Programming Flex 3

Chapter 10. Framework Utilities and Advanced Component Concepts

As you’ve already learned in earlier chapters, the Flex framework provides a large library of components, including layout containers and UI controls. However, in addition to the components themselves, the framework also provides libraries that offer you advanced features and functionality when working with those components. In this chapter, we’ll look at the features and functionality these libraries provide. Specifically, we’ll discuss tool tips, pop ups, cursor management, drag-and-drop, the ability to customize list-based items, and focus management and keyboard control.

Tool Tips

When an application contains graphics, it can often be helpful to users if you provide text-based descriptions to accompany the graphics. This is especially beneficial when the meaning of a particular UI element is not immediately obvious. It can also be useful for low-sighted and non-sighted users who rely on screen readers. Rather than cluttering the user interface with many text-based descriptions of graphics, however, many applications use tool tips, which are blocks of text that appear when the user moves the mouse over a visual element. In the following sections you’ll learn how to work with Flex tool tips.

Adding Tool Tips

All components that inherit from UIComponent (which includes all UI controls and layout containers) implement a toolTip getter/setter property, which allows you to assign a string to the object that it will use to ...