J2ME in a Nutshell

Name

Form

Synopsis

Form is a subclass of Screen that is used to build form-like screens using Items. It inherits from its superclass the ability to have a title, a ticker and to have associated Commands and a CommandListener.

Items are usually added to a Form using the append(Item item) method, which adds the Item to the end of an internal list maintained by the Form. There are also two overloaded versions of this method that accept arguments of type String and Image. These methods are simply wrappers that add respectively a StringItem and an ImageItem to the form, with an empty label. It is also possible to insert an Item in between those already added by calling the insert() method, which requires the index of the Item before which the new one is to be added. The set() method can be used to replace an Item at a given index with a new one. Finally, the delete() method removes the Item at the supplied index. The total number of Items on a Form can be obtained from the size() method.

When rendered on the screen, Items appear on the Form from top to bottom in the order in which they appear in the Form’s internal list. With the exception of StringItem and ImageItem, each Item is rendered on a line of its own. When the Item is too wide to fit the screen, it may be shortened or, in the case of a StringItem, the text will overflow onto following lines as necessary. A Form is always as wide as the display area available to it, but its height may exceed the total viewable area of the screen. ...