JTabbedPane in JPanel?

Question

I have a simple problem when I want to add tabs in my jpanel. The alignment of the tabs get horizontal instead of vertical, wich looks like crap =/.

It looks like this:

If I discard the panel instead and add the tabbedPane directly to the frame, everything works fine. If you uncomment the three lines of code and remove the getContentPane().add(jtp); you can reproduce my probleme.

working Code:

public class TabbedPane extends JFrame
{
    public TabbedPane()
    {
        setTitle("Tabbed Pane");
        setSize(300, 300); // set size so the user can "see" it
        JTabbedPane jtp = new JTabbedPane();

        // JPanel panel = new JPanel();//uncomment all three lines
        // panel.add(jtp);
        // getContentPane().add(panel);

        getContentPane().add(jtp);//remove me

        JPanel jp1 = new JPanel();// This will create the first tab
        JPanel jp2 = new JPanel();// This will create the second tab

        JLabel label1 = new JLabel();
        label1.setText("This is Tab 1");
        jp1.add(label1);

        jtp.addTab("Tab1", jp1);
        jtp.addTab("Tab2", jp2);

        JButton test = new JButton("Press");
        jp2.add(test);

        setVisible(true); // otherwise you won't "see" it
    }

    public static void main(String[] args)
    {
        TabbedPane tab = new TabbedPane();
    }

}

Thanks a lot!

Answer 1

If I discard the panel instead and add the tabbedPane directly to the frame, everything works fine.

The default layout of JPanel is FlowLayout , which "lets each component assume its natural (preferred) size." The default layout of JFrame is BorderLayout , the CENTER of which ignores preferred size. In either case, invoking setSize() precludes the layout from functioning initially; re-size the frame to see the effect. Instead, use pack() , which "Causes this Window to be sized to fit the preferred size and layouts of its subcomponents."

setDefaultCloseOperation(EXIT_ON_CLOSE);
pack();
setVisible(true); // otherwise you won't "see" it

Answer 2

There are many things I would change in that code, starting with the recommendations of @trashgod. OTOH this is the minimal change needed in order to stretch the tabbed pane to the width/height of the parent container.

// give the panel a layout that will stretch components to available space
JPanel panel = new JPanel(new GridLayout());//uncomment all three lines
panel.add(jtp);
getContentPane().add(panel);

//getContentPane().add(jtp);//remove me

For more details see this answer .

Answer 3

Well firstly you can try this:

    JPanel panel = new JPanel();//uncomment all three lines
    panel.setLayout(new GridLayout());
    JPanel jp1 = new JPanel();// This will create the first tab
    JPanel jp2 = new JPanel();// This will create the second tab

    JLabel label1 = new JLabel();
    label1.setText("This is Tab 1");
    jp1.add(label1);

    jtp.addTab("Tab1", jp1);
    jtp.addTab("Tab2", jp2);

    JButton test = new JButton("Press");
    jp2.add(test);
    getContentPane().add(jtp);

and in the main:

    TabbedPane tab = new TabbedPane();
    tab.pack();
    tab.setVisible(true);

May I suggest using MigLayout to set layouts, it will make your life easier. Hope it helps.

Answer 4

Try GridbagLayout . Once you have mastered it, you can design UI of any sort with this layout.

Answer 5

I agree with prasanth regarding the use of GridBagLayout

I have gone through this problem once and I solved it by adding the JTabbedPane to the panel via GridBagLayout , make sure you add the JTabbedPane using the ipadx and ipady according to your requirements in your GridBagConstraints object eg

JPanel myPanel=new JPanel();
myPanel.setLayout(new GridBagLayout());
JTabbedPane jTP=new JTabbedPane();
jTP.add("Tab1",new JPanel());//substitute your component instead of "new JPanel"
GridBagConstraints myConstraints=new GridBagConstraints();
myConstraints.ipadx=400;//streches the component being added along x axis - 200 px on both sides
myConstraints.ipady=600;//streches the component being added along y axis - 200 px on both sides
myPanel.add(jTP,myConstraints);

You can adjust both these properties according to what is perfect for your need