... common,are grouped together as s ubclasses of JTextComponent. Similarly JButton and JToggleButtonare subclasses of JAbstractButton, which represents properties common to both buttons andcheckboxes. ... ∗So, in practice, top-down design is often combined with bottom-up design. In bottom-updesign, the appr oach is to start “at the bottom,” with problems that you already know how to solve (and for ... problem and subdividing it intoconven ient p ieces, top-down programming tends to produce a design that is unique to thatproblem. It is unlikely that you will be able to take a large chunk of programming...