HandDriverUPM/NaughtyAttributes/Editor/PropertyDrawers/InputAxisPropertyDrawer.cs

using System.Collections.Generic;
using System.IO;
using System.Linq;
using UnityEditor;
using UnityEngine;

namespace NaughtyAttributes.Editor
{
	[CustomPropertyDrawer(typeof(InputAxisAttribute))]
	public class InputAxisPropertyDrawer : PropertyDrawerBase
	{
		private static readonly string AssetPath = Path.Combine("ProjectSettings", "InputManager.asset");
		private const string AxesPropertyPath = "m_Axes";
		private const string NamePropertyPath = "m_Name";

		protected override float GetPropertyHeight_Internal(SerializedProperty property, GUIContent label)
		{
			return (property.propertyType == SerializedPropertyType.String)
				? GetPropertyHeight(property)
				: GetPropertyHeight(property) + GetHelpBoxHeight();
		}

		protected override void OnGUI_Internal(Rect rect, SerializedProperty property, GUIContent label)
		{
			EditorGUI.BeginProperty(rect, label, property);

			if (property.propertyType == SerializedPropertyType.String)
			{
				var inputManagerAsset = AssetDatabase.LoadAssetAtPath(AssetPath, typeof(object));
				var inputManager = new SerializedObject(inputManagerAsset);

				var axesProperty = inputManager.FindProperty(AxesPropertyPath);
				var axesSet = new HashSet<string>();
				axesSet.Add("(None)");

				for (var i = 0; i < axesProperty.arraySize; i++)
				{
					var axis = axesProperty.GetArrayElementAtIndex(i).FindPropertyRelative(NamePropertyPath).stringValue;
					axesSet.Add(axis);
				}

				var axes = axesSet.ToArray();

				string propertyString = property.stringValue;
				int index = 0;
				// check if there is an entry that matches the entry and get the index
				// we skip index 0 as that is a special custom case
				for (int i = 1; i < axes.Length; i++)
				{
					if (axes[i].Equals(propertyString, System.StringComparison.Ordinal))
					{
						index = i;
						break;
					}
				}

				// Draw the popup box with the current selected index
				int newIndex = EditorGUI.Popup(rect, label.text, index, axes);

				// Adjust the actual string value of the property based on the selection
				string newValue = newIndex > 0 ? axes[newIndex] : string.Empty;

				if (!property.stringValue.Equals(newValue, System.StringComparison.Ordinal))
				{
					property.stringValue = newValue;
				}
			}
			else
			{
				string message = string.Format("{0} supports only string fields", typeof(InputAxisAttribute).Name);
				DrawDefaultPropertyAndHelpBox(rect, property, message, MessageType.Warning);
			}

			EditorGUI.EndProperty();
		}
	}
}