Scrollable flow panel

Question

I need to create a panel where I can put some rectangles and it automatically reorder just inserting a scrollbar and growing up vertically. Also this panel can be resizable and again the rectangles must to be reordered to correctly be displayed inside the panel.

Answer 1

Use a JScrollPane. If you never want a horizontal scroll bar you can add the following:

scrollPane.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);

(By default the scroll pane will add horizontal and vertical scroll bars when required.)

The scroll pane itself will only be resizeable if you add it to a Container with the appropriate layout manager; e.g.

JFrame frm = new JFrame();
frm.setLayout(new BorderLayout());
JScrollPane sp = new JScrollPane();
frm.add(sp, BorderLayout.CENTER); // Adding a component to the CENTER will cause the component to grow as the frame is resized.

Answer 2

If I understand the question you want components to wrap to the next line so that the panel grows vertically while the width remains fixed. If so then check out the WrapLayout