Make JWindow retain focus when children are focused, including another window as child

问题

I have created JWindow, which has several JTextInput fields. This JWindow parent is JFrame. Now the situation - if text fields are clicked - they get the focus BUT JWindow also stays focused. That is good. But if I create another JWindow (child of first JWindow), and set it visible, then focus on first JWindow is lost, and the child JWindow is focused. This is bad. Is there some way to retain focus on the parent JWindow, and to make the child JWindow get the focus like JTextInput fields?

回答1:

JWindow without parent never will be focusable, carefully then JTextComponents never will be editable

for example

import java.awt.*;
import javax.swing.*;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;

public class WindowTest {

    private JFrame frame;
    private boolean bol = true;

    public WindowTest() {
        frame = new JFrame("Window Test");
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frame.setSize(300, 300);
        frame.setVisible(true);
        JWindow win = new JWindow(frame);
        win.setLayout(new GridLayout(0, 1));
        JTextField text = new JTextField("Show Window");
        text.getDocument().addDocumentListener(new DocumentListener() {
            @Override
            public void insertUpdate(DocumentEvent e) {
                if (!bol) {
                    JWindow win = new JWindow();
                    win.setLayout(new GridLayout(0, 1));
                    win.add(new JTextField("JTextField"));
                    win.add(new JTextField("JTextField"));
                    win.add(new JLabel("<html> Concurency Issues in Swing<br>"
                            + " never to use Thread.sleep(int) <br>"
                            + " durring EDT, simple to freeze GUI </html>"));
                    win.pack();
                    win.setLocation(350, 150);
                    win.setVisible(true);
                    bol = true;
                }
            }

            @Override
            public void removeUpdate(DocumentEvent e) {
            }

            @Override
            public void changedUpdate(DocumentEvent e) {
            }
        });
        win.add(text);
        win.add(new JTextField("JTextField"));
        win.add(new JTextField("JTextField"));
        win.pack();
        win.setLocation(250, 150);
        win.setVisible(true);

        bol = false;
    }

    public static void main(String args[]) {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                new WindowTest();
            }
        });
    }
}

回答2:

Before setting the child window visible, add a WindowListener. After you call setVisible on the child window, you'll receive the windowActivated callback. At that point call toFront on your parent window to bring it forward. Given the quirkiness of OS z-order handling, you might need/want to call toBack on the child window first, as well as calling requestFocus on the parent window or one of its focusable children afterward.

来源：https://stackoverflow.com/questions/18281701/make-jwindow-retain-focus-when-children-are-focused-including-another-window-as

标签

java

swing

focus

jwindow