Applying tooltip styles from defaults.css file problem

Question

in flex library, create custom tooltip extend ToolTip
CustomToolTip code:
public class CustomToolTip extends ToolTip
then i want use custom skin like ToolTipBorderSkin, so i add into defaults.css
defaults.css code:
CustomToolTip
borderSkin: ClassReference("my.skins.ToolTipBorderSkin");
build it into swc file, then in my application use
when i set textinput tips, it doesn't use the new skin
if write this line in the application, it works fine.
import my.controls.CustomToolTip; CustomToolTip
i don't know why.
Thanks for any help.

Answer 1

Thank you for your reply, alex.
i have assign the tooltip as the tooltipClass
CustomToolTipManagerImpl.as  the code like this;
public class CustomToolTipManagerImpl extends ToolTipManagerImpl
  public function CustomToolTipManagerImpl ()
   super();
   toolTipClass = CustomToolTip;
and custome define the application preloader
public class PreloaderBar extends DownloadProgressBar
  public function PreloaderBar()
   super();
   registerClasses();
  protected function registerClasses():void
   Singleton.registerClass("mx.managers::IToolTipManager2", CustomToolTipManagerImpl);
the application add this line:
preloader="my.preloaders.PreloaderBar"
i build this in flex library, and define the CustomeToolTip borderSkin in defaults.css
if i set borderSkin in actionscript, it is ok, but if i set in defaults.css, it doesn't work
setStyle("borderSkin", ToolTipBorderSkin);