Files
tbd-station-14/Content.Shared/Placeable/ItemPlacerSystem.cs
2023-09-11 09:42:41 +10:00

104 lines
3.6 KiB
C#

using Robust.Shared.Physics.Events;
using Robust.Shared.Physics.Systems;
using System.Linq;
using Robust.Shared.GameStates;
using Robust.Shared.Serialization;
namespace Content.Shared.Placeable;
/// <summary>
/// Tracks placed entities
/// Subscribe to <see cref="ItemPlacedEvent"/> or <see cref="ItemRemovedEvent"/> to do things when items or placed or removed.
/// </summary>
public sealed class ItemPlacerSystem : EntitySystem
{
[Dependency] private readonly PlaceableSurfaceSystem _placeableSurface = default!;
[Dependency] private readonly SharedPhysicsSystem _physics = default!;
public override void Initialize()
{
base.Initialize();
SubscribeLocalEvent<ItemPlacerComponent, StartCollideEvent>(OnStartCollide);
SubscribeLocalEvent<ItemPlacerComponent, EndCollideEvent>(OnEndCollide);
SubscribeLocalEvent<ItemPlacerComponent, ComponentGetState>(OnPlacerGetState);
SubscribeLocalEvent<ItemPlacerComponent, ComponentHandleState>(OnPlacerHandleState);
}
private void OnPlacerHandleState(EntityUid uid, ItemPlacerComponent component, ref ComponentHandleState args)
{
if (args.Current is not ItemPlacerComponentState state)
return;
component.MaxEntities = state.MaxEntities;
component.PlacedEntities.Clear();
var ents = EnsureEntitySet<ItemPlacerComponent>(state.Entities, uid);
component.PlacedEntities.UnionWith(ents);
}
private void OnPlacerGetState(EntityUid uid, ItemPlacerComponent component, ref ComponentGetState args)
{
args.State = new ItemPlacerComponentState()
{
MaxEntities = component.MaxEntities,
Entities = GetNetEntitySet(component.PlacedEntities),
};
}
private void OnStartCollide(EntityUid uid, ItemPlacerComponent comp, ref StartCollideEvent args)
{
if (comp.Whitelist != null && !comp.Whitelist.IsValid(args.OtherEntity))
return;
// Disallow sleeping so we can detect when entity is removed from the heater.
_physics.SetSleepingAllowed(args.OtherEntity, args.OtherBody, false);
var count = comp.PlacedEntities.Count;
if (comp.MaxEntities == 0 || count < comp.MaxEntities)
{
comp.PlacedEntities.Add(args.OtherEntity);
var ev = new ItemPlacedEvent(args.OtherEntity);
RaiseLocalEvent(uid, ref ev);
}
if (comp.MaxEntities > 0 && count >= (comp.MaxEntities - 1))
{
// Don't let any more items be placed if it's reached its limit.
_placeableSurface.SetPlaceable(uid, false);
}
}
private void OnEndCollide(EntityUid uid, ItemPlacerComponent comp, ref EndCollideEvent args)
{
// Re-allow sleeping.
_physics.SetSleepingAllowed(args.OtherEntity, args.OtherBody, true);
comp.PlacedEntities.Remove(args.OtherEntity);
var ev = new ItemRemovedEvent(args.OtherEntity);
RaiseLocalEvent(uid, ref ev);
_placeableSurface.SetPlaceable(uid, true);
}
[Serializable, NetSerializable]
private sealed class ItemPlacerComponentState : ComponentState
{
public uint MaxEntities;
public HashSet<NetEntity> Entities = default!;
}
}
/// <summary>
/// Raised on the <see cref="ItemPlacer"/> when an item is placed and it is under the item limit.
/// </summary>
[ByRefEvent]
public readonly record struct ItemPlacedEvent(EntityUid OtherEntity);
/// <summary>
/// Raised on the <see cref="ItemPlacer"/> when an item is removed from it.
/// </summary>
[ByRefEvent]
public readonly record struct ItemRemovedEvent(EntityUid OtherEntity);