Refactors throw events, makes cream pies ECS (#4500)

Content.Shared/Throwing/ThrowEvents.cs

@@ -0,0 +1,55 @@
+using System;
+using JetBrains.Annotations;
+using Robust.Shared.Analyzers;
+using Robust.Shared.GameObjects;
+
+namespace Content.Shared.Throwing
+{
+    /// <summary>
+    ///     Base class for all throw events.
+    /// </summary>
+    public abstract class ThrowEvent : HandledEntityEventArgs
+    {
+        /// <summary>
+        ///     The entity that threw <see cref="Thrown"/>.
+        /// </summary>
+        public IEntity? User { get; }
+
+        /// <summary>
+        ///     The entity thrown by <see cref="User"/> that hit <see cref="Target"/>
+        /// </summary>
+        public IEntity Thrown { get; }
+
+        /// <summary>
+        ///     The entity hit with <see cref="Thrown"/> by <see cref="User"/>
+        /// </summary>
+        public IEntity Target { get; }
+
+        public ThrowEvent(IEntity? user, IEntity thrown, IEntity target)
+        {
+            User = user;
+            Thrown = thrown;
+            Target = target;
+        }
+    }
+
+    /// <summary>
+    ///     Raised directed on the target entity being hit by the thrown entity.
+    /// </summary>
+    public class ThrowHitByEvent : ThrowEvent
+    {
+        public ThrowHitByEvent(IEntity? user, IEntity thrown, IEntity target) : base(user, thrown, target)
+        {
+        }
+    }
+
+    /// <summary>
+    ///     Raised directed on the thrown entity that hits another.
+    /// </summary>
+    public class ThrowDoHitEvent : ThrowEvent
+    {
+        public ThrowDoHitEvent(IEntity? user, IEntity thrown, IEntity target) : base(user, thrown, target)
+        {
+        }
+    }
+}