Predicted multihanded component (#36712)

* Predicted multihanded component

* Refview

* reh

Content.Shared/Item/MultiHandedItemSystem.cs

@@ -0,0 +1,56 @@
+using Content.Shared.Hands;
+using Content.Shared.Hands.Components;
+using Content.Shared.Hands.EntitySystems;
+using Content.Shared.Inventory.VirtualItem;
+using Content.Shared.Popups;
+using Robust.Shared.Timing;
+
+namespace Content.Shared.Item;
+
+public sealed class MultiHandedItemSystem : EntitySystem
+{
+    [Dependency] private readonly IGameTiming _timing = default!;
+    [Dependency] private readonly SharedHandsSystem _hands = default!;
+    [Dependency] private readonly SharedPopupSystem _popup = default!;
+    [Dependency] private readonly SharedVirtualItemSystem _virtualItem = default!;
+
+    /// <inheritdoc/>
+    public override void Initialize()
+    {
+        SubscribeLocalEvent<MultiHandedItemComponent, GettingPickedUpAttemptEvent>(OnAttemptPickup);
+        SubscribeLocalEvent<MultiHandedItemComponent, VirtualItemDeletedEvent>(OnVirtualItemDeleted);
+        SubscribeLocalEvent<MultiHandedItemComponent, GotEquippedHandEvent>(OnEquipped);
+        SubscribeLocalEvent<MultiHandedItemComponent, GotUnequippedHandEvent>(OnUnequipped);
+    }
+
+    private void OnEquipped(Entity<MultiHandedItemComponent> ent, ref GotEquippedHandEvent args)
+    {
+        for (var i = 0; i < ent.Comp.HandsNeeded - 1; i++)
+        {
+            _virtualItem.TrySpawnVirtualItemInHand(ent.Owner, args.User);
+        }
+    }
+
+    private void OnUnequipped(Entity<MultiHandedItemComponent> ent, ref GotUnequippedHandEvent args)
+    {
+        _virtualItem.DeleteInHandsMatching(args.User, ent.Owner);
+    }
+
+    private void OnAttemptPickup(Entity<MultiHandedItemComponent> ent, ref GettingPickedUpAttemptEvent args)
+    {
+        if (TryComp<HandsComponent>(args.User, out var hands) && hands.CountFreeHands() >= ent.Comp.HandsNeeded)
+            return;
+
+        args.Cancel();
+        _popup.PopupPredictedCursor(Loc.GetString("multi-handed-item-pick-up-fail",
+            ("number", ent.Comp.HandsNeeded - 1), ("item", ent.Owner)), args.User);
+    }
+
+    private void OnVirtualItemDeleted(Entity<MultiHandedItemComponent> ent, ref VirtualItemDeletedEvent args)
+    {
+        if (args.BlockingEntity != ent.Owner || _timing.ApplyingState)
+            return;
+
+        _hands.TryDrop(args.User, ent.Owner);
+    }
+}