feat: add particle system getter and setter for attractor

close #253

Scripts/UIParticleAttractor.cs

@@ -72,22 +72,25 @@ namespace Coffee.UIExtensions
             }
         }
 
+        public ParticleSystem particleSystem
+        {
+            get
+            {
+                return m_ParticleSystem;
+            }
+            set
+            {
+                m_ParticleSystem = value;
+                if (!ApplyParticleSystem()) return;
+                enabled = true;
+            }
+        }
+
         private UIParticle _uiParticle;
 
         private void OnEnable()
         {
-            if (m_ParticleSystem == null)
+            if (!ApplyParticleSystem()) return;
-            {
-                Debug.LogError("No particle system attached to particle attractor script", this);
-                enabled = false;
-                return;
-            }
-
-            _uiParticle = m_ParticleSystem.GetComponentInParent<UIParticle>();
-            if (_uiParticle && !_uiParticle.particles.Contains(m_ParticleSystem))
-            {
-                _uiParticle = null;
-            }
             UIParticleUpdater.Register(this);
         }
 
@@ -200,5 +203,22 @@ namespace Coffee.UIExtensions
             return Vector3.MoveTowards(current, target, speed);
         }
 
+        private bool ApplyParticleSystem()
+        {
+            if (m_ParticleSystem == null)
+            {
+                Debug.LogError("No particle system attached to particle attractor script", this);
+                enabled = false;
+                return false;
+            }
+
+            _uiParticle = m_ParticleSystem.GetComponentInParent<UIParticle>();
+            if (_uiParticle && !_uiParticle.particles.Contains(m_ParticleSystem))
+            {
+                _uiParticle = null;
+            }
+
+            return true;
+        }
     }
 }