Re-organize all projects (#4166)

Content.Shared/Interaction/IUse.cs

@@ -0,0 +1,55 @@
+using System;
+using JetBrains.Annotations;
+using Robust.Shared.Analyzers;
+using Robust.Shared.GameObjects;
+
+namespace Content.Shared.Interaction
+{
+    /// <summary>
+    /// This interface gives components behavior when using the entity in your active hand
+    /// (done by clicking the entity in the active hand or pressing the keybind that defaults to Z).
+    /// </summary>
+    [RequiresExplicitImplementation]
+    public interface IUse
+    {
+        /// <summary>
+        /// Called when we activate an object we are holding to use it
+        /// </summary>
+        /// <returns></returns>
+        [Obsolete("Use UseInHandMessage instead")]
+        bool UseEntity(UseEntityEventArgs eventArgs);
+    }
+
+    public class UseEntityEventArgs : EventArgs
+    {
+        public UseEntityEventArgs(IEntity user)
+        {
+            User = user;
+        }
+
+        public IEntity User { get; }
+    }
+
+    /// <summary>
+    ///     Raised when using the entity in your hands.
+    /// </summary>
+    [PublicAPI]
+    public class UseInHandEvent : HandledEntityEventArgs
+    {
+        /// <summary>
+        ///     Entity holding the item in their hand.
+        /// </summary>
+        public IEntity User { get; }
+
+        /// <summary>
+        ///     Item that was used.
+        /// </summary>
+        public IEntity Used { get; }
+
+        public UseInHandEvent(IEntity user, IEntity used)
+        {
+            User = user;
+            Used = used;
+        }
+    }
+}