java - JScrollPane 不调度事件

Question

我在 JPanel 内的 JScrollPane 内有一个 JTable。我在最后一个 JPanel 中添加了一个 MouseListener。问题是，当鼠标按下 JTable 之外的可用空间时，我无法监听鼠标事件。我有另一个带有 JTextField 的 JPanel，它将事件分派(dispatch)给它的父级 JPanel。可能在 JScrollPane 中设置了一些属性？

SSCCE:

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;

public class SimpleTableDemo extends JPanel {

    public SimpleTableDemo() {
        super(new BorderLayout(0, 0));

        String[] columnNames = { "First Name", "Last Name", "Sport", "# of Years", "Vegetarian" };

        Object[][] data = { { "Kathy", "Smith", "Snowboarding", new Integer(5), new Boolean(false) }, { "John", "Doe", "Rowing", new Integer(3), new Boolean(true) }, { "Sue", "Black", "Knitting", new Integer(2), new Boolean(false) }, { "Jane", "White", "Speed reading", new Integer(20), new Boolean(true) }, { "Joe", "Brown", "Pool", new Integer(10), new Boolean(false) } };

        final JTable table = new JTable(data, columnNames);
        table.setPreferredScrollableViewportSize(new Dimension(500, 70));
        table.setBackground(Color.GREEN);
        table.setFillsViewportHeight(false);

        JScrollPane scrollPane = new JScrollPane(table);

        add(scrollPane, BorderLayout.CENTER);

        JPanel textPanel = new JPanel();
        JTextField textField = new JTextField(50);
        textPanel.add(textField);
        add(textPanel, BorderLayout.NORTH);

        addMouseListener(new MouseAdapter() {
            @Override
            public void mousePressed(MouseEvent e) {
                System.out.println("PRESSED!!!");
            }
        });
    }

    private static void createAndShowGUI() {
        JFrame frame = new JFrame("SimpleTableDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(700, 400);

        SimpleTableDemo newContentPane = new SimpleTableDemo();
        newContentPane.setOpaque(true);
        frame.setContentPane(newContentPane);

        frame.setVisible(true);
    }

    public static void main(String[] args) {
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
}

Answer 1

例如(基于这里的评论)

import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;

public class LostMouseEvent {

    private JPanel panel1 = new JPanel() {
        private static final long serialVersionUID = 1L;

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(600, 400);
        }
    };
    private JPanel panel2 = new JPanel() {
        private static final long serialVersionUID = 1L;

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(500, 300);
        }
    };

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

    public LostMouseEvent() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                JScrollPane pane = new JScrollPane(panel2);
                panel1.setBorder(BorderFactory.createLineBorder(Color.blue));
                panel2.setBorder(BorderFactory.createLineBorder(Color.green));
                panel1.add(pane);
                MouseListener rml = new RealMouseListener();
                panel1.addMouseListener(rml);
                MouseListener fml = new FakeMouseListener();
                pane.addMouseListener(fml);
                JFrame frame = new JFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(panel1);
                frame.pack();
                frame.setVisible(true);

            }
        });
    }

    private class RealMouseListener extends MouseAdapter {

        @Override
        public void mousePressed(MouseEvent me) {
            System.out.println(me);
            Point point = me.getPoint();
            //System.out.println(point);
            System.out.println(me.getX());
            System.out.println(me.getXOnScreen());
            System.out.println(me.getY());
            System.out.println(me.getYOnScreen());
        }
    }

    private class FakeMouseListener extends MouseAdapter {

        @Override
        public void mousePressed(MouseEvent me) {
            JScrollPane pane = (JScrollPane) me.getSource();
            MouseEvent newMe = SwingUtilities.convertMouseEvent(panel2/*pane.getViewport()*/, me, panel1);
            System.out.println(newMe.getX());
            System.out.println(newMe.getXOnScreen());
            System.out.println(newMe.getY());
            System.out.println(newMe.getYOnScreen());
            panel1.dispatchEvent(me);
        }
    }
}