I've found a solution :D here it's the code
The trick were override the updateDisplayList.
Happy hacking.
package
{
import flash.display.DisplayObject;
import mx.controls.Image;
import mx.controls.TextInput;
import mx.core.mx_internal;
use namespace mx_internal;
public class MyTextInput extends TextInput
{
private var _image:Image;
public function MyTextInput()
{
super();
}
override protected function createChildren():void
{
super.createChildren();
_image = new Image();
_image.source = "http://sstatic.net/so/img/replies-off.png",
addChild(DisplayObject(_image));
}
override protected function updateDisplayList(unscaledWidth:Number, unscaledHeight:Number):void
{
super.updateDisplayList(unscaledWidth, unscaledHeight);
this._image.width = 16;
this._image.height = 16;
this._image.x = this.width - this._image.width - 5;
this._image.y = this.height - this._image.height;
this.textField.width = this.width - this._image.width - 5;
}
}
}