Helpful script for displaying uints in the Unity inspector

EnumMaskPropertyDrawer.cs

/*
 Written by: Lucas Antunes (aka ItsaMeTuni), lucasba8@gmail.com
 In: 2/15/2018
 The only thing that you cannot do with this script is sell it by itself without substantially modifying it.
 */

using System;
using UnityEngine;

#if UNITY_EDITOR
using UnityEditor;
[CustomPropertyDrawer(typeof(EnumMaskAttribute))]
public class EnumMaskPropertyDrawer : PropertyDrawer {
  bool foldoutOpen = true;

  object theEnum;
  Array enumValues;
  Type enumUnderlyingType;

  public override float GetPropertyHeight(SerializedProperty property, GUIContent label) {
    if (foldoutOpen)
      return EditorGUIUtility.singleLineHeight * (Enum.GetValues(fieldInfo.FieldType).Length + 2);
    else
      return EditorGUIUtility.singleLineHeight;
  }

  public override void OnGUI(Rect position, SerializedProperty property, GUIContent label) {
    theEnum = fieldInfo.GetValue(property.serializedObject.targetObject);
    enumValues = Enum.GetValues(theEnum.GetType());
    enumUnderlyingType = Enum.GetUnderlyingType(theEnum.GetType());

    //We need to convert the enum to its underlying type, if we don't it will be boxed
    //into an object later and then we would need to unbox it like (UnderlyingType)(EnumType)theEnum.
    //If we do this here we can just do (UnderlyingType)theEnum later (plus we can visualize the value of theEnum in VS when debugging)
    theEnum = Convert.ChangeType(theEnum, enumUnderlyingType);

    EditorGUI.BeginProperty(position, label, property);

    foldoutOpen = EditorGUI.Foldout(new Rect(position.x, position.y, position.width, EditorGUIUtility.singleLineHeight), foldoutOpen, label);

    if (foldoutOpen) {
      //Draw the All button
      if (GUI.Button(new Rect(position.x, position.y + EditorGUIUtility.singleLineHeight * 1, 30, 15), "All")) {
        for (int i = 0; i < Enum.GetNames(fieldInfo.FieldType).Length; i++) {
          ToggleIndex(i, true);
        }
      }

      //Draw the None button
      if (GUI.Button(new Rect(position.x + 32, position.y + EditorGUIUtility.singleLineHeight * 1, 40, 15), "None")) {
        for (int i = 0; i < Enum.GetNames(fieldInfo.FieldType).Length; i++) {
          ToggleIndex(i, false);
        }
      }

      //Draw the list
      for (int i = 0; i < Enum.GetNames(fieldInfo.FieldType).Length; i++) {
        if (EditorGUI.Toggle(new Rect(position.x, position.y + EditorGUIUtility.singleLineHeight * (2 + i), position.width, EditorGUIUtility.singleLineHeight), Enum.GetNames(fieldInfo.FieldType)[i], IsSet(i))) {
          ToggleIndex(i, true);
        } else {
          ToggleIndex(i, false);
        }
      }
    }

    fieldInfo.SetValue(property.serializedObject.targetObject, theEnum);
    property.serializedObject.ApplyModifiedProperties();
  }

  /// <summary>
  /// Get the value of an enum element at the specified index (i.e. at the index of the name of the element in the names array)
  /// </summary>
  object GetEnumValue(int _index) {
    return Convert.ChangeType(enumValues.GetValue(_index), enumUnderlyingType);
  }

  /// <summary>
  /// Sets or unsets a bit in theEnum based on the index of the enum element (i.e. the index of the element in the names array)
  /// </summary>
  /// <param name="_set">If true the flag will be set, if false the flag will be unset.</param>
  void ToggleIndex(int _index, bool _set) {
    if (_set) {
      //enum = enum | val
      theEnum = DoOrOperator(theEnum, GetEnumValue(_index), enumUnderlyingType);
    } else {
      object val = GetEnumValue(_index);
      object notVal = DoNotOperator(val, enumUnderlyingType);

      //enum = enum & ~val
      theEnum = DoAndOperator(theEnum, notVal, enumUnderlyingType);
    }
  }

  /// <summary>
  /// Checks if a bit flag is set at the provided index of the enum element (i.e. the index of the element in the names array)
  /// </summary>
  bool IsSet(int _index) {
    object val = DoAndOperator(theEnum, GetEnumValue(_index), enumUnderlyingType);

    if (enumUnderlyingType == typeof(int)) {
      return (int)val != 0;
    } else if (enumUnderlyingType == typeof(uint)) {
      return (uint)val != 0;
    } else if (enumUnderlyingType == typeof(short)) {
      return (short)val != 0;
    } else if (enumUnderlyingType == typeof(ushort)) {
      return (ushort)val != 0;
    } else if (enumUnderlyingType == typeof(long)) {
      return (long)val != 0;
    } else if (enumUnderlyingType == typeof(ulong)) {
      return (ulong)val != 0;
    } else if (enumUnderlyingType == typeof(byte)) {
      return (byte)val != 0;
    } else if (enumUnderlyingType == typeof(sbyte)) {
      return (sbyte)val != 0;
    } else {
      throw new System.ArgumentException("Type " + enumUnderlyingType.GetType().FullName + " not supported.");
    }
  }

