Detecting Approval button in a Swing FileChooser event

Question

I know that there is another way to do this, but I prefer to see if anyone has an answer for doing it this way. The original way is to get the integer return value after calling the ShowDialog() function; I want to grab it from within the Event (shown below) itself. I've thrown some code in there to check if a file is selected, but I need to check whether the approval button (the OK button) has been selected before it gets there. Does anyone know how to check which button is pressed in a FileChooser dialog, using a setup like below?

Here's my code:

private void FileChooser_OpenMouseClicked(java.awt.event.MouseEvent evt) {
        if(!FileChooser_Open.getSelectedFile().equals(null)) 
        {



        }
    }

Original method:

//In response to a button click:
int returnVal = fc.showOpenDialog(aComponent);

The difference is that the original method gets a return value when the dialog box is closed, while in this method, I do not know of a way to get that return value (I believe the box has already closed, but there is nothing there to catch the return value). I apologize if I do not appear to be making a lot of sense.

edit: More information

So this is how I am creating the dialogue (a menu item, "Open" raises an event, which calls the showOpenDialog() method. As you can see, it is not capturing the return value (bear with me). Is it possible then to get the return value or at design a method to figure out whether the OK button is then pressed in the MouseClicked event? I guess I am trying to focus on an event-based programming style, where the code reacts according to the event raised, and grabbing the checking for the OK / approval button click inside the Open Menu event seems a little...disorganized from my perspective. Perhaps I am too used to C# / WinForm's approach to this problem?

private void MenuItem_OpenActionPerformed(java.awt.event.ActionEvent evt) {                                              
        FileChooser_Open.showOpenDialog(this);
    }  


private void FileChooser_OpenMouseClicked(java.awt.event.MouseEvent evt) {                                              
        if(!FileChooser_Open.getSelectedFile().equals(null)) 
        {



        }
    }

score 1 · Answer 1 · edited May 23 '17 at 11:43

If I understand the question, you might be able to use a JFileChooser#approveSelection() method:

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

public class ApproveSelectionDemo {
  public JComponent makeUI() {
    final JPanel p = new JPanel();
    final JFileChooser fileChooser = new JFileChooser() {
      @Override public void approveSelection() {
        if(!getSelectedFile().exists()) {
          int returnVal = JOptionPane.showConfirmDialog(
                  this, "message", "title", JOptionPane.YES_NO_OPTION);
          if(returnVal!=JOptionPane.YES_OPTION) {
            return;
          }
        }
        super.approveSelection();
      }
    };
    p.add(new JButton(new AbstractAction("Open") {
      @Override public void actionPerformed(ActionEvent e) {
        int retvalue = fileChooser.showOpenDialog(p);
        if(retvalue==JFileChooser.APPROVE_OPTION) {
          System.out.println(fileChooser.getSelectedFile());
        }
      }
    }));
    return p;
  }
  public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
      @Override public void run() {
        createAndShowGUI();
      }
    });
  }
  public static void createAndShowGUI() {
    JFrame f = new JFrame();
    f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    f.getContentPane().add(new ApproveSelectionDemo().makeUI());
    f.setSize(320, 240);
    f.setLocationRelativeTo(null);
    f.setVisible(true);
  }
}

Detecting Approval button in a Swing FileChooser event

1 Answers1