How fetch the Title of a web page loaded in WebView and set it in a textfield? with Javafx

i'm trying to build a web browser using JavaFX .i want to get the title of web page loaded in the WebView. If i get the title i want to set it on a TextField that's what i did :

TextField text1 = new TextField() ;
WebEngine pp = wb.getEngine();
 String ko = pp.getTitle();
 text1.setText(ko);