How do I capture a mouseClicked event from a JTable within a JScrollPane

[Jw Jones]

Greetings, all.

Hopefully there is something simple I'm overlooking, but here goes:

I have a JTable that is within a JScrollPane. If I try to write add a MouseListener to the JTable it never fires. However, a mouse event does fire for the JScrollPane which it is added to. Is there a way to prevent the JScrollPane from capturing the event or passing it along to the JTable?

Sorry if this is a stupid question.

-Jay

[Rob Spoor]

How have you added your mouse listener? And what does it look like? Because I've added mouse listeners to JTables without any problems, just with "addMouseListener". And just about all my JTables are in JScrollPanes.

[Jw Jones]

Rob Prime wrote:How have you added your mouse listener? And what does it look like? Because I've added mouse listeners to JTables without any problems, just with "addMouseListener". And just about all my JTables are in JScrollPanes.

Thanks for responding, Rob. I'm using the MVC model, so I'll try to give the relevant code snippets:

JPanel on which the JScrollPane & JTable reside(View):

...
jScrollPane1.setViewPortView(tableJTable);

public void addTableMouseListener(MouseListener ml)
{
      tableJTable.addMouseListener(ml);
}
...

In the Controller class, I have the following code:

class TableController {
     public TableController(JPanel panel)
     {
         panel.addTableMouseListener(new TableMouseListener());
     }

     class TableMouseListener extends MouseListener {
     public void mousePressed(MouseEvent e) { }

    public void mouseReleased(MouseEvent e) {}

    public void mouseEntered(MouseEvent e) {}

    public void mouseExited(MouseEvent e) {}

    public void mouseClicked(MouseEvent e) {
       System.out.println("Row Selected");
    }
}

Hopefully I'm not leaving out any of the relevant code. I have an action listener on a JButton that's added on the same JPanel in similar fashion that works as expected. The only thing I can see is that the JScrollPane is capturing the mouse listener events before it reaches the table. If I add a mouse listener to the JScrollPane, it works fine. Very confusing.

[Jw Jones]

Rob Prime wrote:How have you added your mouse listener? And what does it look like? Because I've added mouse listeners to JTables without any problems, just with "addMouseListener". And just about all my JTables are in JScrollPanes.

Rob, thanks for the quick response. I posted the relevant code by my session timed out before I submitted it & I ended up losing it all. I'll post it again later.

Once again, thanks!

-Jay

[Rob Spoor]

The following little test works as it should:

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

public class Test extends MouseAdapter
{
    public static void main(String[] args) throws Exception
    {
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        String[] headers = {"A", "B", "C"};
        Object[][] data = {{1, 2, 3}, {4, 5, 6}};
        JTable table = new JTable(data, headers);
        JScrollPane scroll = new JScrollPane();
        scroll.setViewportView(table);
        frame.add(scroll);
        frame.pack();
        frame.setVisible(true);
        table.addMouseListener(new Test());
        scroll.addMouseListener(new Test());
    }

    @Override
    public void mouseClicked(MouseEvent e)
    {
        System.out.println(e.getSource().getClass());
    }
}

Just one question: are you sure that you create an instance of TableController? Because if you add a mouse listener to a JTable inside a JScrollPane, it should catch events. In fact, if I don't add the mouse listener to the table in the above example, nothing happens if you click the table.

By the way, if you want to know which rows and columns are selected, a ListSelectionListener is probably more useful:

table.getSelectionModel().addListSelectionListener(...);

Just remember to use JTable's own methods for retrieving the selection.

[Jw Jones]

Rob Prime wrote:The following little test works as it should:

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

public class Test extends MouseAdapter
{
    public static void main(String[] args) throws Exception
    {
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        String[] headers = {"A", "B", "C"};
        Object[][] data = {{1, 2, 3}, {4, 5, 6}};
        JTable table = new JTable(data, headers);
        JScrollPane scroll = new JScrollPane();
        scroll.setViewportView(table);
        frame.add(scroll);
        frame.pack();
        frame.setVisible(true);
        table.addMouseListener(new Test());
        scroll.addMouseListener(new Test());
    }

    @Override
    public void mouseClicked(MouseEvent e)
    {
        System.out.println(e.getSource().getClass());
    }
}

Just one question: are you sure that you create an instance of TableController? Because if you add a mouse listener to a JTable inside a JScrollPane, it should catch events. In fact, if I don't add the mouse listener to the table in the above example, nothing happens if you click the table.

By the way, if you want to know which rows and columns are selected, a ListSelectionListener is probably more useful:

table.getSelectionModel().addListSelectionListener(...);

Just remember to use JTable's own methods for retrieving the selection.

No doubt that the TableController is instantiated. I have several ActionListeners & KeyListeners that are working correctly that are controlled by that class. I seem to have no problem with anything but JTable listeners. They appear to be my kryptonite.

I have just started looking at the ListSelectionListener, although so far I am getting the same results.

[Michael Dunn]

> Hopefully I'm not leaving out any of the relevant code.

you probably have, and posting code typed from memory is never a good idea

class TableMouseListener extends MouseListener {

would be 'implements MouseListener' in your real code.

might be time for you to post a working (not doing as it should) sample program,
so we can see exactly what you're doing

[Jw Jones]

Michael Dunn wrote:> Hopefully I'm not leaving out any of the relevant code.

you probably have, and posting code typed from memory is never a good idea

class TableMouseListener extends MouseListener {

would be 'implements MouseListener' in your real code.

might be time for you to post a working (not doing as it should) sample program,
so we can see exactly what you're doing

You're right. I found the source of the issue, although I'm not sure exactly how I'm going to resolve. Thanks for the help, guys.

[Jw Jones]

Just to let you guys know, I fixed it using the ListSelectionListener suggested by Rob, although the main problem was my own stupidity.

Thanks for the prompt replies & sorry for wasting time over something that ending up being related to something entirely different.


-Jay

[Rob Spoor]

Jw Jones wrote:although the main problem was my own stupidity.

Just out of curiosity, what was the cause?

[Jw Jones]

Rob Prime wrote:

Jw Jones wrote:although the main problem was my own stupidity.

Just out of curiosity, what was the cause?

I have to initialize the JTable early on in the app before I know what data actually needs to populate it. It's at this time that I add the listeners. But, after a selection is made in another table, I repopulate the JTable with a:

jtable = new JTable(rows, cols);

which, of course, removes the listeners attachment to the jtable object. So now I store the listeners in variables & add them back after I reinitialize jtable. This might be awkward but it works. I am definitely open to a more elegant solution.

Again, thanks guys for all your input & the promptness with which you delivered it.

[Rob Spoor]

Instead of creating a whole new JTable, only create a whole new TableModel:

jtable.setModel(new DefaultTableModel(rows, cols));

In fact, when you create a JTable the way you do, JTable automatically creates a backing DefaultTableModel for it to use.

[Jw Jones]

Rob Prime wrote:Instead of creating a whole new JTable, only create a whole new TableModel:

jtable.setModel(new DefaultTableModel(rows, cols));

In fact, when you create a JTable the way you do, JTable automatically creates a backing DefaultTableModel for it to use.

Ahhh. I'll definitely try that. I have used JTables so little that I wasn't aware of that.

Sincere thanks, Rob.

-Jay