module-inspector/Editor/Drawers/AngleDisplayAsAttributeDrawer.cs

using Module.Inspector.Editor.Utilities;
using UnityEditor;
using UnityEngine;

namespace Module.Inspector.Editor
{
    [CustomPropertyDrawer(typeof(AngleDisplayAsAttribute))]
    internal sealed class AngleDisplayAsAttributeDrawer : DrawerPropertyDrawer
    {
        public override bool Draw(Rect position, DrawerPropertyAttribute attribute, SerializedProperty property, GUIContent label, EditorPropertyUtility.Result result)
        {
            if (property.propertyType != SerializedPropertyType.Float)
                return false;
            
            var att = (AngleDisplayAsAttribute)attribute;
            
            EditorGUI.BeginChangeCheck();
            EditorGUI.BeginProperty(position, label, property);
            {
                if (att.type == EAngle.Euler)
                {
                    float toEuler = Mathf.Rad2Deg * property.floatValue;
                    float temp = EditorGUI.FloatField(position, label, toEuler) * Mathf.Deg2Rad;

                    if (!Mathf.Approximately(temp, property.floatValue))
                        property.floatValue = temp;
                }
                else
                {
                    float toRadian = Mathf.Deg2Rad * property.floatValue;
                    float temp = EditorGUI.FloatField(position, label, toRadian) * Mathf.Rad2Deg;

                    if (!Mathf.Approximately(temp, property.floatValue))
                        property.floatValue = temp;
                }
            }
            EditorGUI.EndProperty();
            bool changed = EditorGUI.EndChangeCheck();

            if (changed)
                property.serializedObject.ApplyModifiedProperties();
            
            return true;
        }
        
        public override string GetErrorMessage(SerializedProperty property)
        {
            return "Only supports floats";
        }
    }
}