Add OnNeighborsChanged event to SteerForNeighborGroup2D

2D/Behaviors/SteerForNeighborGroup2D.cs

@@ -1,5 +1,7 @@
+using System;
 using System.Collections.Generic;
 using UnityEngine;
+using UnityEngine.Profiling;
 using UnitySteer.Attributes;
 
 namespace UnitySteer2D.Behaviors
@@ -116,6 +118,12 @@ public List<Vehicle2D> Neighbors
             get { return _neighbors; }
         }
 
+        /// <summary>
+        /// Delegate which is called when the detected neighbors list is changed
+        /// </summary>
+        public Action<SteerForNeighborGroup2D> OnNeighborsChanged = delegate { };
+
+
         #endregion
 
         #region Methods
@@ -162,6 +170,14 @@ private void HandleDetection(Radar2D radar)
                     _neighbors.Add(other);
                 }
             }
+
+            if (OnNeighborsChanged != null)
+            {
+                Profiler.BeginSample("Neighbor event handler");
+                OnNeighborsChanged(this);
+                Profiler.EndSample();
+            }
+
         }
 
         protected override Vector2 CalculateForce()

CHANGELOG.md

@@ -1,5 +1,9 @@
 # UnitySteer changelog
 
+## WIP
+
+* Added OnNeighborsChanged event to SteerForNeighbourGroup2D
+
 ## v3.1
 
 * 2D support thanks to @GandaG and @pjohalloran.