按下时更改JButton的文本

Question

I want to change the text of a JButton when it is pressed. So far, the text does change when the button is pressed, but when I move my mouse outside the button, the text reverts to what it was before (in this case, an empty string). How do I ensure that the text stays changed on the JButton?

Here is my code:

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class Tile extends JButton implements ActionListener {
    private int xPos, yPos;
    private char value;

    Tile(int x, int y) {
        xPos = x;
        yPos = y;
        setFont(this.getFont().deriveFont(Font.PLAIN, 45f));
        addActionListener(this);
    }

    @Override
    public int getX() {
        return xPos;
    }

    @Override
    public int getY() {
        return yPos;
    }

    public char getValue() {
        return value;
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        value = 'X';
        setText(Character.toString(value));
    }
}

Answer 1

the text does change when the button is pressed, but when I move my mouse outside the button, the text reverts to what it was before

Therefore, I guess you would need to read the apidocs about the selected state and aimed state of button.

ButtonModel (Java Platform SE 8 )
In details, the state model for buttons works as follows when used with the mouse: Pressing the mouse on top of a button makes the model both armed and pressed. As long as the mouse remains down, the model remains pressed, even if the mouse moves outside the button. On the contrary, the model is only armed while the mouse remains pressed within the bounds of the button (it can move in or out of the button, but the model is only armed during the portion of time spent within the button). A button is triggered, and an ActionEvent is fired, when the mouse is released while the model is armed - meaning when it is released over top of the button after the mouse has previously been pressed on that button (and not already released). Upon mouse release, the model becomes unarmed and unpressed.

import java.awt.*;
import javax.swing.*;

public class TileTest {
  private JComponent makeUI() {
    JButton button1 = new JButton("A");
    button1.addChangeListener(e -> {
      JButton b = (JButton) e.getSource();
      ButtonModel m = b.getModel();
      boolean isPressedAndArmed = m.isPressed() && m.isArmed();
      b.setText(isPressedAndArmed ? "X" : "A");
    });

    JButton button2 = new JButton("B");
    button2.addChangeListener(e -> {
      JButton b = (JButton) e.getSource();
      ButtonModel m = b.getModel();
      boolean isPressed = m.isPressed();
      b.setText(isPressed ? "X" : "B");
    });

    JPanel p = new JPanel();
    p.add(button1);
    p.add(button2);
    return p;
  }
  public static void main(String[] args) {
    EventQueue.invokeLater(() -> {
      JFrame f = new JFrame();
      f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
      f.getContentPane().add(new TileTest().makeUI());
      f.setSize(320, 240);
      f.setLocationRelativeTo(null);
      f.setVisible(true);
    });
  }
}