J2ME in a Nutshell

Name

List

Synopsis

List presents a list of alternatives to the user and allows one or more of them to be selected. Most of the methods of the List class are implementations of those specified by the Choice interface, which it implements, and are described in the reference entry for Choice. Since List is derived from Screen, it occupies the entire screen of the device and, unlike ChoiceGroup, cannot appear together with other controls.

A List can be constructed in Choice.EXCLUSIVE mode, when it behaves as a group of radio buttons, in Choice.MULTIPLE mode when it acts like a collection of check boxes or in Choice.IMPLICIT mode, which is usually used to create a full-screen menu. Both IMPLICIT and EXCLUSIVE modes allow only one entry in the LIST to be selected at any given time. The difference between these modes is the way they handle event notification as described below.

At any given time, one entry in the List control has the input focus. The user can move the focus to any entry in the list using keys on the keypad or the pointer, depending on the platform. The entry with the input focus will be highlighted in some way to distinguish it from the other entries and its state can be toggled between selected and unselected using a platform-dependent gesture.

Unlike ChoiceGroup, a List is not associated with an ItemStateListener because it is not an Item. How the application is made aware of selection changes depends on the mode.

In MULTIPLE and EXCLUSIVE modes, selection changes ...