Flex Smart Combo (aka look ahead combo)

package com.universalmind.controls
{
import flash.events.Event;
import flash.events.FocusEvent;
import flash.events.MouseEvent;

import mx.controls.ComboBox;

public class SmartCombo extends ComboBox
{
private var _trackText:String = "";
private var _caseSensitiveSearching : Boolean = true;

public function SmartCombo()
{
//TODO: implement function super();
}

public function set caseSensitiveSearching (bool : Boolean) : void {
_caseSensitiveSearching = bool;
}

public function get caseSensitiveSearching () : Boolean {
return _caseSensitiveSearching;
}

override protected function textInput_changeHandler(event:Event):void {
_trackText = this.textInput.text;

// variables used in the loop var label : String = null;
var matchingIdx : int = 0;
var foundMatch : Boolean = false;
var searchString : String = this.textInput.text;

if ( caseSensitiveSearching == false ) searchString = searchString.toLowerCase();


// using a for each loop on dataProvider does not strongly // couple to it only being an ArrayCollection... simlar // with weak typing on the items in the set for each ( var item : Object in this.dataProvider )
{
// using itemToLabel() checks a few things like // if the item is a String, or it there's a // labelFunction being used label = this.itemToLabel( item );


// if searching should not be case sensitive // do a toLowerCase() on label if ( this.caseSensitiveSearching == false )
{
label = label.toLowerCase();
}


// find the first item that starts with searchString // if there's a match, break out of the loop if ( label.substr( 0, searchString.length ) == searchString )
{
this.dropdown.selectedIndex = matchingIdx;
this.dropdown.scrollToIndex( matchingIdx );
foundMatch = true
break;
}
matchingIdx++;
}


// if there was no match found set selectedIndex to -1 // (unselect the list) if ( foundMatch == false )
{
this.dropdown.selectedIndex = -1;
}
}

override public function close(trigger:Event=null):void{
super.close(trigger);
if (this.text == "")
{
this.selectedIndex = 0;
}
this.editable = false;
}

override protected function focusOutHandler(event:FocusEvent):void
{
super.focusOutHandler(event);
if (this.text == "")
{
this.selectedIndex = 0;
}
this.textInput.selectionEndIndex = this.textInput.width;
this.editable = false;
}

override protected function focusInHandler(event:FocusEvent):void
{
super.focusInHandler(event);
this.editable = true;
this.textInput.setFocus();
this.open();
}


}
}