The constructor starts by calling its parent class's
constructor, which makes it a proper Frame
widget. It is not gridded in the parent; that is the
caller's job. Then the contained widgets are created and
gridded within self.
# - - - M e n u B a r . _ _ i n i t _ _
def __init__ ( self, parent ):
"""Constructor for MenuBar"""
#-- 1 --
# [ self := self as a Frame, ungridded ]
Frame.__init__ ( self, parent )
The button is a menubutton,
but there are many submenus. This whole drop-down menu
structure is built by Section 12.2, “MenuBar.__createHelp(): Create the
menu”.
#-- 2 --
# [ self := self with a new Menubutton added and
# gridded, leading to the help menu cascades ]
self.__helpButton = self.__createHelp()
self.__helpButton.grid ( row=0, column=0 )
The button is linked to the
.quit() method that exists on all Tkinter
widgets.
#-- 3 --
# [ self := self with a Quit button added and gridded
# that terminates execution ]
self.__quitButton = Button ( self, text='Quit',
font=BUTTON_FONT, command=self.quit )
self.__quitButton.grid ( row=0, column=1 )