We Keep Coding

How to display one Jframe at a time? [duplicate]

I'm trying to make a little game that will first show the player a simple login screen where they can enter their name (I will need it later to store their game state info), let them pick a difficulty level etc, and will only show the main game screen once the player has clicked the play button. I'd also like to allow the player to navigate to a (hopefully for them rather large) trophy collection, likewise in what will appear to them to be a new screen.
So far I have a main game window with a grid layout and a game in it that works (Yay for me!). Now I want to add the above functionality.
How do I go about doing this? I don't think I want to go the multiple JFrame route as I only want one icon visible in the taskbar at a time (or would setting their visibility to false effect the icon too?) Do I instead make and destroy layouts or panels or something like that?
What are my options? How can I control what content is being displayed? Especially given my newbie skills?

A simple modal dialog such as a JDialog should work well here. The main GUI which will likely be a JFrame can be invisible when the dialog is called, and then set to visible (assuming that the log-on was successful) once the dialog completes. If the dialog is modal, you'll know exactly when the user has closed the dialog as the code will continue right after the line where you call setVisible(true) on the dialog. Note that the GUI held by a JDialog can be every bit as complex and rich as that held by a JFrame.
Another option is to use one GUI/JFrame but swap views (JPanels) in the main GUI via a CardLayout. This could work quite well and is easy to implement. Check out the CardLayout tutorial for more.
Oh, and welcome to stackoverflow.com!

Here is an example of a Login Dialog as #HovercraftFullOfEels suggested.
Username: stackoverflow Password: stackoverflow
import java.awt.*;
import java.awt.event.*;
import java.util.Arrays;
import javax.swing.*;
public class TestFrame extends JFrame {
private PassWordDialog passDialog;
public TestFrame() {
passDialog = new PassWordDialog(this, true);
passDialog.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new TestFrame();
frame.getContentPane().setBackground(Color.BLACK);
frame.setTitle("Logged In");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
}
});
}
}
class PassWordDialog extends JDialog {
private final JLabel jlblUsername = new JLabel("Username");
private final JLabel jlblPassword = new JLabel("Password");
private final JTextField jtfUsername = new JTextField(15);
private final JPasswordField jpfPassword = new JPasswordField();
private final JButton jbtOk = new JButton("Login");
private final JButton jbtCancel = new JButton("Cancel");
private final JLabel jlblStatus = new JLabel(" ");
public PassWordDialog() {
this(null, true);
}
public PassWordDialog(final JFrame parent, boolean modal) {
super(parent, modal);
JPanel p3 = new JPanel(new GridLayout(2, 1));
p3.add(jlblUsername);
p3.add(jlblPassword);
JPanel p4 = new JPanel(new GridLayout(2, 1));
p4.add(jtfUsername);
p4.add(jpfPassword);
JPanel p1 = new JPanel();
p1.add(p3);
p1.add(p4);
JPanel p2 = new JPanel();
p2.add(jbtOk);
p2.add(jbtCancel);
JPanel p5 = new JPanel(new BorderLayout());
p5.add(p2, BorderLayout.CENTER);
p5.add(jlblStatus, BorderLayout.NORTH);
jlblStatus.setForeground(Color.RED);
jlblStatus.setHorizontalAlignment(SwingConstants.CENTER);
setLayout(new BorderLayout());
add(p1, BorderLayout.CENTER);
add(p5, BorderLayout.SOUTH);
pack();
setLocationRelativeTo(null);
setDefaultCloseOperation(DISPOSE_ON_CLOSE);
addWindowListener(new WindowAdapter() {
#Override
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
jbtOk.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if (Arrays.equals("stackoverflow".toCharArray(), jpfPassword.getPassword())
&& "stackoverflow".equals(jtfUsername.getText())) {
parent.setVisible(true);
setVisible(false);
} else {
jlblStatus.setText("Invalid username or password");
}
}
});
jbtCancel.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
setVisible(false);
parent.dispose();
System.exit(0);
}
});
}
}

I suggest you insert the following code:
JFrame f = new JFrame();
JTextField text = new JTextField(15); //the 15 sets the size of the text field
JPanel p = new JPanel();
JButton b = new JButton("Login");
f.add(p); //so you can add more stuff to the JFrame
f.setSize(250,150);
f.setVisible(true);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Insert that when you want to add the stuff in. Next we will add all the stuff to the JPanel:
p.add(text);
p.add(b);
Now we add the ActionListeners to make the JButtons to work:
b.addActionListener(this);
public void actionPerforemed(ActionEvent e)
{
//Get the text of the JTextField
String TEXT = text.getText();
}
Don't forget to import the following if you haven't already:
import java.awt.event*;
import java.awt.*; //Just in case we need it
import java.x.swing.*;
I hope everything i said makes sense, because sometimes i don't (especially when I'm talking coding/Java) All the importing (if you didn't know) goes at the top of your code.

