EnumLabel.cs

/**
EnumLabel.cs

Copyright (c) 2016 Hassaku

This software is released under the MIT License.
http://opensource.org/licenses/mit-license.php
*/
using UnityEngine;
using UnityEngine.Assertions;
using System;
using System.Text.RegularExpressions;
#if UNITY_EDITOR
using UnityEditor;
#endif

[AttributeUsage(AttributeTargets.Field)]
public class EnumLabelAttribute : PropertyAttribute{

    public string[] EnumNames { get; private set; }

    public EnumLabelAttribute(Type enumType) {
        Assert.IsTrue(enumType.IsEnum, "[EnumLabel] type of attribute parameter is not enum.");
        EnumNames = Enum.GetNames(enumType);
    }
}

#if UNITY_EDITOR
[CustomPropertyDrawer(typeof(EnumLabelAttribute))]
public class EnumLabelDrawer : PropertyDrawer {

    public override void OnGUI(Rect position, SerializedProperty property, GUIContent label) {

        EnumLabelAttribute attr = attribute as EnumLabelAttribute;
        Match match = new Regex(@"Element (?<index>\d+)").Match(label.text);
        if(!match.Success){
            EditorGUI.PropertyField(position, property, label);
            return;
        }
        int index = int.Parse(match.Groups["index"].Value);

        if (index < attr.EnumNames.Length) {
            EditorGUI.PropertyField(position, property, new GUIContent(attr.EnumNames[index]), true);
        }
        else {
            EditorGUI.PropertyField(position, property, label, true);
        }
    }

    public override float GetPropertyHeight(SerializedProperty property, GUIContent label) {
        return EditorGUI.GetPropertyHeight(property);
    }
}
#endif