  /// <summary>
  /// Call the bitwise OR operator (|) on _lhs and _rhs given their types.
  /// Will basically return _lhs | _rhs
  /// </summary>
  /// <param name="_lhs">Left-hand side of the operation.</param>
  /// <param name="_rhs">Right-hand side of the operation.</param>
  /// <param name="_type">Type of the objects.</param>
  /// <returns>Result of the operation</returns>
  static object DoOrOperator(object _lhs, object _rhs, Type _type) {
    if (_type == typeof(int)) {
      return ((int)_lhs) | ((int)_rhs);
    } else if (_type == typeof(uint)) {
      return ((uint)_lhs) | ((uint)_rhs);
    } else if (_type == typeof(short)) {
      //ushort and short don't have bitwise operators, it is automatically converted to an int, so we convert it back
      return unchecked((short)((short)_lhs | (short)_rhs));
    } else if (_type == typeof(ushort)) {
      //ushort and short don't have bitwise operators, it is automatically converted to an int, so we convert it back
      return unchecked((ushort)((ushort)_lhs | (ushort)_rhs));
    } else if (_type == typeof(long)) {
      return ((long)_lhs) | ((long)_rhs);
    } else if (_type == typeof(ulong)) {
      return ((ulong)_lhs) | ((ulong)_rhs);
    } else if (_type == typeof(byte)) {
      //byte and sbyte don't have bitwise operators, it is automatically converted to an int, so we convert it back
      return unchecked((byte)((byte)_lhs | (byte)_rhs));
    } else if (_type == typeof(sbyte)) {
      //byte and sbyte don't have bitwise operators, it is automatically converted to an int, so we convert it back
      return unchecked((sbyte)((sbyte)_lhs | (sbyte)_rhs));
    } else {
      throw new System.ArgumentException("Type " + _type.FullName + " not supported.");
    }
  }

  /// <summary>
  /// Call the bitwise AND operator (&) on _lhs and _rhs given their types.
  /// Will basically return _lhs & _rhs
  /// </summary>
  /// <param name="_lhs">Left-hand side of the operation.</param>
  /// <param name="_rhs">Right-hand side of the operation.</param>
  /// <param name="_type">Type of the objects.</param>
  /// <returns>Result of the operation</returns>
  static object DoAndOperator(object _lhs, object _rhs, Type _type) {
    if (_type == typeof(int)) {
      return ((int)_lhs) & ((int)_rhs);
    } else if (_type == typeof(uint)) {
      return ((uint)_lhs) & ((uint)_rhs);
    } else if (_type == typeof(short)) {
      //ushort and short don't have bitwise operators, it is automatically converted to an int, so we convert it back
      return unchecked((short)((short)_lhs & (short)_rhs));
    } else if (_type == typeof(ushort)) {
      //ushort and short don't have bitwise operators, it is automatically converted to an int, so we convert it back
      return unchecked((ushort)((ushort)_lhs & (ushort)_rhs));
    } else if (_type == typeof(long)) {
      return ((long)_lhs) & ((long)_rhs);
    } else if (_type == typeof(ulong)) {
      return ((ulong)_lhs) & ((ulong)_rhs);
    } else if (_type == typeof(byte)) {
      return unchecked((byte)((short)_lhs & (short)_rhs));
    } else if (_type == typeof(sbyte)) {
      //byte and sbyte don't have bitwise operators, it is automatically converted to an int, so we convert it back
      return unchecked((sbyte)((sbyte)_lhs & (sbyte)_rhs));
    } else {
      throw new System.ArgumentException("Type " + _type.FullName + " not supported.");
    }
  }

  /// <summary>
  /// Call the bitwise NOT operator (~) on _lhs given its type.
  /// Will basically return ~_lhs
  /// </summary>
  /// <param name="_lhs">Left-hand side of the operation.</param>
  /// <param name="_type">Type of the object.</param>
  /// <returns>Result of the operation</returns>
  static object DoNotOperator(object _lhs, Type _type) {
    if (_type == typeof(int)) {
      return ~(int)_lhs;
    } else if (_type == typeof(uint)) {
      return ~(uint)_lhs;
    } else if (_type == typeof(short)) {
      //ushort and short don't have bitwise operators, it is automatically converted to an int, so we convert it back
      return unchecked((short)~(short)_lhs);
    } else if (_type == typeof(ushort)) {

      //ushort and short don't have bitwise operators, it is automatically converted to an int, so we convert it back
      return unchecked((ushort)~(ushort)_lhs);
    } else if (_type == typeof(long)) {
      return ~(long)_lhs;
    } else if (_type == typeof(ulong)) {
      return ~(ulong)_lhs;
    } else if (_type == typeof(byte)) {
      //byte and sbyte don't have bitwise operators, it is automatically converted to an int, so we convert it back
      return (byte)~(byte)_lhs;
    } else if (_type == typeof(sbyte)) {
      //byte and sbyte don't have bitwise operators, it is automatically converted to an int, so we convert it back
      return unchecked((sbyte)~(sbyte)_lhs);
    } else {
      throw new System.ArgumentException("Type " + _type.FullName + " not supported.");
    }
  }
}
#endif

[System.AttributeUsage(System.AttributeTargets.Field, AllowMultiple = false)]
public class EnumMaskAttribute : PropertyAttribute {

}