Multiple panels in JFrame

Question

The useless Layout Manager guy is back again, I just can't seem to get my head around these darn layouts and make them work the way I want.

Anyway, I want to have a JFrame which has one large panel at the top (I call it a header) which runs from the left to right side of the frame at the north part of the frame, then four panels below it, two just below the header and two below those, and finally a "footer" panel, basically the same as the header panel, only at the south part of the frame.

Like this:

I had code which had the four middle panels working fine, but the header panel just messed everything up, and I have since been testing with the demo layout manager code for GridBagLayout, GridLayout again and BoxLayout. I can't getting any to work as I want.

For the aware of you here, you will probably notice I've already had a question related to this, and if having two similar questions are not allowed, please make me aware and I will move this to my previous question and this can be closed.

public Shop() {
        shopUI = new JFrame("Shop Menu");
        shopUI.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        shopUI.setBounds(100, 100, 700, 500);
        shopUI.setResizable(false);

        allPanels = new JPanel();

        headerPanel = new JPanel();
        headerPanel.setLayout(new BorderLayout());
        headerPanel.setBackground(Color.cyan);

        mainPanel = new JPanel();
        mainPanel.setLayout(new GridLayout(2,2));

        topLeft = new JPanel();
        topLeft.setBackground(Color.pink);

        topRight = new JPanel();
        topRight.setBackground(Color.black);

        bottomLeft = new JPanel();
        bottomLeft.setBackground(Color.green);

        bottomRight = new JPanel();
        bottomRight.setBackground(Color.blue);

        footerPanel = new JPanel();
        footerPanel.setLayout(new BorderLayout());
        footerPanel.setBackground(Color.magenta);

        mainPanel.add(topLeft);
        mainPanel.add(topRight);
        mainPanel.add(bottomLeft);
        mainPanel.add(bottomRight);

        allPanels.add(headerPanel, BorderLayout.NORTH);
        allPanels.add(footerPanel, BorderLayout.SOUTH);
        allPanels.add(mainPanel);

        shopUI.add(allPanels);

        shopUI.setVisible(true);
}

Answer 1

I suggest learning about border layout.

for what you want, put the header in the NORTH of the border panel, and the footer in the SOUTH. How you do your other panels depends a bit on what you want them to do; if you always want them to be the same size as each other, you can use a gridlayout for them; if not, you can use boxlayout to lay either the two pairs horizontally or the two pairs vertically, again depending on what you want them to do when the frame resizes.

I think using layout managers is simplified by deciding what you want to happen in the first place, including what happens when the frame is resized. That's a large part of what layouts are all about, anyway -- what stretches, what lines up, etc.

Anyway. what you have there looks like classic BorderLayout to me. Let us know if you need further help. Incidentally, BorderLayout is default for JFrame...

edit...

this will get more interesting when you put something in the panels...

package simpleborderlayout;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridLayout;

import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Main
{

    public static void main(String[] args)
    {
        Main main = new Main(args);
        main.go();
    }

    public Main(String ... args)
    {}

    public void go()
    {
        JPanel headerPanel = getPanel(Color.RED);
        JPanel footerPanel = getPanel(Color.BLUE);

        JPanel p1 = getPanel(Color.GRAY);
        JPanel p2 = getPanel(Color.GRAY);
        JPanel p3 = getPanel(Color.GRAY);
        JPanel p4 = getPanel(Color.GRAY);

        GridLayout gridLayout = new GridLayout(2,2);
        JPanel middlePanel = new JPanel(gridLayout);
        middlePanel.add(p1);
        middlePanel.add(p2);
        middlePanel.add(p3);
        middlePanel.add(p4);

        JFrame mainFrame = new JFrame();
        mainFrame.add(headerPanel, BorderLayout.NORTH);
        mainFrame.add(middlePanel, BorderLayout.CENTER);
        mainFrame.add(footerPanel, BorderLayout.SOUTH);
        mainFrame.pack();

        mainFrame.setVisible(true);

    }

    private JPanel getPanel(Color c)
    {
        JPanel result = new JPanel();
        result.setBorder(BorderFactory.createLineBorder(c));
        return result;
    }

}