About selecting a parent class

Most components have some common behavior and functionality. Flash includes two base classes to supply this commonality. By subclassing these classes, your components begin with a basic set of methods, properties, and events.

The following table briefly describes the two base classes:

Full class	Extends	Description
mx.core.UIObject	MovieClip	UIObject is the base class for all graphical objects. It can have shape, draw itself, and be invisible. UIObject provides the following functionality: Editing styles Event handling Resizing by scaling
mx.core.UIComponent	UIObject	UIComponent is the base class for all components. It can participate in tabbing, accept low-level events such as keyboard and mouse input, and be disabled so it does not receive mouse and keyboard input. UIComponent provides the following functionality: Creating focus navigation Enabling and disable components Resizing components

Full class

Extends

Description

mx.core.UIObject

MovieClip

UIObject is the base class for all graphical objects. It can have shape, draw itself, and be invisible.

UIObject provides the following functionality:

Editing styles
Event handling
Resizing by scaling

mx.core.UIComponent

UIObject

UIComponent is the base class for all components. It can participate in tabbing, accept low-level events such as keyboard and mouse input, and be disabled so it does not receive mouse and keyboard input.

UIComponent provides the following functionality:

Creating focus navigation
Enabling and disable components
Resizing components