Adds IThrowCollide, Creaming people with cream pies and tactical stun baton throws (#2122)

Content.Shared/Interfaces/GameObjects/Components/Interaction/IThrowCollide.cs

@@ -0,0 +1,72 @@
+using System;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Interfaces.GameObjects;
+using Robust.Shared.Map;
+
+namespace Content.Shared.Interfaces.GameObjects.Components
+{
+    public interface IThrowCollide
+    {
+        void HitBy(ThrowCollideEventArgs eventArgs) {}
+        void DoHit(ThrowCollideEventArgs eventArgs) {}
+    }
+
+    public class ThrowCollideEventArgs : EventArgs
+    {
+        /// <summary>
+        ///     The entity that threw <see cref="Thrown"/> and hit <see cref="Target"/>.
+        /// </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 EntityCoordinates Location { get; }
+
+        public ThrowCollideEventArgs(IEntity user, IEntity thrown, IEntity target, EntityCoordinates location)
+        {
+            User = user;
+            Thrown = thrown;
+            Target = target;
+            Location = location;
+        }
+    }
+
+    public class ThrowCollideMessage : EntitySystemMessage
+    {
+        /// <summary>
+        ///     If this message has already been "handled" by a previous system.
+        /// </summary>
+        public bool Handled { get; set; }
+
+        /// <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 EntityCoordinates Location { get; }
+
+        public ThrowCollideMessage(IEntity user, IEntity thrown, IEntity target, EntityCoordinates location)
+        {
+            User = user;
+            Thrown = thrown;
+            Target = target;
+            Location = location;
+        }
+    }
+}