In this section we only concerned ourselves with MenuBar and PullDown menu child widgets of MainWindow.
As has been previously mentioned the MainWindow can have several other children.
We cannot really study this aspect further as we have not introduced the other widgets themselves. (For example scroll bars)
We will refer to the MainWindow widget many times in this course.
NOTE: The attachment of widget to a parent MainWindow is standard - for example in menu_pull.c we attach a Label widget as a child which we then colour accordingly.