Develop Reference

How to access value from one JDialog to another? [duplicate]

How do I wire output to paneWithList?
PaneWithList has a listener on its JList so that the selected row is output to the console. How can I direct that output to the JTextPane on output?
Could PaneWithList fire an event which Main picks up? Would PropertyChangeSupport suffice?
Main.java:
package dur.bounceme.net;
import javax.swing.JTabbedPane;
public class Main {
private static JTabbedPane tabs;
private static PaneWithList paneWithList;
private static PaneWithTable paneWithTable;
private static Output output;
public static void main(String[] args) {
tabs = new javax.swing.JTabbedPane();
paneWithList = new PaneWithList();
paneWithTable = new PaneWithTable();
tabs.addTab("list", paneWithList);
tabs.addTab("table", paneWithTable);
tabs.addTab("output", output);
}
}

Here's an example using the observer pattern, also seen here, here and here. Note that it would also be possible to listen to the combo's model.
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.*;
/**
* #see http://en.wikipedia.org/wiki/Observer_pattern
* #see https://stackoverflow.com/a/10523401/230513
*/
public class PropertyChangeDemo {
public PropertyChangeDemo() {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setResizable(false);
f.add(new ObserverPanel());
f.pack();
f.setLocationByPlatform(true);
f.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
PropertyChangeDemo example = new PropertyChangeDemo();
}
});
}
}
class ObserverPanel extends JPanel {
private JLabel title = new JLabel("Value received: ");
private JLabel label = new JLabel("null", JLabel.CENTER);
public ObserverPanel() {
this.setBorder(BorderFactory.createTitledBorder("ObserverPanel"));
JPanel panel = new JPanel(new GridLayout(0, 1));
panel.add(title);
panel.add(label);
this.add(panel);
ObservedPanel observed = new ObservedPanel();
observed.addPropertyChangeListener(new PropertyChangeListener() {
#Override
public void propertyChange(PropertyChangeEvent e) {
if (e.getPropertyName().equals(ObservedPanel.PHYSICIST)) {
String value = e.getNewValue().toString();
label.setText(value);
}
}
});
this.add(observed);
}
}
class ObservedPanel extends JPanel {
public static final String PHYSICIST = "Physicist";
private static final String[] items = new String[]{
"Alpher", "Bethe", "Gamow", "Dirac", "Einstein"
};
private JComboBox combo = new JComboBox(items);
private String oldValue;
public ObservedPanel() {
this.setBorder(BorderFactory.createTitledBorder("ObservedPanel"));
combo.addActionListener(new ComboBoxListener());
this.add(combo);
}
private class ComboBoxListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent ae) {
String newValue = (String) combo.getSelectedItem();
firePropertyChange(PHYSICIST, oldValue, newValue);
oldValue = newValue;
}
}
}

I'd be use JMenu with JMenuItems with contents layed by using CardLayout rather than very complicated JTabbedPane(s)

