tim/prune/load/FileLoader.java

   1 package tim.prune.load;
   2
   3 import java.awt.BorderLayout;
   4 import java.awt.CardLayout;
   5 import java.awt.Component;
   6 import java.awt.Dimension;
   7 import java.awt.FlowLayout;
   8 import java.awt.GridLayout;
   9 import java.awt.event.ActionEvent;
  10 import java.awt.event.ActionListener;
  11 import javax.swing.*;
  12 import javax.swing.event.DocumentEvent;
  13 import javax.swing.event.DocumentListener;
  14 import javax.swing.event.ListSelectionEvent;
  15 import javax.swing.event.ListSelectionListener;
  16 import javax.swing.table.TableCellEditor;
  17
  18 import java.io.File;
  19
  20 import tim.prune.App;
  21 import tim.prune.I18nManager;
  22 import tim.prune.data.Altitude;
  23 import tim.prune.data.Field;
  24
  25
  26 /**
  27  * Special class to handle file loading including GUI options,
  28  * and conversion to a Track object
  29  */
  30 public class FileLoader
  31 {
  32         private File _file = null;
  33         private App _app = null;
  34         private JFrame _parentFrame = null;
  35         private JDialog _dialog = null;
  36         private JPanel _cardPanel = null;
  37         private CardLayout _layout = null;
  38         private JButton _backButton = null, _nextButton = null;
  39         private JButton _finishButton = null;
  40         private JButton _moveUpButton = null, _moveDownButton = null;
  41         private JRadioButton[] _delimiterRadios = null;
  42         private JTextField _otherDelimiterText = null;
  43         private JLabel _statusLabel = null;
  44         private DelimiterInfo[] _delimiterInfos = null;
  45         private JFileChooser _fileChooser = null;
  46         private FileCacher _fileCacher = null;
  47         private JList _snippetBox = null;
  48         private FileExtractTableModel _fileExtractTableModel = null;
  49         private JTable _fieldTable;
  50         private FieldSelectionTableModel _fieldTableModel = null;
  51         private JComboBox _unitsDropDown = null;
  52         private int _selectedField = -1;
  53         private char _currentDelimiter = ',';
  54
  55         // previously selected values
  56         private char _lastUsedDelimiter = ',';
  57         private int _lastNumFields = -1;
  58         private Field[] _lastSelectedFields = null;
  59         private int _lastAltitudeFormat = Altitude.FORMAT_NONE;
  60
  61         // constants
  62         private static final int SNIPPET_SIZE = 6;
  63         private static final int MAX_SNIPPET_WIDTH = 80;
  64         private static final char[] DELIMITERS = {',', '\t', ';', ' '};
  65
  66
  67         /**
  68          * Inner class to listen for delimiter change operations
  69          */
  70         private class DelimListener implements ActionListener, DocumentListener
  71         {
  72                 public void actionPerformed(ActionEvent e)
  73                 {
  74                         informDelimiterSelected();
  75                 }
  76                 public void changedUpdate(DocumentEvent e)
  77                 {
  78                         informDelimiterSelected();
  79                 }
  80                 public void insertUpdate(DocumentEvent e)
  81                 {
  82                         informDelimiterSelected();
  83                 }
  84                 public void removeUpdate(DocumentEvent e)
  85                 {
  86                         informDelimiterSelected();
  87                 }
  88         }
  89
  90
  91         /**
  92          * Constructor
  93          * @param inApp Application object to inform of track load
  94          * @param inParentFrame parent frame to reference for dialogs
  95          */
  96         public FileLoader(App inApp, JFrame inParentFrame)
  97         {
  98                 _app = inApp;
  99                 _parentFrame = inParentFrame;
 100         }
 101
 102
 103         /**
 104          * Select an input file and open the GUI frame
 105          * to select load options
 106          */
 107         public void openFile()
 108         {
 109                 if (_fileChooser == null)
 110                         _fileChooser = new JFileChooser();
 111                 if (_fileChooser.showOpenDialog(_parentFrame) == JFileChooser.APPROVE_OPTION)
 112                 {
 113                         _file = _fileChooser.getSelectedFile();
 114                         if (preCheckFile(_file))
 115                         {
