Develop Reference

How do I check if the JFrame is fullscreen?

I'm trying to code an app using JFrame. But I have encountered an issue when trying to check if the window is full screen or not. I want my button to be in the same position when it's full and half screen. Here's my code.
package App.Gui;
import java.awt.Dimension;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.WindowConstants;
import App.Gui.Event.ExitEvent;
public class WindowSettings {
private final static ImageIcon imageIcon = new ImageIcon("C:\\Users\\zeesh\\FirstApp\\src\\image\\Untitled.png");
public static void setWindow() {
JFrame frame = new JFrame("Debug Configurations");
JPanel panel = new JPanel();
frame.getContentPane();
JButton button = new JButton("X");
Dimension size = button.getPreferredSize();
button.setBounds(1125, 20, 50, 50);
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
ExitEvent.exit();
}
});
panel.setLayout(null);
panel.add(button);
panel.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.add(panel);
frame.setIconImage(imageIcon.getImage());
frame.setSize(1200, 750);
frame.setVisible(true);
}
}

Make use of appropriate layouts, for example
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.FontMetrics;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
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;
public class Main {
public static void main(String[] args) {
new Main();
}
public Main() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame();
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new BorderLayout());
JButton button = new SquareButton("X");
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
System.out.println("Hello");
}
});
JPanel topPane = new JPanel(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.anchor = GridBagConstraints.EAST;
gbc.weightx = 1;
gbc.insets = new Insets(20, 50, 20, 50);
topPane.add(button, gbc);
add(topPane, BorderLayout.NORTH);
JPanel contentPane = new JPanel(new GridBagLayout());
contentPane.add(new JLabel("Stuff goes here"));
add(contentPane);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(1200, 750);
}
}
class SquareButton extends JButton {
SquareButton(String s) {
super(s);
}
#Override
public Dimension getPreferredSize() {
FontMetrics fm = getFontMetrics(getFont());
int stringWidth = fm.stringWidth(getText());
int stringHeight = fm.getHeight();
int size = Math.max(stringHeight, stringWidth);
return new Dimension(size + 22, size + 22);
}
}
}
See Laying Out Components Within a Container for more details
But, wait, you want to overlap the button over the top of the content? Well, that's not that hard...
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.FontMetrics;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
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;
public class Main {
public static void main(String[] args) {
new Main();
}
public Main() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame();
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new GridBagLayout());
JButton button = new SquareButton("X");
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
System.out.println("Hello");
}
});
GridBagConstraints gbc = new GridBagConstraints();
gbc.anchor = GridBagConstraints.NORTHEAST;
gbc.gridx = 0;
gbc.gridy = 0;
gbc.weightx = 1;
gbc.insets = new Insets(20, 50, 20, 50);
add(button, gbc);
gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
gbc.weightx = 1;
gbc.weighty = 1;
gbc.fill = GridBagConstraints.BOTH;
JPanel contentPane = new JPanel(new GridBagLayout());
contentPane.setBackground(Color.MAGENTA);
contentPane.add(new JLabel("Stuff goes here"));
add(contentPane, gbc);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(1200, 750);
}
}
class SquareButton extends JButton {
SquareButton(String s) {
super(s);
}
#Override
public Dimension getPreferredSize() {
FontMetrics fm = getFontMetrics(getFont());
int stringWidth = fm.stringWidth(getText());
int stringHeight = fm.getHeight();
int size = Math.max(stringHeight, stringWidth);
return new Dimension(size + 22, size + 22);
}
}
}

Java - GridBagLayout components on top disappear on resize

I use a JLabel and in front of it a JTextField so that I can represent a defense-like stat with a value. I use the following code:
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.insets = new Insets(10, 10, 10, 10);
JLabel jl = new JLabel();
ImageIcon ii = new ImageIcon("C:\\Users\\Max\\Desktop\\shield.png");
jl.setIcon(ii);
gbc.gridy = 0;
gbc.gridx = 0;
add(jl, gbc);
gbc.insets = new Insets(5, 10, 10, 10);
JTextField jtf = new JTextField(2);
jtf.setHorizontalAlignment(JTextField.CENTER);
gbc.ipadx = 10;
gbc.ipady = 10;
gbc.gridy = 0;
gbc.gridx = 0;
jtf.setFocusable(false);
add(jtf, gbc);
And get:
Everything is fine, however, if I try to resize the window, the JTextField disappears for ever and only the JLabel shows. Why is that so?

