BBCode permission

I'm writing a plugin for my forum where you can click on a custom BBCodeButton from the Redactor Iconbar/Editor.
Well this new Button should only be visible for user with permission. I've set up the permission option, and got a PHPfunction to look it up but my question is: Where should I check it to enable/disable the custom BBCode button wether the permission is set true or false?
I tried it in
public static function EditorSetup(XenForo_View $view, $formCtrlName, &$message, array &$editorOptions, &$showWysiwyg)
but its too early.