Swing application using netBeans IDE

[Gopu Akraju]

I have a swing application developed using text editor. As I found it bit difficult to play around with layout manager, I thought of giving it a try using netbeans and slowly converting my original application. I have few buttons and JPanel. I am trying to add dynamically generated components like Jlabel and Jcheck box into my JPanel. Everything works perfectly fine without any error but I am not seeing any dynamically generated components inside my JPanel. What might be the problem? Thanks.

[Gopu Akraju]

I tried a small example as below. I created JPanel inside the frame using palette. And I added the code below into actionPerformed of a button.

JLabel title = new JLabel("Percent of Calories from Fat");
jPanel1.add(title);
jPanel1.revalidate();

Nothing is visible inside the JPanel (jPanel1). But when I count the number of components inside that JPanel, I am getting the correct number of components generated inside that JPanel. Why the dynamically generated components are invisible? Thanks.

[Gopu Akraju]

This is a small example. The label is not visible in the JPanel. Since I used netbeans I am posting the entire code generated. Please let me know why the component JLabel is not visible inside the panel. Still I couldn't figure it out.

/*
* test1.java
*
* Created on April 8, 2008, 3:11 PM
*/
package testing;
import javax.swing.JLabel;
public class test1 extends javax.swing.JFrame {
/** Creates new form test1 */
public test1() {
initComponents();
}
/** This method is called from within the constructor to
* initialize the form.
* WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
*/
// <editor-fold defaultstate="collapsed" desc=" Generated Code ">
private void initComponents() {
jButton1 = new javax.swing.JButton();
jPanel1 = new javax.swing.JPanel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jButton1.setText("create Label");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
org.jdesktop.layout.GroupLayout jPanel1Layout = new org.jdesktop.layout.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
.add(0, 553, Short.MAX_VALUE)
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
.add(0, 253, Short.MAX_VALUE)
);
org.jdesktop.layout.GroupLayout layout = new org.jdesktop.layout.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
.add(layout.createSequentialGroup()
.add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
.add(layout.createSequentialGroup()
.add(49, 49, 49)
.add(jButton1))
.add(layout.createSequentialGroup()
.addContainerGap()
.add(jPanel1, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)))
.addContainerGap(64, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
.add(layout.createSequentialGroup()
.add(33, 33, 33)
.add(jButton1)
.add(103, 103, 103)
.add(jPanel1, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
.addContainerGap(144, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
JLabel title = new JLabel("Percent of Calories from Fat");
jPanel1.add(title);
jPanel1.revalidate();
System.out.println("Label created");
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new test1().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton jButton1;
private javax.swing.JPanel jPanel1;
// End of variables declaration
}

[ April 08, 2008: Message edited by: Gopu Akraju ]

[Syam Sathyan George]

Hi,

Add the following code to locate your component in case its not drawn in visible are due to size issues. Trust me Netbeans generated Group Layouts can be tricky in space determination of components before laying them out!!

JLabel label =new JLabel("Hi");
label.setBorder(BorderFactory.createLineBorder(Color.Blue));
label.setPrefferedSize(new Dimension(60,30));

panel.add(label);


--Syam.Sathyan

[Gopu Akraju]

I tried as mentioned by Syam. But still it is not visible.

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
JLabel title = new JLabel("Percent of Calories from Fat");
title.setBorder(BorderFactory.createLineBorder(Color.blue));
title.setPreferredSize(new Dimension(60,30));
jPanel1.add(title);
jPanel1.revalidate();
System.out.println("Label created");
} 

[Shashika Thiran]

I,m not expert in java.I have same problem you mention.Accidently i found solution for that question.
Answer:
Create jframe in netbeans.
add panel to frame.
then right click on panel & go set layout.
select Grid layout.
now

Jlabel l=new Jlabel("Hiiii");
jpanel.add(l);
jpanel.revalidate();

It's work for me.