OldThink/Content.Client/Paper/UI/PaperSystem.cs

using Robust.Client.GameObjects;

using static Content.Shared.Paper.SharedPaperComponent;

namespace Content.Client.Paper;

public sealed class PaperSystem : VisualizerSystem<PaperVisualsComponent>
{
    protected override void OnAppearanceChange(EntityUid uid, PaperVisualsComponent component, ref AppearanceChangeEvent args)
    {
        if (args.Sprite == null)
            return;

        if (args.Component.TryGetData(PaperVisuals.Status , out PaperStatus writingStatus))
            args.Sprite.LayerSetVisible(PaperVisualLayers.Writing, writingStatus == PaperStatus.Written);

        if (args.Component.TryGetData(PaperVisuals.Stamp, out string stampState))
        {
            args.Sprite.LayerSetState(PaperVisualLayers.Stamp, stampState);
            args.Sprite.LayerSetVisible(PaperVisualLayers.Stamp, true);
        }
    }
}

public enum PaperVisualLayers
{
    Stamp,
    Writing
}