How to use Custom property drawers in a ScriptableObject inspector?

Unity Engine
1

My custom property drawers are being applied to fields of MonoBehaviours when drawing a gameobject inspector. But an inspector of a ScriptableObject asset ignores custom property drawers, it shows the default field drawers instead.

Is there a way around this?

1 Like
2

Works for me…

//menu.cs  -  example
using UnityEngine;
using System.Collections;

public class menu : MonoBehaviour {

	public myOb someObject;

	void Reset () {
		someObject = (myOb) ScriptableObject.CreateInstance( typeof( myOb ) );
		someObject.asd = new Vector3( 1, 1, 1 );
	}

}



//myOb.cs
using UnityEngine;
using System.Collections;

public class myOb: ScriptableObject {
	public Vector3 asd;
	public float qwe;
}


//obDrawer.cs
using UnityEngine;
using UnityEditor;
using System.Collections;

[CustomPropertyDrawer( typeof( myOb ) )]
public class obDrawer : PropertyDrawer {

	public override float GetPropertyHeight ( SerializedProperty property, GUIContent label ) {
		return 32;
	}

	public override void OnGUI ( Rect position, SerializedProperty property, GUIContent label ) {
		position = EditorGUI.PrefixLabel( position, GUIUtility.GetControlID( FocusType.Passive ), label );
		position.height = 16;

		EditorGUIUtility.labelWidth = 50f;
		SerializedObject SO = new SerializedObject( property.objectReferenceValue );

		SerializedProperty myProp = SO.FindProperty( "asd" );
		myProp.vector3Value = EditorGUI.Vector3Field( position, "asd: ", myProp.vector3Value );

		myProp = SO.FindProperty( "qwe" );
		position.y += 16;
		myProp.floatValue = EditorGUI.FloatField( position, "qwe: ", myProp.floatValue );

		SO.ApplyModifiedProperties();
	}
}
1 Like
3

I think he meant without a wrapping MonoBehaviour…

ScriptableObject can be saved as .asset and browsed directly.

4

Thank you both for your replies. LightStriker is right, I’m working with .asset files that are ScriptableObjects. They contain rules for population a scene with GameObjects, which is why they are not part of a scene themselves. Selecting such a file will bring up the usual inspector, with default property drawers for all public fields. It’s just that this inspector ignores my custom drawers.

5

It works fine for me, within ScriptableObject assets. Here’s a cut-down example:

// MyPropertyType.cs

using System;

[Serializable]
public class MyPropertyType
{
	public string Value;
}

// Editor/MyPropertyDrawer.cs

using UnityEditor;
using UnityEngine;

[CustomPropertyDrawer(typeof(MyPropertyType))]
public class MyPropertyDrawer : PropertyDrawer
{
	private float _height = 100;
	private float _indent = 30;

	public override float GetPropertyHeight(SerializedProperty property, GUIContent label)
	{
		return _height;
	}
	
	public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
	{
		EditorGUI.BeginProperty(position, label, property);
		
		EditorGUI.PrefixLabel(position, GUIUtility.GetControlID(FocusType.Passive),
		                      new GUIContent(label.text));

		var valueProperty = property.FindPropertyRelative("Value");
		
		float labelHeight = base.GetPropertyHeight(property, label);

		var region = new Rect(position.x + _indent, position.y + labelHeight, position.width - _indent - 10, position.height - labelHeight - 10);
		
		EditorGUI.BeginChangeCheck();
		var newValue = EditorGUI.TextArea(region, valueProperty.stringValue);
		if (EditorGUI.EndChangeCheck())
		{
			valueProperty.stringValue = newValue;
		}

		EditorGUI.EndProperty();
	}
}

// TestScriptableObject.cs

using UnityEngine;

public class TestScriptableObject : ScriptableObject
{
	public MyPropertyType Field1;
	public MyPropertyType Field2;
}

// Editor/CreateTestScriptableObject.cs

using UnityEditor;
using UnityEngine;

public class CreateTestScriptableObject
{
	[MenuItem("Assets/Create/TestScriptableObject")]
	public static void CreateAsset()
	{
		var asset = ScriptableObject.CreateInstance<TestScriptableObject>();
		AssetDatabase.CreateAsset(asset, "Assets/Whatever.asset");
		AssetDatabase.SaveAssets();
	}
}

Execute the menu option to create “Whatever.asset”, then select it, and the Inspector should show multi-line TextArea boxes for editing the strings within the MyPropertyType fields.

6

Make sure you haven’t got the Inspector in “debug” mode though - in that mode it won’t use custom PropertyDrawers. I guess it’s a feature, as it lets you edit things the PropertyDrawers don’t expose.

1 Like
7

Thank you for the full example. Based on it I figured out why my custom drawer was ignored: the ScriptableObject class name has to match the name of the file it lives in, like it is for MonoBehaviours.

This is pretty obscure, because with non-matching names the asset still works fine besides ignoring custom drawers.

8 Likes
8

Hey one question, i have also a Scriptable Object type and used the scripts above to get my PropertyDrawer working, it works well for single Objects but as soon as i want to display a list of this Object in the inspector i get a strange behaviour. When i change lets say element 1 of the list every other element of this List gets the same value assigned. How can i fix this?

9

I’ve had the same problem as OP, except all my files were already matching the classes names.
In the end it turned out I was using an old asset I created very early, the PropertyDrawer did in fact work on newly created assets.

1 Like