/**
   * This notifies the user that they are about to lose entered data (i.e. they've made changes and
   * are about to a) change classes or b) go to another entry), and allows them to save their data
   * if they so choose...
   */
  public void checkForUnsavedChanges() {
    if (dataSource == null || dataSource.isActive() == false)
      return; // no point prompting - nothing to save with!

    /*
     *    Only ever check the entry once (sometimes promptForSave can be called
     *    multiple time - remember that the 'save' function gets called by a
     *    separate thread).
     */

    if (tableData.changedByUser()) {
      String save = CBIntText.get("Save");
      String discard = CBIntText.get("Discard");

      int result =
          JOptionPane.showOptionDialog(
              owner,
              CBIntText.get("Submit changes to the Directory?"),
              CBIntText.get("Save Data"),
              JOptionPane.DEFAULT_OPTION,
              JOptionPane.QUESTION_MESSAGE,
              null,
              new Object[] {save, discard},
              save);
      if (result == 0) {
        writeTableData(); // nb - this queues a request to the directory
      }
    }
  }
  /**
   * Normally called by the 'Yes' button listener of the virtual entry dialog. This method opens the
   * New Entry dialog in simple mode (or Change Classes dialog). If the user selects one or more
   * object classes they are added to the entry and displayed in the table editor.
   */
  public void processVirtualEntry() {

    ChangeObjectClassWin userData = null;
    if (dataSource.getSchemaOps() == null) {
      JOptionPane.showMessageDialog(
          owner,
          CBIntText.get(
              "Because there is no schema currently published by the\ndirectory, changing an entry's object class is unavailable."),
          CBIntText.get("No Schema"),
          JOptionPane.INFORMATION_MESSAGE);
      return;
    } else {
      shutVirtualEntryDialog(); // TE: kill the prompt window.
      userData =
          new ChangeObjectClassWin(dataSource, currentEntry.getDN(), null, this, owner, true);
      userData.setSize(400, 250);
      CBUtility.center(userData, owner); // TE: centres window.
      userData.setVisible(true);

      while (userData.isVisible()) // TE: don't do anything until the New Entry window is closed.
      {
        try {
          wait();
        } catch (Exception e) {
          userData.dispose();
        }
      }
    }

    if (userData.newObjectClasses
        != null) // TE: if the user has selected one or more object classes - add them to the entry
                 // in the directory.
    {
      try {
        DXOps dxOps = new DXOps(dataSource.getLdapContext());
        dxOps.addAttribute(currentEntry.getDN(), userData.newObjectClasses);
        dataSource.getEntry(
            currentEntry
                .getDN()); // TE: hack??  forces the entry to be read again - otherwise we don't
                           // display the naming value.
      } catch (NamingException e) {
        CBUtility.error(
            TableAttributeEditor.this,
            CBIntText.get(
                "Unable to add new object classes to {0}.",
                new String[] {currentEntry.getDN().toString()}),
            e);
      }
    }
  }
  /** Opens the change class dialog. */
  public void changeClass() { // JPanel mainPanel
    /*
     *    MINOR MAGIC
     *
     *    This code reuses the 'new entry window'.  In order to make things
     *    sane, we prompt the user to save any serious changes before continuing.
     *    (Things can get really wierd if the user changes the name and then
     *    tries to change the objectclass - best to avoid the whole issue.)
     */
    myEditor.stopCellEditing();

    if (virtualEntry) {
      doVirtualEntryDisplay();
      return;
    }

    /*
     *    classChangedOriginalEntry saves the original state of the entry
     *    between visits to NewEntryWin.  (- I wonder if it would be neater
     *    to just reset the 'oldEntry' state of the table every time? ).
     *    Check it's not been set already (i.e. Pathological User is paying
     *    multiple visits to the NewEntryWin.)
     */
    if (classChangedOriginalEntry == null) classChangedOriginalEntry = tableData.getOldEntry();

    DXEntry newEntry = tableData.getNewEntry();
    DN newDN = newEntry.getDN();

    /*
     *    Pathalogical user has messed with the name, *and* wants to
     *    change the object classes...
     */
    if (newDN.equals(classChangedOriginalEntry.getDN()) == false) {
      checkForUnsavedChanges();
      /*
      if (promptForSave() == false)  // we may need to reset the 'newEntry' data
      {                                   // if the user discards their changes.

          tableData.reset();              // resets the table before going on.

          newEntry = tableData.getNewEntry();
          newDN = newEntry.getDN();
      }
      else // user has saved data - so now we need to reset the 'classChangedOriginalEntry'
      {
      */
      // to the changed (and hopefully saved!) data.
      // NB: If the directory write fails, then the change classes will also fail...
      classChangedOriginalEntry = tableData.getNewEntry();
    }

    /*
     *    Open NewEntryWin, allowing the user to reset the objectclass attribute.
     */

    /*
            NewEntryWin userData = new NewEntryWin(newDN.parentDN(), newDN,
                                    dataSource,
                                    newEntry.getAsNonNullAttributes(),
                                    newDN.getLowestRDN().toString(), TableAttributeEditor.this,
                                    CBUtility.getParentFrame(mainPanel));
    */
    if (dataSource.getSchemaOps() == null) {
      JOptionPane.showMessageDialog(
          owner,
          CBIntText.get(
              "Because there is no schema currently published by the\ndirectory, changing an entry's object class is unavailable."),
          CBIntText.get("No Schema"),
          JOptionPane.INFORMATION_MESSAGE);
      return;
    } else {
      ChangeObjectClassWin userData =
          new ChangeObjectClassWin(
              dataSource,
              newDN,
              newEntry.getAsNonNullAttributes(),
              this,
              CBUtility.getParentFrame(this),
              false);
      userData.setSize(400, 250);
      CBUtility.center(userData, owner); // TE: centres window.
      userData.setVisible(true);
    }
  }