Instead of adding the game directly to JFrame, you can add your content to JPanel (let's call it GamePanel) and add this panel to the frame. Do the same thing for login screen: add all content to JPanel (LoginPanel) and add it to frame. When your game will start, you should do the following:
Add LoginPanel to frame
Get user input and load it's details
Add GamePanel and destroy LoginPanel (since it will be quite fast to re-create new one, so you don't need to keep it memory).

how to move JButton to specific position

this is a very easy code because I just started learning java.
how do I move the button to specific position/points. Please be brief and make your answer simple and easy to understand because I just started learning java.
this is my code:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class finals extends JFrame implements ActionListener{
JButton login = new JButton("Log-In");
JButton enroll = new JButton("Enroll");
JPanel con = new JPanel();
JFrame frame = new JFrame();
public finals(){
frame.setTitle("Enrollment");
setContentPane(con);
setLayout(new FlowLayout());
login.setLocation(122, 120);
con.add(login);
System.out.println(login.getLocation());
frame.add(con);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(300,150);
frame.setVisible(true);
}
public void actionPerformed(ActionEvent e){
}
public static void main(String Args[]){
new finals();
}
}

make your answer simple and easy to understand
Don't attempt to specify a pixel location of a component! What is so special about (122, 12)? Nothing, its just a random number you picked.
Let the layout manager do its job. For example you can use a FlowLayout and set the alignment to CENTER so the component is centered on the row.
Or if you don't like that you can use a BoxLayout, and add a "horizontal strut" to the panel to help control positioning.
Read the section from the Swing tutorial on Layout Managers for more information and working examples.
I just started learning java.
Don't forget to check out the Table of Contents from the above tutorial link for more basic information about creating GUI's.

You have to put your JPanel layout to "null".
Just add this : con.setLayout(null);

Java GUI FullScreen window with smaller window inside

I am working on a Java desktop application. It uses MySQL database to store all data etc. I use swing for the GUI.
The GUI of this application is layed out as follows:
Main Window taking the entire screen size (with image in the
background)
Internal Window 800 x 600 centered within the Main
Window (that holds current content that can be switched between
using menu and/or event within the application.
LoginPanel.java:
import javax.swing.*;
import java.awt.*;
public class LoginPanel {
private JPanel loginPanel;
public void loginForm()
{
JButton loginSubmit = new JButton("Login");
loginPanel = new JPanel();
loginPanel.add(loginSubmit);
loginPanel.setSize(800, 600);
}
public JComponent getGUI()
{
return loginPanel;
}
public static void main(String[] args)
{
}
}
Main.java:
import javax.swing.*;
import java.awt.*;
public class Main {
public static void main(String[] args)
{
JFrame mainFrame;
mainFrame = new JFrame();
mainFrame.setLayout(new BorderLayout());
mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainFrame.setTitle("Caledonian Library System");
LoginPanel loginObj = new LoginPanel();
mainFrame.add(loginObj.getGUI());
mainFrame.pack();
mainFrame.setVisible(true);
}
}
Should I maybe use box layout? any suggestions?

Ok, I have just run a test program, and have achieved the result you are looking for. I have used a GridBagLayout which defaults to centre into the Container it is added to. It will not show up with the borders or other buttons built into a JFrame (though you can add a border if you wish later).
JFrame mainframe = new JFrame();
JPanel mainPanel = new JPanel();
GridBagLayout gridLayout = new GridBagLayout();
mainPanel.setLayout(gridLayout);
//GridBagConstraints allow you to set various features of the way the components appear
//in the grid. You can set this up as you wish, but defaults are fine for this example
GridBagConstraints gridConstraints = new GridBagConstraints();
//Just using FlowLayout as a test for now
JPanel centerPanel = new JPanel(new FlowLayout());
centerPanel.add(new JLabel("Hello"));
centerPanel.add(new JLabel("Centered"));
mainPanel.add(centerPanel, gridConstraints);
mainFrame.add(mainPanel);
If you found that the space around the side of your centered panel wasn't being used, and you wanted it to be use, you could try nesting mainPanel inside another panel that is using a BorderLayout, making sure that it is in BorderLayout.CENTER.
In the example I didn't bother changing GridBagConstraints from the default, as it was ok for this demonstration. However you can edit it as you wish, and then apply to each component you add to the GridBagLayout, making sure to include the GridBagConstraints object in each mainPanel.add(). Check the GridBagLayout tutorials for some good information.
Of course, if you would like more components in the centre other than the main window, you can then simply add them to the mainPanel (making sure to change the position in the GridLayout). There are going to be numerous ways of achieving what you want, but it really depends on what you feel looks good. The Layout Managers will do all of the resizing work for you.

