Develop Reference

How to hide a JPopupMenu by pressing a button?

I'm making a program that has a popup menu with two buttons, one of which should close the popup menu, but I have no idea how to do that and googling hasn't gone too well.
I've tried using popup.hide() but then the menu wouldn't come back, despite doing so when I tried just moving the popup. It also required me to put a SuppressWarning in that case and it took a few seconds for it to close at all. Is there any better way of doing it?
I'm not sure what kind of code is relevant, but here's the relevant buttons and their roles in this(I skipped all the creating the GUI parts that didn't seem relevant, everything looks good and I know that the buttons are working):
package test;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
interface CustomButton {
JButton create();
void react(JPopupMenu popup, JFrame frame);
}
class ErrandsButton implements CustomButton {
private JButton errands = new JButton("Errands");
public JButton create() {
return errands;
}
public void react(JPopupMenu popup, JFrame frame) {
errands.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
popup.show(frame, 120, 65);
}
});
}
}
class Test {
static JFrame frame = new JFrame("List");
static CustomButton errands = new ErrandsButton();
static JButton cancelTask = new JButton("Cancel");
static JPopupMenu popup = new JPopupMenu();
static void cancelTask() {
cancelTask.addActionListener(new ActionListener() {
#SuppressWarnings("deprecation")
public void actionPerformed(ActionEvent e) {
popup.hide();
}
});
}
public static void main(String args[]) {
createInterface();
cancelTask();
errands.react(popup, frame);
}
static void createInterface() {
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(500, 500);
JPanel popup1 = new JPanel();
JPanel button = new JPanel();
popup1.add(cancelTask);
popup.add(popup1);
frame.add(popup);
button.add(errands.create());
frame.getContentPane().add(BorderLayout.CENTER, button);
frame.setVisible(true);
}
}

Use popup.setVisible(true) and popup.setVisible(false).

frame.add(popup); is the problem. Do not add a JPopupMenu to a Container. Instead, use setComponentPopupMenu.
Alternatively, you could do the work yourself by adding a MouseListener whose mousePressed, mouseReleased and mouseClicked methods call isPopupTrigger and show. (It is vital that you do this in all three of those methods—different platforms have different conditions for showing popup menus.)
But really, using setComponentPopupMenu is easier.

Java- How to add more textfields by clicking a button?

I have created a frame in Java which has some textfields and buttons in it. Assuming that user wants more textfields (for example to add more data), I want to put a button and when a user clicks the button, then a new textfield should appear. then user can fill data in it and again by clicking that button another textfield should appear.
How can I do this ? What code I need to write for the button to show more and more text fields by clicking button?
Thank you !

It would be wise that instead of adding components to your JFrame directly, you add them to a JPanel. Though related to your problem, have a look at this small example, hopefully might be able to give you some hint, else ask me what is out of bounds.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class JFrameExample
{
private JFrame frame;
private JButton button;
private JTextField tfield;
private String nameTField;
private int count;
public JFrameExample()
{
nameTField = "tField";
count = 0;
}
private void displayGUI()
{
frame = new JFrame("JFrame Example");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new GridLayout(0, 1, 2, 2));
button = new JButton("Add JTextField");
button.addActionListener(new ActionListener()
{
#Override
public void actionPerformed(ActionEvent ae)
{
tfield = new JTextField();
tfield.setName(nameTField + count);
count++;
frame.add(tfield);
frame.revalidate(); // For JDK 1.7 or above.
//frame.getContentPane().revalidate(); // For JDK 1.6 or below.
frame.repaint();
}
});
frame.add(button);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String... args)
{
SwingUtilities.invokeLater(new Runnable()
{
#Override
public void run()
{
new JFrameExample().displayGUI();
}
});
}
}

Supposing that you have a main container called panel and a button variable button which is already added to panel, you can do:
// handle the button action event
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
// create the new text field
JTextField newTextField = new JTextField();
// add it to the container
panel.add(newTextField);
panel.validate();
panel.repaint();
}
});
When adding the new text field, you may need to mention some layout related characteristics, depending on the layout manager you are using (for instance if you use GridBagLayout, you will need to specify the constraints).

