HelpURLFieldDrawer.cs

#if UNITY_EDITOR
using UnityEditor;
using UnityEngine;
 
namespace SCG.SpaceAdMobile
{
    [CustomPropertyDrawer(typeof(HelpURLFieldAttribute))]
    public class HelpURLFieldDrawer : PropertyDrawer
    {
        private const float ButtonWidth = 20f;
 
        public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
        {
            var helpURL = (HelpURLFieldAttribute)attribute;
 
            var labelWidth = EditorGUIUtility.labelWidth;
            var labelRect = new Rect(position.x, position.y, labelWidth, position.height);
 
            var fieldRect = new Rect(position.x + labelWidth + 2f, position.y,
                position.width - labelWidth - ButtonWidth, position.height);
 
            var buttonRect = new Rect(position.x + labelWidth + fieldRect.width + 3f, position.y, ButtonWidth, position.height);
 
            EditorGUI.LabelField(labelRect, label);
            EditorGUI.PropertyField(fieldRect, property, GUIContent.none);
 
            if (GUI.Button(buttonRect, "?"))
            {
                Application.OpenURL(helpURL.Url);
            }
        }
 
        public override float GetPropertyHeight(SerializedProperty property, GUIContent label) => 
            EditorGUI.GetPropertyHeight(property, label, true);
    }
}
#endif