Re: Applet - Creating new objects from a Button Listener

From:
theneb <onetwofour@gmail.com>
Newsgroups:
comp.lang.java.programmer
Date:
5 May 2007 07:07:31 -0700
Message-ID:
<1178374051.356612.225310@o5g2000hsb.googlegroups.com>
On 23 Apr, 00:34, Knute Johnson <nos...@rabbitbrush.frazmtn.com>
wrote:

thenebwrote:

Hello everyone, I'm attempting to create JComponents from when a
button is clicked. However I'm assuming I'm missing something? (Or
it's not possible)

This is some quick prototype code which shows my intentions.

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

public class myApplet extends Applet implements ActionListener{

   private JPanel buttonPanel;
   private HashMap<String,testButton> buttons;

   private testButton myButton, secondButton, thirdButton;

   public void init(){
           buttonPanel = new JPanel();
           buttons = new HashMap<String,testButton>();
           buttons.put(String.valueOf(buttons.size()),new testButton());
           buttonPanel.add(buttons.get(String.valueOf(buttons.size()-1)));
           add(buttonPanel);
   }//end init

   public void start(){
           System.out.println("START");
   }

   public void actionPerformed(ActionEvent event) {
           System.out.println("Action");
   }

private class testButton extends JButton implements ActionListener{

   public testButton(){
           setText("Button "+buttons.size());
           addActionListener(this);
   }

   public void actionPerformed(ActionEvent event) {
           System.out.println("Adding New Button");
           buttons.put(String.valueOf(buttons.size()),new testButton());
           buttonPanel.add(buttons.get(String.valueOf(buttons.size()-1)));
   }

}

}//end myApplet

Example here:http://www.theneb.co.uk/applet-test/test.html

Cheers


After you add or remove components from a container you need to call
validate() and usually repaint(). This will cause the LayoutManager to
re-layout your components. If your containers are JComponents (which
JApplet is not) you can call revalidate() on the container to have the
LayoutManager re-layout the component.

Also, you are using JButtons and an Applet. You should not mix AWT and
Swing components. If you are going to use JButtons, use a JApplet.

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

public class test extends JApplet {
     public void init() {
         setLayout(new FlowLayout());

         JButton add = new JButton("Add a Button");
         add.addActionListener(new ActionListener() {
             public void actionPerformed(ActionEvent ae) {
                 test.this.add(new Tutton("Press Me"));
                 test.this.validate();
                 test.this.repaint();
             }
         });
         add(add);
     }

     class Tutton extends JButton implements ActionListener {
         public Tutton(String text) {
             super(text);
             addActionListener(this);
         }
         public void actionPerformed(ActionEvent ae) {
             test.this.remove((JComponent)ae.getSource());
             test.this.validate();
             test.this.repaint();
         }
     }

}

--

Knute Johnson
email s/nospam/knute/


Appoligies for a late reply, thanks to all. My code now fully works.

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