Question

I have been searching around for an easy way to implement a JScrollPlane. I am trying to add it to a JPanel, and it will contain a dynamic number of JPanels (which will be filled with other stuff).

Here is my (failing miserably) attempt to make said JScrollPane:

final JPanel info = new JPanel();
final JScrollPane infoS = new JScrollPane(info,ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED,ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED);
info.setLayout(new GridLayout(0,1));
info.setLocation(10,78);
info.setSize(420,490);
infoS.setPreferredSize(new Dimension(600, 600));
gui.add(infoS);

Answer 1

The primary problem you’re having is the fact that the default layout manager’s layout is set to FlowLayout, which means that the JScrollPane will want to use it’s preferred size to be layout with, which may not fill the entire panel.

Instead, use a BorderLayout

final JPanel info = new JPanel(new BorderLayout()); // <-- Change me :D
final JScrollPane infoS = new JScrollPane(info,ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED,ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED);
// These are bad ideas, setLocation and setSize won't work, as the panel should be
// under the control of a layout manager
//info.setLocation(10,78);
//info.setSize(420,490);
//infoS.setPreferredSize(new Dimension(600, 600));
gui.add(infoS);