It would be very nice to have some API for specifying
max/min width/height, relative to preferred size. For
example:

setMaximumSize(UNRESTRICTED, PREFERRED);
or
setMaximumWidth(Component.UNRESTRICTED_SIZE);
setMaximumHeight(Component.PREFERRED_SIZE);
setMinimumWidth(Component.PREFERRED_SIZE);

And maybe some API for specifying preferred size:
setPreferredWidth(Component.PREFERRED_SIZE, 20);
(to make it 20 pixels wider than normally preferred)
setPreferredWidth(Component.PREFERRED_SIZE, .2);
(to make it 20% wider than normally preferred)

API like this would let me cut out a few inner
classes from the Tutorial's examples, since I
wouldn't have to subclass a component just to
override, say, getMaximumSize. And the setPreferredWidth
method would let me avoid some blanket calls
like setPreferredSize(new Dimension(200, 100)),
which backfire if the user has a huge default font.