 116                                 _dialog = new JDialog(_parentFrame, I18nManager.getText("dialog.openoptions.title"), true);
 117                                 _dialog.setLocationRelativeTo(_parentFrame);
 118                                 _dialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
 119                                 _dialog.getContentPane().add(makeDialogComponents());
 120
 121                                 // select best separator according to row counts (more is better)
 122                                 int bestDelim = getBestOption(_delimiterInfos[0].getNumWinningRecords(),
 123                                         _delimiterInfos[1].getNumWinningRecords(), _delimiterInfos[2].getNumWinningRecords(),
 124                                         _delimiterInfos[3].getNumWinningRecords());
 125                                 if (bestDelim >= 0)
 126                                         _delimiterRadios[bestDelim].setSelected(true);
 127                                 else
 128                                         _delimiterRadios[_delimiterRadios.length-1].setSelected(true);
 129                                 informDelimiterSelected();
 130                                 _dialog.pack();
 131                                 _dialog.show();
 132                         }
 133                         else
 134                         {
 135                                 JOptionPane.showMessageDialog(_parentFrame, I18nManager.getText("error.load.noread"),
 136                                         I18nManager.getText("error.load.dialogtitle"), JOptionPane.ERROR_MESSAGE);
 137                         }
 138                 }
 139         }
 140
 141
 142         /**
 143          * Check the given file for readability and funny characters,
 144          * and count the fields for the various separators
 145          * @param inFile file to check
 146          */
 147         private boolean preCheckFile(File inFile)
 148         {
 149                 // Check file exists and is readable
 150                 if (inFile == null || !inFile.exists() || !inFile.canRead())
 151                 {
 152                         return false;
 153                 }
 154                 // Use a FileCacher to read the file into an array
 155                 _fileCacher = new FileCacher(inFile);
 156
 157                 // Check each line of the file
 158                 String[] fileContents = _fileCacher.getContents();
 159                 boolean fileOK = true;
 160                 _delimiterInfos = new DelimiterInfo[5];
 161                 for (int i=0; i<4; i++) _delimiterInfos[i] = new DelimiterInfo(DELIMITERS[i]);
 162
 163                 String currLine = null;
 164                 String[] splitFields = null;
 165                 int commaFields = 0, semicolonFields = 0, tabFields = 0, spaceFields = 0;
 166                 for (int lineNum=0; lineNum<fileContents.length && fileOK; lineNum++)
 167                 {
 168                         currLine = fileContents[lineNum];
 169                         // check for invalid characters
 170                         if (currLine.indexOf('\0') >= 0) {fileOK = false;}
 171                         // check for commas
 172                         splitFields = currLine.split(",");
 173                         commaFields = splitFields.length;
 174                         if (commaFields > 1) _delimiterInfos[0].incrementNumRecords();
 175                         _delimiterInfos[0].updateMaxFields(commaFields);
 176                         // check for tabs
 177                         splitFields = currLine.split("\t");
 178                         tabFields = splitFields.length;
 179                         if (tabFields > 1) _delimiterInfos[1].incrementNumRecords();
 180                         _delimiterInfos[1].updateMaxFields(tabFields);
 181                         // check for semicolons
 182                         splitFields = currLine.split(";");
 183                         semicolonFields = splitFields.length;
 184                         if (semicolonFields > 1) _delimiterInfos[2].incrementNumRecords();
 185                         _delimiterInfos[2].updateMaxFields(semicolonFields);
 186                         // check for spaces
 187                         splitFields = currLine.split(" ");
 188                         spaceFields = splitFields.length;
 189                         if (spaceFields > 1) _delimiterInfos[3].incrementNumRecords();
