如何在 SwingGui 中调用鼠标右键单击事件？

Question

I have a table. If I right-click I got a JPopUpMenu but before the pop-up I want to select the row where the right-click event is done. Here is what I've tried.

path_tbl.addMouseListener(new MouseAdapter() {
        @Override
        public void mousePressed(MouseEvent e) {
            System.out.println(e.getPoint());

            Point point = e.getPoint();
            int selectedRow = path_tbl.rowAtPoint(point);
            path_tbl.setRowSelectionInterval(selectedRow, selectedRow);
        }
    });

In that event, I cannot get any output from the console when I right-click. However, when I left-click, points are printed to the console.

java.awt.Point[x=105,y=76]

So, this event only works when I left-click. How can I make this event work with right-click?

Answer 1

Since you want custom mouse behavior, you should not use setComponentPopupMenu .

Instead, display the JPopupMenu yourself, using JPopupMenu's show method:

JPopupMenu menu = /* ... */;

path_tbl.addMouseListener(new MouseAdapter() {
    private void showPopupMenuFor(MouseEvent e) {
        if (menu.isPopupTrigger(e)) {
            Point point = e.getPoint();
            int row = path_tbl.rowAtPoint(point);

            if (!path_tbl.isRowSelected(row)) {
                path_tbl.setRowSelectionInterval(row, row);
            }

            menu.show(path_tbl, e.getX(), e.getY());
        }
    }

    @Override
    public void mousePressed(MouseEvent e) {
        showPopupMenuFor(e);
    }

    @Override
    public void mouseReleased(MouseEvent e) {
        showPopupMenuFor(e);
    }

    @Override
    public void mouseClicked(MouseEvent e) {
        showPopupMenuFor(e);
    }
});

You must check the MouseEvent in both mousePressed and mouseReleased, because exactly when a context menu is triggered depends on the platform and the look-and-feel. (Checking in mouseClicked may or may not be necessary, but it doesn't hurt.)

Answer 2

In most cases, I'm lazy, so if I don't need to do something, then I'd prefer not to. In this case, I'd prefer to make use of the existing API works as much as possible, meaning, make use of JComponent#setComponentPopupMenu , as it will take care of the "how" and "when" the popup should be shown, based on the current platform.

However, as you have discovered, by default, JTable will NOT select the row when the user presses the "right" mouse button, for that, you could just continue with your current workflow, but, checking to see if the MouseEvent is actually a "right" click.

Lucky for us, some of the original Swing developers were also "lazy" and they provided us with SwingUtilities.isRightMouseButton , yea 🎉

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.Vector;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JPopupMenu;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.table.DefaultTableModel;

public final class Main {
    public static void main(String[] args) {
        new Main();
    }

    public Main() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame frame = new JFrame();
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        public TestPane() {
            setLayout(new BorderLayout());
            DefaultTableModel model = new DefaultTableModel(0, 10);
            for (int row = 0; row < 10; row++) {
                Vector data = new Vector(10);
                for (int col = 0; col < 10; col++) {

                    String value = row + "x" + ((char) (col + 'A'));
                    data.add(value);

                }
                model.addRow(data);
            }

            JPopupMenu menu = new JPopupMenu();
            menu.add("Hello");
            menu.add("This looks interesting");
            menu.add("I like bi-planes");

            JTable table = new JTable(model);
            table.setComponentPopupMenu(menu);
            table.addMouseListener(new MouseAdapter() {
                @Override
                public void mouseClicked(MouseEvent e) {
                    if (SwingUtilities.isRightMouseButton(e)) {
                        Point point = e.getPoint();
                        int row = table.rowAtPoint(point);

                        if (!table.isRowSelected(row)) {
                            table.setRowSelectionInterval(row, row);
                        }
                    }
                }

            });
            add(new JScrollPane(table));
        }

    }
}