The following simple code:
import java.awt.BorderLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
public class ButtonTextMain {
public static void main(final String[] args) {
SwingUtilities.invokeLater(() -> {
final JTextField field = new JTextField(20);
final JButton button = new JButton("Click to change text");
button.addActionListener(e -> button.setText(field.getText()));
final JPanel panel = new JPanel(new BorderLayout());
panel.add(field, BorderLayout.CENTER);
panel.add(button, BorderLayout.PAGE_END);
final JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(panel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
});
}
}
can always reproduce the same bug (at least for my setups, which are given below).
The program is supposed to change the button text, according to the text-field's text, when the button is clicked.
The problem is that the text of the button reverts/changes back to its previous value on its own unexpectedly.
The problem arises when I use the Tab to alternate/navigate between the button and the text-field. Here are the specific steps which always reproduce the same bug on my setups:
- Run the program.
- Resize the frame to be a bit bigger than it was.
- Type some short text in the text-field.
- Press Tab to navigate the focus to the button.
- Press Spacebar to invoke the button.
- Press Tab to navigate the focus back to the text-field.
- Type any letter you like into the text-field.
Notes:
- I know that step 2 is relevant, because if I ommit it then the bug does not reproduce.
- After step 2 (and before 3), the mouse should not be needed any more. Leave it. The focus of the program should be in the text-field as it was when the program launched.
- In step 3 I usually type something like
abc
but the error repoduces for any other input I tried. - In step 6 you can also use Shift Tab to navigate back to the text-field.
- On step 7, after typing the first letter, you will see that the button's text changes back to its initial/previous value.
My first tested setup:
Apache NetBeans IDE 8.2, which is a bit outdated.
java -version
yields:java version "1.8.0_321" Java(TM) SE Runtime Environment (build 1.8.0_321-b07) Java HotSpot(TM) Client VM (build 25.321-b07, mixed mode)
javac -version
yieldsjavac 1.8.0_161
. There is a missmatch here with the runtime environment.
My second tested setup:
Apache NetBeans IDE 11.0.
java -version
yields:java version "12.0.2" 2019-07-16 Java(TM) SE Runtime Environment (build 12.0.2 10) Java HotSpot(TM) 64-Bit Server VM (build 12.0.2 10, mixed mode, sharing)
javac -version
yieldsjavac 12.0.2
.
The operating system is Windows 10 on both setups.
So the question is: did I do something wrong, and if so, what is it please? First of, can anybody else reproduce the bug I am getting on their setup?
Update:
I can also reproduce this behaviour on the system L&F too, by using:
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
inside just before the JTextField
creation (and catching exceptions, etc).
CodePudding user response:
Based on the above comments I retested and now I am able to reproduce the problem. The issue occurs when you increase the vertical height of the text field (by some minimal amount).
I guess I tested before by only increasing the horizontal size of the text field.
I found a simple work around:
import java.awt.BorderLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
public class ButtonTextMain {
public static void main(final String[] args) {
SwingUtilities.invokeLater(() -> {
final JTextField field = new JTextField(20);
final JButton button = new JButton("Click to change text");
button.addActionListener(e ->
{
button.setText(field.getText());
//button.getParent().revalidate();
button.getParent().repaint();
});
final JPanel panel = new JPanel(new BorderLayout());
panel.add(field, BorderLayout.CENTER);
panel.add(button, BorderLayout.PAGE_END);
final JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setContentPane(panel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
});
}
}
This definitely seems like a bug to me.
Having said that, rarely would you want the vertical height of the text field to increase in size. So maybe you can find a layout manager that only affects the horizontal size and not the vertical height?
CodePudding user response:
I don't have this problem. I use VScode, java version 1.8.0.25. I think problem is your compiler.