Professional Adobe® Flex® 3

Chapter 32. Using the List Components

This chapter starts the discussion on Flex 3's various list-based components. The topics covered include:

• ListBase

• List

• Menu

• TileBase

• HorizontalList

• TileList

ListBase Is Everywhere

You had a chance to learn about Collections API and the dataProvider property in Chapter 30. Having knowledge of the Collections API and dataProvider is very important to taking the next step in the discussion: mx.controls.listClasses.ListBase.

ListBase is an important class because it lays down the foundation necessary for managing how the user sees and interacts with the dataProvider data in your Flex applications. As an added benefit, ListBase inherits from mx.core.ScrollControlBase, providing ListBase objects data scrolling capabilities for situations in which there isn't enough display area allocated to the control to show all items at once.

The functionality derived from using the ListBase class as a base class is extensive. ListBase encompasses a user's interaction with the data displayed to that user within the controls that extend the ListBase class. Here is a list of controls that extend ListBase:

• mx.controls.List

• mx.controls.Menu

• mx.controls.Tree

• mx.controls.FileSystemList (Adobe AIR only)

• mx.controls.FileSystemTree (Adobe AIR only)

• mx.controls.HorizontalList

• mx.controls.TileList

• mx.controls.DataGrid

As you can see, Flex applications interact with the ListBase class indirectly through some of the UI controls most commonly used by Flex developers.

Those of you who are familiar ...