Moved interaction interfaces from Server to Shared.

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

@@ -0,0 +1,39 @@
+using System;
+using Robust.Shared.Interfaces.GameObjects;
+using Robust.Shared.Map;
+
+namespace Content.Shared.Interfaces.GameObjects.Components
+{
+    /// <summary>
+    /// This interface allows the component's entity to be dragged and dropped by mouse onto another entity and gives it
+    /// behavior when that occurs.
+    /// </summary>
+    public interface IDragDrop
+    {
+        /// <summary>
+        /// Invoked server-side when this component's entity is being dragged and dropped on another.
+        ///
+        /// There is no other server-side drag and drop check other than a range check, so make sure to validate
+        /// if this object can be dropped on the target object!
+        /// </summary>
+        /// <returns>true iff an interaction occurred and no further interaction should
+        /// be processed for this drop.</returns>
+        bool DragDrop(DragDropEventArgs eventArgs);
+    }
+
+    public class DragDropEventArgs : EventArgs
+    {
+        public DragDropEventArgs(IEntity user, GridCoordinates dropLocation, IEntity dropped, IEntity target)
+        {
+            User = user;
+            DropLocation = dropLocation;
+            Dropped = dropped;
+            Target = target;
+        }
+
+        public IEntity User { get; }
+        public GridCoordinates DropLocation { get; }
+        public IEntity Dropped { get; }
+        public IEntity Target { get; }
+    }
+}