Question

This might be a very simple thing that I’m overlooking, but I just can’t seem to figure it out.

I have the following method that updates a JTable:

class TableModel extends AbstractTableModel {    
        public void updateTable() {
            try {
                // update table here
             ...
    } catch (NullPointerException npe) {
                isOpenDialog = true;
                JOptionPane.showMessageDialog(null, "No active shares found on this IP!");
                isOpenDialog = false;
            }
        }
    }

However, I don’t want isOpenDialog boolean to be set to false until the OK button on the message dialog is pressed, because if a user presses enter it will activate a KeyListener event on a textfield and it triggers that entire block of code again if it’s set to false.

Part of the KeyListener code is shown below:

public class KeyReleased implements KeyListener {
        ...

    @Override
    public void keyReleased(KeyEvent ke) {
        if(txtIPField.getText().matches(IPADDRESS_PATTERN)) {
            validIP = true;
        } else {
            validIP = false;
        }

        if (ke.getKeyCode() == KeyEvent.VK_ENTER) {
            if (validIP && !isOpenDialog) {
                updateTable();
            }
        }
    }
}

Does JOptionPane.showMessageDialog() have some sort of mechanism that prevents executing the next line until the OK button is pressed? Thank you.

Answer 1

The JOptionPane creates a modal dialog and so the line beyond it will by design not be called until the dialog has been dealt with (either one of the buttons have been pushed or the close menu button has been pressed).

More important, you shouldn’t be using a KeyListener for this sort of thing. If you want to have a JTextField listen for press of the enter key, add an ActionListener to it.