Develop Reference

How to use a JPanel as JButton?

I must use a swing-ui designer tool to create my UI, that only supports graphically editing JPanels. Those panels (they basically contain complex button designs) to work like a JButton. I cannot use anything other than JPanel as base class of these panels (UI editor limitation).
What is the most generic solution to do this?
Create a custom button that uses the panel's draw method instead of
it's own?
Create a base-panel class that reimplements the whole
button?
Another more elegant solution?

Here is a quick demo, to show you how you could use borders to simulate a button.
The demo also reacts to mouse and key events :
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.Border;
import javax.swing.border.EtchedBorder;
public class JPanelButton extends JPanel {
Border raisedetched = BorderFactory.createEtchedBorder(EtchedBorder.RAISED);
Border loweredetched = BorderFactory.createEtchedBorder(EtchedBorder.LOWERED);
public static void main(final String[] args) {
JFrame frame = new JFrame();
final JPanelButton panel = new JPanelButton();
panel.raiseBorder();
panel.addMouseListener(new MouseAdapter() {
#Override
public void mousePressed(final MouseEvent e) {
panel.lowerBorder();
}
#Override
public void mouseReleased(final MouseEvent e) {
panel.raiseBorder();
}
});
panel.setFocusable(true); // you need this or the panel won't get the key events
panel.addKeyListener(new KeyAdapter() {
#Override
public void keyPressed(final KeyEvent e) {
panel.lowerBorder();
}
#Override
public void keyReleased(final KeyEvent e) {
panel.raiseBorder();
}
});
frame.setContentPane(panel);
frame.setSize(100, 100);
frame.setVisible(true);
}
public void raiseBorder() {
setBorder(raisedetched);
}
public void lowerBorder() {
setBorder(loweredetched);
}
}

Simply add MouseListener.
JPanel jp = new JPanel();
jp.addMouseListener(new MouseAdapter(){
public void mouseClicked(MouseEvent e) {
System.out.println("Clicked");
}
});
If this answer isn't specific enough, leave a comment and I'll give you more explanation.

unable to close JOptionPane properly in chain order

I am displaying a JOptionPane suppose A on a button click from JFrame, and again displaying another JOptionPane suppose B on a button click from JOptionPane A, and I have a button on JOptionPane B suppoce button1, on the click event of button1, I am using code JOptionPane.getRootFrame().dispose() for closing the JOptionPane B, but it closes both A and B, please help me how can close only B but not A.
here is my sample code
i want second JOptionPane must be open
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
public class SampleCode extends JFrame {
public SampleCode() {
setSize(new Dimension(500, 500));
setLocation(450, 150);
but1 = new JButton("Click me");
add(but1);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setVisible(true);
but1.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
but1Function();
}
});
}
public static void main(String args[]) {
new SampleCode();
}
void but1Function() {
JPanel panel1 = new JPanel();
JButton but2 = new JButton("Open new dialog");
panel1.add(but2);
but2.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
JPanel pan2 = new JPanel();
JButton but3 = new JButton("click me to close");
pan2.add(but3);
but3.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
JOptionPane.getRootFrame().dispose();
}
});
JOptionPane.showMessageDialog(null, pan2);
}
});
JOptionPane jp = new JOptionPane(panel1, JOptionPane.CLOSED_OPTION,
JOptionPane.DEFAULT_OPTION, null, new Object[] {}, null);
JDialog dialog = jp.createDialog(null, "This one must be remain open");
dialog.setLocation(500, 200);
dialog.setSize(new Dimension(345, 200));
dialog.setVisible(true);
}
JButton but1;
}

You don't want to get the root frame nor dispose of it. You want to get the window that is displaying the JOptionPane, a Window that should be a modal JDialog. So instead, use SwingUtilities.getWindowAncestor(someComponentInJOptionPane), and call dispose() on that Window if you want to programmatically dispose of your JOPtionPane.
import java.awt.Component;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class OptionPaneFun {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#SuppressWarnings("serial")
public void run() {
final JPanel panel1 = new JPanel();
panel1.add(new JButton(new AbstractAction("Show new option pane") {
{
putValue(MNEMONIC_KEY, KeyEvent.VK_S);
}
#Override
public void actionPerformed(ActionEvent e1) {
final JPanel panel2= new JPanel();
panel2.add(new JButton(new AbstractAction("Dispose of this option pane") {
{
putValue(MNEMONIC_KEY, KeyEvent.VK_D);
}
#Override
public void actionPerformed(ActionEvent e2) {
Component comp = (Component) e2.getSource();
Window win = SwingUtilities.getWindowAncestor(comp);
if (win != null) {
win.dispose();
}
}
}));
JOptionPane.showMessageDialog(panel1, panel2);
}
}));
JOptionPane.showMessageDialog(null, panel1);
}
});
}
}