 190                         _delimiterInfos[3].updateMaxFields(spaceFields);
 191                         // increment counters
 192                         int bestScorer = getBestOption(commaFields, tabFields, semicolonFields, spaceFields);
 193                         if (bestScorer >= 0)
 194                                 _delimiterInfos[bestScorer].incrementNumWinningRecords();
 195                 }
 196                 return fileOK;
 197         }
 198
 199
 200         /**
 201          * Get the index of the best one in the list
 202          * @return the index of the maximum of the four given values
 203          */
 204         private static int getBestOption(int inOpt0, int inOpt1, int inOpt2, int inOpt3)
 205         {
 206                 int bestIndex = -1;
 207                 int maxScore = 1;
 208                 if (inOpt0 > maxScore) {bestIndex = 0; maxScore = inOpt0;}
 209                 if (inOpt1 > maxScore) {bestIndex = 1; maxScore = inOpt1;}
 210                 if (inOpt2 > maxScore) {bestIndex = 2; maxScore = inOpt2;}
 211                 if (inOpt3 > maxScore) {bestIndex = 3; maxScore = inOpt3;}
 212                 return bestIndex;
 213         }
 214
 215
 216         /**
 217          * Make the components for the open options dialog
 218          * @return Component for all options
 219          */
 220         private Component makeDialogComponents()
 221         {
 222                 JPanel wholePanel = new JPanel();
 223                 wholePanel.setLayout(new BorderLayout());
 224
 225                 // add buttons to south
 226                 JPanel buttonPanel = new JPanel();
 227                 buttonPanel.setLayout(new FlowLayout(FlowLayout.CENTER));
 228                 _backButton = new JButton(I18nManager.getText("button.back"));
 229                 _backButton.addActionListener(new ActionListener() {
 230                         public void actionPerformed(ActionEvent e)
 231                         {
 232                                 _layout.previous(_cardPanel);
 233                                 _backButton.setEnabled(false);
 234                                 _nextButton.setEnabled(true);
 235                                 _finishButton.setEnabled(false);
 236                         }
 237                 });
 238                 _backButton.setEnabled(false);
 239                 buttonPanel.add(_backButton);
 240                 _nextButton = new JButton(I18nManager.getText("button.next"));
 241                 _nextButton.addActionListener(new ActionListener() {
 242                         public void actionPerformed(ActionEvent e)
 243                         {
 244                                 prepareSecondPanel();
 245                                 _layout.next(_cardPanel);
 246                                 _nextButton.setEnabled(false);
 247                                 _backButton.setEnabled(true);
 248                                 _finishButton.setEnabled(true);
 249                         }
 250                 });
 251                 buttonPanel.add(_nextButton);
 252                 _finishButton = new JButton(I18nManager.getText("button.finish"));
 253                 _finishButton.addActionListener(new ActionListener() {
 254                         public void actionPerformed(ActionEvent e)
 255                         {
 256                                 finished();
 257                         }
 258                 });
 259                 _finishButton.setEnabled(false);
 260                 buttonPanel.add(_finishButton);
 261                 JButton cancelButton = new JButton(I18nManager.getText("button.cancel"));
 262                 cancelButton.addActionListener(new ActionListener() {
 263                         public void actionPerformed(ActionEvent e)
 264                         {
 265                                 _dialog.dispose();
 266                         }
 267                 });
 268                 buttonPanel.add(cancelButton);
 269                 wholePanel.add(buttonPanel, BorderLayout.SOUTH);
 270
 271                 // Make the two cards, for delimiter and fields
 272                 _cardPanel = new JPanel();
 273                 _layout = new CardLayout();
 274                 _cardPanel.setLayout(_layout);
 275                 JPanel firstCard = new JPanel();
 276                 firstCard.setLayout(new BorderLayout());
 277
 278                 JPanel delimsPanel = new JPanel();
