In addition, this chapter describes text entry fields and scrolling lists. If you need to, you can design your own controls, following the guidelines in this chapter. Controls are graphic objects that cause instant actions or audible results when the user manipulates them with the mouse. Users set controls that change settings to modify future actions. Controls also allow users to make choices or assign parameters in a range.
Controls display existing choices so that they are visible to users.
Because of their appearance and behavior, controls enhance the user's sense of direct manipulation. When an operation requires more than one object or when it needs additional information before it executes, the Macintosh interface uses dialog boxes or alert boxes to convey and gather information. These dialog boxes and alert boxes use controls that users manipulate to provide the additional input. Controls are also found in windows. Controls provide users with familiar tools and formats for responding to the computer's need for information.