Swing / JScrollPane / setPrefferedSize question...

Java 2D
#1

Hey all.

I’ve basically got code like this:

JFrame has a JScrollPane in it which contains a JPanel. All this is created, the JFrame is shown, user can do whatever they want. User chooses a menu item that loads in a background image to the JPanel. The JPanel does the code to load in the image, then it says setPreferredSize(image.width, image.height). Unfortunately, the JScrollBar refuses to recognize the difference change until I resize the window. Then once the window is resized, scroll bars appear within the JScrollPane.

Does anyone know of some sort of update method I can call on the JScrollBar or the JPanel (or anything, really) that will cause the JScrollBar to recognize that the preferred size of the JPanel changed?

Thanks.

#2

Try calling revalidate() on the JScrollPane.

All JComponents have that method (from memory…)

#3

It might help you to see it in a larger context. This classic example helps:

How to Use Scroll Panes

#4

Revalidate did the job. Weird, because I thought I had tried that before. Thanks guys.