Move BarSign appearance logic to client. (#11524)

* git mv

* Client-side bar sign appearance

* fix yaml

Content.Client/BarSign/BarSignSystem.cs

@@ -0,0 +1,53 @@
+using Content.Shared.BarSign;
+using Content.Shared.Power;
+using Robust.Client.GameObjects;
+using Robust.Shared.GameStates;
+using Robust.Shared.Prototypes;
+
+namespace Content.Client.BarSign;
+
+public sealed class BarSignSystem : VisualizerSystem<BarSignComponent>
+{
+    [Dependency] private readonly IPrototypeManager _prototypeManager = default!;
+
+    public override void Initialize()
+    {
+        base.Initialize();
+        SubscribeLocalEvent<BarSignComponent, ComponentHandleState>(OnHandleState);
+    }
+
+    private void OnHandleState(EntityUid uid, BarSignComponent component, ref ComponentHandleState args)
+    {
+        if (args.Current is not BarSignComponentState state)
+            return;
+
+        component.CurrentSign = state.CurrentSign;
+        UpdateAppearance(component);
+    }
+
+    protected override void OnAppearanceChange(EntityUid uid, BarSignComponent component, ref AppearanceChangeEvent args)
+    {
+        UpdateAppearance(component, args.Component, args.Sprite);
+    }
+
+    private void UpdateAppearance(BarSignComponent sign, AppearanceComponent? appearance = null, SpriteComponent? sprite = null)
+    {
+        if (!Resolve(sign.Owner, ref appearance, ref sprite))
+            return;
+
+        appearance.TryGetData(PowerDeviceVisuals.Powered, out bool powered);
+
+        if (powered
+            && sign.CurrentSign != null
+            && _prototypeManager.TryIndex(sign.CurrentSign, out BarSignPrototype? proto))
+        {
+            sprite.LayerSetState(0, proto.Icon);
+            sprite.LayerSetShader(0, "unshaded");
+        }
+        else
+        {
+            sprite.LayerSetState(0, "empty");
+            sprite.LayerSetShader(0, null, null);
+        }
+    }
+}