UILayerVisibleSwitcherOnSceneView.cs

using UnityEditor;
using UnityEngine;

namespace Kogane.Internal
{
    [InitializeOnLoad]
    internal static class UILayerVisibleSwitcherOnSceneView
    {
        private const string BUTTON_TEXT = " UI ";

        private static readonly Rect       m_buttonPosition = new Rect( 2, 2, 50, 20 );
        private static readonly int        m_uiLayerMask    = LayerMask.GetMask( "UI" );
        private static readonly GUIContent m_visibleContent = EditorGUIUtility.IconContent( "scenevis_visible_hover" );
        private static readonly GUIContent m_hiddenContent  = EditorGUIUtility.IconContent( "scenevis_hidden_hover" );

        static UILayerVisibleSwitcherOnSceneView()
        {
            m_visibleContent.text = BUTTON_TEXT;
            m_hiddenContent.text  = BUTTON_TEXT;

            SceneView.duringSceneGui += OnGUI;
        }

        private static void OnGUI( SceneView sceneView )
        {
            Handles.BeginGUI();

            var isVisible = ( Tools.visibleLayers & m_uiLayerMask ) != 0;
            var content   = isVisible ? m_visibleContent : m_hiddenContent;

            if ( GUI.Button( m_buttonPosition, content ) )
            {
                Tools.visibleLayers ^= m_uiLayerMask;
                SceneView.RepaintAll();
            }

            Handles.EndGUI();
        }
    }
}