There is no relationship between the position of the label and the position of the text field, this means that the label and field are free to move independently of each other
There is a z-ordering issue, components lower in the container order are painted after those higher in the container order (reverse order), meaning that the label is actually getting painted before the shield when the whole container is updated. The reason that it might sometimes work is because components can actually be painted independently of each other, meaning that the textfield could actually get painted without need to notify either the parent container or the label
For example...
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
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();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.insets = new Insets(5, 10, 10, 10);
JTextField jtf = new JTextField(2);
jtf.setHorizontalAlignment(JTextField.CENTER);
gbc.ipadx = 10;
gbc.ipady = 10;
gbc.gridy = 0;
gbc.gridx = 0;
jtf.setFocusable(false);
add(jtf, gbc);
gbc = new GridBagConstraints();
try {
JLabel jl = new JLabel();
ImageIcon ii = new ImageIcon(ImageIO.read(getClass().getResource("/shield01.png")));
jl.setIcon(ii);
gbc.gridy = 0;
gbc.gridx = 0;
add(jl, gbc);
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
}
A possibly better solution would be to create a "background" component which took an image and painted it as the background of the component and then add your text field to it.
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.EmptyBorder;
public class TestBackground {
public static void main(String[] args) {
new TestBackground();
}
public TestBackground() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new BorderLayout());
try {
BackgroundPane pane = new BackgroundPane(ImageIO.read(getClass().getResource("/shield02.png")));
pane.setLayout(new GridBagLayout());
pane.setBorder(new EmptyBorder(5, 5, 5, 5));
GridBagConstraints gbc = new GridBagConstraints();
JTextField jtf = new JTextField(2);
jtf.setHorizontalAlignment(JTextField.CENTER);
gbc.ipadx = 10;
gbc.ipady = 10;
gbc.gridy = 0;
gbc.gridx = 0;
jtf.setFocusable(false);
pane.add(jtf, gbc);
add(pane);
} catch (IOException exp) {
exp.printStackTrace();
}
}
}
public class BackgroundPane extends JPanel {
private BufferedImage img;
public BackgroundPane(BufferedImage img) {
this.img = img;
}
#Override
public Dimension getPreferredSize() {
return img != null ? new Dimension(img.getWidth(), img.getHeight()) : super.getPreferredSize();
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (img != null) {
int x = (getWidth() - img.getWidth()) / 2;
int y = (getHeight() - img.getHeight()) / 2;
g.drawImage(img, x, y, this);
}
}
}
}

How can I create and edit a panel thats exclusively on the right half of the screen?

This class generates a window or frame(Im not too sure what the proper title would be) that has a back button and a ship select button on the left side. I would like to add a panel that takes up the right half of the frame. I am trying to add some more options specific to "Ship Selection" so I am assuming a panel is the correct way to go about it but am not entirely sure. Thanks in advance.
private class OptionsPanel extends JPanel{
private Galaga parent;
public OptionsPanel(Galaga p) {
super();
parent = p;
//layout components however you wish
setLayout(null);
JButton backButton = new JButton("<< Back");
backButton.setBounds(5, 20, 100, 20);
backButton.setFont(new Font("Arial", Font.PLAIN, 15));
backButton.setForeground(Color.white);
backButton.setBackground(Color.black);
backButton.setOpaque(true);
backButton.setBorderPainted(false);
backButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
parent.getLayeredPane().remove(parent.getOptionsPanel());
parent.getLayeredPane().add(parent.getButtonPanel(), new Integer(10));
parent.invalidate();
}
});
add(backButton);
JButton shipSelectButton = new JButton("Ship Selection");
shipSelectButton.setBounds(10, 60, 200, 40);
shipSelectButton.setFont(new Font("Arial", Font.PLAIN, 20));
shipSelectButton.setForeground(Color.white);
shipSelectButton.setBackground(Color.black);
shipSelectButton.setOpaque(true);
shipSelectButton.setBorderPainted(false);
shipSelectButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
}
});
add(shipSelectButton);
}
}
}

The most basic option is to use a GridLayout
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class LayoutExamples {
public static void main(String[] args) {
new LayoutExamples();
}
public LayoutExamples() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new GridLayout(0, 2));
frame.add(new OptionsPanel());
frame.add(new OtherPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class OtherPane extends JPanel {
public OtherPane() {
setBackground(Color.RED);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(100, 200);
}
}
public class OptionsPanel extends JPanel {
public OptionsPanel() {
super();
//layout components however you wish
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
gbc.insets = new Insets(8, 8, 8, 8);
gbc.anchor = GridBagConstraints.NORTHWEST;
JButton backButton = new JButton("<< Back");
backButton.setFont(new Font("Arial", Font.PLAIN, 15));
backButton.setForeground(Color.white);
backButton.setBackground(Color.black);
backButton.setOpaque(true);
backButton.setBorderPainted(false);
backButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
}
});
add(backButton, gbc);
JButton shipSelectButton = new JButton("Ship Selection");
shipSelectButton.setFont(new Font("Arial", Font.PLAIN, 20));
shipSelectButton.setForeground(Color.white);
shipSelectButton.setBackground(Color.black);
shipSelectButton.setOpaque(true);
shipSelectButton.setBorderPainted(false);
shipSelectButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
}
});
gbc.insets = new Insets(12, 8, 12, 12);
gbc.gridx = 0;
gbc.gridy = 1;
gbc.anchor = GridBagConstraints.NORTHWEST;
gbc.weighty = 1;
gbc.weightx = 1;
add(shipSelectButton, gbc);
}
}
}
Pixel perfect layouts are an illusion in modern UI design. You don't have control over how things like fonts or even a single line will be rendered. Differences in rendering pipelines and DPI settings (for example) will change the metrics/size requirements of the components between platforms.
Swing is designed to use layout managers, make appropriate use of them.

