Java - JScrollPane view layout with SpringLayout

Question

I have a JScrollPane that has a view component which uses SpringLayout.

final JPanel panel = new JPanel(new SpringLayout());
// add stuff to panel here
final JScrollPane scrollPane = new JScrollPane(panel, JScrollPane.VERTICAL_SCROLLBAR_NEVER, JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
getContentPane().add(scrollPane);

The JScrollPane doesn't seem to work, any help would be greatly appreciated!

Answer 1

Quoting from How to Use Scroll Panes

Unless you explicitly set a scroll pane's preferred size, the scroll pane computes it based on the preferred size of its nine components (the viewport, and, if present, the two scroll bars, the row and column headers, and the four corners). The largest factor, and the one most programmers care about, is the size of the viewport used to display the client.

• so you would have to either call setPreferedSize(Dimension d) on JScrollPane instance

  final JPanel panel = new JPanel(new SpringLayout());
  // add stuff to panel here
  final JScrollPane scrollPane = new JScrollPane(panel, JScrollPane.VERTICAL_SCROLLBAR_NEVER, JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
  scrollPane.setPreferredSize(new Dimension(300, 300));
  add(scrollPane);
  

• or override getPreferredSize() of your JPanel/ component used as view port

  final JPanel panel = new JPanel(new SpringLayout()) {
  
      @Override
      public Dimension getPreferredSize() {
           return new Dimension(300, 300);
       }
   };
   // add stuff to panel here
   final JScrollPane scrollPane = new JScrollPane(panel, JScrollPane.VERTICAL_SCROLLBAR_NEVER, JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
  add(scrollPane);
  

Other notes:

• do not extend JFrame class unnecessarily.

• simply call add(..) on JFrame instance as the call is forwarded to contentPane.