 279                 delimsPanel.setLayout(new GridLayout(0, 2));
 280                 delimsPanel.add(new JLabel(I18nManager.getText("dialog.delimiter.label")));
 281                 delimsPanel.add(new JLabel("")); // blank label to go to next grid row
 282                 // radio buttons
 283                 _delimiterRadios = new JRadioButton[5];
 284                 _delimiterRadios[0] = new JRadioButton(I18nManager.getText("dialog.delimiter.comma"));
 285                 delimsPanel.add(_delimiterRadios[0]);
 286                 _delimiterRadios[1] = new JRadioButton(I18nManager.getText("dialog.delimiter.tab"));
 287                 delimsPanel.add(_delimiterRadios[1]);
 288                 _delimiterRadios[2] = new JRadioButton(I18nManager.getText("dialog.delimiter.semicolon"));
 289                 delimsPanel.add(_delimiterRadios[2]);
 290                 _delimiterRadios[3] = new JRadioButton(I18nManager.getText("dialog.delimiter.space"));
 291                 delimsPanel.add(_delimiterRadios[3]);
 292                 JPanel otherPanel = new JPanel();
 293                 otherPanel.setLayout(new FlowLayout(FlowLayout.LEFT, 0, 0));
 294                 _delimiterRadios[4] = new JRadioButton(I18nManager.getText("dialog.delimiter.other"));
 295                 otherPanel.add(_delimiterRadios[4]);
 296                 _otherDelimiterText = new JTextField(new OneCharDocument(), null, 2);
 297                 otherPanel.add(_otherDelimiterText);
 298                 // Group radio buttons
 299                 ButtonGroup delimGroup = new ButtonGroup();
 300                 DelimListener delimListener = new DelimListener();
 301                 for (int i=0; i<_delimiterRadios.length; i++)
 302                 {
 303                         delimGroup.add(_delimiterRadios[i]);
 304                         _delimiterRadios[i].addActionListener(delimListener);
 305                 }
 306                 _otherDelimiterText.getDocument().addDocumentListener(delimListener);
 307                 delimsPanel.add(new JLabel(""));
 308                 delimsPanel.add(otherPanel);
 309                 _statusLabel = new JLabel("");
 310                 delimsPanel.add(_statusLabel);
 311                 firstCard.add(delimsPanel, BorderLayout.SOUTH);
 312                 // load snippet to show first few lines
 313                 _snippetBox = new JList(_fileCacher.getSnippet(SNIPPET_SIZE, MAX_SNIPPET_WIDTH));
 314                 _snippetBox.setEnabled(false);
 315                 firstCard.add(makeLabelledPanel("dialog.openoptions.filesnippet", _snippetBox), BorderLayout.CENTER);
 316
 317                 // Second screen, for field order selection
 318                 JPanel secondCard = new JPanel();
 319                 secondCard.setLayout(new BorderLayout());
 320                 // table for file contents
 321                 _fileExtractTableModel = new FileExtractTableModel();
 322                 JTable extractTable = new JTable(_fileExtractTableModel);
 323                 JScrollPane tableScrollPane = new JScrollPane(extractTable);
 324                 extractTable.setPreferredScrollableViewportSize(new Dimension(350, 80));
 325                 extractTable.getTableHeader().setReorderingAllowed(false);
 326                 secondCard.add(makeLabelledPanel("dialog.openoptions.tabledesc", tableScrollPane), BorderLayout.NORTH);
 327                 JPanel innerPanel2 = new JPanel();
 328                 innerPanel2.setLayout(new BorderLayout());
 329                 _fieldTable = new JTable(new FieldSelectionTableModel());
 330                 _fieldTable.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
 331                 // add listener for selected table row
 332                 _fieldTable.getSelectionModel().addListSelectionListener(
 333                         new ListSelectionListener() {
 334                                 public void valueChanged(ListSelectionEvent e) {
 335                                         ListSelectionModel lsm = (ListSelectionModel) e.getSource();
 336                                         if (lsm.isSelectionEmpty()) {
 337                                                 //no rows are selected
 338                                                 selectField(-1);
 339                                         } else {
 340                                                 selectField(lsm.getMinSelectionIndex());
 341                                         }
 342                                 }
 343                         });
