So I have come across a peculiar problem.
My interface is just a single label, and a JSlider.
My code(stripped):
import javax.swing.*;
import java.awt.*;
public class Broken {
JLabel value = new JLabel();
JSlider slider = new JSlider(0, 255, 0);
public Broken() {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
JPanel panel = new JPanel();
value.setText("Some Value");
panel.add(value);
JFrame frame = new JFrame("Frame Name");
frame.setLayout(new GridLayout(2, 1));
frame.add(panel);
frame.add(slider);
frame.pack();
frame.setVisible(true);
}
});
}
public static void main(String[] args) {
new Broken();
}
}
What happens is the label doesn't show up. If I resize the screen from the right to the smallest possible, suddenly the text appears, and it will stay there if I resize back to what it was. I have no idea what's happening, this truly seems like a bug to me.
Before and after resizing screenshots:
Despite your efforts, you're not on the EventDispatchThread when you're creating your JLabel (or JSlider, for that matter). To test, I subclassed JLabel just see if the code was on the EDT when it's constructor is called:
import java.awt.*;
import javax.swing.*;
public class Broken {
JLabel value = new XLabel(); // called before constructor, so not on EDT
JSlider slider = new JSlider(0, 255, 0); // same here
public Broken() {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
JPanel panel = new JPanel();
value.setText("Some Value");
panel.add(value);
JFrame frame = new JFrame("Frame Name");
frame.setLayout(new GridLayout(2, 1));
frame.add(panel);
frame.add(slider);
frame.pack();
frame.setVisible(true);
}
});
}
public static void main(String[] args) {
new Broken();
}
class XLabel extends JLabel {
public XLabel() {
super();
System.out.println("EDT? " + SwingUtilities.isEventDispatchThread());
}
}
}
To fix, place the invokeLater call in main, so as to wrap the entire construction of your class onto the EDT:
import java.awt.*;
import javax.swing.*;
public class Broken2 {
JLabel value = new JLabel();
JSlider slider = new JSlider(0, 255, 0);
public Broken2() {
JPanel panel = new JPanel();
value.setText("Some Value");
panel.add(value);
JFrame frame = new JFrame("Frame Name2");
frame.setLayout(new GridLayout(2, 1));
frame.add(panel);
frame.add(slider);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
// Generally the proper way. Create Whole app on EDT
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new Broken2();
}
});
}
}
Related
I made a Java program and part of the program's function is to track the user's mouse X and Y coordinates.
The tracking works nicely but there's a small problem that bothers me.
When I move my mouse around the screen, the other components automatically change position.
Here's a MRE(Minimal Reproducible Example):
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.awt.event.ActionListener;
public class Test {
static Timer t;
static JLabel label1;
static InnerTest inner;
static int mouseX;
static int mouseY;
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
buildFrame();
runTimer();
}
});
}
public static void buildFrame() {
JFrame frame = new JFrame();
label1 = new JLabel("Test1");
JLabel label2 = new JLabel("Test Test");
JLabel label3 = new JLabel("Test Label Label");
JPanel panel = new JPanel();
panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
panel.add(label1);
panel.add(label2);
panel.add(label3);
label1.setAlignmentX(Component.CENTER_ALIGNMENT);
label2.setAlignmentX(Component.CENTER_ALIGNMENT);
label3.setAlignmentX(Component.CENTER_ALIGNMENT);
frame.getContentPane().add(panel);
frame.setSize(400, 200);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
public static void runTimer() {
inner = new InnerTest();
t = new Timer(20, inner);
t.start();
}
static class InnerTest implements ActionListener {
public void actionPerformed(ActionEvent e) {
mouseX = MouseInfo.getPointerInfo().getLocation().x * 100;
mouseY = MouseInfo.getPointerInfo().getLocation().y * 100;
label1.setText(" ( "+String.valueOf(mouseX)+" , "+String.valueOf(mouseY)+" )");
}
}
}
How do I keep the components still when another component is updating?
The components are added to the same panel so each is centered based on the maximum width of all three components. As the width of the top label changes the others are also adjusted.
The solution is to separate the top label from the other two labels.
One way would be:
//panel.add(label1);
panel.add(label2);
panel.add(label3);
//label1.setAlignmentX(Component.CENTER_ALIGNMENT);
label1.setHorizontalAlignment(JLabel.CENTER); // added
label2.setAlignmentX(Component.CENTER_ALIGNMENT);
label3.setAlignmentX(Component.CENTER_ALIGNMENT);
frame.add(label1, BorderLayout.PAGE_START); // added
frame.getContentPane().add(panel);
I have the main class that instantiates a GridBagLayout with a JLabel visbility set to false.
