Fix typing indicators! (#29492)

* First commit

* Removed pause stuff

* Make the event better

* Forgot to add the comment

* Proto id stuff

* cool comments

* serializer

* Added the time stuff

Content.Shared/Chat/TypingIndicator/TypingIndicatorEvents.cs

@@ -0,0 +1,60 @@
+using Robust.Shared.Serialization;
+using Content.Shared.Inventory;
+using Robust.Shared.Prototypes;
+using Robust.Shared.Serialization.Manager.Exceptions;
+
+namespace Content.Shared.Chat.TypingIndicator;
+
+/// <summary>
+///     Networked event from client.
+///     Send to server when client started/stopped typing in chat input field.
+/// </summary>
+[Serializable, NetSerializable]
+public sealed class TypingChangedEvent : EntityEventArgs
+{
+    public readonly bool IsTyping;
+
+    public TypingChangedEvent(bool isTyping)
+    {
+        IsTyping = isTyping;
+    }
+}
+
+/// <summary>
+///     This event will be broadcast right before displaying an entities typing indicator.
+///     If _overrideIndicator is not null after the event is finished it will be used.
+/// </summary>
+[Serializable, NetSerializable]
+public sealed class BeforeShowTypingIndicatorEvent : IInventoryRelayEvent
+{
+    public SlotFlags TargetSlots { get; } = SlotFlags.WITHOUT_POCKET;
+
+    private ProtoId<TypingIndicatorPrototype>? _overrideIndicator = null;
+    private TimeSpan? _latestEquipTime = null;
+    public BeforeShowTypingIndicatorEvent()
+    {
+        _overrideIndicator = null;
+        _latestEquipTime = null;
+    }
+    /// <summary>
+    ///     Will only update the time and indicator if the given time is more recent than
+    ///     the stored time or if the stored time is null.
+    /// </summary>
+    ///  <returns>
+    ///     True if the given time is more recent than the stored time, and false otherwise.
+    ///  </returns>
+    public bool TryUpdateTimeAndIndicator(ProtoId<TypingIndicatorPrototype>? indicator, TimeSpan? equipTime)
+    {
+        if (equipTime != null && (_latestEquipTime == null || _latestEquipTime < equipTime))
+        {
+            _latestEquipTime = equipTime;
+            _overrideIndicator = indicator;
+            return true;
+        }
+        return false;
+    }
+    public ProtoId<TypingIndicatorPrototype>? GetMostRecentIndicator()
+    {
+        return _overrideIndicator;
+    }
+}