added more utilty packges

Packages/com.jovian.inspector/Editor/Attributes/AttributeBase.cs

@@ -0,0 +1,47 @@
+using System;
+using UnityEngine;
+
+namespace InspectorToolkit.Internal
+{
+	[AttributeUsage(AttributeTargets.Field)]
+	public abstract class AttributeBase : PropertyAttribute
+	{
+#if UNITY_EDITOR
+		/// <summary>
+		/// Validation is called before all other methods.
+		/// Once in OnGUI and once in GetPropertyHeight
+		/// </summary>
+		public virtual void ValidateProperty(UnityEditor.SerializedProperty property)
+		{
+		}
+		
+		
+		public virtual void OnBeforeGUI(Rect position, UnityEditor.SerializedProperty property, GUIContent label)
+		{
+		}
+
+		/// <summary>
+		/// Called once per AttributeBase group.
+		/// I.e. if something with higher order is drawn, later will be skipped
+		/// </summary>
+		/// <returns>false if nothing is drawn</returns>
+		public virtual bool OnGUI(Rect position, UnityEditor.SerializedProperty property, GUIContent label)
+		{
+			return false;
+		}
+
+		public virtual void OnAfterGUI(Rect position, UnityEditor.SerializedProperty property, GUIContent label)
+		{
+		}
+
+		/// <summary>
+		/// Overriding occurs just like OnGUI. Once per group, attribute with higher priority first
+		/// </summary>
+		/// <returns>Null if not overrided</returns>
+		public virtual float? OverrideHeight()
+		{
+			return null;
+		}
+#endif
+	}
+}