I would like to set the label visible when the program is running, I have tried this but it won't work. It will just display the default layout.
Main class:
gui = new gui();
gui.display();
gui.label.setVisible(true);
Gridbag layout class:
public JFrame frame;
public JLabel label1;
/**
* Launch the application.
*/
public static void display(){
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
gridLayout window = new gridLayout();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
* Create the application.
*/
public gridLayout() {
initialize();
}
/**
* Initialize the contents of the frame.
*/
#SuppressWarnings("static-access")
public void initialize() {
frame = new JFrame();
frame.setBounds(100, 100, 600, 1000);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
GridBagLayout gridBagLayout = new GridBagLayout();
frame.getContentPane().setLayout(gridBagLayout);
}
label1 = new JLabel(new ImageIcon("hi"));
GridBagConstraints gbc_label1 = new GridBagConstraints();
gbc_label1.insets = new Insets(0, 0, 5, 5);
gbc_label1.gridx = 1;
gbc_label1.gridy = 1;
label1.setVisible(false);
frame.getContentPane().add(label1, gbc_label1);
You want to display a label while a programme is running, right? This has nothing to do with the layout manager.
I give you an example where the label is visible as long as a dialog (representing your task/programme) is displayed; and I hope you can adopt it to your needs. Possibly you have to put the programme/task in an own thread.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Y extends JFrame {
public static final long serialVersionUID = 100L;
public Y() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(300, 240);
JLabel lb= new JLabel("Programme is running ...");
lb.setVisible(false);
add(lb, BorderLayout.CENTER);
JButton b= new JButton("Launch programme (dialog)");
b.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
lb.setVisible(true);
JDialog dlg= new JDialog(Y.this, "The dialog", true);
dlg.setSize(100, 100);
dlg.setVisible(true);
lb.setVisible(false);
}
});
add(b, BorderLayout.SOUTH);
setVisible(true);
}
static public void main(String args[]) {
EventQueue.invokeLater(Y::new);
}
}
I'm having some trouble with a simple application I'm creating to count the number of clicks per second. The code is as follows:
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
import javax.swing.border.Border;
public class CPSFrame implements ActionListener {
JFrame frame;
JPanel borderPanel, settings;
JButton click;
String[] timesList = {"5","10","15","20","25","30"};
JComboBox times;
JTextField showCps;
public CPSFrame() {
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
CPSFrame c = new CPSFrame();
c.drawGui();
}
});
}
public void drawGui() {
frame = new JFrame();
borderPanel = new JPanel();
settings = new JPanel();
click = new JButton("Click me!");
times = new JComboBox(timesList);
showCps = new JTextField();
frame.setBounds(100, 100, 450, 300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("CPS Calculator");
{
borderPanel.setLayout(new BorderLayout(0, 0));
frame.add(borderPanel);
{
borderPanel.add(click);
settings.setLayout(new GridLayout(1, 0, 0, 0));
borderPanel.add(settings, BorderLayout.SOUTH);
{
settings.add(times);
settings.add(showCps);
}
}
}
frame.pack();
frame.setVisible(true);
}
#Override
public void actionPerformed(ActionEvent evt) {
}
}
For some reason, if I resize the JFrame and press click, both times and showCPS disappear. I have a feeling it has something to do with the way I have the BorderLayout set up, but I'm not sure.
Here is a video of what is happening.
edit: updated the code and added a video of what is happening.
Works fine for me (Java 1.6, Win) and nothing disappears after resize and click. Try to specify the location of c.click explicitly c.borderPanel.add(c.click,BorderLayout.CENTER);
Maybe there are Java implementations (platforms, versions) where BorderLayout don't like unspecified location.
I'm having a problem trying to change JPanels by using buttons. I have a JFrame with 2 panels, 1 of them is for the buttons, which i want them to always be showed. The other one is the one that i will be switching everytime i press one ot the buttons of the other panel. The problem is that everytime i press them nothing really ever displays, i keep my buttons but the other panel that i call does not appear.
Code for one of the buttons is as follows
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
ReparacaoPanel r = new ReparacaoPanel(this, this.jPanel1);
this.getContentPane().remove(this.jPanel1);
this.getContentPane().add(r);
//this.setContentPane(r);
this.visiblePanel.setVisible(false);
this.visiblePanel = r;
this.pack();
this.setVisible(true);
r.setLocation(200, 200);
this.getContentPane().revalidate();
this.repaint();
}
If i try to use "this.setContentPane(r);" (it sets the frame to only show the panel) the panel shows. But when i try to call it as i'm trying to do in the code above nothing is showed apart from the panel that has the buttons.
