Swing New User Interface - Opinions Please

[Stephen Boston]

Hi! Please take a look at the following code for a new user interface (that I plan to use sometime in the future). I've tied no events to any of the text fields or buttons. I'm mainly interested in your opinions in how I constructed the form itself.

I used several JPanels and 3 differnt Layout Managers to get my alignment set up. Is there a better way? Did I go over board on the Layout Managers?

This is pretty tough for someone that has only used VB to create desktop application interfaces.

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

public class MultiPanel extends JFrame
{
private JPanel buttonPanel;
private JPanel textPanel;
private JPanel flowPanel;

JLabel lbUserName = new JLabel("User Name:");
JLabel lbPassword = new JLabel("Password:");
JLabel lbConfirmPassword = new JLabel("Confirm Password");

JTextField tfUserName = new JTextField();

JTextField tfPassword = new JPasswordField();
JTextField tfConfirmPassword = new JPasswordField();

JButton bnOk = new JButton("Ok");
JButton bnCancel = new JButton("Cancel");

public MultiPanel()
{
super("New Membership");
Container c = getContentPane();
buttonPanel = new JPanel();
textPanel = new JPanel();
flowPanel =  new JPanel();

buttonPanel.setLayout(new GridLayout(1,0));
buttonPanel.add(bnOk);
buttonPanel.add(bnCancel);

flowPanel.setLayout(new FlowLayout());
flowPanel.add(buttonPanel);

textPanel.setLayout(new GridLayout(3,2,5,5));
textPanel.add(lbUserName);
textPanel.add(tfUserName);
textPanel.add(lbPassword);
textPanel.add(tfPassword);
textPanel.add(lbConfirmPassword);
textPanel.add(tfConfirmPassword);

c.add(flowPanel, BorderLayout.SOUTH);
c.add(textPanel, BorderLayout.NORTH);

setSize(300,200);
show();
 
}
public static void main(String args[])
{
MultiPanel app = new MultiPanel();
app.addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
});
}

}
  

Thanks for any observations you care to make.

Steve

[Michael Dunn]

Looks fine.

Unless you intend to include a "do you really want to quit" option, or similar,
the window listener can be replaced by
setDefaultCloseOperation(EXIT_ON_CLOSE);//in the constructor, or
app.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//in main()

[Stephen Boston]

Thank your for your input!

Yes that is the way I was headed.

How does this look? Action Handlers added now. Does this look like the correct way to do it?

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

public class MultiPanel extends JFrame 
{
private JPanel buttonPanel;
private JPanel textPanel;
private JPanel flowPanel;

JLabel lbUserName = new JLabel("User Name:");
JLabel lbPassword = new JLabel("Password:");
JLabel lbConfirmPassword = new JLabel("Confirm Password");

JTextField tfUserName = new JTextField();

JTextField tfPassword = new JPasswordField();
JTextField tfConfirmPassword = new JPasswordField();

JButton bnOk = new JButton("Ok");
JButton bnCancel = new JButton("Cancel");

public MultiPanel()
{
super("New Membership");
Container c = getContentPane();
buttonPanel = new JPanel();
textPanel = new JPanel();
flowPanel =  new JPanel();

addWindowCloseOperation();

ActionHandler aHandler = new ActionHandler();

buttonPanel.setLayout(new GridLayout(1,0));
buttonPanel.add(bnOk);
bnOk.addActionListener(aHandler);
buttonPanel.add(bnCancel);
bnCancel.addActionListener(aHandler);

flowPanel.setLayout(new FlowLayout());
flowPanel.add(buttonPanel);

textPanel.setLayout(new GridLayout(3,2,5,5));
textPanel.add(lbUserName);
textPanel.add(tfUserName);
textPanel.add(lbPassword);
textPanel.add(tfPassword);
textPanel.add(lbConfirmPassword);
textPanel.add(tfConfirmPassword);

c.add(flowPanel, BorderLayout.SOUTH);
c.add(textPanel, BorderLayout.NORTH);
setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);

setSize(300,200);
show();
 

}
    private void addWindowCloseOperation() 
    {
        addWindowListener(new WindowAdapter() 
        {
            public void windowClosing(WindowEvent e) 
            {
                boolean result = closePrompt();
                if(result)
                {
                System.exit(0);
                }
            }
        });
    }
 
private boolean closePrompt()
{
int result  = JOptionPane.showConfirmDialog(null, "Are your sure you want to quit?","Quit Prompt",JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE);

if ( result == JOptionPane.YES_OPTION)
{
return true;
}
else
{
return false;
}

}
private class ActionHandler implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
String passWord;
String confirmPassword;
if(e.getSource() == bnCancel)
{
boolean myResult = closePrompt();
if(myResult)
{
System.exit(0);
}
}
else
{
if(e.getSource() == bnOk)
{
System.out.println(tfUserName.getText());
passWord = tfPassword.getText();
confirmPassword = tfConfirmPassword.getText();
System.out.println("Ok clicked");
if(passWord.equals(confirmPassword))
{
System.out.println("Match");
}
else
{
JOptionPane.showMessageDialog(null, "Password and Confirm password do not match!","Error",JOptionPane.ERROR_MESSAGE);
tfPassword.setText("");
tfConfirmPassword.setText("");
tfPassword.requestFocus();
}
}
}
}
}
public static void main(String args[])
{
MultiPanel app = new MultiPanel();
}

}
  

[Michael Dunn]

Looks OK, and easy to follow.

couple of minor things

1. tfPassword.requestFocus();
from the java api docs for requestFocus():
"Because the focus behavior of this method is platform-dependent, developers
are strongly encouraged to use requestFocusInWindow when possible."

2. passWord = tfPassword.getText();
from the java api docs for getText():
"For security reasons, this method is deprecated. Use the * getPassword
method instead."

the return value of getPassword() is a character array, which is easily
convertable to a string - one of the string constructors accepts a character
array as an argument.

[Stephen Boston]

Thank you Michael!
I will modify my app to include those suggestions.

My head hurts, but I think I'm starting to get the swing of things. :roll: