What is mx_internal? When and How to use it?

I prefer the following two URLs to know better about the mx_internal on flex.

http://raghuonflex.wordpress.com/2007/09/03/mx_internal-a-life-saver/

http://codeofdoom.com/wordpress/2009/03/12/when-and-how-to-use-mx_internal-in-flex/

Flex Multiline Button

Here is the code that will help us to create a multilined button component in flex.

package com.kw.components
{
 import flash.display.DisplayObject;
 import flash.text.TextLineMetrics;

 import mx.controls.Button;
 import mx.core.IFlexDisplayObject;
 import mx.core.mx_internal;
 use namespace mx_internal;

 public class KWButton extends Button
 {
 public function KWButton()
 {
 super();
 }
 public var tagid:Number;
 override protected function createChildren():void
 {
 if (!textField)
 {
 textField = new NoTruncationUITextField();
 textField.styleName = this;
 addChild(DisplayObject(textField));
 }
 super.createChildren();
 textField.multiline = true;
 textField.wordWrap = true;
 textField.width = width;
 }
 override protected function measure():void
 {
 if (!isNaN(explicitWidth))
 {
 var tempIcon:IFlexDisplayObject = getCurrentIcon();
 var w:Number = explicitWidth;
 if (tempIcon)
 w -= tempIcon.width + getStyle("horizontalGap") + getStyle("paddingLeft") + getStyle("paddingRight");
 textField.width = w;
 }
 super.measure();
 }
 override public function measureText(s:String):TextLineMetrics
 {
 textField.text = s;
 var lineMetrics:TextLineMetrics = textField.getLineMetrics(0);
 lineMetrics.width = textField.textWidth + 4;
 lineMetrics.height = textField.textHeight + 4;
 return lineMetrics;
 }
 }
}
import mx.core.UITextField;
class NoTruncationUITextField extends UITextField
{
 public function NoTruncationUITextField()
 {
 super();
 }
 override public function truncateToFit(s:String = null):Boolean
 {
 return false;
 }
}

Time conversion, Seconds to minutes, hours

Here is the function that will help you to convert the given seconds to time format.

public static function formatTime ( time:Number ):String
 {
 var remainder:Number;            
 var hours:Number = time / ( 60 * 60 );            
 remainder = hours - (Math.floor ( hours ));            
 hours = Math.floor ( hours );            
 var minutes:Number = remainder * 60;            
 remainder = minutes - (Math.floor ( minutes ));            
 minutes = Math.floor ( minutes );            
 var seconds:Number = remainder * 60;            
 remainder = seconds - (Math.floor ( seconds ));            
 seconds = Math.floor ( seconds );            
 var hString:String = hours < 10 ? "0" + hours : "" + hours;    
 var mString:String = minutes < 10 ? "0" + minutes : "" + minutes;
 var sString:String = seconds < 10 ? "0" + seconds : "" + seconds;                        
 if ( time < 0 || isNaN(time)) return "00:00";                        
 if ( hours > 0 )
 {            
 return hString + ":" + mString + ":" + sString;
 }else
 {
 return mString + ":" + sString;
 }
 }