Inheritance: DraggablePopupWindow
        //---------------------------------------------------------------------
        // Public
        //---------------------------------------------------------------------

        public static void ShowWindow()
        {
            Rect position = new Rect(CalcWindowPosition(), WINDOW_SIZE);
            RainbowFoldersWelcome window = GetDraggableWindow <RainbowFoldersWelcome>();

            window.Show <RainbowFoldersWelcome>(position);
        }
        private static void ShowWelcomeWindow(string guid, Rect rect)
        {
            if (EditorPrefs.GetBool(RainbowFoldersWelcome.PREF_KEY))
            {
                // ReSharper disable once DelegateSubtraction
                EditorApplication.projectWindowItemOnGUI -= ShowWelcomeWindow;
                return;
            }

            RainbowFoldersWelcome.ShowWindow();
            EditorPrefs.SetBool(RainbowFoldersWelcome.PREF_KEY, true);
        }