Overlapping MouseListeners

[Steven Hatfield]

Hi all!

I need some help with getting 2 MouseListeners working at the same time on 2 different overlapping JPanels.
I have created a sample class that shows what is happening. Perhaps this is "the way that it is", but I need a way around the problem.

I have a background panel and a foreground panel. I need to track the mouse position in the background panel, even when it is over the foreground panel. The problem is that when the mouse is over the foreground panel, the background panel stops "listening".

Is there a way to keep both of the mouse listeners listening?

Thanks,
Steven

    
import javax.swing.*;
import javax.swing.event.MouseInputAdapter;
import java.awt.*;
import java.awt.event.MouseEvent;

public class AppMain {

    public static void main(String[] args) {
        new AppMain();
    }

    public AppMain() {

        JFrame mainWindow = new JFrame("Mouse Listener Test");
        mainWindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        mainWindow.setSize(500, 500);
        mainWindow.setVisible(true);

        // This label holds mouse pointer information for the background panel
        JLabel locLabelOne = new JLabel();
        // This label holds mouse pointer information for the foreground panel
        JLabel locLabelTwo = new JLabel();

        // The panel on which everything else sits
        JPanel backgroundPanel = new JPanel();
        backgroundPanel.setName("Background Panel");
        backgroundPanel.setLayout(new BoxLayout(backgroundPanel, BoxLayout.Y_AXIS));
        mainWindow.add(backgroundPanel);

        // This panel is a "foreground" panel that sits on top of the background panel
        JPanel secondPanel = new JPanel();
        secondPanel.setName("Blue Panel");
        secondPanel.setBackground(Color.blue);
        addMouseListener(backgroundPanel, locLabelOne);

        // Make a big blue box that you can pass the mouse pointer over to see the problem first hand
        Dimension d = new Dimension(150, 150);
        secondPanel.setSize(d);
        secondPanel.setMinimumSize(d);
        secondPanel.setMaximumSize(d);

        backgroundPanel.add(secondPanel);
        backgroundPanel.add(locLabelOne);
        backgroundPanel.add(locLabelTwo);

        addMouseListener(secondPanel, locLabelTwo);
    }

    private void addMouseListener(final Component c, final JLabel textLabel) {
        MouseInputAdapter mia = new MouseInputAdapter() {
            @Override
            public void mouseMoved(MouseEvent e) {
                textLabel.setText("[" + c.getName() + "] x,y = " + e.getX() + "," + e.getY());
            }
        };
        c.addMouseMotionListener(mia);
        c.addMouseListener(mia);
    }
}
		

[Rob Spoor]

Moving to our GUI forum.

[Jonas Wille]

You can always calculate the position from the mouse for the backgroundcomponent.

Something like this could probably do the trick.

 
fore = new MouseInputAdapter() {   
    @Override  
    public void mouseMoved(MouseEvent e) {   
        System.out.println("[fore] x,y = " + e.getX() + "," + e.getY());
        System.out.println("[back] x,y = " + (e.getX()+secondPanel.getBounds().getX()) + "," + (e.getY()+secondPanel.getBounds().getY()));
    }   
}; 
    	
back = new MouseInputAdapter() {   
    @Override  
    public void mouseMoved(MouseEvent e) {   
        System.out.println("[back] x,y = " + e.getX() + "," + e.getY());
    }   
}; 

[Kevin Workman]

Or you could use a Glass Pane to detect the background MouseEvents instead.

Tutorial: How to Use Root Panes
Another article that's extremely helpful: A well-behaved GlassPane

[Rob Spoor]

Kevin, welcome to the Ranch, and thanks for your great advice

[Darryl Burke]

Kevin Workman wrote:

H Kevin, good to see you sharing your knowledge here too!

[Kevin Workman]

Darryl Burke wrote:

Kevin Workman wrote:

H Kevin, good to see you sharing your knowledge here too!

Heh, thanks. Ever since the Sun Forums died, I've been looking a new home. It's nice to see a familiar face, er, name.

[Steven Hatfield]

Kevin Workman wrote:Or you could use a Glass Pane to detect the background MouseEvents instead.

Tutorial: How to Use Root Panes
Another article that's extremely helpful: A well-behaved GlassPane

This required a bit of work, and some luck, but I was able to get the GlassPane to work.

I used the sample GlassPane class from here: http://www.javafaq.nu/java-example-code-472.html
and changed it to accept the label that will be updated in my sample program. Now I get positioning within the blue box, the background, and overall positioning with the GlassPane. Fantastic!

Thank you!

[Kevin Workman]

Steven Hatfield wrote:
This required a bit of work, and some luck, but I was able to get the GlassPane to work.

I used the sample GlassPane class from here: http://www.javafaq.nu/java-example-code-472.html
and changed it to accept the label that will be updated in my sample program. Now I get positioning within the blue box, the background, and overall positioning with the GlassPane. Fantastic!

Thank you!

Cool, I'm glad you got it working. GlassPanes (and the other parts of a Root Pane) can be a bit tricky at first, but they start to make more sense as you use them more. Good luck!