I have JSplitPane with a JScrollPane on the top and a JPanel on the bottom. I'm using vertical split. When user tries to move the divider up and down a line (like the line in MS Paint) appears and it moves up and down respectively. This is very weird.
Just for testing, I tried horizontal split and this weird line didn't appear.
Does anyone have any idea on what might cause that line to appear while resizing the divider?