For my own reference, and for anyone using the Netbeans GUI builder, this works so far as it goes:
The PanelWithList class:
package dur.bounceme.net;
public class PanelWithList extends javax.swing.JPanel {
public PanelWithList() {
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.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jScrollPane1 = new javax.swing.JScrollPane();
jList1 = new javax.swing.JList();
jScrollPane2 = new javax.swing.JScrollPane();
jTextArea1 = new javax.swing.JTextArea();
jList1.setModel(new javax.swing.AbstractListModel() {
String[] strings = { "Item 1", "Item 2", "Item 3", "Item 4", "Item 5" };
public int getSize() { return strings.length; }
public Object getElementAt(int i) { return strings[i]; }
});
jList1.setSelectionMode(javax.swing.ListSelectionModel.SINGLE_SELECTION);
jList1.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent evt) {
jList1MouseClicked(evt);
}
});
jList1.addKeyListener(new java.awt.event.KeyAdapter() {
public void keyReleased(java.awt.event.KeyEvent evt) {
jList1KeyReleased(evt);
}
});
jScrollPane1.setViewportView(jList1);
jTextArea1.setColumns(20);
jTextArea1.setRows(5);
jScrollPane2.setViewportView(jTextArea1);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
this.setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(54, 54, 54)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 247, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, 308, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(167, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(35, 35, 35)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(jScrollPane2)
.addComponent(jScrollPane1))
.addContainerGap(166, Short.MAX_VALUE))
);
}// </editor-fold>
private void jList1MouseClicked(java.awt.event.MouseEvent evt) {
row();
}
private void jList1KeyReleased(java.awt.event.KeyEvent evt) {
row();
}
// Variables declaration - do not modify
private javax.swing.JList jList1;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JScrollPane jScrollPane2;
private javax.swing.JTextArea jTextArea1;
// End of variables declaration
private void row() {
Object o = jList1.getSelectedValue();
String s = (String)o;
jTextArea1.setText(s);
this.firePropertyChange("list", -1, 1);
}
}
and Frame.java as a driver:
package dur.bounceme.net;
public class Frame extends javax.swing.JFrame {
public Frame() {
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.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jTabbedPane1 = new javax.swing.JTabbedPane();
panelWithList1 = new dur.bounceme.net.PanelWithList();
panelWithTable1 = new dur.bounceme.net.PanelWithTable();
newJPanel1 = new dur.bounceme.net.PanelWithCombo();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
panelWithList1.addPropertyChangeListener(new java.beans.PropertyChangeListener() {
public void propertyChange(java.beans.PropertyChangeEvent evt) {
panelWithList1PropertyChange(evt);
}
});
jTabbedPane1.addTab("tab1", panelWithList1);
jTabbedPane1.addTab("tab2", panelWithTable1);
jTabbedPane1.addTab("tab3", newJPanel1);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 937, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jTabbedPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 913, Short.MAX_VALUE)
.addContainerGap()))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 555, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jTabbedPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 521, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(22, Short.MAX_VALUE)))
);
pack();
}// </editor-fold>
private void panelWithList1PropertyChange(java.beans.PropertyChangeEvent evt) {
System.out.println("panelWithList1PropertyChange ");
}
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
/*
* Set the Nimbus look and feel
*/
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/*
* If Nimbus (introduced in Java SE 6) is not available, stay with the
* default look and feel. For details see
* http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(Frame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(Frame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(Frame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(Frame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/*
* Create and display the form
*/
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Frame().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JTabbedPane jTabbedPane1;
private dur.bounceme.net.PanelWithCombo newJPanel1;
private dur.bounceme.net.PanelWithList panelWithList1;
private dur.bounceme.net.PanelWithTable panelWithTable1;
// End of variables declaration
}
The key being that panelWithList1PropertyChange is the listener on 'panelWithList' itself.
Because PanelWithList.firePropertyChange("list", -1, 1); cannot send Object nor String that I see, I'm not exactly sure how to get the value selected all the way from the JList up to the JFrame.
Hmm, well the API says yes it can send Objects. Have to check that out.
I think it's necessary to get some info about the model which the JList is using up to the JFrame. However, doesn't that break MVC? Or maybe that's the wrong approach.

send a input String from JPanel 1 to JPanel2 [duplicate]

How do I wire output to paneWithList?
PaneWithList has a listener on its JList so that the selected row is output to the console. How can I direct that output to the JTextPane on output?
Could PaneWithList fire an event which Main picks up? Would PropertyChangeSupport suffice?
Main.java:
package dur.bounceme.net;
import javax.swing.JTabbedPane;
public class Main {
private static JTabbedPane tabs;
private static PaneWithList paneWithList;
private static PaneWithTable paneWithTable;
private static Output output;
public static void main(String[] args) {
tabs = new javax.swing.JTabbedPane();
paneWithList = new PaneWithList();
paneWithTable = new PaneWithTable();
tabs.addTab("list", paneWithList);
tabs.addTab("table", paneWithTable);
tabs.addTab("output", output);
}
}

