initImageCell: method is the designated initializer for NSCells that display images. The
initTextCell: method is the designated initializer for NSCells that display text. Override one or both of these methods if you implement a subclass of NSCell that performs its own initialization. If you need to use target and action behavior, you may prefer to subclass NSActionCell or one of its subclasses, which provide the default implementation of this behavior.
If you want to implement your own mouse-tracking or mouse-up behavior, consider overriding
stopTracking:at:inView:mouseIsUp:. If you want to implement your own drawing, override
If the subclass contains instance variables that hold pointers to objects, consider overriding
copyWithZone: to duplicate the objects. The default version copies only pointers to the objects.