Problem in adding Jpanel to JFrame (Updated)

[Swapnil Sonawane]

Here is my code:

ApplicationDriver.java

 
// application
 
import java.awt.*;
import javax.swing.*;
public class ApplicationDriver {
    
    // The application window
    static MainFrame window;
 
    public static void main(String[] args) {
    
        // Create the app window
        try {
        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
    } 
    catch (Exception e) { 
    }

    window = new MainFrame();
    // Get the window toolkit
        Toolkit theKit = window.getToolkit();
        
        // Get screen size
        Dimension wndSize = theKit.getScreenSize();

window.setBounds(0,0,wndSize.width, wndSize.height);
LoginPanel contentPane = new LoginPanel();
contentPane.setVisible(true);
window.getContentPane().add(contentPane);
    window.setVisible(true);
    window.setResizable(false);
     }
}

MainFrame.java

 import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
 

/**
 * @author Swapnil Sonawane
 */
public class MainFrame extends JFrame {
public MainFrame() {
initComponents();
}
 
private void menuItem9MouseClicked(MouseEvent e) {
// TODO add your code here
}
 
private void menuItem9ActionPerformed(ActionEvent e) {
// TODO add your code here
}
 
private void initComponents() {
// JFormDesigner - Component initialization - DO NOT MODIFY  //GEN-BEGIN:initComponents
// Generated using JFormDesigner Evaluation license - Swapnil Sonawane
menuBar1 = new JMenuBar();
menu5 = new JMenu();
radioButtonMenuItem1 = new JRadioButtonMenuItem();
radioButtonMenuItem2 = new JRadioButtonMenuItem();
menuItem1 = new JMenuItem();
menu2 = new JMenu();
menu1 = new JMenu();
menuItem2 = new JMenuItem();
menuItem3 = new JMenuItem();
menuItem4 = new JMenuItem();
menu3 = new JMenu();
menu6 = new JMenu();
menuItem5 = new JMenuItem();
menuItem6 = new JMenuItem();
menuItem10 = new JMenuItem();
menu4 = new JMenu();
menuItem7 = new JMenuItem();
menuItem8 = new JMenuItem();
menuItem9 = new JMenuItem();
 
//======== this ========
setTitle("Library Time Manager 1.0");
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
setResizable(false);
LoginPanel contentPane = new LoginPanel();
contentPane.setVisible(true);
setContentPane(contentPane);


 
{ // compute preferred size
Dimension preferredSize = new Dimension();
for(int i = 0; i < contentPane.getComponentCount(); i++) {
Rectangle bounds = contentPane.getComponent(i).getBounds();
preferredSize.width = Math.max(bounds.x + bounds.width, preferredSize.width);
preferredSize.height = Math.max(bounds.y + bounds.height, preferredSize.height);
}
Insets insets = contentPane.getInsets();
preferredSize.width += insets.right;
preferredSize.height += insets.bottom;
contentPane.setMinimumSize(preferredSize);
contentPane.setPreferredSize(preferredSize);
}

setLocationRelativeTo(getOwner());
 
//---- buttonGroup1 ----
ButtonGroup buttonGroup1 = new ButtonGroup();
buttonGroup1.add(radioButtonMenuItem1);
buttonGroup1.add(radioButtonMenuItem2);
// JFormDesigner - End of component initialization  //GEN-END:initComponents
}
 
// JFormDesigner - Variables declaration - DO NOT MODIFY  //GEN-BEGIN:variables
 
private JMenuBar menuBar1;
private JMenu menu5;
private JRadioButtonMenuItem radioButtonMenuItem1;
private JRadioButtonMenuItem radioButtonMenuItem2;
private JMenuItem menuItem1;
private JMenu menu2;
private JMenu menu1;
private JMenuItem menuItem2;
private JMenuItem menuItem3;
private JMenuItem menuItem4;
private JMenu menu3;
private JMenu menu6;
private JMenuItem menuItem5;
private JMenuItem menuItem6;
private JMenuItem menuItem10;
private JMenu menu4;
private JMenuItem menuItem7;
private JMenuItem menuItem8;
private JMenuItem menuItem9;
// JFormDesigner - End of variables declaration  //GEN-END:variables
}

LoginPanel.java

   import javax.swing.*;
/**
 * @author Swapnil Sonawane
 */
public class LoginPanel extends JPanel {
public LoginPanel() {
initComponents();
}
 
private void initComponents() {
// JFormDesigner - Component initialization - DO NOT MODIFY  //GEN-BEGIN:initComponents
// Generated using JFormDesigner Evaluation license - Swapnil Sonawane
label1 = new JLabel();
label2 = new JLabel();
passwordField1 = new JPasswordField();
button1 = new JButton();
button2 = new JButton();
 
//======== this ========
 

//---- label1 ----
label1.setText("Enter the password to proceed . .");
label1.setHorizontalAlignment(SwingConstants.CENTER);
 
//---- label2 ----
label2.setText("Password:");
 
