Draw on top of collider handles in editor

Example code that draws a line on top of the top of a BoxCollider2D in a custom editor:

Code (CSharp):

1.  
2. using UnityEngine;
3. using UnityEditor;
4.  
5. [CustomEditor(typeof(SomeBehaviour))]
6. public class SomeInspector : Editor
7. {
8.     public void OnSceneGUI()
9.     {
10.         var bounds = ((SomeBehaviour)target).GetComponent<BoxCollider2D>().bounds;
11.         float z = 0f;
12.         Handles.color = Color.blue;
13.         Handles.DrawLine(new Vector3(bounds.min.x, bounds.max.y, z), new Vector3(bounds.max.x, bounds.max.y, z));
14.     }
15. }
16.  

Code (CSharp):

1.  
2. using UnityEngine;
3.  
4. [RequireComponent(typeof(BoxCollider2D))]
5. public class SomeBehaviour : MonoBehaviour
6. {
7. }
8.  

Draws on top of gizmos wireframe as it should regardless of component order:


Does not draw on top of handles in edit mode if BoxCollider2D is placed below SomeBehaviour:


How can I draw on top of handles in edit mode regardless of component order?

 

In the editor, subscribe to SceneView.onSceneGUIDelegate/SceneView.duringSceneGui. It is called after OnSceneGUI and OnToolGUI, meaning it will draw on top of both.

Code (CSharp):

1. using UnityEngine;
2. using UnityEditor;
3. [CustomEditor(typeof(SomeBehaviour))]
4. public class SomeInspector : Editor
5. {
6.     public void OnEnable()
7.     {
8.         SceneView.onSceneGUIDelegate += OnAfterSceneGUI;
9.     }
10.  
11.     public void OnDisable()
12.     {
13.         SceneView.onSceneGUIDelegate -= OnAfterSceneGUI;
14.     }
15.  
16.     public void OnAfterSceneGUI(SceneView sceneView)
17.     {
18.         var bounds = ((SomeBehaviour)target).GetComponent<BoxCollider2D>().bounds;
19.         float z = 0f;
20.         Handles.color = Color.blue;
21.         Handles.DrawLine(new Vector3(bounds.min.x, bounds.max.y, z), new Vector3(bounds.max.x, bounds.max.y, z));
22.     }
23. }