CatStation/Content.Shared/Power/EntitySystems/ItemSlotRequiresPowerSystem.cs

using Content.Shared.Containers.ItemSlots;
using Content.Shared.Power.Components;

namespace Content.Shared.Power.EntitySystems;

public sealed partial class ItemSlotRequiresPowerSystem : EntitySystem
{
    [Dependency] private SharedPowerReceiverSystem _receiver = default!;

    public override void Initialize()
    {
        base.Initialize();
        SubscribeLocalEvent<ItemSlotRequiresPowerComponent, ItemSlotInsertAttemptEvent>(OnInsertAttempt);
    }

    private void OnInsertAttempt(Entity<ItemSlotRequiresPowerComponent> ent, ref ItemSlotInsertAttemptEvent args)
    {
        if (!_receiver.IsPowered(ent.Owner))
        {
            args.Cancelled = true;
        }
    }
}