(JAVA) How to make Scroll, when adding new componet?

Question

If I add a new component, the scrollpane does not up update. Can I update it without creating a new JScrollPane?

 public void start(){
        getBox_Topics().setBorder(new TitledBorder(new EtchedBorder(),"Topics of vote"));
        add(new JScrollPane(getBox_Topics(),
                JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
                JScrollPane.HORIZONTAL_SCROLLBAR_NEVER));
        pack();
        setHandler(new ClientHandler_Thread(this));
        getHandler().start();
        setVisible(true);
    }

Buttons add the new component in Box:

@Berger Far from of this class, that haven't contains JScrollPane — Alexander Minyaev, Nov 06 '17 at 14:23
Try calling `revalidate()` on the panel that contains the added components . — Arnaud, Nov 06 '17 at 14:29
@Berger Ok. What name the listener, that calling after adding new component? — Alexander Minyaev, Nov 06 '17 at 14:40
Have a look at this question, it should be the same problem : https://stackoverflow.com/questions/22513032/how-to-force-refresh-repaint-a-jscrollpane — Arnaud, Nov 06 '17 at 14:42

score 0 · Accepted Answer · answered Nov 06 '17 at 15:58

The Box/JPanel must is fixed size. Or it must have MaximumSize.

public void start(){
    getBox_Topics().setBorder(new TitledBorder(new EtchedBorder(),"Topics of vote"));
    setScrollPane(new JScrollPane(getBox_Topics()));
    add(getScrollPane());
    getScrollPane().setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
    getBox_Topics().addContainerListener(new ContainerListener() {
        @Override
        public void componentAdded(ContainerEvent containerEvent) {
            getScrollPane().revalidate();
            getScrollPane().repaint();
        }

        @Override
        public void componentRemoved(ContainerEvent containerEvent) {

        }
    });
    pack();
    setHandler(new ClientHandler_Thread(this));
    getHandler().start();
    setVisible(true);
}

(JAVA) How to make Scroll, when adding new componet?

1 Answers1