Draw Inspector within another Inspector

Hey everyone,

so while trying to draw an inspector within another inspector I almost decided to jump out of the window, but instead decided to post a thread. Maybe some Unity Dev or UI Guru can help me out. I'm on 2019.1.14f1.

The TL;DR is: using InspectorElement doesn't create PropertyFields, but instead they are empty. See this image:


The detailed version: I created a few simple scripts to test how to do it. The premise is simple: Draw the members from TestComponent2 in the Inspector of TestComponent1.

Code (CSharp):

1. public class TestComponent1 : MonoBehaviour
2. {
3.     public int TestValue1 = 15;
4.     public TestComponent2 RefToComponent;
5. }
6.  

Code (CSharp):

1. public class TestComponent2 : MonoBehaviour
2. {
3.     public int TestValue2 = 55;  
4. }

I have then created a simple CustomEditor for TestComponent2:

Code (CSharp):

1. [CustomEditor(typeof(TestComponent2))]
2. public class TestComponent2Editor : Editor
3. {
4.     public override VisualElement CreateInspectorGUI()
5.     {
6.         VisualElement root = new VisualElement();
7.         root.Add(new PropertyField(serializedObject.FindProperty("TestValue2")));
8.         return root;
9.     }
10. }

So far so good because eerything works as intended. Now to the apparently tricky stuff: I want to display the above inspector in the inspector of TestComponent1.

Code (CSharp):

1. [CustomEditor(typeof(TestComponent1))]
2. public class TestComponent1Editor : Editor
3. {
4.     public override VisualElement CreateInspectorGUI()
5.     {
6.         VisualElement root = new VisualElement();
7.         var prop = serializedObject.FindProperty("RefToComponent");
8.         root.Add(new PropertyField(serializedObject.FindProperty("TestValue1")));
9.         root.Add(new PropertyField(prop));
10.         if (prop.objectReferenceValue != null)
11.             root.Add(new InspectorElement(prop.objectReferenceValue));
12.         return root;
13.     }
14. }
15.  

The important bit is this line:
root.Add(new InspectorElement(prop.objectReferenceValue));
This innocent line actually doesn't really do anything. It creates the necessary elements but the PropertyField's are empty. There is nothing attached to it. How do I work around this issue?

 

What I did was I got the Editor for the object with

Code (CSharp):

1. editor = Editor.CreateEditor(object)

, then I check if it's a UIElements Inspector:

Code (CSharp):

1. var root = editor.CreateInspectorGUI()

then you have to check if the root is null. If the root is null, that means that it doesn't use UI Elements, so you can create a new IMGUIContainer, and in onGUIHandler callback, call

Code (CSharp):

1. editor.OnInspectorGUI()

.

You might need to fiddle around with it to get it to work with what you're working with, but that should give you a good starting point. Oh, and if it is a UI Elements inspector, then you'll of course want to add the "root" to your container element.

 

Thank you for taking the time to respond. I've played around with it a bit but to no avail. Still comming up with empty property fields. Can you provide your working example for me to analyse?

 

Oh, I see what your problem is. Your classes aren't serializable. You should be using the attribute System.Serializable.

Aside from that, I believe that you should be using ScriptableObjects. If I remember correctly, it is inadvisable to just use a regular class.

 

MonoBehaviours don't need the attribute System.Serializable because they are seriaizable by default. I don't use regular classes anywhere.

 

Oh, my mistake. Could you share a screenshot of what your inspector looks like?

 

It looks like your issue may be related to this bug I've just encountered here https://forum.unity.com/threads/adding-property-field-to-root-after-createinspectorgui.788402/

Although I'm doing something pretty different in my case I get a hierarchy that looks similar to yours with those empty Property Fields so I'm betting the underlying issue is the same or similar.