Adobe® Flex® 3 Bible

Chapter 18. Using Advanced List Controls

All list controls are not created equal. The two simplest list controls — the List and the ComboBox — display a single column of values and support the common functionality of custom labels, item renderers, and so on. But the ComboBox is really a compound control that allows the users to enter their own arbitrary values.

More complex list controls — such as the family of DataGrid components, the Tree control, and the TileList and HorizontalList—have their own unique capabilities. And as described briefly in Chapter 17, the AIR-based list controls have the ability to populate data from the local file system.

In Chapter 17, I described functionality that's common to all list controls, from the most fundamental to the most advanced. In this chapter, I describe the unique capabilities of specific data-driven controls, starting with the ComboBox and working up to the TileList, HorizontalList, and DataGrid.

Note

To use the sample code for this chapter, import the chapterl8.zip project from the Web site files into any folder on your disk.

Using the ComboBox Control

The ComboBox control is most like the basic List control in that it displays items in a single column. In terms of class inheritance, the two controls are related as cousins with a common ancestor. Figure 18.1 shows the two controls' direct superclass, up to their common UlComponent superclass.

Figure 18.1. The List and ComboBox inheritance hierarchies

Using an editable ComboBox

The ComboBox