 344                 JPanel tablePanel = new JPanel();
 345                 tablePanel.setLayout(new BorderLayout());
 346                 tablePanel.add(_fieldTable.getTableHeader(), BorderLayout.NORTH);
 347                 tablePanel.add(_fieldTable, BorderLayout.CENTER);
 348                 innerPanel2.add(tablePanel, BorderLayout.CENTER);
 349
 350                 JPanel innerPanel3 = new JPanel();
 351                 innerPanel3.setLayout(new BoxLayout(innerPanel3, BoxLayout.Y_AXIS));
 352                 _moveUpButton = new JButton(I18nManager.getText("button.moveup"));
 353                 _moveUpButton.addActionListener(new ActionListener() {
 354                         public void actionPerformed(ActionEvent e)
 355                         {
 356                                 int currRow = _fieldTable.getSelectedRow();
 357                                 closeTableComboBox(currRow);
 358                                 _fieldTableModel.moveUp(currRow);
 359                                 _fieldTable.setRowSelectionInterval(currRow-1, currRow-1);
 360                         }
 361                 });
 362                 innerPanel3.add(_moveUpButton);
 363                 _moveDownButton = new JButton(I18nManager.getText("button.movedown"));
 364                 _moveDownButton.addActionListener(new ActionListener() {
 365                         public void actionPerformed(ActionEvent e)
 366                         {
 367                                 int currRow = _fieldTable.getSelectedRow();
 368                                 closeTableComboBox(currRow);
 369                                 _fieldTableModel.moveDown(currRow);
 370                                 _fieldTable.setRowSelectionInterval(currRow+1, currRow+1);
 371                         }
 372                 });
 373                 innerPanel3.add(_moveDownButton);
 374                 innerPanel3.add(Box.createVerticalStrut(70));
 375
 376                 innerPanel2.add(innerPanel3, BorderLayout.EAST);
 377                 secondCard.add(innerPanel2, BorderLayout.CENTER);
 378                 JPanel altUnitsPanel = new JPanel();
 379                 altUnitsPanel.setLayout(new FlowLayout(FlowLayout.LEFT));
 380                 altUnitsPanel.add(new JLabel(I18nManager.getText("dialog.openoptions.altitudeunits")));
 381                 String[] units = {I18nManager.getText("units.metres"), I18nManager.getText("units.feet")};
 382                 _unitsDropDown = new JComboBox(units);
 383                 altUnitsPanel.add(_unitsDropDown);
 384                 secondCard.add(altUnitsPanel, BorderLayout.SOUTH);
 385                 _cardPanel.add(firstCard, "card1");
 386                 _cardPanel.add(secondCard, "card2");
 387
 388                 wholePanel.add(_cardPanel, BorderLayout.CENTER);
 389                 return wholePanel;
 390         }
 391
 392
 393         /**
 394          * Close the combo box on the selected row of the field table
 395          * @param inRow currently selected row number
 396          */
 397         private void closeTableComboBox(int inRow)
 398         {
 399                 TableCellEditor editor = _fieldTable.getCellEditor(inRow, 1);
 400                 if (editor != null)
 401                 {
 402                         editor.stopCellEditing();
 403                 }
 404         }
 405
 406
 407         /**
 408          * change the status based on selection of a delimiter
 409          */
 410         protected void informDelimiterSelected()
 411         {
 412                 for (int i=0; i<(_delimiterRadios.length-1); i++)
 413                 {
 414                         if (_delimiterRadios[i].isSelected())
 415                         {
 416                                 int numRecords = _delimiterInfos[i].getNumRecords();
 417                                 if (numRecords == 0)
 418                                 {
 419                                         _statusLabel.setText(I18nManager.getText("dialog.openoptions.deliminfo.norecords"));
 420                                 }
 421                                 else
 422                                 {
 423                                         _statusLabel.setText("" + numRecords + " " + I18nManager.getText("dialog.openoptions.deliminfo.records")
 424                                                 + _delimiterInfos[i].getMaxFields() + " " + I18nManager.getText("dialog.openoptions.deliminfo.fields"));
 425                                 }
