Putting a jpanel into a jframe

Question

I have a main JFrame which was created by:
public class ControllerGUI extends javax.swing.JFrameand inside this somewhere is a JPanel called myPanel.
I have a seperate class which is a JPanel created by:
public class Calc extends javax.swing.JPanelI am quite new to swing and have been using the GUI builder in Netbeans, so could someone please tell me how to put the seperate Calc JPanel into the JPanel myPanel which is in the JFrame. Is it something to do with creating a container for it? Thanks.
Thanks.

Answer 1

Not sure if you're still around, but here's a very simple example of putting a JPanel derived object into another JPanel. The Calc class here extends JPanel. It does nothing but shows a 3 by 3 grid of JLabels:
import java.awt.Color;
import java.awt.GridLayout;
import javax.swing.BorderFactory;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingConstants;
class Calc extends JPanel
    public Calc()
        setBorder(BorderFactory.createEmptyBorder(15, 0, 15, 0));
        // what the heck, have it show a 3x3 label grid
        setLayout(new GridLayout(0, 3, 10, 10)); // sets layout for the grid
        for (int i = 0; i < 3; i++)
            for (int j = 0; j < 3; j++)
                String labelString = "[" + (i + 1) + ", " + (j + 1) + "]";
                JLabel label = new JLabel(labelString);
                label.setBorder(BorderFactory.createLineBorder(Color.blue));
                label.setHorizontalAlignment(SwingConstants.CENTER);
                add(label); // adds each label to the grid
}Now I'll add it to myPanel which is a JPanel object, but before adding it, I'll set the myPanel's layout to be BorderLayout, and I'll add the Calc class to the CENTER position:
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class FooFrame extends JFrame
    // declare and initialize the myPanel JPanel object and
    // the myCalc Calc object:
    private JPanel myPanel = new JPanel();
    private Calc myCalc = new Calc();
    public FooFrame(String s)
        super(s);
        getContentPane().add(myPanel); // add myPanel to the contentPane making it the main panel
        setPreferredSize(new Dimension(500, 400));
        myPanel.setLayout(new BorderLayout());  // here set the layout of mypanel
        myPanel.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
        // create a title panel and add it to the top of myPanel
        JLabel title = new JLabel("Application Title");
        JPanel titlePanel = new JPanel(new FlowLayout()); // redundant since jpanels
                                                        //use flowlayout by default
        titlePanel.add(title);
        myPanel.add(titlePanel, BorderLayout.PAGE_START); // adds title to top of myPanel
        // create a button panel and add it to the bottom of myPanel
        // here we'll use gridlayout
        JPanel buttonPanel = new JPanel(new GridLayout(1, 2, 15, 0));
        JButton okButton = new JButton("OK"); // create buttons
        JButton cancelButton = new JButton("Cancel");
        buttonPanel.add(okButton); // add buttons to button panel
        buttonPanel.add(cancelButton);
        myPanel.add(buttonPanel, BorderLayout.PAGE_END); // adds buttonpanel to bottom of myPanel
        //** add the myCalc object to the center of the myPanel via borderlayout
        myPanel.add(myCalc, BorderLayout.CENTER);
    // initialize and show the JFrame
    private static void createAndShowUI()
        JFrame frame = new FooFrame("FooFrame");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    // but be careful to show the JFrame in a thread-safe manner:
    public static void main(String[] args)
        java.awt.EventQueue.invokeLater(new Runnable()
            public void run()
                createAndShowUI();
}