UniversalViewer/Assets/Scripts/SharedBasic/Editor/ConditionalAttributes.cs

/* Title : Attribute for show a field if other field is true or false.
 * Author : Anth
*/
using UnityEngine;
using UnityEditor;

/// <summary>
/// Atttribute for show a field if other field is true or false.
/// </summary>
[System.AttributeUsage(System.AttributeTargets.Field, Inherited = false, AllowMultiple = true)]
public sealed class ShowIfAttribute : PropertyAttribute
{
    public string ConditionalSourceField;
    public bool expectedValue;
    public bool HideInInspector;

    /// <summary>
    /// Create the attribute for show a field x if field y is true or false.
    /// </summary>
    /// <param name="ConditionalSourceField">name of field y type boolean </param>
    /// <param name="expectedValue"> what value should have the field y for show the field x</param>
    /// <param name="HideInInspector"> if should hide in the inspector or only disable</param>
    public ShowIfAttribute(string ConditionalSourceField, bool expectedValue, bool HideInInspector = false)
    {
        this.ConditionalSourceField = ConditionalSourceField;
        this.expectedValue = expectedValue;
        this.HideInInspector = HideInInspector;
    }
}


[CustomPropertyDrawer(typeof(ShowIfAttribute))]
public class ConditionalHidePropertyDrawer : PropertyDrawer
{
    public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
    {
#if UNITY_EDITOR
        ShowIfAttribute condHAtt = (ShowIfAttribute)attribute;
        bool enabled = GetConditionalSourceField(property, condHAtt);
        GUI.enabled = enabled;

        // if is enable draw the label
        if (enabled)
            EditorGUI.PropertyField(position, property, label, true);
        // if is not enabled but we want not hide it, then draw it disabled
        else if (!condHAtt.HideInInspector)
            EditorGUI.PropertyField(position, property, label, false);
        // else hide it ,dont draw it
        else return;
#endif
    }

    public override float GetPropertyHeight(SerializedProperty property, GUIContent label)
    {
#if UNITY_EDITOR
        ShowIfAttribute condHAtt = (ShowIfAttribute)attribute;
        bool enabled = GetConditionalSourceField(property, condHAtt);

        // if is enable draw the label
        if (enabled)
        {
            return EditorGUI.GetPropertyHeight(property, label, true);
        }
        // if is not enabled but we want not hide it, then draw it disabled
        else
        {
            if (!condHAtt.HideInInspector)
                return EditorGUI.GetPropertyHeight(property, label, false);
            // else hide it
            else
                return -EditorGUIUtility.standardVerticalSpacing; // Oculta el campo visualmente.
        }
#else
        return 0f;
#endif
    }

    /// <summary>
    /// Get if the conditional what expected is true.
    /// </summary>
    /// <param name="property"> is used for get the value of the property and check if return enable true or false </param>
    /// <param name="condHAtt"> is the attribute what contains the values what we need </param>
    /// <returns> only if the field y is same to the value expected return true</returns>
    private bool GetConditionalSourceField(SerializedProperty property, ShowIfAttribute condHAtt)
    {
#if UNITY_EDITOR
        bool enabled = false;
        string propertyPath = property.propertyPath;
        string conditionPath = propertyPath.Replace(property.name, condHAtt.ConditionalSourceField);
        SerializedProperty sourcePropertyValue = property.serializedObject.FindProperty(conditionPath);

        if (sourcePropertyValue != null)
        {
            enabled = sourcePropertyValue.boolValue;
            if (enabled == condHAtt.expectedValue) enabled = true;
            else enabled = false;
        }
        else
        {
            string warning = "ConditionalHideAttribute: No se encuentra el campo booleano [" + condHAtt.ConditionalSourceField + "] en " + property.propertyPath;
            warning += " Aseg<65>rate de especificar correctamente el nombre del campo condicional.";
            Debug.LogWarning(warning);
        }

        return enabled;
#else
        return false;
#endif
    }
}