The static method "getRootFrame()" returns your root frame which is the only one and it's the same for both your components (A and B). What you need to do - you have to put two frames in your root frame (call them frameA and frameB) and put paneA to frameA and paneB to frameB. Instead of calling this static method just invoke frameB.dispose() on reference frameB which you already have.

Try to add
panel.validiate();
After the dispose command. I had the same problem once and it helped a lot when I used this trick.
Basically when you add this command, it is telling the frame to validate or actually do it.
Read the oracle docs for more info.

Adding a panel from a method to a frame

I didn't really know how else to phrase that but essentially:
-I have a few separate "pieces" that I am trying to add onto a master frame; to keep the code from getting unwieldy I have each "piece" be its own class.
-I'm getting stuck on adding the panells onto the master frame, because the classes themselves aren't panels, rather the method of the class creates the panel, which creates issues that I don't know how to solve.
PIECE (works on its own when I have it make a dialog instead of be a panel):
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class PieceThing3 extends JPanel //<switched from JDialog
{
//set up variables here
private ActionListener pieceAction = new ActionListener()
{
public void actionPerformed (ActionEvent ae)
{
// Action Listener (this also works)
}
};
private void createPiece()
{
//setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
//setLocationByPlatform(true);
// the above are commented out when I switch from dialog to panel
JPanel contentPane = new JPanel();
//something that uses pieceAction is here
//two buttons, b and s, with action listeners are here
contentPane.add(b);
contentPane.add(s);
add(contentPane);
//pack();
//again, commented out to switch from dialog
setVisible(true);
System.out.println("hi I'm done");
//just to check and make sure it's done
}
public static void main(String[] args)
{
// TODO Auto-generated method stub
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new PieceThing3().createPiece();
}
});
}
}
Sorry that is very vague, but the intricacies are not as important as the general idea - it works perfectly when I have it create its own dialog box, but now I am trying to get it to make a panel within a master code, below:
MASTER:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class CollectGUI extends JFrame{
private void createDialog(){
this.setSize(2000,1000);
this.setLocation(0,0);
this.setTitle("TITLE");
PieceThing3 pt = new PieceThing3();
//HERE, if I do pt.main(null); while it is in "dialog mode" (rather than panel) it pops up a dialog box and everything is hunky dory. But I don't know how to get it to add the method as a panel.
this.add(pt.main(null));
//this gives an error
this.setVisible(true);
}
public static void main(String[] args) {
// TODO Auto-generated method stub
new CollectGUI().createDialog();
}
}
As I said in the comments, if I just do pt.main(null) when pt is set to make a dialog, it does it, but if I try to add pt.main(null) as a panel it throws an error. Can anybody give me some insight on how to add a method of a class rather than a class? I'm pretty stumped.
THANK YOU!!

