Applies preset layermask on scene open and restores it on scene closed. Made for use in custom ui prefab editing scenes to show the UI layer automatically.

CanvasEditorHelper.cs

#if UNITY_EDITOR
using UnityEngine;
using UnityEditor;

/// <summary>
/// Applies preset layermask on scene open and restores it on scene closed.
/// Made for use in custom ui prefab editing scenes to show the UI layer automatically.
/// </summary>
[ExecuteInEditMode]
public class CanvasEditorHelper : MonoBehaviour
{
    public LayerMask MaskPreset;

    private LayerMask oldMask;

    private void OnEnable()
    {
        oldMask = Tools.visibleLayers;
        Tools.visibleLayers = MaskPreset;
    }

    private void OnDestroy()
    {
        Tools.visibleLayers = oldMask;
    }
}
#endif