AttributeBase.cs

using System;
using UnityEngine;

namespace MyBox.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
	}
}