I have no idea what i'm doing wrong, it does not seem to be a problem with the JPanel that i'm trying to call as it shows if used alone.
Anyone can help me out?
Consider this working example for switching manually between panels. Which produces this output.
.........
Some tiny NumberPanel
Every new instance shows another number in the center.
import javax.swing.JPanel;
public class NumberPanel extends JPanel {
private static int counter = 0;
public NumberPanel() {
setLayout(new BorderLayout(0, 0));
JLabel lblNewLabel = new JLabel("" + counter++);
lblNewLabel.setHorizontalAlignment(SwingConstants.CENTER);
add(lblNewLabel);
}
}
Setting up a frame
private void initialize() {
frame = new JFrame();
frame.setBounds(100, 100, 450, 300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel();
frame.getContentPane().add(panel, BorderLayout.SOUTH);
JButton btnNewButton = new JButton("New button");
btnNewButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
frame.getContentPane().remove(numberPanel);
numberPanel = new NumberPanel();
frame.getContentPane().add(numberPanel, BorderLayout.CENTER);
frame.pack();
}
});
panel.add(btnNewButton);
numberPanel = new NumberPanel();
frame.getContentPane().add(numberPanel, BorderLayout.CENTER);
frame.pack();
}
Testprogram
import java.awt.BorderLayout;
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.JPanel;
public class TestPanelSwitch {
private JFrame frame;
private NumberPanel numberPanel;
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
TestPanelSwitch window = new TestPanelSwitch();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
public TestPanelSwitch() {
initialize();
}
private void initialize() {
// see above
}
}
Back to the Question
I think you only need to pack your frame, like in the anonymous ActionListener.
frame.getContentPane().remove(numberPanel);
numberPanel = new NumberPanel();
frame.getContentPane().add(numberPanel, BorderLayout.CENTER);
frame.pack();
EDIT
As leonidas mentioned it is also possible to revalidate the frame. This requires only to replace the upper call to pack by theese.
frame.invalidate();
frame.validate();
I'm having a problem with this. I have a JPanel and normally I would create a JLabel like this:
JLabel lblNewLabel = new JLabel("New label");
lblNewLabel.setBounds(0, 0, 135, 14);
panel.add(lblNewLabel);
but I want each time I click a button, in that panel to be created a new JLabel with the same size, but with a different height possition. I tried:
panel.add(new JLabel(stringName));
but this way I don't get to set it's bounds. stringName I get from a JTextField.
First off, use a layout. Done correctly the layout will place the components like you want. Secondly, when dynamically adding a component to a layout you need to tell the layout to update. Here is an example, it adds a label each time a button is pressed:
public static void main(String[] args) {
final JFrame frame = new JFrame("Test");
frame.setLayout(new GridLayout(0, 1));
frame.add(new JButton(new AbstractAction("Click to add") {
#Override
public void actionPerformed(ActionEvent e) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
frame.add(new JLabel("Bla"));
frame.validate();
frame.repaint();
}
});
}
}));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(400, 300);
SwingUtilities.invokeLater(new Runnable() {
#Override public void run() {
frame.setVisible(true);
}
});
}
As said by #AndrewThompson use a correct LayoutManager, you should not be messing with setBounds etc.
Here is an example I made (Simply adds a JLabel to the JPanel each time the JButton is clicked):
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class Test {
public Test() {
createAndShowUI();
}
private void createAndShowUI() {
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
initComponents(frame);
frame.setResizable(false);
frame.pack();
frame.setVisible(true);
}
private void initComponents(final JFrame frame) {
final JPanel panel = new JPanel();
JButton button = new JButton("Add label");
button.addActionListener(new ActionListener() {
int count = 1;
#Override
public void actionPerformed(ActionEvent e) {
JLabel _lbl = new JLabel("Label " + count);//make label and assign text in 1 line
panel.add(_lbl);//add label we made
panel.revalidate();
panel.repaint();
frame.pack();//so our frame resizes to compensate for new components
count++;
}
});
frame.add(panel, BorderLayout.CENTER);
frame.add(button, BorderLayout.SOUTH);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new Test();
}
});
}
}
Try swapping the order of of your commands, add the panel first then set the location.