Here's an example using the observer pattern, also seen here, here and here. Note that it would also be possible to listen to the combo's model.
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.*;
/**
* #see http://en.wikipedia.org/wiki/Observer_pattern
* #see https://stackoverflow.com/a/10523401/230513
*/
public class PropertyChangeDemo {
public PropertyChangeDemo() {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setResizable(false);
f.add(new ObserverPanel());
f.pack();
f.setLocationByPlatform(true);
f.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
PropertyChangeDemo example = new PropertyChangeDemo();
}
});
}
}
class ObserverPanel extends JPanel {
private JLabel title = new JLabel("Value received: ");
private JLabel label = new JLabel("null", JLabel.CENTER);
public ObserverPanel() {
this.setBorder(BorderFactory.createTitledBorder("ObserverPanel"));
JPanel panel = new JPanel(new GridLayout(0, 1));
panel.add(title);
panel.add(label);
this.add(panel);
ObservedPanel observed = new ObservedPanel();
observed.addPropertyChangeListener(new PropertyChangeListener() {
#Override
public void propertyChange(PropertyChangeEvent e) {
if (e.getPropertyName().equals(ObservedPanel.PHYSICIST)) {
String value = e.getNewValue().toString();
label.setText(value);
}
}
});
this.add(observed);
}
}
class ObservedPanel extends JPanel {
public static final String PHYSICIST = "Physicist";
private static final String[] items = new String[]{
"Alpher", "Bethe", "Gamow", "Dirac", "Einstein"
};
private JComboBox combo = new JComboBox(items);
private String oldValue;
public ObservedPanel() {
this.setBorder(BorderFactory.createTitledBorder("ObservedPanel"));
combo.addActionListener(new ComboBoxListener());
this.add(combo);
}
private class ComboBoxListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent ae) {
String newValue = (String) combo.getSelectedItem();
firePropertyChange(PHYSICIST, oldValue, newValue);
oldValue = newValue;
}
}
}

I'd be use JMenu with JMenuItems with contents layed by using CardLayout rather than very complicated JTabbedPane(s)

For my own reference, and for anyone using the Netbeans GUI builder, this works so far as it goes:
The PanelWithList class:
package dur.bounceme.net;
public class PanelWithList extends javax.swing.JPanel {
public PanelWithList() {
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.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jScrollPane1 = new javax.swing.JScrollPane();
jList1 = new javax.swing.JList();
jScrollPane2 = new javax.swing.JScrollPane();
jTextArea1 = new javax.swing.JTextArea();
jList1.setModel(new javax.swing.AbstractListModel() {
String[] strings = { "Item 1", "Item 2", "Item 3", "Item 4", "Item 5" };
public int getSize() { return strings.length; }
public Object getElementAt(int i) { return strings[i]; }
});
jList1.setSelectionMode(javax.swing.ListSelectionModel.SINGLE_SELECTION);
jList1.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent evt) {
jList1MouseClicked(evt);
}
});
jList1.addKeyListener(new java.awt.event.KeyAdapter() {
public void keyReleased(java.awt.event.KeyEvent evt) {
jList1KeyReleased(evt);
}
});
jScrollPane1.setViewportView(jList1);
jTextArea1.setColumns(20);
jTextArea1.setRows(5);
jScrollPane2.setViewportView(jTextArea1);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
this.setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(54, 54, 54)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 247, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, 308, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(167, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(35, 35, 35)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(jScrollPane2)
.addComponent(jScrollPane1))
.addContainerGap(166, Short.MAX_VALUE))
);
}// </editor-fold>
private void jList1MouseClicked(java.awt.event.MouseEvent evt) {
row();
}
private void jList1KeyReleased(java.awt.event.KeyEvent evt) {
row();
}
// Variables declaration - do not modify
private javax.swing.JList jList1;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JScrollPane jScrollPane2;
private javax.swing.JTextArea jTextArea1;
// End of variables declaration
private void row() {
Object o = jList1.getSelectedValue();
String s = (String)o;
jTextArea1.setText(s);
this.firePropertyChange("list", -1, 1);
}
}
and Frame.java as a driver:
package dur.bounceme.net;
public class Frame extends javax.swing.JFrame {
public Frame() {
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.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jTabbedPane1 = new javax.swing.JTabbedPane();
panelWithList1 = new dur.bounceme.net.PanelWithList();
panelWithTable1 = new dur.bounceme.net.PanelWithTable();
newJPanel1 = new dur.bounceme.net.PanelWithCombo();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
panelWithList1.addPropertyChangeListener(new java.beans.PropertyChangeListener() {
public void propertyChange(java.beans.PropertyChangeEvent evt) {
panelWithList1PropertyChange(evt);
}
});
jTabbedPane1.addTab("tab1", panelWithList1);
jTabbedPane1.addTab("tab2", panelWithTable1);
jTabbedPane1.addTab("tab3", newJPanel1);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 937, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jTabbedPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 913, Short.MAX_VALUE)
.addContainerGap()))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 555, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jTabbedPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 521, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(22, Short.MAX_VALUE)))
);
pack();
}// </editor-fold>
private void panelWithList1PropertyChange(java.beans.PropertyChangeEvent evt) {
System.out.println("panelWithList1PropertyChange ");
}
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
/*
* Set the Nimbus look and feel
*/
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/*
* If Nimbus (introduced in Java SE 6) is not available, stay with the
* default look and feel. For details see
* http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(Frame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(Frame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(Frame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(Frame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/*
* Create and display the form
*/
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Frame().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JTabbedPane jTabbedPane1;
private dur.bounceme.net.PanelWithCombo newJPanel1;
private dur.bounceme.net.PanelWithList panelWithList1;
private dur.bounceme.net.PanelWithTable panelWithTable1;
// End of variables declaration
}
The key being that panelWithList1PropertyChange is the listener on 'panelWithList' itself.
Because PanelWithList.firePropertyChange("list", -1, 1); cannot send Object nor String that I see, I'm not exactly sure how to get the value selected all the way from the JList up to the JFrame.
Hmm, well the API says yes it can send Objects. Have to check that out.
I think it's necessary to get some info about the model which the JList is using up to the JFrame. However, doesn't that break MVC? Or maybe that's the wrong approach.

