Adobe FLEX 2 - CREATING AND EXTENDING COMPONENTS Manual page 176

The following example shows the ModalText.as file that defines this control:
package myComponents
{
// Import all necessary classes.
import mx.core.UIComponent;
import mx.controls.Button;
import mx.controls.TextArea;
import flash.events.Event;
import flash.text.TextLineMetrics;
// ModalText dispatches a change event when the text of the child
// TextArea control changes, a textChanged event when you set the text
// property of ModalText, and a placementChanged event
// when you change the textPlacement property of ModalText.
[Event(name="change", type="flash.events.Event")]
[Event(name="textChanged", type="flash.events.Event")]
[Event(name="placementChanged", type="flash.events.Event")]
/*** a) Extend UIComponent. ***/
public class ModalText extends UIComponent {
/*** b) Implement the class constructor. ***/
public function ModalText() {
super();
}
/*** c) Define variables for the two child components. ***/
// Declare two variables for the component children.
private var text_mc:TextArea;
private var mode_mc:Button;
/*** d) Embed new skins used by the Button component. ***/
// You can create a SWF file that contains symbols
// ModalUpSkin, ModalOverSkin, and ModalDownSkin.
// If you do not have skins, comment out these lines.
[Embed(source="Modal2.swf", symbol="blueCircle")]
public var modeUpSkinName:Class;
[Embed(source="Modal2.swf", symbol="blueCircle")]
public var modeOverSkinName:Class;
[Embed(source="Modal2.swf", symbol="greenSquare")]
public var modeDownSkinName:Class;
/*** e) Implement the createChildren() method. ***/
// Test for the existence of the children before creating them.
// This is optional, but we do this so a subclass can create a
176 Creating Advanced Visual Components in ActionScript
with the names