How do I add ScrollPane to a panel in Java?

Question

I want to add different buttons, vertically stacked, to a JPanel at run-time and use a JScrollPane so that all buttons will be visible (with some scrolling).

In order to do this, I have added my JPanel to a JScrollPane, after which I add buttons to my JPanel.

However, when I do this the vertical scrollbar does not allow me to see all images. For example when I add 7 buttons I can only scroll to see 5 full images and half of the 6 images.

Why doesn't my scrollbar allow me to display all 7 buttons?

Answer 1

Make scroll pane a wrapper over your panel - new JScrollPane (myPanel) and add it instead of naked panel in your panel's container.

You also may want to play with its setPreferredSize() method.

Answer 2

Create the panel and scrollpane like:

JPanel panel = new JPanel();
JScrollPane scrollPane = new JScrollPane( panel );

When you add buttons to the panel at run time the code should be:

panel.add( button );
panel.revalidate();

As long as you are using a layout manager the preferred size will be recalculated and the scrollbar will appear.