Develop Reference

Button that opens a new JFrame

I'm writing a program where I am supposed to have a title screen for a game, where you can click a 'play' button that opens a different window and simultaneously closes the other one. What I am attempting to do is utilize an ActionListener for a button that makes the current window invisible while simultaneously making a different window visible. I am having a hard time getting this to work and am encountering a lot of syntax and logical errors. I'm quite certain there is a better way to do this, so any pointers will be greatly appreciated. I am using swing. Disclaimer: beginner java level programmer lol :p
My first class includes this (does not include my imports):
public static void main(String[] args) {
//Creating the Frame
MyFrame menuFrame = new MyFrame();
// (here i have code for the frame in my actual program)
}
static class MyFrame extends JFrame {
MyFrame () {
this.setDefaultCloseOperation
(JFrame.EXIT_ON_CLOSE);
this.getContentPane().add(new JLabel(new ImageIcon("logo.png")));
this.pack();
this.setVisible(true);
new EightOff.returnHomeListener (this);
}
}
}
My other class that has the other frame being opened includes the following button and action listener where I am trying to reference my frame from GameMenu:
public class EightOff
{
private static JButton returnHome = new JButton("Return to Game Menu");
public static class returnHomeListener implements ActionListener {
public returnHomeListener(GameMenu.MyFrame myFrame) {
}
#Override
public void actionPerformed(ActionEvent e)
{
returnHomeListener (JFrame visibleFrame) {
visibleFrame.toSetVisible (true);
}
}
}
}

You should start by having a look at How to Use Buttons, Check Boxes, and Radio Buttons and How to Write an Action Listener
The ActionListener should be registered to the button, so if can be notified when some action occurs, for example...
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Main {
public static void main(String[] args) {
new Main();
}
public Main() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JButton button = new JButton("Click me");
button.addActionListener(new TestActionListener());
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(button);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestActionListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
JOptionPane.showMessageDialog(null, "I'd prfefer if you did't do that");
}
}
}
In order to make changes to a object, you first need a reference to that object. This is pretty basic, Java 101 kind of stuff and you should have a look at Passing Information to a Method or a Constructor for more details.
You should also have a read of the JavaDocs for JFrame to get a better understanding of what properties and functionality the class provides.
Having a look at How to Make Frames also wouldn't hurt.
I'd recommend having a look at How to use CardLayout instead of trying to hide/show windows, you'll have a better user experience generally.

AddMouseListener into another AddMouseListener

I had a problem while calling two mouse events, one into the other. I wanted to show a second frame (frame2) when the user clicks on a component (component1) from the first frame (frame1), then returns to the previous frame (frame1) if the component2 is clicked on. All this using one file.
This is what I wrote:
component1.addMouseListener(this on);
#Override
public void mouseClicked(MouseEvent e)
{
if(e.getSource() == component1)
{
frame1.dispose();
frame2.setVisible(true);
component2.addMouseListener(new MouseAdapter() {
public void mouseClicked() {
frame2.dispose();
frame1.setVisible(true);
}
});
}
}
The first event works, but not the second.
Thank you for answering.

Here is a fully functional example where there are 2 frames, each with a label that, when clicked, hides one frame and shows the other, done in Java 10. See if this works for you and explain how your code differs from this. Note that I only created 2 MouseListeners, one for each frame. I did not recreate the MouseListener in the other MouseListener's code. Also, I did not dispose the frame, which will likely cause problems. If I had disposed frame1, I would most likely have to create a new JFrame and assign it to the frame1 instance member.
Please note you have to click on the label itself, not somewhere else on the frame.
import javax.swing.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
public class TwoFrames {
public static void main(String[] args) {
TwoFrames twoFrames = new TwoFrames();
twoFrames.start();
}
private void start() {
setupFrames();
}
JFrame frame1 = new JFrame("Frame 1"),
frame2 = new JFrame("Frame 2");
JLabel component1 = new JLabel("Click me 1"),
component2 = new JLabel("Click me 2");
private void setupFrames() {
frame1.getContentPane().add(component1);
frame2.getContentPane().add(component2);
component1.setOpaque(true);
component2.setOpaque(true);
component1.addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
frame1.setVisible(false);
frame2.setVisible(true);
}
});
component2.addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
frame2.setVisible(false);
frame1.setVisible(true);
}
});
frame1.setSize(300, 300);
frame2.setSize(400, 400);
frame1.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame2.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
SwingUtilities.invokeLater(() -> frame1.setVisible(true));
}
}

The dispose() method actually destroys the window and so, frame1 should become null and you are most likely getting a null pointer exception.
Consider calling frame1.setVisible(false) and frame2.setVisible(false) instead of the dispose() method.
Also, you could consider using to separate mouse listener objects instead of adding a new mouse listener to component2 when component1 is clicked.