Having trouble moving a jButton

I'm trying to use Matisse in NetBeans to create a simple game...like Myst. I just want it to display a Frame that has things like a text field and buttons/inventory on the right. I can do that. Then I created a Jpanel that displays on the Frame. I've input some pictures and created a set of cards to make visible and invisible when needed. Each card/scene needs to have buttons that will be different for each scene. Basically I want to make transparent buttons for the user to press that do things (i.e. move to next picture/scene, find a key, etc...). I can create different buttons in each picture, but I can't seem to move them anywhere. I have a suspicion it's due to Matisse, but I don't know.
Here is some of the code, I'm sure it's crude as it's my first implementation of anything in Java. At the very bottom in the Scene to display I've added a button, that displays. I pretty much know now that the setBounds won't work due to the way position works...how would I then place it somewhere. Right now it just displays at the top mid of the picture.
SceneFrame:
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package main;
import scene.SecondPanel;
import scene.FirstPanel;
import scene.Scene;
import javax.swing.JButton;
public class SceneFrame extends javax.swing.JFrame {
private FirstPanel sceneP;
private SecondPanel sceneSP;
/**
* Creates new form SceneFrame
*/
public SceneFrame() {
initComponents();
addCards();
}
public void addCards() {
sceneP = new FirstPanel();
SceneManager.add("SecondPanel", sceneP);
sceneSP = new SecondPanel();
SceneManager.add("FirstPanel", sceneSP);
sceneP.setVisible(false);
}
/**
* 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.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
SceneManager = new scene.ScenePanel();
jButton1 = new javax.swing.JButton();
jButton2 = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
javax.swing.GroupLayout SceneManagerLayout = new javax.swing.GroupLayout(SceneManager);
SceneManager.setLayout(SceneManagerLayout);
SceneManagerLayout.setHorizontalGroup(
SceneManagerLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 517, Short.MAX_VALUE)
);
SceneManagerLayout.setVerticalGroup(
SceneManagerLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 421, Short.MAX_VALUE)
);
jButton1.setText("jButton1");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
jButton2.setText("jButton2");
jButton2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton2ActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(SceneManager, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jButton2, javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(jButton1, javax.swing.GroupLayout.Alignment.TRAILING))
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(139, 139, 139)
.addComponent(jButton1)
.addGap(18, 18, 18)
.addComponent(jButton2)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
.addGroup(layout.createSequentialGroup()
.addComponent(SceneManager, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(0, 97, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
sceneP.setVisible(false);
//SceneManager.showScene("SecondPanel");
sceneSP.setVisible(true);
}
private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {
sceneSP.setVisible(false);
//SceneManager.showScene("FirstPanel");
sceneP.setVisible(true);
}
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(SceneFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(SceneFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(SceneFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(SceneFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new SceneFrame().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JPanel SceneManager;
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton2;
// End of variables declaration
}
Scene:
package scene;
import java.awt.Color;
import javax.swing.JPanel;
import java.awt.Image;
import javax.swing.ImageIcon;
public abstract class Scene extends JPanel {
public Image image;
private String sceneName;
public Scene(String cn) {
setName(cn);
this.setSize(600, 600);
this.setBackground(Color.WHITE);
}
public String getCardName() {
return sceneName;
}
public abstract void addControlButtons();
// public abstract void implementControlButtons();
}
A Panel to display:
/**
* Creates a new ForestScene Object.
*/
public SecondPanel() {
super("SecondPanel");
JButton Button2 = new JButton("SwagCity");
try {
image = (new ImageIcon(getClass().getResource("/resources/ForestPath.jpg"))).getImage();
} catch (Exception e) {/*How to handle?*/
}
this.addControlButtons();
}
#Override
public void addControlButtons(){
JButton bButton = new JButton("bButton");
//bButton.setBounds(200, 300, 500, 600); //How to display where I want?
bButton.setAlignmentX(1000);
this.add(bButton);
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
//Graphics2D g2 = (Graphics2D) g;
if (image != null) {
boolean val = g.drawImage(image, 0, 0, 800, 600, this);
} else {
System.out.println("Image not found");
}
}
}

