundRestart);
+    }
+
+    private void Update(RefreshEquipmentHudEvent<T> ev)
+    {
+        IsActive = true;
+        UpdateInternal(ev);
+    }
+
+    public void Deactivate()
+    {
+        if (!IsActive)
+            return;
+
+        IsActive = false;
+        DeactivateInternal();
+    }
+
+    protected virtual void UpdateInternal(RefreshEquipmentHudEvent<T> args) { }
+
+    protected virtual void DeactivateInternal() { }
+
+    private void OnStartup(EntityUid uid, T component, ComponentStartup args)
+    {
+        RefreshOverlay(uid);
+    }
+
+    private void OnRemove(EntityUid uid, T component, ComponentRemove args)
+    {
+        RefreshOverlay(uid);
+    }
+
+    private void OnPlayerAttached(PlayerAttachedEvent args)
+    {
+        RefreshOverlay(args.Entity);
+    }
+
+    private void OnPlayerDetached(PlayerDetachedEvent args)
+    {
+        if (_player.LocalPlayer?.ControlledEntity == null)
+            Deactivate();
+    }
+
+    private void OnCompEquip(EntityUid uid, T component, GotEquippedEvent args)
+    {
+        RefreshOverlay(args.Equipee);
+    }
+
+    private void OnCompUnequip(EntityUid uid, T component, GotUnequippedEvent args)
+    {
+        RefreshOverlay(args.Equipee);
+    }
+
+    private void OnRoundRestart(RoundRestartCleanupEvent args)
+    {
+        Deactivate();
+    }
+
+    protected virtual void OnRefreshEquipmentHud(EntityUid uid, T component, InventoryRelayedEvent<RefreshEquipmentHudEvent<T>> args)
+    {
+        args.Args.Active = true;
+    }
+
+    protected virtual void OnRefreshComponentHud(EntityUid uid, T component, RefreshEquipmentHudEvent<T> args)
+    {
+        args.Active = true;
+    }
+
+    private void RefreshOverlay(EntityUid uid)
+    {
+        if (uid != _player.LocalPlayer?.ControlledEntity)
+            return;
+
+        var ev = new RefreshEquipmentHudEvent<T>(TargetSlots);
+        RaiseLocalEvent(uid, ev);
+
+        if (ev.Active)
+            Update(ev);
+        else
+            Deactivate();
+    }
+}