def on_touch_down(self, touch):
        '''Receive a touch down event.

        :Parameters:
            `touch`: :class:`~kivy.input.motionevent.MotionEvent` class
                Touch received. The touch is in parent coordinates. See
                :mod:`~kivy.uix.relativelayout` for a discussion on
                coordinate systems.

        :Returns: bool
            If True, the dispatching of the touch event will stop.
            If False, the event will continue to be dispatched to the rest
            of the widget tree.
        '''
        if self.disabled and self.collide_point(*touch.pos):
            print("self={} is disabled, not dispatching".format(self))
            return True
        for child in self.children[:]:
            print("--- dispatch to {}".format(child))
            if child.dispatch('on_touch_down', touch):
                return True


# This is the output of pressing the button initially
'''
--- dispatch to <kivy.uix.stacklayout.StackLayout object at 0x7fd64d5bd8d0>
--- dispatch to <kivy.uix.button.Button object at 0x7fd64da571e8>
--- dispatch to <kivy.uix.button.Button object at 0x7fd64d5bdc10>
--- dispatch to <kivy.uix.boxlayout.BoxLayout object at 0x7fd64d5bda08>
--- dispatch to <kivy.uix.button.Button object at 0x7fd64d5bdba8>
--- dispatch to <kivy.uix.relativelayout.RelativeLayout object at 0x7fd64d5bdad8>
--- dispatch to <kivy.uix.widget.Widget object at 0x7fd64d5bdb40>
--- dispatch to <kivy.uix.button.Button object at 0x7fd64d5bd9a0>
--- dispatch to <kivy.uix.button.Button object at 0x7fd64d5bda70>
--- dispatch to <kivy.uix.button.Button object at 0x7fd64d5bd938>
'''

# This is the output of second press
'''
--- dispatch to <kivy.uix.stacklayout.StackLayout object at 0x7fd64d5bd8d0>
--- dispatch to <kivy.uix.button.Button object at 0x7fd64da571e8>
--- dispatch to <kivy.uix.button.Button object at 0x7fd64d5bdc10>
--- dispatch to <kivy.uix.boxlayout.BoxLayout object at 0x7fd64d5bda08>
--- dispatch to <kivy.uix.button.Button object at 0x7fd64d5bdba8>
--- dispatch to <kivy.uix.relativelayout.RelativeLayout object at 0x7fd64d5bdad8>
self=<kivy.uix.relativelayout.RelativeLayout object at 0x7fd64d5bdad8> is disabled, not dispatching
'''