You need to add JFrame.frame.setLayout(null) so that you can adjust your fields(button,textfields) on to the frame.I too had a similar problem

I've figured out that it must be the layoutManager confusing something. If i set: this.setLayout(null); I can then set the bounds of the button and it displays where and how I want. I apologize if the question did not have enough information, but I did not know myself anymore than I told you. If anyone has anything to add about what I did, I'll be glad to select that as my answer.

JPanel dynamically generate outside from its original location

I'm dynamically generating some text boxes and labels inside a JPanel but when I place that panel inside a JTabbedPane it's not generate inside its original location. it always go to somewhere else.
Code inside JFrame class constructor:
panel = jPanel1;
panel.setLayout(new FlowLayout());
add(panel, BorderLayout.LINE_START);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
Code inside a JButton:
JLabel lbl = new JLabel();
lbl.setText("Label");
panel.add(lbl);
JTextField txt = new JTextField(12);
txt.setText("Text field");
panel.add(txt);
panel.revalidate();
validate();
The button is use to generate text boxes and labels dynamically. jPanel1 is a panel placed inside a frame. its works perfectly with directly placed inside a frame but after it is placed inside a tabbed pane it's messing around.
Is there a method to refresh panel and remove components inside it after generating components inside it?
here is the complete Jframe class:
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.LayoutManager;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
/**
*
* #author sajithru
*/
public class DynamicTextboxes extends javax.swing.JFrame {
/**
* Creates new form DynamicTextboxes
*/
private JPanel panel;
public DynamicTextboxes() {
initComponents();
panel = jPanel1;
panel.setLayout(new FlowLayout());
add(panel, BorderLayout.LINE_START);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
}
/**
* 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.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jButton1 = new javax.swing.JButton();
jTabbedPane1 = new javax.swing.JTabbedPane();
jPanel1 = new javax.swing.JPanel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jButton1.setText("jButton1");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 206, Short.MAX_VALUE)
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 258, Short.MAX_VALUE)
);
jTabbedPane1.addTab("tab1", jPanel1);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(190, 190, 190)
.addComponent(jButton1)
.addContainerGap(216, Short.MAX_VALUE))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jTabbedPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 211, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(16, 16, 16)
.addComponent(jTabbedPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 286, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jButton1)
.addContainerGap(40, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
JLabel lbl = new JLabel();
lbl.setText("Label");
panel.add(lbl);
JTextField txt = new JTextField(12);
txt.setText("Text field");
panel.add(txt);
panel.revalidate();
validate();
}
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(DynamicTextboxes.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(DynamicTextboxes.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(DynamicTextboxes.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(DynamicTextboxes.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new DynamicTextboxes().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton jButton1;
private javax.swing.JPanel jPanel1;
private javax.swing.JTabbedPane jTabbedPane1;
// End of variables declaration
}

