How to resize a panel if a child component is added with it at runtime?

Question

I have a window, containing a frame and JScrollBar. JScrollBar has panel, whose size i want to change at run time if any child component is added with it. Child component size is constant and should not change.

I have Horizontal scrollBar disabled. So if placement of Child Component exceeds panel width, it should go to next row and panel height should change automatically.

Here is code snippet

JScrollPane scrollPane = new JScrollPane();

menuPane = new JPanel();
menuPane.setLayout(new FlowLayout(FlowLayout.CENTER));

scrollPane.setViewportView(menuPane);

MenuTray mtFile = new MenuTray("File");    // MenuTray extends JPanel
menuPane.add(mtFile);

Menu mNew = new Menu((new ImageIcon(MenuScreen.class.getResource("/com/srinar/res/New.png"))), "New"); // Menu extends JLabel
mtFile.add(mNew);

frame.getContentPane().add(scrollPane);

For better help sooner, post a [MCVE] or [Short, Self Contained, Correct Example](http://www.sscce.org/). — Andrew Thompson, May 19 '16 at 06:41
It (the spec.) seems like a good description for a `JList` with an appropriate renderer.. — Andrew Thompson, May 19 '16 at 06:42
For [example](http://stackoverflow.com/a/5760093/230513) and [example](http://stackoverflow.com/a/25170471/230513). — trashgod, May 19 '16 at 09:21
I see an edit for an uncompilable code snippet. Any chance of seeing an MCVE any time soon? — Andrew Thompson, May 19 '16 at 14:44

score 2 · Answer 1 · answered May 19 '16 at 14:28

. So if placement of Child Component exceeds panel width, it should go to next row and panel height should change automatically

The FlowLayout will wrap components automatically but it doesn't recalculate the preferred size with the components on the new row.

Instead you can use the Wrap Layout which extends FlowLayout so it can recalculate the preferred size correctly when components wrap.

Note, the wrapping will occur even if you don't use a scroll pane.

How to resize a panel if a child component is added with it at runtime?

1 Answers1