//---- button1 ----
button1.setText("Enter");
 
//---- button2 ----
button2.setText("Quit");
 
GroupLayout layout = new GroupLayout(this);

setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup()
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup()
.addGroup(layout.createSequentialGroup()
.addGap(93, 93, 93)
.addComponent(label1, GroupLayout.PREFERRED_SIZE, 212, GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addGap(117, 117, 117)
.addGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING, false)
.addGroup(layout.createSequentialGroup()
.addComponent(button1)
.addPreferredGap(LayoutStyle.ComponentPlacement.RELATED, GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(button2))
.addGroup(layout.createSequentialGroup()
.addComponent(label2, GroupLayout.PREFERRED_SIZE, 78, GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(passwordField1, GroupLayout.PREFERRED_SIZE, 67, GroupLayout.PREFERRED_SIZE)))))
.addContainerGap(95, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup()
.addGroup(layout.createSequentialGroup()
.addGap(35, 35, 35)
.addComponent(label1)
.addGap(55, 55, 55)
.addGroup(layout.createParallelGroup(GroupLayout.Alignment.BASELINE)
.addComponent(label2)
.addComponent(passwordField1, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE))
.addGap(63, 63, 63)
.addGroup(layout.createParallelGroup(GroupLayout.Alignment.BASELINE)
.addComponent(button1)
.addComponent(button2))
.addContainerGap(90, Short.MAX_VALUE))
);
// JFormDesigner - End of component initialization  //GEN-END:initComponents
}
 
private JLabel label1;
private JLabel label2;
private JPasswordField passwordField1;
private JButton button1;
private JButton button2;
// JFormDesigner - End of variables declaration  //GEN-END:variables
}
 

But I do not get the JPanel inside the JFrame. I can only see the JFrame. I am confused a lot.


EDIT 1: LoginPanel.java and MainFrame.java updated and irrelavent code removed. I got the JPanel inside the JFrame. How can I position it to the center? What if I want to change the content pane? Would simply creating an instance of some other JPanel like LoginPanel and passing it to setContentPane do?

[ October 09, 2008: Message edited by: Swapnil Sonawane ]
[ October 09, 2008: Message edited by: Swapnil Sonawane ]

[pete stein]

Originally posted by Swapnil Sonawane:
Here is my code:

and a lot of code it is. Please consider cutting this down to a reasonable size. You will have a greater chance that people will read it this way.

But I do not get the JPanel inside the JFrame. I can only see the JFrame. I am confused a lot.

What JPanel? When is it supposed to become visible? The more details you provide the easier it is for someone to know what you are trying to do, what is going wrong, what needs fixing.

One other thing: I see that you are coding Swing via NetBeans which I do not recommend at this stage in your Swing education as doing this will set this education back by at least 6 to 12 months. Sure use it after you know what you are doing, but not til then.

[Rob Spoor]

You add the controls to the GroupLayout, but nowhere do you actually add anything to any of the JPanels themselves.

Also, contentPane.setLayout(null); in MainFrame is a bad idea, especially if you never set the bounds of its components manually. Now the LoginPanel is at location 0,0 with a size of 0x0.

[Rob Spoor]

Originally posted by pete stein:
and a lot of code it is. Please consider cutting this down to a reasonable size. You will have a greater chance that people will read it this way.

I agree, but only partly. In this case, only the menu creation could be removed. All the other code is actually necessary for finding out the problem. You can't test a user interface without building it, now can you?

[Swapnil Sonawane]

I will clean up and post something that makes sense. I have to get the things clear.

1) Instead of having those labels and textfields in the loginpanel, I had created an instance of JPanel inside the LoginPanel. This happened because I made a mistake while using the GUI builder. I will rectify this now.
[ October 09, 2008: Message edited by: Swapnil Sonawane ]

[Rob Spoor]

You won't have to (although it doesn't hurt ), but again: add the components!

You need to add the following:

panel2.add(label1);
panel2.add(label2);
panel2.add(button1);
panel2.add(button2);
panel2.add(passwordField1);
this.add(panel2);

The order doesn't really matter, and the "this." part can be omitted. You can also specify some constraints when adding, although I don't think that's necessary with GroupLayout. It certainly isn't for FlowLayout (JPanel's default).

[Swapnil Sonawane]

I have rectified that part already. But I have some other doubt. Changing the location of LoginPane using setLocation or setBounds method doesn't change its location. Why does this happen?

[pete stein]

You may want to post your new code. Having said this, I recommend that you read up on using the Layout managers in the Sun Swing tutorials. You can find it here: Lesson: Laying Out Components Within a Container

It will show you how to lay out your components and JPanels without using null layout, without using setBounds.
[ October 09, 2008: Message edited by: pete stein ]

[Swapnil Sonawane]

I have edited my original code. But now I have switched to GridBagLayout (code not posted). After I include that in the JFrame, it is getting packed, but I don't want that and I haven't done the packing in the code.