JScrollPane does not scroll properly: scrollRectToVisible acting up?

Question

I have got the following basic setup on a Part of my GUI:

A JScrollPane On it, a JPanel with a BoxLayout (new BoxLayout(tablePanel, BoxLayout.PAGE_AXIS)) And on this Panel, a Bunch ob Panels.

I am trying to scroll to the Panel that has been highlighted... this works ALMOST. Currenly, if a Panel is only half-visible on the bottom Part, the ScrollPane scrolls to make it fully visible.. great. If it is half-visible on the TOP part, it does not... I could live with that. But if a totally invisible Panel at the very bottom is highlighted, the system does not comment, but neither does it scroll there!

            if(selectedPanel!=null){
            Rectangle targetRectangle = new Rectangle(selectedPanel.getX(), selectedPanel.getY(), selectedPanel.getWidth(), selectedPanel.getHeight());
            Rectangle r = scrollPane.getVisibleRect();
            if (!r.contains(targetRectangle)) {
                tablePanel.scrollRectToVisible(targetRectangle);
            }
        }

I am unfortunately not 100% sure how it behaves when the second-to-last panel is selected while not visible, because I cannot make that happen without some code-gymnastics; perhaps someone can help with the information I can give at this point.

Answer 1

1. you have to compare Rectangle from/returns JViewport(visible rectangle from JScrollPane), not from JScrollPane

2. use selectedPanel.getBounds instead of (selectedPanel.getX(), selectedPanel.getY(), selectedPanel.getWidth(), selectedPanel.getHeight());

3. still isn't centerred, have to divide JVievports and selectedPanel with 2

4. the same result as to use single code line JComponentPlacedIntoJScrollPane.scrollRectToVisible(selectedPanel.getBounds())

5. for better help sooner post an SSCCE/MCVE, short, runnable, compilable