如何使垂直滚动条不可见？

Question

How do I make a vertical and or horizontal scroll bar invisible on a JScrollPane in java.

I've tried this, but doesn't work:

scrollPane.getVerticalScrollBar().setVisible(false);

Also, I would like to know how to make the bar visible again once it is not at a null state (I don't know the technical term) ie, see pic below. Bar is visible, but at a "null" state.

Also, is there a way to have the scroll bar remain invisible, but still allow for scrolling?

Answer 1

The method you want is JScrollPane.setVerticalScrollBarPolicy()

Valid values are:

• ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED
• ScrollPaneConstants.VERTICAL_SCROLLBAR_NEVER
• ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS

I'm not entirely sure what you need, but it seems that you want to be using ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED .

If those policies are not enough, you can write your wrapped view to implement the Scrollable interface, and you can change the policy inside the Scrollable.getScrollableTracksViewportHeight() method.