[Unity] Hide field with property state

HideWithPropertyAttribute.cs

using UnityEngine;

/// Adding this attribute to a property will hide according to the property `PropName`'s state
public class HideWithPropertyAttribute : PropertyAttribute {
    public string PropName;
    public bool HideWhenTrue;

    public HideWithPropertyAttribute(string propName, bool hideWhenTrue = false) {
        PropName = propName;
        HideWhenTrue = hideWhenTrue;
    }
}

HideWithPropertyAttributeDrawer.cs

using UnityEditor;
using UnityEngine;

[CustomPropertyDrawer(typeof(HideWithPropertyAttribute))]
public class HideWithPropertyAttributeDrawer : PropertyDrawer {
    SerializedProperty Parent(SerializedProperty property, string name) {
        var prop = property.GetParent(false);
        prop = prop.FindPropertyRelative(name);
        return prop;
    }

    public override float GetPropertyHeight(SerializedProperty property, GUIContent label) {
        var attr = attribute as HideWithPropertyAttribute;
        var prop = Parent(property, attr.PropName);
        if (prop == null) {
            return base.GetPropertyHeight(property, label);
        }
        if (prop.boolValue == attr.HideWhenTrue) {
            return 0;
        }
        return base.GetPropertyHeight(property, label);
    }

    public override void OnGUI(Rect position, SerializedProperty property, GUIContent label) {
        var attr = attribute as HideWithPropertyAttribute;
        var prop = Parent(property, attr.PropName);
        if (prop == null) return;
        if (prop.boolValue == attr.HideWhenTrue) {
            return;
        }
        
        position.height = base.GetPropertyHeight(property, label);
        EditorGUI.PropertyField(position, property, label);
    }
}