How can I build 2 JButton instances of the same width

I have 2 buttons, one named btnShort and one named btnLong. I'd like them to be of the same width, so what would be the best option?
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class TestCode2 {
public static void main(String[] args) {
JFrame window = new JFrame("Test2");
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setSize(400, 200);
// ---------------------------------------------------------------------
GridBagLayout layout = new GridBagLayout();
GridBagConstraints constraints = new GridBagConstraints();
JPanel container = new JPanel(layout);
window.add(container);
constraints.gridy = 0;
JButton btnShort = new JButton("Short");
layout.setConstraints(btnShort, constraints);
container.add(btnShort);
constraints.gridy = 1;
JButton btnLong = new JButton("That's a long button");
layout.setConstraints(btnLong, constraints);
container.add(btnLong);
//This one won't work because button dimension is not known yet...
//btnShort.setPreferredSize(new Dimension(btnLong.getWidth(), btnLong.getHeight()));
// ---------------------------------------------------------------------
window.setVisible(true);
}
}

Set the GridBagConstraints fill property to GridBagConstraints.HORIZONTAL so that both JButton components occupy equal width in the container
constraints.fill = GridBagConstraints.HORIZONTAL;

Make use of an appropriate layout manager, like GridBagLayout and it's constraints...
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Buttons {
public static void main(String[] args) {
new Buttons();
}
public Buttons() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException ex) {
} catch (InstantiationException ex) {
} catch (IllegalAccessException ex) {
} catch (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 {
public TestPane() {
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
gbc.fill = GridBagConstraints.HORIZONTAL;
add(new JButton("I'm a very long button"), gbc);
add(new JButton("I'm not"), gbc);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
}
}

How to stop JTextFields from running off the Frame

I want to stop the text field from running off the GUI or print the text field on a new "line".
Here is the code:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Window extends JFrame {
private JTextField TextField0;
private JTextField TextField1;
private JCheckBox CheckBox0;
private JPanel panel;
//CONSTRUCTOR
public Window() {
super("Checkbox");
setLayout(new FlowLayout());
panel = new JPanel();
add(panel, BorderLayout.CENTER);
TextField0 = new JTextField("Add field",15);
panel.add(TextField0);
TextField1 = new JTextField("Add field", 15);
CheckBox0 = new JCheckBox("");
HandlerClass handler = new HandlerClass();
TextField0.addActionListener(handler);
}
public class HandlerClass implements ActionListener {
public void actionPerformed(ActionEvent event) {
if(event.getSource()==TextField0) {
CheckBox0.setText(String.format("%s",event.getActionCommand()));
panel.remove(TextField0);
panel.add(CheckBox0);
panel.add(TextField1);
panel.revalidate();
panel.repaint();
}
}
}
}

There's not really anything you can do...
JTextField will allow the text to overflow the viewable area of the textfield (trimming the text on the screen)
You could try using a JTextArea, which supports multi line text
You could also try packing the frame
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class TestTextField {
public static void main(String[] args) {
new TestTextField();
}
public TestTextField() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
String text = "This is a long piece of text that seems to go on and on and on and on an on....and some more...";
JTextField field = new JTextField(10);
JTextArea ta1 = new JTextArea(10, 2);
JTextArea ta2 = new JTextArea(10, 2);
field.setText(text);
ta1.setText(text);
ta2.setText(text);
configure(ta1);
configure(ta2);
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
gbc.weightx = 1;
gbc.fill = GridBagConstraints.HORIZONTAL;
frame.add(field, gbc);
frame.add(ta1, gbc);
frame.add(new JScrollPane(ta2), gbc);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
protected void configure(JTextArea ta) {
ta.setWrapStyleWord(true);
ta.setLineWrap(true);
}
});
}
}

Set the layout of your panel to a Boxlayout instead of a Borderlayout. See the following link for the different layouts and how to use them:
http://docs.oracle.com/javase/tutorial/uiswing/layout/visual.html