You are definitely on the right track working to maintain separation of concerns and implement your gui in a number of distinct components. Try something like this:
Panel1
import javax.swing.JLabel;
import javax.swing.JPanel;
public class Panel1 extends JPanel {
public Panel1() {
this.add(new JLabel("This is panel 1"));
}
}
Panel2
import javax.swing.JLabel;
import javax.swing.JPanel;
public class Panel2 extends JPanel {
public Panel2() {
this.add(new JLabel("This is panel 2"));
}
}
JFrame
import java.awt.BorderLayout;
import javax.swing.JFrame;
import org.yaorma.example.jframe.panel.panel1.Panel1;
import org.yaorma.example.jframe.panel.panel2.Panel2;
public class ExampleJFrame extends JFrame {
public ExampleJFrame() {
super("Example JFrame Application");
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setSize(400,400);
this.setLayout(new BorderLayout());
Panel1 pan1 = new Panel1();
Panel2 pan2 = new Panel2();
this.add(pan1, BorderLayout.NORTH);
this.add(pan2, BorderLayout.SOUTH);
this.setVisible(true);
}
}
main:
public class ExampleApplication {
public static void main(String[] args) throws Exception {
new ExampleJFrame();
}
}
EDIT:
Here's a Panel1 with a little more content.
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import org.yaorma.example.action.sayhello.SayHelloAction;
public class Panel1 extends JPanel {
//
// instance variables
//
private JButton pressMeButton;
//
// constructor
//
public Panel1() {
this.setLayout(new BorderLayout());
this.add(new JLabel("This is panel 1"), BorderLayout.NORTH);
this.initPressMeButton();
}
//
// button
//
private void initPressMeButton() {
this.pressMeButton = new JButton("Press Me");
this.pressMeButton.addActionListener(new PressMeButtonActionListener());
this.add(pressMeButton, BorderLayout.SOUTH);
}
//
// method to get the parent jframe
//
private JFrame getParentJFrame() {
Container con = this;
while(con != null) {
con = con.getParent();
if(con instanceof JFrame) {
return (JFrame)con;
}
}
return null;
}
//
// action listener for Press Me button
//
private class PressMeButtonActionListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
JFrame jFrame = getParentJFrame();
SayHelloAction action = new SayHelloAction(jFrame);
action.execute();
}
}
}
Action called by button:
import javax.swing.JFrame;
import javax.swing.JOptionPane;
public class SayHelloAction {
private JFrame owner;
public SayHelloAction(JFrame owner) {
this.owner = owner;
}
public void execute() {
JOptionPane.showMessageDialog(owner, "Hello World");
}
}

JTextArea scroll to bottom only if text is appended

I am trying to create a JTextArea which scrolls to bottom every time a text is appended to that text area. Otherwise, the user should be able to scroll top and see previous message. I used this code:
JTextArea terminalText = new JTextArea();
JPanel terminal = new JPanel();
terminal.setLayout(new BorderLayout());
add(terminal); //Adds the terminal to mother JPanel
//I added scrollbar to my JTextArea
JScrollPane scroll = new JScrollPane(terminalText);
terminal.add(scroll, BorderLayout.CENTER);
scroll.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
scroll.getVerticalScrollBar().addAdjustmentListener(new AdjustmentListener() {
public void adjustmentValueChanged(AdjustmentEvent e) {
e.getAdjustable().setValue(e.getAdjustable().getMaximum());
}});
So far this code seems to make my text area scroll to bottom of the terminalText text area every time I append something to terminalText using terminalText.append.
However, the user cannot use scroll bar to scroll to the top to see previous message. Is there a way to fix this? Should I be using DocumentListener to achieve this?

Check out Smart Scrolling.
If the scrollbar is at the bottom, then as text is appended you will see the new text.
If the user has scrolled to a different position, then the viewport will stay there until the user scrolls back to the bottom.

As a simple (and rough) proof of concept...
This basically adds a DocumentListener to the JTextArea and on any Document event, use setCaretPosition to move the caret to the end of the document.
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Date;
import java.util.WeakHashMap;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.text.JTextComponent;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JTextArea ta = new JTextArea(10, 20);
ta.setWrapStyleWord(true);
ta.setLineWrap(true);
MoveToTheBottom.install(ta);
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new JScrollPane(ta));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
Timer timer = new Timer(500, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
ta.append(new Date().toString() + "\n");
}
});
timer.start();
}
});
}
public static class MoveToTheBottom implements DocumentListener {
private static WeakHashMap<JTextComponent, DocumentListener> registry = new WeakHashMap<>(25);
private JTextComponent parent;
protected MoveToTheBottom(JTextComponent parent) {
this.parent = parent;
parent.getDocument().addDocumentListener(this);
}
public static void install(JTextComponent parent) {
MoveToTheBottom bottom = new MoveToTheBottom(parent);
registry.put(parent, bottom);
}
public static void uninstall(JTextComponent parent) {
DocumentListener listener = registry.remove(parent);
if (listener != null) {
parent.getDocument().removeDocumentListener(listener);
}
}
#Override
public void insertUpdate(DocumentEvent e) {
parent.setCaretPosition(e.getDocument().getLength());
}
#Override
public void removeUpdate(DocumentEvent e) {
parent.setCaretPosition(e.getDocument().getLength());
}
#Override
public void changedUpdate(DocumentEvent e) {
parent.setCaretPosition(e.getDocument().getLength());
}
}
}
The example demonstrates a possible re-usable API which you can use to "install" and "uninstall" the support as reqiured

