def default_root
      # child Layout classes will return *their* UIView subclass from self.targets
      view_class = self.class.targets || MotionKit.default_view_class
      view_class.alloc.initWithFrame(UIScreen.mainScreen.applicationFrame)
    end
def default_root
      # child Layout classes will return *their* UIView subclass from self.targets
      view_class = self.class.targets || MotionKit.default_view_class
      view_class.alloc.initWithFrame(UIScreen.mainScreen.applicationFrame)
    end
platform specific default root view