||A small window that allows the user to choose a color.
||A Panel that shows an array of little colored squares to allow the
user to pick a color.
||A layout manager used by the PropSheets.
||Class that defines the interface for several different kinds of
panels that can edit a group of properties.
||A PropSheet that shows only properties in a given Category.
||A widget that allows the user to edit rectangles in the property
||A window that displays a tabbed Property Sheet user interface with
one tab for each PropSheet instance that is added to this object.