How do I get a PopupMenu to show up when I left-click on a TrayIcon in Java?

问题

Currently, the PopupMenu will show up when I right-click on the TrayIcon in the SystemTray. However, I want it to do the same when I left-click on the TrayIcon.

I thought I might accomplish this by using a mouseListener on the TrayIcon, but I don't know what method to invoke in the mouseClicked event to achieve the desired results.

icon = new TrayIcon(img, tooltip, popup);

     icon.addMouseListener(
           new MouseAdapter() {
              public void mouseClicked(MouseEvent e) {
                 popup.setEnabled(true);
              }
           });

Using the setEnabled() method does not make the popup menu appear when I left-click the TrayIcon. It actually has no noticeable effect. I'm wondering what method I should use in the mouseClicked() body in order to make the popup show up when it is left-clicked.

回答1:

Basically, in your mouse listener, you need to determine which button was pressed (and optional, how many times).

The critical piece of code is this...

if (e.getButton() == MouseEvent.BUTTON1 && e.getClickCount() == 1) { ... }

I've also included some additional code that makes sure the popup does not cover the task bar and is displayed within the viewable area of the screen (it's a nit pick of mine ;))

public class TestTrayIcon02 {

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (Exception ex) {
                }
                try {
                    final TrayIcon ti = new TrayIcon(ImageIO.read(getClass().getResource("/Smiley.png")), "Have a nice day");
                    final JPopupMenu popup = new JPopupMenu();

                    JMenuItem mi = new JMenuItem("Get me some");
                    mi.addActionListener(new ActionListener() {
                        @Override
                        public void actionPerformed(ActionEvent e) {
                            SystemTray.getSystemTray().remove(ti);
                            System.exit(0);
                        }
                    });

                    popup.add(mi);
                    ti.addMouseListener(new MouseAdapter() {
                        @Override
                        public void mouseClicked(MouseEvent e) {
                            if (e.getButton() == MouseEvent.BUTTON1 && e.getClickCount() == 1) {
                                Rectangle bounds = getSafeScreenBounds(e.getPoint());
                                Point point = e.getPoint();
                                int x = point.x;
                                int y = point.y;
                                if (y < bounds.y) {
                                    y = bounds.y;
                                } else if (y > bounds.y + bounds.height) {
                                    y = bounds.y + bounds.height;
                                }
                                if (x < bounds.x) {
                                    x = bounds.x;
                                } else if (x > bounds.x + bounds.width) {
                                    x = bounds.x + bounds.width;
                                }
                                if (x + popup.getPreferredSize().width > bounds.x + bounds.width) {
                                    x = (bounds.x + bounds.width) - popup.getPreferredSize().width;
                                }
                                if (y + popup.getPreferredSize().height > bounds.y + bounds.height) {
                                    y = (bounds.y + bounds.height) - popup.getPreferredSize().height;
                                }
                                popup.setLocation(x, y);
                                popup.setVisible(true);
                            }
                        }
                    });

                    SystemTray.getSystemTray().add(ti);
                } catch (Exception ex) {
                    ex.printStackTrace();
                }
            }
        });
    }

    public static Rectangle getSafeScreenBounds(Point pos) {

        Rectangle bounds = getScreenBoundsAt(pos);
        Insets insets = getScreenInsetsAt(pos);

        bounds.x += insets.left;
        bounds.y += insets.top;
        bounds.width -= (insets.left + insets.right);
        bounds.height -= (insets.top + insets.bottom);

        return bounds;

    }

    public static Insets getScreenInsetsAt(Point pos) {
        GraphicsDevice gd = getGraphicsDeviceAt(pos);
        Insets insets = null;
        if (gd != null) {
            insets = Toolkit.getDefaultToolkit().getScreenInsets(gd.getDefaultConfiguration());
        }
        return insets;
    }

    public static Rectangle getScreenBoundsAt(Point pos) {
        GraphicsDevice gd = getGraphicsDeviceAt(pos);
        Rectangle bounds = null;
        if (gd != null) {
            bounds = gd.getDefaultConfiguration().getBounds();
        }
        return bounds;
    }

    public static GraphicsDevice getGraphicsDeviceAt(Point pos) {

        GraphicsDevice device = null;

        GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
        GraphicsDevice lstGDs[] = ge.getScreenDevices();

        ArrayList<GraphicsDevice> lstDevices = new ArrayList<GraphicsDevice>(lstGDs.length);

        for (GraphicsDevice gd : lstGDs) {

            GraphicsConfiguration gc = gd.getDefaultConfiguration();
            Rectangle screenBounds = gc.getBounds();

            if (screenBounds.contains(pos)) {

                lstDevices.add(gd);

            }

        }

        if (lstDevices.size() > 0) {
            device = lstDevices.get(0);
        } else {
            device = ge.getDefaultScreenDevice();
        }

        return device;

    }
}

回答2:

What you're trying to do is apparently not possible:

You cannot show the PopupMenu with its show method since you need to specify a JComponent but your TrayIcon isn't one (weird enough though that TrayIcon still manages to do it, so apparently there is a way, don't ask me though..). So, as MadProgrammer suggested, you should try using JPopupMenu instead. Don't add it to your TrayIcon for that won't be possible, but display your JPopupMenu by adding a MouseListener to your TrayIcon. That should do the trick:

final TrayIcon tray = new TrayIcon( img, tooltip, null);
final JPopupMenu menu = new JPopupMenu();
... // your menu initialization.
tray.addMouseListener( new MouseAdapter() {
    @Override
    public void mouseClicked(MouseEvent evt) {
        menu.setLocation( evt.getPoint() );
        menu.setVisible( true );
    }
}

来源：https://stackoverflow.com/questions/14670516/how-do-i-get-a-popupmenu-to-show-up-when-i-left-click-on-a-trayicon-in-java