Draw custom type Fields in the Inspector

Unity Engine
1

I’ve been trying for a while to draw fields for custom classes/structs.
Right now the only clue I have involves serializing the Editor itself :

    [CustomEditor(typeof(Constellation))]
    public class ConstellationEditor : Editor {
        [SerializeField]StarLink captured; // custom Struct, NOT a property of the Editor's target.

        public override void OnInspectorGUI () {
            var obj = new SerializedObject (this);
            EditorGUILayout.PropertyField (obj.FindProperty("captured"), true);
        }
      
    }

When doing so, the StarLink field does show in the inspector using its custom PropertyDrawer, but it appears disabled and it’s values can’t be edited.
I picked this solution from this thread about EditorWindows.Tried it for myself, and it does work flawlessly when using an EditorWindow instead of an inspector.

2

Did you find the example of how to write an Editor and how to use SerializedObject already?

3

I did, but that is for editing values on the Editor’s target. I’m trying to edit a property of the Editor itself, a temporary data that won’t be saved to the target until it is deemed valid.
(The solution I picked up there was from people trying to expose a field in an EditorWindow, where there is no target.)