This chapter describes the multi-purpose software controls called gadgets.
Gadgets are software controls symbolized by an image that the user can
operate with the mouse or keyboard.  They are the Amiga's equivalent of
buttons, knobs and dials.

Much of the user's input to an application takes place through gadgets in
the application's windows and requesters.  Gadgets are also used by
Intuition itself for handling screen and window movement and depth
arrangement, as well as window sizing and closing.

Intuition maintains gadget imagery, watches for activation and
deactivation and performs other management required by the gadget.  The
application can choose its level of involvement from simply receiving
gadget activation messages to processing the actual mouse button presses
and movements.  To make gadget programming even easier, Release 2 of the
Amiga operating system includes the new GadTools library.  Applications
written for Release 2 should take advantage of this new library (described
separately in the "gadtools library" chapter).

 about gadgets                    gadget pointer movements 
 gadget imagery                   gadget structure 
 gadget selection                 boolean gadget type 
 gadget size and position         proportional gadget type 
 gadget highlighting              string gadget type 
 gadget refreshing                custom gadgets 
 gadget enabling and disabling    function reference