Я быстро сделал небольшое приложение, которое мы надеемся решить вашу проблему, вот весь код:
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.util.ArrayList;
import javax.swing.GroupLayout;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
public class BackspaceTest extends JFrame implements KeyListener {
// In this example I've used 4 Text Fields, each of which takes 1 character
private JTextField text1, text2, text3, text4;
// I've stored the Text Fields in a ArrayList so we can easily shuffle trough them later
private ArrayList<JTextField> fieldList = new ArrayList<>();
// Numerical value for tracking the currently focused TextField
private int focusIndex;
// This constructor is the first thing that gets called from main
public BackspaceTest() {
init();
}
private void init() {
// Initialize the text fields with 1 character column size
text1 = new JTextField(1);
text2 = new JTextField(1);
text3 = new JTextField(1);
text4 = new JTextField(1);
// Key listeners for implementing 1 character limitations and Backspace functionality
text1.addKeyListener(this);
text2.addKeyListener(this);
text3.addKeyListener(this);
text4.addKeyListener(this);
// The focus listener keeps track of currently focused Text Fields
text1.addFocusListener(new TextFocusListener());
text2.addFocusListener(new TextFocusListener());
text3.addFocusListener(new TextFocusListener());
text4.addFocusListener(new TextFocusListener());
// The default focus is on the first field
text1.requestFocus();
fieldList.add(text1);
fieldList.add(text2);
fieldList.add(text3);
fieldList.add(text4);
// Puts the items on the screen
createLayout(text1, text2, text3, text4);
setTitle("Backspace Test");
setLocationRelativeTo(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
private void createLayout(JComponent... arg) {
JPanel panel = (JPanel) getContentPane();
GroupLayout gl = new GroupLayout(panel);
panel.setLayout(gl);
gl.setAutoCreateContainerGaps(true);
gl.setAutoCreateGaps(true);
gl.setHorizontalGroup(gl.createSequentialGroup()
.addComponent(arg[0])
.addComponent(arg[1])
.addComponent(arg[2])
.addComponent(arg[3])
);
gl.setVerticalGroup(gl.createParallelGroup()
.addComponent(arg[0])
.addComponent(arg[1])
.addComponent(arg[2])
.addComponent(arg[3])
);
gl.linkSize(text1, text2, text3, text4);
pack();
}
class TextFocusListener implements FocusListener {
@Override
public void focusGained(FocusEvent e) {
focusIndex = fieldList.indexOf(getFocusOwner());
System.out.println(focusIndex);
}
@Override
public void focusLost(FocusEvent e) { }
}
@Override
public void keyTyped(KeyEvent e) { }
@Override
public void keyPressed(KeyEvent e) {
JTextField focusedText = fieldList.get(focusIndex);
// Check if BACKSPACE is pressed and if Text Field is empty and if it's not the first field
if (e.getKeyCode() == KeyEvent.VK_BACK_SPACE &&
focusedText.getText().equals("") &&
focusIndex > 0) {
fieldList.get(--focusIndex).requestFocus();
}
}
@Override
public void keyReleased(KeyEvent e) {
// This limits the amount of characteres to 1. I'm not fully pleased with it but it works for this demonstration
if (text1.getText().length() >= 1)
text1.setText(text1.getText().substring(0, 1));
if (text2.getText().length() >= 1)
text2.setText(text2.getText().substring(0, 1));
if (text3.getText().length() >= 1)
text3.setText(text3.getText().substring(0, 1));
if (text4.getText().length() >= 1)
text4.setText(text4.getText().substring(0, 1));
}
// Here's where the program starts
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
new BackspaceTest().setVisible(true);
}
});
}
});
Если у вас нет времени, чтобы запустить его, посмотрите на строку 96, я думаю, Focus Listener - хороший способ решить вашу проблему. Надеюсь, это поможет вам, удачи!
Большое спасибо ** camickr **. Я попробую ваш пример. –