title: Create a modal javafx.stage.FileChooser inside a swing application
body: <p>I have a Swing application the main window of which inherits <code>JFrame</code> class. This app is on transition to JavaFX so there is a lot on JavaFX components including control panels.
   I need to show native file chooser from non UI thread in modal way relatively to main <code>JFrame</code>.
  This could be achieved by setting an owner of <code>FileChooser</code> class, but it requires <code>javafx.stage.Window</code> to be the owner.
  Is there some hack to set <code>JFrame</code> as owner of javafx <code>FileChooser</code> or <code>Stage</code>?</p>