ConditionalFieldAttribute.cs

/**********
Hides a field in the inspector in Unity3D according to the value of a boolean or enum field.

Warning: Code is blind-generated by AI without human inspection, use at your own risk.

Usage:

    // Show 'myField' only when 'isEnabled' is true
    public bool isEnabled;
    [ConditionalField("isEnabled")]
    public int myField;

    // Show 'myField' only when 'myEnum' == MyEnum.Option2
    public enum MyEnum { Option1, Option2, Option3 }
    public MyEnum myEnum;
    [ConditionalField("myEnum", 1)] // 1 is the index of Option2
    public int myField;

Author: chatgpt.com
Supervisor: fangzhangmnm, Jan.9 2026
License: MIT
**********/

using UnityEngine;
#if UNITY_EDITOR
using UnityEditor;
#endif

public class ConditionalFieldAttribute : PropertyAttribute
{
    public string condition;
    public int enumIndex;     // used when condition is an enum
    public bool useEnum;
    public bool inverse;

    // Bool condition constructor (keeps your old behavior)
    public ConditionalFieldAttribute(string condition, bool inverse = false)
    {
        this.condition = condition;
        this.inverse = inverse;
        this.useEnum = false;
    }

    // Enum condition constructor (show when enum == enumIndex)
    public ConditionalFieldAttribute(string condition, int enumIndex, bool inverse = false)
    {
        this.condition = condition;
        this.enumIndex = enumIndex;
        this.inverse = inverse;
        this.useEnum = true;
    }
}

#if UNITY_EDITOR
[CustomPropertyDrawer(typeof(ConditionalFieldAttribute))]
public class ConditionalFieldDrawer : PropertyDrawer
{
    public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
    {
        if (ShouldShow(property))
            EditorGUI.PropertyField(position, property, label, true);
    }

    public override float GetPropertyHeight(SerializedProperty property, GUIContent label)
    {
        return ShouldShow(property) ? EditorGUI.GetPropertyHeight(property, label, true) : 0f;
    }

    private bool ShouldShow(SerializedProperty property)
    {
        var condAttr = (ConditionalFieldAttribute)attribute;
        var conditionProp = property.serializedObject.FindProperty(condAttr.condition);
        if (conditionProp == null) return true; // fail open, or change to false if you prefer

        bool enabled;

        if (condAttr.useEnum)
        {
            // Compare by enum *index* (works fine for typical enums like yours: 0,1,2...)
            enabled = (conditionProp.propertyType == SerializedPropertyType.Enum)
                && (conditionProp.enumValueIndex == condAttr.enumIndex);
        }
        else
        {
            enabled = (conditionProp.propertyType == SerializedPropertyType.Boolean)
                && conditionProp.boolValue;
        }

        if (condAttr.inverse) enabled = !enabled;
        return enabled;
    }
}
#endif