Panel inside an applet

Question

Hi,
I have try to include a panel in applet with the code as follow:
private LoginPanel loginPanel = null;
public void init() {
loginPanel = new LoginPanel();
add(loginPanel);
the LoginPanel class is as follow:
import java.awt.*;
public class LoginPanel extends Panel {
private Button submitButton = null;
private Button resetButton = null;
private Label userIDLabel = null;
private Label userPwdLabel = null;
protected TextField userIDTextField = null;
protected TextField userPwdTextField = null;
public LoginPanel() {
super();
setFont(new Font("Serif", Font.PLAIN, 12));
setBackground(Color.white);
setLayout(new FlowLayout());
userIDLabel = new Label("User ID: ");
userIDLabel.setBackground(Color.yellow);
userPwdLabel = new Label("User Password: ");
userPwdLabel.setBackground(Color.yellow);
public void paint(Graphics g) {
Dimension d = getSize();
Point p = getLocation();
g.drawRect(p.x, p.y, d.width-1, d.height-1);
However, the paint function of the LoginPanel can't draw the the rectangle. Is there any problem with the code??
Thank you very much.

Answer 1

Hi,
Your problem relates to layoutManagers and has nothing to do with painting. By default an Applet and a Panel use FlowLayout manager. Your problem is that you don't give anything a size except for the applet. Therefore, your LoginPanel is very small. You have two choices to make it work.
1. Use a BorderLayout for the Applet layout manager and it will make sure that your LoginApplet is the same size as the Applet.
  public void init()
    loginPanel = new LoginPanel();
    setLayout( new BorderLayout() );
    add( loginPanel );
  }2. There is no setPrefferedSize method in AWT so you will need to override the getPrefferedSize method inside your LoginPanel class to give it some size. This is because FlowLayout will call this class in order to perform its' layout.
  public Dimension getPreferredSize()
    return( new Dimension( 500, 300 ) );
  }Regards,
Manfred.