Manual Mouse drag Resizing of JOptionPanel containing a JScrollPane

Question

I have a JScrollPane that has a filedrop feature to allow the dragging of files. I have the JScrollPane being called with a JOptionPanel.showConfirmDialog so there are ok and cancel buttons. I want to be able to put my mouse on the edge of the window and drag to resize it. I have researched many different ways but most of them involve frames and none of them had JOptionPanes in them. How can I do this or make a resizable panel with ok and cancel buttons like a showConfirmDialog.

here is the function for my panels:

public static List<String> displayFilePanel() {
        // Declare return object
        final List<String> listOfFiles = new ArrayList<String>();

        // Create scrollable panel to hold file list
        final JTextArea text = new JTextArea();
        JScrollPane scrollPane = new JScrollPane(text);  
        text.setLineWrap(true);  
        text.setWrapStyleWord(true); 
        scrollPane.setPreferredSize( new Dimension( 800, 800 ) );


        // Drag and drop feature
        // Add each file to listofFiles
        //new FileDrop( System.out, text, /*dragBorder,*/ new FileDrop.Listener() for debugging
        new FileDrop( null, text, /*dragBorder,*/ new FileDrop.Listener()
        {   public void filesDropped( java.io.File[] files )
            {   for( int i = 0; i < files.length; i++ )
                {   try
                    {   
                        text.append( files[i].getCanonicalPath() + "\n" );
                        listOfFiles.add(files[i].getCanonicalPath());
                    }   // end try
                    catch( java.io.IOException e ) {}
                }   // end for: through each dropped file
            }   // end filesDropped
        }); // end FileDrop.Listener

        int result = JOptionPane.showConfirmDialog(null, scrollPane, "Files To rename",
            JOptionPane.OK_CANCEL_OPTION, JOptionPane.PLAIN_MESSAGE);
        if (result == JOptionPane.OK_OPTION) {
            //System.out.println(text.getText());
        } else {
            System.out.println("File Pane Cancelled");

            //if Cancelled is pressed clear the listOfFiles so a blank list is returned
            listOfFiles.clear();
        }


        return listOfFiles;
    }

Answer 1

Okay, I think I understand...

JOptionPane#initDialog, which is a private method, sets the dialog to non-resizable...which is nice of them...but you want a resizable window instead...

About the only choice you have is to make the dialog yourself, for example...

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.Window;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.JDialog;
import javax.swing.JOptionPane;
import static javax.swing.JOptionPane.VALUE_PROPERTY;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class CustomOptionPane {

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

    public CustomOptionPane() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                final JTextArea text = new JTextArea(10, 20);
                JScrollPane scrollPane = new JScrollPane(text);
                text.setLineWrap(true);
                text.setWrapStyleWord(true);

                final JOptionPane optionPane = new JOptionPane(scrollPane, JOptionPane.PLAIN_MESSAGE, JOptionPane.YES_NO_CANCEL_OPTION);
                final JDialog dialog = new JDialog((Window) null, "Files To rename");

                dialog.add(optionPane, BorderLayout.CENTER);
                dialog.pack();
                dialog.setLocationRelativeTo(null);

                final PropertyChangeListener listener = new PropertyChangeListener() {
                    @Override
                    public void propertyChange(PropertyChangeEvent event) {
                // Let the defaultCloseOperation handle the closing
                        // if the user closed the window without selecting a button
                        // (newValue = null in that case).  Otherwise, close the dialog.
                        if (dialog.isVisible()
                                && (event.getPropertyName().equals(VALUE_PROPERTY))
                                && event.getNewValue() != null
                                && event.getNewValue() != JOptionPane.UNINITIALIZED_VALUE) {
                            dialog.setVisible(false);
                        }
                    }
                };

                WindowAdapter adapter = new WindowAdapter() {
                    private boolean gotFocus = false;

                    public void windowClosing(WindowEvent we) {
                        optionPane.setValue(null);
                    }

                    public void windowClosed(WindowEvent e) {
                        optionPane.removePropertyChangeListener(listener);
                        dialog.getContentPane().removeAll();
                    }

                    public void windowGainedFocus(WindowEvent we) {
                        // Once window gets focus, set initial focus
                        if (!gotFocus) {
                            optionPane.selectInitialValue();
                            gotFocus = true;
                        }
                    }
                };
                dialog.addWindowListener(adapter);
                dialog.addWindowFocusListener(adapter);
                dialog.addComponentListener(new ComponentAdapter() {
                    @Override
                    public void componentShown(ComponentEvent ce) {
                        // reset value to ensure closing works properly
                        optionPane.setValue(JOptionPane.UNINITIALIZED_VALUE);
                    }
                });

                optionPane.addPropertyChangeListener(listener);

                dialog.setModal(true);
                dialog.setVisible(true);

                System.out.println(optionPane.getValue());
            }
        });
    }

}

Answer 2

As shown here, you can add a JOptionPane to a JDialog, which is a resizable, top-level container. A complete example is shown in this answer.

JDialog dialog = new JDialog();
JOptionPane optPane = new JOptionPane();
…
dialog.add(optPane);