Detect removal of component

I create a Popup using the PopupFactory.getPopup method. According to the documentation, I am required to call the hide() method on the popup when it is no longer needed.
In my application, the popup is the child of a JLabel which may be removed from the current frame in a number of different situations. (Either the JLabel itself or one of its parent containers is removed.) Rather that calling hide() in every single place (and making the Popup object available in all these places) I would prefer to be able to detect the removal of the JLabel or one of its parent containers.
How can I detect the removal? I naively assumed that the removal of a component meant the removal/hiding of its children, but as the code below shows, the popup survives the removal of the JLabel.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Xyzzy extends JFrame {
static Xyzzy frame;
static JPanel panel;
static JLabel text1;
static JLabel text2;
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
frame = new Xyzzy();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(new BoxLayout(frame.getContentPane(), BoxLayout.PAGE_AXIS));
panel = new JPanel();
panel.setLayout(new BoxLayout(panel, BoxLayout.LINE_AXIS));
frame.add(panel);
text1 = new JLabel("text1");
text2 = new JLabel("text2");
panel.add(text1);
frame.add(new JButton(new AbstractAction("Add popup") {
public void actionPerformed(ActionEvent e) {
PopupFactory factory = PopupFactory.getSharedInstance();
Popup popup = factory.getPopup(text1, new JLabel("POPUP"),frame.getX()+300,frame.getY()+300);
popup.show();
}
}));
frame.add(new JButton(new AbstractAction("New label") {
public void actionPerformed(ActionEvent e) {
panel.remove(text1);
panel.add(text2);
panel.revalidate();
}
}));
frame.setSize(600, 600);
frame.setVisible(true);
}
});
}
}
This code creates a JFrame displaying the text "text1" and two buttons. If you press the button labeled "Add popup", a Popup with the text "POPUP" appears in the window. This Popup is a child of text1. Press the "New label" button and "text1" is removed from the display, but the Popup survives.
I need to be able to detect when text1 or the containing panel is removed so that I can hide the popup. I want to avoid adding code where the actual remove() method is called.

You can use HierarchyListener:
public void actionPerformed(ActionEvent e) {
PopupFactory factory = PopupFactory.getSharedInstance();
final Popup popup = factory.getPopup(text1, new JLabel("POPUP"),frame.getX()+300,frame.getY()+300);
text1.addHierarchyListener(new HierarchyListener() {
public void hierarchyChanged(HierarchyEvent e) {
if (e.getID() == HierarchyEvent.HIERARCHY_CHANGED
&& (e.getChangeFlags() & HierarchyEvent.SHOWING_CHANGED) != 0) {
popup.hide();
}
}
});
popup.show();
}

Make a Panel open when i click a button

does anyone know how to make a GUI button open up a new JPanel in java? its not on google. its to show an about panel. thanks for the help!

I guess JDialog is what you need.
See this for details : How to Make Dialogs
Here is a sample :
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
public class CreateDialogFromOptionPane {
public static void main(final String[] args) {
JFrame parent = new JFrame();
JButton button = new JButton();
button.setText("Click me to show dialog!");
parent.add(button);
parent.pack();
parent.setVisible(true);
button.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
JOptionPane optionPane = new JOptionPane("Is this what you need?", JOptionPane.QUESTION_MESSAGE,JOptionPane.YES_NO_OPTION);
JDialog dialog = optionPane.createDialog("Dialog");
dialog.setVisible(true);
}
});
}
}

I think that by implements CardLayout you can solve that

first you would need to create an event handler for your button, then in your handler you should create your panel and make it visible. if you want more of a popup you should use like:
JOptionPane.showMessageDialog(frame, "This is my message");
that will create a warning message, you could also create your own costume dialog i would suggest reading this

You can show panel using an undecorated JDialog
public static void main(String args[])
{
final JDialog bwin = new JDialog();
bwin.addWindowFocusListener(new WindowFocusListener()
{
#Override
public void windowLostFocus(WindowEvent e)
{
bwin.setVisible(false);
bwin.dispose();
}
#Override
public void windowGainedFocus(WindowEvent e)
{
}
});
bwin.setUndecorated(true);
JLabel label = new JLabel("About");
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
panel.add(label);
panel.setPreferredSize(new Dimension(200,200));
bwin.add(panel);
bwin.pack();
bwin.setVisible(true);
}

action listener to JDialog for clicked button

I have main application where is table with values. Then, I click "Add" button, new CUSTOM (I made it myself) JDialog type popup comes up. There I can input value, make some ticks and click "Confirm". So I need to read that input from dialog, so I can add this value to table in main application.
How can I listen when "confirm" button is pressed, so I can read that value after that?
addISDialog = new AddISDialog();
addISDialog.setVisible(true);
addISDialog.setLocationRelativeTo(null);
//somekind of listener...
//after "Confirm" button in dialog was pressed, get value
value = addISDialog.ISName;

