Core JFC Java Foundation Classes 2nd edition - Read

1402 Chapter I I The Table Control
stored into. Since no column-based editors or Tenderers are installed, the
getColumnClass method that is used here is critical, because the value it
returns for each column determines which editor and renderer will be used.
The first column, which contains strings, will be rendered and edited by
the class-based renderer and editor for Object—a JLabel and a JText-
Field, respectively. These are sufficient because they both work in terms of
Strings, no matter what type of Object they are actually dealing with. The
second column contains Color objects. There is no standard renderer or editor
for Color, so the table would naturally use a JLabel to render and a
JTextField to edit the result of applying the toString method to the
Color object—which would produce a meaningless result. Here, however,
our ColorRenderer and ColorEditor will be installed as class-based
objects for the Color class so that they are used instead. If you run this
example with the command:
Java JFCBook.Chapter11.CustomEditorExample
you get a result that looks like Figure 11-17. Although the gray-scale reproduction
of this screen shot is not ideal, you can see that each persons name is
accompanied by a small icon filled with that person s favorite color, or at least
its gray-scale equivalent!
Figure 11-17 A table with a custom renderer for colors.
Implementing a Custom Color Renderer
Next, lets look at the implementation of ColorRenderer. This renderer will
be given a value from the table of type Color and will need to display a small
Icon filled with that color. Like the other Tenderers that you've seen, this one
is derived from Def aultTableCellRenderer and therefore uses a JLabel
as the host component. JLabel is a good choice for this example because, as
you know, it can display an Icon as well as, or instead of, text, so all the ren-