Output layout of entities not as expected

I'm a beginner in Java, especially in the GUI Design area. I created a simple Java Swing interface to accept a string from the user and display it using a JOptionPane (ActionListener not yet implemented.)
The main problem I'm facing is with the alignment of the objects in the output. No matter what bounds I give to the objects, they always appear in one line. Also, sometimes, the output Frame will show absolutely nothing. After multiple runs, it will finally show me the objects, but not in the layout I expected them to be.
This is my code:
package guiapp;
import javax.swing.*;
import java.awt.*;
public class GUIApp {
private static JFrame frame;
private static JPanel panel;
private static JLabel label;
private static JTextField text;
private static JButton click;
public static void CreateGUI(){
frame = new JFrame("Hello to NetBeans!");
frame.setSize(750, 750);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
panel = new JPanel();
panel.setBackground(Color.BLUE);
label = new JLabel("Enter a string: ");
label.setBounds(50,35,150,40);
label.setVisible(true);
text = new JTextField();
text.setBounds(250,35,150,40);
text.setVisible(true);
click = new JButton("Click here!");
click.setBounds(150,80,150,40);
click.setVisible(true);
panel.add(text);
panel.add(label);
panel.add(click);
frame.add(panel);
frame.setVisible(true);
}
public static void main(String[] args) {
CreateGUI();
}
}
Can someone please tell me where I'm going wrong? I seem to have got the layout syntax wrong.

No matter what bounds I give to the objects, they always appear in one
line.
This is probably because of the default layout manager of JPanel: FlowLayout. On the other hand Swing is designed to be used with layout managers and the use of methods such as setBounds(...), setLocation(...) and setSize(...) is discouraged. See Laying out Components within a Container lesson.

Move from a frame to a frame in Swing [closed]

Closed. This question needs to be more focused. It is not currently accepting answers.
Want to improve this question? Update the question so it focuses on one problem only by editing this post.
Closed 6 years ago.
Improve this question
Unfortunately, our team leader has decided that we'll use Swing for this light desktop app. I have no previous experience in working with Swing. I will be working on the GUI side of the project. I've already created a frame with elements within it and wrote the logic in the event listeners. Now I want to redirect the user to a new frame after he's logged in.
How do I do that? Thanks
P.S. I'd appreciate if you could point me to a good tutorial for beginners

It sounds like you have your terminology mixed up. When we hear "Frame" we think JFrame which is equivalent to "Window". So most of the time we'd recommend not using multiple windows, but changing the content of the window. The content is generally made with a "JPanel".
So generally, you set up your JFrame, you set the content with this:
JPanel loginPanel = new JPanel();
frame.setContentPane(loginPanel);
If you want to replace your login panel with a new panel, just pass the new panel to that function:
JPanel mainMenuPanel = new JPanel();
frame.setContentPane(mainMenuPanel);
(of course you want some content in those panels)
Here's a simple example:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class PanelRetriever{
Box panel1;
JPanel panel2;
public PanelRetriever(final JFrame frame){
//Build the first login panel
panel1 = Box.createVerticalBox();
panel1.setBackground(Color.orange);
panel1.setOpaque(true);
panel1.add(Box.createVerticalGlue());
panel1.add(new JTextField(10));
JButton login = new JButton("Login");
login.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent arg0) {
frame.setContentPane(getPanel2());
frame.validate();
}});
panel1.add(login);
panel1.add(Box.createVerticalGlue());
//Build second panel
panel2 = new JPanel();
panel2.setBackground(Color.blue);
panel2.setOpaque(true);
JButton logout = new JButton("Logout");
logout.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent e) {
frame.setContentPane(getPanel1());
frame.validate();
}});
panel2.add(logout, BorderLayout.CENTER);
}
public Container getPanel1(){
return panel1;
}
public Container getPanel2(){
return panel2;
}
public static void main(String args[])
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
JFrame frame = new JFrame();
PanelRetriever pr = new PanelRetriever(frame);
frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
frame.setContentPane(pr.getPanel1());
frame.setPreferredSize(new Dimension(500, 400));
frame.pack();
frame.setVisible(true);
}
});
}
}

Your frame should stay the same, just create and show new JPanel instead old one.
See below JPanel painting process:

As #Gilbert Le Blanc has pointed out (+1 to him). In Swing it is bad practice to use multiple JFrames.
To accomplish what you want:
Use CardLayout which allows dynamic switching of components
Or use JFrame#removeAll() and add a new JPanel (+1 Fess)
Try using JDialog/JOptionPane and then redirect to main JFrame
here is a good link on the topic: How to Make Dialogs

In Swing, you have one JFrame. You use JDialogs to get user id and password input from the user.
Here's a link to the Oracle Swing Tutorial.

You can just create a new frame in much the same way as you already have;
MyFrame f = new MyFrame(); //MyFrame extends javax.swing.JFrame
And then bring it to the front with;
f.setVisible(true);
f.toFront();