I suspect that you are using setBounds(), or something similar, to position components in a Container that has some (default) layout lying in wait for your call to revalidate(). Instead, invoke pack() on the enclosing Window before calling setVisible().
Addendum: I tried using pack() … but result is still the same.
Your layout is cutting off the new rows. The example below uses pack() to resize the enclosing Window. This related example illustrates revalidate() and repaint(). Also consider using a JScrollPane, seen here.
import java.awt.BorderLayout;
import java.awt.GridLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
/**
* #see https://stackoverflow.com/a/17165034/230513
*/
public class DynamicTextboxes extends javax.swing.JFrame {
/**
* Creates new form DynamicTextboxes
*/
public DynamicTextboxes() {
initComponents();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
}
private void initComponents() {
jButton1 = new javax.swing.JButton();
jTabbedPane1 = new javax.swing.JTabbedPane();
jPanel1 = new javax.swing.JPanel(new GridLayout(0, 1));
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jButton1.setText("jButton1");
jButton1.addActionListener(new java.awt.event.ActionListener() {
#Override
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
jPanel1.add(createPanel());
jTabbedPane1.addTab("tab1", jPanel1);
add(jTabbedPane1);
JPanel p = new JPanel();
p.add(jButton1);
add(p, BorderLayout.SOUTH);
pack();
setLocationByPlatform(true);
}
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
jPanel1.add(createPanel());
pack();
}
private JPanel createPanel() {
JPanel p = new JPanel();
JLabel lbl = new JLabel();
lbl.setText("Label");
p.add(lbl);
JTextField txt = new JTextField(12);
txt.setText("Text field");
p.add(txt);
return p;
}
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
new DynamicTextboxes().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton jButton1;
private javax.swing.JPanel jPanel1;
private javax.swing.JTabbedPane jTabbedPane1;
// End of variables declaration
}

Java refreshing second form

I have two forms. First one is to decide numbers of button by using jslider. Second form is to display jbuttons according to jslider value. When i click jbutton2, the second form shows and display buttons. It is working perfectly. However, I want to create jbutton on the second form without clicking jbutton2 in the first form.
Instead, when I change jslider, it should create jbuttons on the second form at the run time and once i change jslider it should create that amount of button again on the second form and refreshing the second form button numbers according to jslider value.
I have tried revalidate();, repaint(); but they do not work, they dont refresh the second form.
So, How can I refresh second form when the jslider ,that is on the first form, changes ? Please help.....
Edit:I am using default Jframe of netbeans....
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
public class NewJFrame7 extends javax.swing.JFrame {
/**
* Creates new form NewJFrame7
*/
public NewJFrame7() {
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.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jSlider1 = new javax.swing.JSlider();
jButton2 = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jSlider1.setMajorTickSpacing(2);
jSlider1.setMaximum(20);
jSlider1.setMinimum(1);
jSlider1.setPaintLabels(true);
jSlider1.setPaintTicks(true);
jSlider1.setToolTipText("");
jSlider1.addChangeListener(new javax.swing.event.ChangeListener() {
public void stateChanged(javax.swing.event.ChangeEvent evt) {
jSlider1StateChanged(evt);
}
});
jButton2.setText("jButton2");
jButton2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton2ActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(29, 29, 29)
.addComponent(jSlider1, javax.swing.GroupLayout.PREFERRED_SIZE, 295, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(273, Short.MAX_VALUE))
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(262, 262, 262)
.addComponent(jButton2)
.addContainerGap(262, Short.MAX_VALUE)))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(87, 87, 87)
.addComponent(jSlider1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(168, Short.MAX_VALUE))
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(138, 138, 138)
.addComponent(jButton2)
.addContainerGap(139, Short.MAX_VALUE)))
);
pack();
}// </editor-fold>
private void jSlider1StateChanged(javax.swing.event.ChangeEvent evt) {
// TODO add your handling code here:
}
private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
form2 = true;
new NewJFrame8().setVisible(true);
}
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
/*
* Set the Nimbus look and feel
*/
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/*
* If Nimbus (introduced in Java SE 6) is not available, stay with the
* default look and feel. For details see
* http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(NewJFrame7.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(NewJFrame7.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(NewJFrame7.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(NewJFrame7.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/*
* Create and display the form
*/
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new NewJFrame7().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton jButton2;
private javax.swing.JSlider jSlider1;
// End of variables declaration
}
2.form
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
public class NewJFrame8 extends javax.swing.JFrame {
/**
* Creates new form NewJFrame8
*/
public NewJFrame8() {
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.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jPanel1 = new javax.swing.JPanel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addContainerGap(371, Short.MAX_VALUE)
.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(19, 19, 19))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(48, 48, 48)
.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(242, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
/*
* Set the Nimbus look and feel
*/
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/*
* If Nimbus (introduced in Java SE 6) is not available, stay with the
* default look and feel. For details see
* http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(NewJFrame8.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(NewJFrame8.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(NewJFrame8.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(NewJFrame8.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/*
* Create and display the form
*/
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new NewJFrame8().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JPanel jPanel1;
// End of variables declaration
}

One layout constraint (BorderLayout.CENTER) to place them, and one component to appear therein. (With apologies to Tolkien.)