If the dialog will disappear after the user presses confirm:
and you wish to have the dialog behave as a modal JDialog, then it's easy, since you know where in the code your program will be as soon as the user is done dealing with the dialog -- it will be right after you call setVisible(true) on the dialog. So you simply query the dialog object for its state in the lines of code immediately after you call setVisible(true) on the dialog.
If you need to deal with a non-modal dialog, then you'll need to add a WindowListener to the dialog to be notified when the dialog's window has become invisible.
If the dialog is to stay open after the user presses confirm:
Then you should probably use a PropertyChangeListener as has been suggested above. Either that or give the dialog object a public method that allows outside classes the ability to add an ActionListener to the confirm button.
For more detail, please show us relevant bits of your code, or even better, an sscce.
For example to allow the JDialog class to accept outside listeners, you could give it a JTextField and a JButton:
class MyDialog extends JDialog {
private JTextField textfield = new JTextField(10);
private JButton confirmBtn = new JButton("Confirm");
and a method that allows outside classes to add an ActionListener to the button:
public void addConfirmListener(ActionListener listener) {
confirmBtn.addActionListener(listener);
}
Then an outside class can simply call the `addConfirmListener(...) method to add its ActionListener to the confirmBtn.
For example:
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class OutsideListener extends JFrame {
private JTextField textField = new JTextField(10);
private JButton showDialogBtn = new JButton("Show Dialog");
private MyDialog myDialog = new MyDialog(this, "My Dialog");
public OutsideListener(String title) {
super(title);
textField.setEditable(false);
showDialogBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if (!myDialog.isVisible()) {
myDialog.setVisible(true);
}
}
});
// !! add a listener to the dialog's button
myDialog.addConfirmListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String text = myDialog.getTextFieldText();
textField.setText(text);
}
});
JPanel panel = new JPanel();
panel.add(textField);
panel.add(showDialogBtn);
add(panel);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(400, 300);
}
private static void createAndShowGui() {
JFrame frame = new OutsideListener("OutsideListener");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
class MyDialog extends JDialog {
private JTextField textfield = new JTextField(10);
private JButton confirmBtn = new JButton("Confirm");
public MyDialog(JFrame frame, String title) {
super(frame, title, false);
JPanel panel = new JPanel();
panel.add(textfield);
panel.add(confirmBtn);
add(panel);
pack();
setLocationRelativeTo(frame);
}
public String getTextFieldText() {
return textfield.getText();
}
public void addConfirmListener(ActionListener listener) {
confirmBtn.addActionListener(listener);
}
}
Caveats though: I don't recommend subclassing JFrame or JDialog unless absolutely necessary. It was done here simply for the sake of brevity. I also myself prefer to use a modal dialog for solving this problem and just re-opening the dialog when needed.
Edit 2
An example of use of a Modal dialog:
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class OutsideListener2 extends JFrame {
private JTextField textField = new JTextField(10);
private JButton showDialogBtn = new JButton("Show Dialog");
private MyDialog2 myDialog = new MyDialog2(this, "My Dialog");
public OutsideListener2(String title) {
super(title);
textField.setEditable(false);
showDialogBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if (!myDialog.isVisible()) {
myDialog.setVisible(true);
textField.setText(myDialog.getTextFieldText());
}
}
});
JPanel panel = new JPanel();
panel.add(textField);
panel.add(showDialogBtn);
add(panel);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(400, 300);
}
private static void createAndShowGui() {
JFrame frame = new OutsideListener2("OutsideListener");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
class MyDialog2 extends JDialog {
private JTextField textfield = new JTextField(10);
private JButton confirmBtn = new JButton("Confirm");
public MyDialog2(JFrame frame, String title) {
super(frame, title, true); // !!!!! made into a modal dialog
JPanel panel = new JPanel();
panel.add(new JLabel("Please enter a number between 1 and 100:"));
panel.add(textfield);
panel.add(confirmBtn);
add(panel);
pack();
setLocationRelativeTo(frame);
ActionListener confirmListener = new ConfirmListener();
confirmBtn.addActionListener(confirmListener); // add listener
textfield.addActionListener(confirmListener );
}
public String getTextFieldText() {
return textfield.getText();
}
private class ConfirmListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
String text = textfield.getText();
if (isTextValid(text)) {
MyDialog2.this.setVisible(false);
} else {
// show warning
String warning = "Data entered, \"" + text +
"\", is invalid. Please enter a number between 1 and 100";
JOptionPane.showMessageDialog(confirmBtn,
warning,
"Invalid Input", JOptionPane.ERROR_MESSAGE);
textfield.setText("");
textfield.requestFocusInWindow();
}
}
}
// true if data is a number between 1 and 100
public boolean isTextValid(String text) {
try {
int number = Integer.parseInt(text);
if (number > 0 && number <= 100) {
return true;
}
} catch (NumberFormatException e) {
// one of the few times it's OK to ignore an exception
}
return false;
}
}

Why don't you check if your jDialog is visible?
yourJD.setVisible(true);
while(yourJD.isVisible())try{Thread.sleep(50);}catch(InterruptedException e){}
this works, also.

import javax.swing.JOptionPane;
or if you're already swinging
import javax.swing.*;
will have you covered.
After conditional trigger JOptionPane to send your warning or whatever modal message:
JOptionPane.showMessageDialog(
null,
"Your warning String: I can't do that John",
"Window Title",
JOptionPane.ERROR_MESSAGE);
check your options for JOptionPane.* to determine message type.