I am displaying a PDF document with following code (from the constructor of a class that extends JFrame):

        SwingController controller = new SwingController();
        controller.setPageViewMode(DocumentViewControllerImpl.ONE_PAGE_VIEW, true);

        DocumentViewControllerImpl vc = (DocumentViewControllerImpl) controller.getDocumentViewController();
        vc.setDocument(doc);
        vc.setCurrentPageIndex(currentPageIndex);
        vc.setZoom(0.5F);

        JScrollPane scroll = (JScrollPane) vc.getViewContainer();

        panel1.add(scroll, BorderLayout.CENTER);

        pack();
        setLocationRelativeTo(getOwner());

Then, I would like to ViewContainer to show any page I want, by using the following code inside a button listener:

        vc.setCurrentPageIndex(currentPageIndex);

Problem: whan I change the page this way, the viewContainer shrinks down to a very tiny area.

Put it in a different way: what is the right way to change the PDF page shown in the ViewContainer?