User Guide

450 Chapter 6: Components Dictionary
List component
The List component is a scrollable single- or multiple-selection list box. A list can also display
graphics, including other components. You add the items displayed in the list by using the Values
dialog box that appears when you click in the labels or data parameter fields. You can also use the
List.addItem() and List.addItemAt() methods to add items to the list.
The List component uses a zero-based index, where the item with index 0 is the top item
displayed. When adding, removing, or replacing list items using the List class methods and
properties, you may need to specify the index of the list item.
The list receives focus when you click it or tab to it, and you can then use the following keys to
control it:
Note: The page size used by the Page Up and Page Down keys is one less than the number of items
that fit in the display. For example, paging down through a ten-line drop-down list will show items 0-
9, 9-18, 18-27, and so on, with one item overlapping per page.
For more information about controlling focus, see “Creating custom focus navigation”
on page 50 or “FocusManager class” on page 419.
A live preview of each List instance on the Stage reflects changes made to parameters in the
Property inspector or Component inspector during authoring.
When you add the List component to an application, you can use the Accessibility panel to
make it accessible to screen readers. First, you must add the following line of code to
enable accessibility:
mx.accessibility.ListAccImpl.enableAccessibility();
You enable accessibility for a component only once, regardless of how many instances you have of
the component. For more information, see Chapter 17, “Creating Accessible Content,” in Using
Flash.
Key Description
Alphanumeric keys Jump to the next item that has
Key.getAscii() as the first character in its
label.
Control Toggle key that allows multiple noncontiguous selections and
deselections.
Down Arrow Selection moves down one item.
Home Selection moves to the top of the list.
Page Down Selection moves down one page.
Page Up Selection moves up one page.
Shift Allows for contiguous selection.
Up Arrow Selection moves up one item.
CHAPTER 6
Components Dictionary