Do check this sample Program, is this what you need. revalidate() and repaint() is what works here for this.
import java.awt.*;
import javax.swing.event.*;
import javax.swing.*;
public class SliderExample
{
private JSlider slider;
private static final int MIN_BUTTONS = 2;
private static final int SOME_BUTTONS = 4;
private static final int MAX_BUTTONS = 6;
private void createAndDisplayGUI()
{
ButtonPanel bp = new ButtonPanel();
JFrame frame = new JFrame("JSlider Example : ");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationByPlatform(true);
JPanel contentPane = new JPanel();
slider = new JSlider(JSlider.HORIZONTAL, MIN_BUTTONS, MAX_BUTTONS
, SOME_BUTTONS);
slider.addChangeListener(new ChangeListener()
{
public void stateChanged(ChangeEvent ce)
{
int value = (int) slider.getValue();
ButtonPanel.panel.removeAll();
for (int i = 0; i < value; i++)
{
ButtonPanel.panel.add(new JButton("JButton " + i));
}
ButtonPanel.panel.revalidate();
ButtonPanel.panel.repaint();
}
});
contentPane.add(slider);
frame.getContentPane().add(contentPane);
frame.pack();
frame.setVisible(true);
frame.requestFocusInWindow();
}
public static void main(String... args)
{
Runnable runnable = new Runnable()
{
public void run()
{
new SliderExample().createAndDisplayGUI();
}
};
SwingUtilities.invokeLater(runnable);
}
}
class ButtonPanel extends JFrame
{
public static JPanel panel;
public ButtonPanel()
{
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationByPlatform(true);
panel = new JPanel();
panel.setLayout(new GridLayout(0, 2));
getContentPane().add(panel);
setSize(300, 300);
setVisible(true);
}
}

import java.awt.*;
import java.awt.event.*;
import javax.swing.event.*;
import javax.swing.*;
public class SliderExample
{
private JSlider slider;
private static final int MIN_BUTTONS = 2;
private static final int SOME_BUTTONS = 4;
private static final int MAX_BUTTONS = 6;
private JButton[] buttonArray;
private ActionListener actionButton = new ActionListener()
{
public void actionPerformed(ActionEvent ae)
{
JButton button = (JButton) ae.getSource();
System.out.println(button.getText());
}
};
private void createAndDisplayGUI()
{
ButtonPanel bp = new ButtonPanel();
JFrame frame = new JFrame("JSlider Example : ");
frame.setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
frame.setLocationByPlatform(true);
JPanel contentPane = new JPanel();
slider = new JSlider(JSlider.HORIZONTAL, MIN_BUTTONS, MAX_BUTTONS
, SOME_BUTTONS);
slider.addChangeListener(new ChangeListener()
{
public void stateChanged(ChangeEvent ce)
{
int value = (int) slider.getValue();
ButtonPanel.panel.removeAll();
buttonArray = new JButton[value];
for (int i = 0; i < value; i++)
{
buttonArray[i] = new JButton(String.valueOf(i));
buttonArray[i].addActionListener(actionButton);
ButtonPanel.panel.add(buttonArray[i]);
}
ButtonPanel.panel.revalidate();
ButtonPanel.panel.repaint();
}
});
contentPane.add(slider);
frame.getContentPane().add(contentPane);
frame.pack();
frame.setVisible(true);
frame.requestFocusInWindow();
}
public static void main(String... args)
{
Runnable runnable = new Runnable()
{
public void run()
{
new SliderExample().createAndDisplayGUI();
}
};
SwingUtilities.invokeLater(runnable);
}
}
class ButtonPanel extends JFrame
{
public static JPanel panel;
public ButtonPanel()
{
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationByPlatform(true);
panel = new JPanel();
panel.setLayout(new GridLayout(0, 2));
getContentPane().add(panel);
setSize(300, 300);
setVisible(true);
}
}
For your statement this.buttonArray[i].addActionListener(this);, the reason as to why this is not working, is because, you are inside the object of anonymous class new ChangeListener(), which doesn't have anything named buttonArray[i] inside itself, it's the Instance Variable of SliderExample class, so either place an object of SliderExample class or if you are referring to your code, then use the Object of the class which initializes the array like inside inside NewFrame8 you had written JButton[] buttonArray = new JButton[120];, so use NewFrame8's object instead of this to refer to the buttonArray[i] thingy.