CatStation/Content.Server/Chat/TypingIndicator/TypingIndicatorSystem.cs

using Content.Shared.ActionBlocker;
using Content.Shared.Chat.TypingIndicator;
using Robust.Server.GameObjects;

namespace Content.Server.Chat.TypingIndicator;

// Server-side typing system
// It receives networked typing events from clients
// And sync typing indicator using appearance component
public sealed class TypingIndicatorSystem : SharedTypingIndicatorSystem
{
    [Dependency] private readonly ActionBlockerSystem _actionBlocker = default!;
    [Dependency] private readonly SharedAppearanceSystem _appearance = default!;

    public override void Initialize()
    {
        base.Initialize();
        SubscribeLocalEvent<PlayerAttachedEvent>(OnPlayerAttached);
        SubscribeLocalEvent<TypingIndicatorComponent, PlayerDetachedEvent>(OnPlayerDetached);
        SubscribeNetworkEvent<TypingChangedEvent>(OnClientTypingChanged);
    }

    private void OnPlayerAttached(PlayerAttachedEvent ev)
    {
        // when player poses entity we want to make sure that there is typing indicator
        EnsureComp<TypingIndicatorComponent>(ev.Entity);
        // we also need appearance component to sync visual state
        EnsureComp<AppearanceComponent>(ev.Entity);
    }

    private void OnPlayerDetached(EntityUid uid, TypingIndicatorComponent component, PlayerDetachedEvent args)
    {
        // player left entity body - hide typing indicator
        SetTypingIndicatorState(uid, TypingIndicatorState.None); // Corvax-TypingIndicator
    }

    private void OnClientTypingChanged(TypingChangedEvent ev, EntitySessionEventArgs args)
    {
        var uid = args.SenderSession.AttachedEntity;
        if (!Exists(uid))
        {
            Logger.Warning($"Client {args.SenderSession} sent TypingChangedEvent without an attached entity.");
            return;
        }

        // check if this entity can speak or emote
        if (!_actionBlocker.CanEmote(uid.Value) && !_actionBlocker.CanSpeak(uid.Value))
        {
            // nah, make sure that typing indicator is disabled
            SetTypingIndicatorState(uid.Value, TypingIndicatorState.None); // Corvax-TypingIndicator
            return;
        }

        SetTypingIndicatorState(uid.Value, ev.State); // Corvax-TypingIndicator
    }

    private void SetTypingIndicatorState(EntityUid uid, TypingIndicatorState state, AppearanceComponent? appearance = null) // Corvax-TypingIndicator
    {
        // if (!Resolve(uid, ref appearance, false)) // Corvax-TypingIndicator
        //     return;

        _appearance.SetData(uid, TypingIndicatorVisuals.State, state); // Corvax-TypingIndicator
    }
}