Make DoAfters use DamageChangedMessage instead of an event (#3115)

Content.Shared/GameObjects/Components/Damage/DamageChangedMessage.cs

@@ -31,5 +31,21 @@ namespace Content.Shared.GameObjects.Components.Damage
         ///     List containing data on each <see cref="DamageType"/> that was changed.
         /// </summary>
         public IReadOnlyList<DamageChangeData> Data { get; }
+
+        public bool TookDamage
+        {
+            get
+            {
+                foreach (var datum in Data)
+                {
+                    if (datum.Delta > 0)
+                    {
+                        return true;
+                    }
+                }
+
+                return false;
+            }
+        }
     }
 }

Content.Shared/GameObjects/Components/Damage/DamageableComponent.cs

@@ -39,8 +39,6 @@ namespace Content.Shared.GameObjects.Components.Damage
         private readonly HashSet<DamageClass> _supportedClasses = new();
         private DamageFlag _flags;
 
-        public event Action<DamageChangedEventArgs>? HealthChangedEvent;
-
         // TODO DAMAGE Use as default values, specify overrides in a separate property through yaml for better (de)serialization
         [ViewVariables] public string DamageContainerId { get; set; } = default!;
 
@@ -460,7 +458,6 @@ namespace Content.Shared.GameObjects.Components.Damage
         protected virtual void OnHealthChanged(DamageChangedEventArgs e)
         {
             Owner.EntityManager.EventBus.RaiseEvent(EventSource.Local, e);
-            HealthChangedEvent?.Invoke(e);
 
             var message = new DamageChangedMessage(this, e.Data);
             SendMessage(message);

Content.Shared/GameObjects/Components/Damage/IDamageableComponent.cs

@@ -9,14 +9,6 @@ namespace Content.Shared.GameObjects.Components.Damage
 {
     public interface IDamageableComponent : IComponent, IExAct
     {
-        /// <summary>
-        ///     Called when the entity's <see cref="IDamageableComponent"/> values change.
-        ///     Of note is that a "deal 0 damage" call will still trigger this event
-        ///     (including both damage negated by resistance or simply inputting 0 as
-        ///     the amount of damage to deal).
-        /// </summary>
-        event Action<DamageChangedEventArgs> HealthChangedEvent;
-
         /// <summary>
         ///     Sum of all damages taken.
         /// </summary>