Refresh a Jlist from another JFrame

i want to refresh a JList when i push a button in another JFrame.
So i have a JFrame GuiBoss that manages employees (add,delete,update).When i press the button add, another Jframe opens, in wich i create a new employee.
//Open the "add_form" where i give details about a new employee.
private void btnAddActionPerformed(java.awt.event.ActionEvent evt) {
GuiBoss gb = new GuiBoss(contrb,boss);
Add_form af = new Add_form(gb,contrb,boss);
af.setVisible(true);
}
//refresh the list with the new employee added.
public void refresh(Employee e){
System.out.println("I reach this point!");
//if i print e.getName() it works, printing the right name that i give in the "add_form"
listModel.addElement(e);
//listModel.clear(); //don't work either.
}
My problem is that when i submit the details about the new employee i call the function refresh(Employee e) from the GuiBoss frame , the message ("I reach this point!") shows up on the console, the size of the listModel changes, but the list it doesen't refresh.
Also i must say that i set the model properly for the list.
//take data from form and call refresh(Employee e) from the main frame("GuiBoss")
private void btnAddActionPerformed(java.awt.event.ActionEvent evt) {
//String Id = txtID.getText();
String UserName = txtName.getText();
txtHour.setVisible(false);
boolean b = false;
if(rbtnYes.isSelected() == true){
b = true;
}
if(rbtnNo.isSelected() == true){
b = false;
}
if(rbtnYes.isSelected()==false && rbtnNo.isSelected() == false){
System.out.println("Select the presence!");
}
else{
txtOra.setVisible(true);
String Hour = txtHour.getText();
e = new Employee(UserName,b,Hour,boss); //boss i get from main frame when i start this add new employee form
contrb.addEmployee(e);
gb.refresh(e); //gb is of type GuiBoss were i have the function that does
// the refresh
}
}
Please let me know if u have any ideeas.Thanks.

Instead of popping up another frame, why not use a modal JDialog to collect the information about the new employee. When the dialog is closed, you can then extract the details from the dialog and refresh the list from within the current frame.
This prevents the need to expose portions of your API unnecessarily.
Check out How to use Dialogs for details.
Updated
Assuming you've set the model correctly, then your code should work...as per this example...
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.DefaultListModel;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.ListModel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class TestList03 {
public static void main(String[] args) {
new TestList03();
}
public TestList03() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private DefaultListModel model;
public TestPane() {
setLayout(new BorderLayout());
model = new DefaultListModel();
JList list = new JList(model);
add(new JScrollPane(list));
JButton btn = new JButton("Add");
btn.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
model.addElement("New Element");
}
});
add(btn, BorderLayout.SOUTH);
}
}
}
That would suggest that there is something else wrong that you're not showing us...
Updated with possible fix for reference issues
This basically demonstrates passing a reference of the main panel to a sub factory that is responsible for actually adding the value back into the main panel. Normally I'd use a interface of some kind instead of exposing the entire panel to simply provide access to a single method, but this was a quick example.
It uses both a normal implements and inner class as ActionListener to demonstrate the two most common means for passing a reference of "self" to another class.
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.DefaultListModel;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.ListModel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class TestList03 {
public static void main(String[] args) {
new TestList03();
}
public TestList03() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel implements ActionListener {
private DefaultListModel model;
public TestPane() {
setLayout(new BorderLayout());
model = new DefaultListModel();
JList list = new JList(model);
add(new JScrollPane(list));
JPanel buttons = new JPanel(new FlowLayout(FlowLayout.CENTER));
JButton btn1 = new JButton("Add 1");
btn1.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
new Factory(TestPane.this, "Added by Button 1");
}
});
buttons.add(btn1);
JButton btn2 = new JButton("Add 2");
btn2.addActionListener(this);
buttons.add(btn2);
add(buttons, BorderLayout.SOUTH);
}
public void addItem(String text) {
model.addElement(text);
}
#Override
public void actionPerformed(ActionEvent e) {
new Factory(TestPane.this, "Added by Button 2");
}
}
public class Factory {
public Factory(TestPane testPane, String text) {
testPane.addItem(text);
}
}
}