Updating JPanel content in JFrame by using a frame state variable

I'm trying to find a way how to update a panel content after changing a state variable.
Concretely in the example below, there is simple JPanel inside JFrame with two buttons. When the app starts, its state variable ("window") equals "home" so home button should be invisible. After clicking on the page button the state variable change and so both buttons visibility should change after frame repainting. (i.e. the page button should disappear and the home button should appear).
In this case, it is possible to solve it without the state variable just using setVisibility() method for buttons. But in my app, I would like to have more JComponetns connected to the state variable. Is there a way how to do it?
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import java.awt.BorderLayout;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
public class JPanelUpdateTest {
private JFrame frame;
private String window = "home";
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
JPanelUpdateTest window = new JPanelUpdateTest();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
public JPanelUpdateTest() {
initialize();
}
private void initialize() {
frame = new JFrame("JPanelUpdateTest");
frame.setBounds(100, 100, 450, 300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel();
frame.getContentPane().add(panel, BorderLayout.CENTER);
JButton btnHome = new JButton("home");
btnHome.setVisible(window == "home" ? false : true);
btnHome.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
window = "page";
panel.revalidate();
frame.repaint();
}
});
panel.add(btnHome);
JButton btnPage = new JButton("page");
btnPage.setVisible(window == "page" ? false : true);
btnPage.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
window = "home";
panel.revalidate();
frame.repaint();
}
});
panel.add(btnPage);
}
}

The problem is that initialize is only being called once, at object creation, and it should only be called once, and because of this the setVisible(...) code is not being called from the ActionListeners. Instead you need to put the mechanisms for changing the views within the ActionListeners themselves, not just changing state, not unless you are using a "bound property" and PropertyChangeListeners.
Myself, I'd recommend using a CardLayout to assist you in your swapping, and rather than directly changing Strings, call a public method of your class -- planning for when and if the ActionListener (controller) code is ever removed from the view class.
Also, regarding:
btnPage.setVisible(window == "page" ? false : true);
don't compare Strings using == or !=. Use the equals(...) or the equalsIgnoreCase(...) method instead. Understand that == checks if the two object references are the same which is not what you're interested in. The methods on the other hand check if the two Strings have the same characters in the same order, and that's what matters here.
Also, if all you want to do is change the text and behavior that a JButton is doing, then you can change this easily by using setText(...) to change only the text, and for a deeper change, call setAction(Action action) to change text and state.

How to close multiple JFrame and JDialog windows?

I'm working on a program which has multiple JFrame and JDialog windows.
I have a JFrame which contains a button, when I click on this button a JDialog window opens up. In this JDialog windows there is another button, which when is clicked it opens up a second JDialog window. In the second JDialog window I have a last button.
What I want to do is to close both JDialog windows and JFrame window when this last button is clicked.
This is how the opening order is:
JFrame Frame1;
JButton Button1;
JDialog Dialog1;
JButton Button2;
JDialog Dialog2;
JButton Button3;
Button1ActionPerformed(ActionEvent e){
new Dialog(Frame1Frame);
}
Button2ActionPerformed(ActionEvent e){
new Dialog2(Dialog1Frame)
}
Button3ActionPerformed(ActionEvent e){
//Here I wnat to add the code that closes JDialog2 JDialog1 and JFrame1 windows.
}
I have tried super.dispose(); but it doesn't work. Any ideas?

As shown here using Action, your actionPerformed() implementation can dispatch the WINDOW_CLOSING event to the desired Window instances.
#Override
public void actionPerformed(ActionEvent e) {
d1.dispatchEvent(new WindowEvent(d1, WindowEvent.WINDOW_CLOSING));
d2.dispatchEvent(new WindowEvent(d2, WindowEvent.WINDOW_CLOSING));
f1.dispatchEvent(new WindowEvent(f1, WindowEvent.WINDOW_CLOSING));
}

There may be better ways of doing this, but here is one general approach that might help.
In your code you create the windows but you do not store the reference to the windows you created into a variable. For example, you have:
JDialog Dialog1;
Then later, when you create the instance of Dialog1, you have this code:
Button1ActionPerformed(ActionEvent e){
new Dialog(Frame1Frame);
}
This means you have created the Dialog, but you have not retained a reference to the Dialog for later manipulation by your code. If you assign this value here, you should be able to manipulate it later.
If you change your implementation to:
Button1ActionPerformed(ActionEvent e){
Dialog1 = new Dialog(Frame1Frame);
}
Then later in your code you will have a reference to the Dialog in order to manipulate it,
Button3ActionPerformed(ActionEvent e){
Dialog1.dispose();
// you can manipulate the variables of the class from here and close other windows etc.
}

