A better enum dropdown drawer for Unity

AdvancedEnumPropertyDrawer

using System;
using UnityEditor;
using UnityEngine;
using UnityEditor.IMGUI.Controls;

[CustomPropertyDrawer(typeof(Enum), true)]
public class EnumPropertyDrawer : PropertyDrawer
{
    private AdvancedStringOptionsDropdown _dropdown;
    private SerializedProperty _property;
    private Rect _buttonRect;

    public override float GetPropertyHeight(SerializedProperty property, GUIContent label)
    {
        return EditorGUIUtility.singleLineHeight;
    }

    public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
    {
        if (_dropdown == null)
        {
            _dropdown = new AdvancedStringOptionsDropdown(property.enumDisplayNames);
            _dropdown.OnOptionSelected += OnDropdownOptionSelected;
        }

        _property = property;

        position = EditorGUI.PrefixLabel(position, label);

        if (Event.current.type == EventType.Repaint)
            _buttonRect = position;

        if (GUI.Button(
            position,
            new GUIContent(property.enumDisplayNames[property.enumValueIndex]), 
            EditorStyles.popup
        ))
        {
            _dropdown.Show(_buttonRect);
        }
    }

    private void OnDropdownOptionSelected(int index)
    {
        _property.enumValueIndex = index;
        _property.serializedObject.ApplyModifiedProperties();
    }
}

public class AdvancedStringOptionsDropdown : AdvancedDropdown
{
    private string[] _enumNames;

    public event Action<int> OnOptionSelected;

    public AdvancedStringOptionsDropdown(string[] stringOptions) : base(new AdvancedDropdownState())
    {
        _enumNames = stringOptions;
    }

    protected override void ItemSelected(AdvancedDropdownItem item)
    {
        OnOptionSelected?.Invoke(item.id);
    }

    protected override AdvancedDropdownItem BuildRoot()
    {
        var root = new AdvancedDropdownItem("");

        for (int i = 0; i < _enumNames.Length; i++)
        {
            var item = new AdvancedDropdownItem(_enumNames[i]);
            item.id = i;

            root.AddChild(item);
        }

        return root;
    }
}

The code doesn't work for arrays of arrays of enums, because the same drawer instance is reused for each elements.
( => each calls made to OnGUI is rewriting the property that is to be updated in OnDropdownOptionSelected )

To fix this, simply move the line 26 "_property = property;" to line 39 : this make sure that the updated property is the one that correspond to the one on which the drop down is opened.

Great & easy fix!