class BaseWidget(object):
	def __init__(self):
		pass
		
class InvisibleWidget(BaseWidget):
	pass
	
class BoxWidget(BaseWidget):
	def __init__(self, pos):
		self.pos = pos
		self.border = None
		self.background = None
		

class Button(BoxWidget):
	def __init__(self, pos, label, callback):
		BoxWidget.__init__(self, pos)
		
	def