If you have the objects reference, you can do:
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
public class Main
{
private static JFrame frame;
private static JButton buttonFrame;
private static JDialog dialog1;
private static JButton buttonDialog1;
private static JDialog dialog2;
private static JButton buttonDialog2;
public static void main(String[] args) {
/* frame */
frame = new JFrame("Main Frame");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(400, 400);
frame.setLocationRelativeTo(null);
buttonFrame = new JButton("open dialog 1");
buttonFrame.addActionListener(new ActionListener() {
#Override public void actionPerformed(ActionEvent e) {
dialog1.setVisible(true);
}
});
frame.add(buttonFrame);
/* dialog 1 */
dialog1 = new JDialog(frame, "Dialog 1");
dialog1.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
dialog1.setSize(300, 300);
dialog1.setLocationRelativeTo(null);
buttonDialog1 = new JButton("open dialog 2");
buttonDialog1.addActionListener(new ActionListener() {
#Override public void actionPerformed(ActionEvent e) {
dialog2.setVisible(true);
}
});
dialog1.add(buttonDialog1);
/* dialog 2 */
dialog2 = new JDialog(dialog1, "Dialog 2");
dialog2.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
dialog2.setSize(200, 200);
dialog2.setLocationRelativeTo(null);
buttonDialog2 = new JButton("close all");
buttonDialog2.addActionListener(new ActionListener() {
#Override public void actionPerformed(ActionEvent e) {
dialog2.dispose();
dialog1.dispose();
frame.dispose();
}
});
dialog2.add(buttonDialog2);
/* show frame */
frame.setVisible(true);
}
}
Otherwise you can use System.exit(0);:
buttonDialog2.addActionListener(new ActionListener() {
#Override public void actionPerformed(ActionEvent e) {
System.exit(0);
}
});

Closing multiple JFrame by another JFrame-
It is possible to close multiple windows, even non-static Java swing windows. Type below small code, step by step.
The below code is mainly for closing the First frame through the second open frame which has been opened by the same First frame.
*Make a **second class global variable** in the first-class & a **button global variable in first-class*
Class2 NiceApp1 = new Class2();
JToggleButton Nice=new JToggleButton("Nice One");
// *After the Class1 above code, you will need a close method. I use a jar of NiceApplication1 with class New Close you can use the same jar or very below close method and can call the close method. You will need to type the method in Class1, just type your **close method in the method**.*
public void method (){
NewClose NiceO = new NewClose();
NiceO.Close(this);
//or
Close();
}
*// Now make a **Button Global variable in Class2**.*
javax.swing.JToggleButton Zero = new javax.swing.JToggleButton();
*// Type in Class2 the below **method**.*
public void methodclass2(JToggleButton Nice){
Zero = Nice;
}
*//Now you will need to type the below code, type the below code in the **Class1 button action** by which you will open the Class2.*
Nice.addActionListener((ActionEvent e) -> {
method();
});
NiceApp1.methodclass2(Nice);
NiceApp1.setVisible(true);
*//Now just type a **single line code** in the second class, type anywhere from which you want to close Class1.*
Zero.doClick();
*//Now the **close method** if you don't have a close method.*
public void Close() {
WindowEvent winclosing = new WindowEvent(this, WindowEvent.WINDOW_CLOSING);
Toolkit.getDefaultToolkit().getSystemEventQueue().postEvent(winclosing);
}
**You have done now if you did the above process.
If you only want to close which opens secondly so by the only close method change the this into your frame variables.
You can also visit NiceApplication1.BlogSpot.Com.
You can use the above code. From Class2 after the button's click, you will see your previous Class1 window will close.**

java sending the frame to front of screen

Is there a way to send the java frame in front of every other opened program. I know you can use
JFrame.setAlwaysOnTop(true);
but that just keeps it in front allways. I want it to only happen when a certain function is called. For instance, When I press a button on a frame, it will wait using Thread.sleep(10000) for ten seconds, but the I want it to just the frame to the front in case you clicked out of the window for a second. Any suggestions?

Take a look at Window#toFront
You may also want to take a look at
WindowListener
Swing Timer
Be careful of using Thread.sleep in a GUI environment, if used incorrectly, this will cause you window to stop updating (painting)

This is surprisingly fiddly.
The exact behavior might also depend on the operating system. But at least on Windows, a call to frame.toFront() will not necessarily bring the window to the front. Instead, it will cause the corresponding entry in the task bar to blink for a few seconds. I tried something like
f.setAlwaysOnTop(true);
f.setAlwaysOnTop(false);
which basically works, but after the window was brought to the front, it is not "active", and none of my attempts to make it active worked (e.g. requesting the focus or so).
The only solution that I found now to (reliably) work (on Windows, at least) was
if (!f.isActive())
{
f.setState(JFrame.ICONIFIED);
f.setState(JFrame.NORMAL);
}
But wonder wheter there is a more elegant solution.
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
public class FrameToTopTest
{
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable()
{
#Override
public void run()
{
createAndShowGUI();
}
});
}
private static void createAndShowGUI()
{
final JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JButton button = new JButton("Bring me to top after 3 seconds");
button.addActionListener(new ActionListener()
{
#Override
public void actionPerformed(ActionEvent e)
{
triggerBringToFront(f, 3000);
}
});
f.getContentPane().add(button);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
private static void triggerBringToFront(final JFrame f, final int delayMS)
{
Timer timer = new Timer(delayMS, new ActionListener()
{
#Override
public void actionPerformed(ActionEvent e)
{
// This will only cause the task bar entry
// for this frame to blink
//f.toFront();
// This will bring the window to the front,
// but not make it the "active" one
//f.setAlwaysOnTop(true);
//f.setAlwaysOnTop(false);
if (!f.isActive())
{
f.setState(JFrame.ICONIFIED);
f.setState(JFrame.NORMAL);
}
}
});
timer.setRepeats(false);
timer.start();
}
}