Hi all!
There’s one particular C# feature I use a lot in my projects, and that is properties: They allow you to execute arbitrary code whenever a variable is read/written. Which is nice and leads to quite clean code.
However, Unity does not serialize properties by default. Which makes sense, since calling arbitrary code when serializing/deserializing objects probably is not a good idea.
Calling the getter/setter in editor automatically when tinkering with the inspector without the need to write a custom Editor has proven extremely useful though. I made my own implementation using PropertyDrawers. Here it is, feel free to copy and paste to your project:
using System;
using System.Reflection;
using UnityEngine;
#if UNITY_EDITOR
using UnityEditor;
#endif
[System.AttributeUsage(System.AttributeTargets.Field)]
public class SerializeProperty : PropertyAttribute
{
public string PropertyName { get; private set; }
public SerializeProperty(string propertyName)
{
PropertyName = propertyName;
}
}
#if UNITY_EDITOR
[CustomPropertyDrawer(typeof(SerializeProperty))]
public class SerializePropertyAttributeDrawer : PropertyDrawer
{
private PropertyInfo propertyFieldInfo = null;
public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
{
UnityEngine.Object target = property.serializedObject.targetObject;
// Find the property field using reflection, in order to get access to its getter/setter.
if (propertyFieldInfo == null)
propertyFieldInfo = target.GetType().GetProperty(((SerializeProperty)attribute).PropertyName,
BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
if (propertyFieldInfo != null){
// Retrieve the value using the property getter:
object value = propertyFieldInfo.GetValue(target,null);
// Draw the property, checking for changes:
EditorGUI.BeginChangeCheck();
value = DrawProperty(position,property.propertyType,propertyFieldInfo.PropertyType,value,label);
// If any changes were detected, call the property setter:
if (EditorGUI.EndChangeCheck() && propertyFieldInfo != null){
// Record object state for undo:
Undo.RecordObject(target, "Inspector");
// Call property setter:
propertyFieldInfo.SetValue(target,value,null);
}
}else{
EditorGUI.LabelField(position,"Error: could not retrieve property.");
}
}
private object DrawProperty(Rect position, SerializedPropertyType propertyType, Type type, object value, GUIContent label)
{
switch (propertyType) {
case SerializedPropertyType.Integer:
return EditorGUI.IntField(position,label,(int)value);
case SerializedPropertyType.Boolean:
return EditorGUI.Toggle(position,label,(bool)value);
case SerializedPropertyType.Float:
return EditorGUI.FloatField(position,label,(float)value);
case SerializedPropertyType.String:
return EditorGUI.TextField(position,label,(string)value);
case SerializedPropertyType.Color:
return EditorGUI.ColorField(position,label,(Color)value);
case SerializedPropertyType.ObjectReference:
return EditorGUI.ObjectField(position,label,(UnityEngine.Object)value,type,true);
case SerializedPropertyType.ExposedReference:
return EditorGUI.ObjectField(position,label,(UnityEngine.Object)value,type,true);
case SerializedPropertyType.LayerMask:
return EditorGUI.LayerField(position,label,(int)value);
case SerializedPropertyType.Enum:
return EditorGUI.EnumPopup(position,label,(Enum)value);
case SerializedPropertyType.Vector2:
return EditorGUI.Vector2Field(position,label,(Vector2)value);
case SerializedPropertyType.Vector3:
return EditorGUI.Vector3Field(position,label,(Vector3)value);
case SerializedPropertyType.Vector4:
return EditorGUI.Vector4Field(position,label,(Vector4)value);
case SerializedPropertyType.Rect:
return EditorGUI.RectField(position,label,(Rect)value);
case SerializedPropertyType.AnimationCurve:
return EditorGUI.CurveField(position,label,(AnimationCurve)value);
case SerializedPropertyType.Bounds:
return EditorGUI.BoundsField(position,label,(Bounds)value);
default:
throw new NotImplementedException("Unimplemented propertyType "+propertyType+".");
}
}
}
#endif
Usage:
class PropertySerializationTest : MonoBehaviour{
[SerializeProperty("Test")] // pass the name of the property as a parameter
public float test;
public float Test{
get{
Debug.Log("Getter called");
return test;
}
set{
Debug.Log("Setter called");
test = value;
}
}
}
I might be doing something wrong though.