 426                         }
 427                 }
 428                 if (_delimiterRadios[_delimiterRadios.length-1].isSelected())
 429                 {
 430                         _statusLabel.setText("");
 431                 }
 432                 // enable/disable next button
 433                 _nextButton.setEnabled(_delimiterRadios[4].isSelected() == false
 434                         || _otherDelimiterText.getText().length() == 1);
 435         }
 436
 437
 438         /**
 439          * Get the delimiter info from the first step
 440          * @return delimiter information object for the selected delimiter
 441          */
 442         public DelimiterInfo getSelectedDelimiterInfo()
 443         {
 444                 for (int i=0; i<4; i++)
 445                         if (_delimiterRadios[i].isSelected()) return _delimiterInfos[i];
 446                 // must be "other" - build info if necessary
 447                 if (_delimiterInfos[4] == null)
 448                         _delimiterInfos[4] = new DelimiterInfo(_otherDelimiterText.getText().charAt(0));
 449                 return _delimiterInfos[4];
 450         }
 451
 452
 453         /**
 454          * Use the delimiter selected to determine the fields in the file
 455          * and prepare the second panel accordingly
 456          */
 457         private void prepareSecondPanel()
 458         {
 459                 DelimiterInfo info = getSelectedDelimiterInfo();
 460                 FileSplitter splitter = new FileSplitter(_fileCacher);
 461                 // Check info makes sense - num fields > 0, num records > 0
 462                 // set "Finished" button to disabled if not ok
 463                 // TODO: Work out if there are header rows or not, save?
 464                 // Try to match header rows with fields
 465                 // Try to match data with fields
 466                 // Add data to GUI elements
 467                 Object[][] tableData = splitter.splitFieldData(info.getDelimiter());
 468                 // possible to ignore blank columns here
 469                 _currentDelimiter = info.getDelimiter();
 470                 _fileExtractTableModel.updateData(tableData);
 471                 _fieldTableModel = new FieldSelectionTableModel();
 472
 473                 // Check number of fields and use last ones if count matches
 474                 Field[] startFieldArray = null;
 475                 if (_lastSelectedFields != null && splitter.getNumColumns() == _lastSelectedFields.length)
 476                         startFieldArray = _lastSelectedFields;
 477                 else
 478                         startFieldArray = splitter.makeDefaultFields();
 479                 _fieldTableModel.updateData(startFieldArray);
 480                 _fieldTable.setModel(_fieldTableModel);
 481                 // add dropdowns to second column
 482                 JComboBox fieldTypesBox = new JComboBox();
 483                 for (int i=0; i<Field.ALL_AVAILABLE_FIELDS.length; i++)
 484                 {
 485                         fieldTypesBox.addItem(Field.ALL_AVAILABLE_FIELDS[i].getName());
 486                 }
 487                 _fieldTable.getColumnModel().getColumn(1).setCellEditor(new DefaultCellEditor(fieldTypesBox));
 488
 489                 // Set altitude format to same as last time if available
 490                 if (_lastAltitudeFormat == Altitude.FORMAT_METRES)
 491                         _unitsDropDown.setSelectedIndex(0);
 492                 else if (_lastAltitudeFormat == Altitude.FORMAT_FEET)
 493                         _unitsDropDown.setSelectedIndex(1);
 494                 // no selection on field list
 495                 selectField(-1);
 496         }
 497
 498
 499         /**
 500          * All options have been selected, so load file
 501          */
 502         private void finished()
 503         {
 504                 // Save delimiter, field array and altitude format for later use
 505                 _lastUsedDelimiter = _currentDelimiter;
 506                 _lastSelectedFields = _fieldTableModel.getFieldArray();
 507                 int altitudeFormat = Altitude.FORMAT_METRES;
 508                 if (_unitsDropDown.getSelectedIndex() == 1)
 509                 {
 510                         altitudeFormat = Altitude.FORMAT_FEET;
 511                 }
 512                 _lastAltitudeFormat = altitudeFormat;
 513                 // give data to App
 514                 _app.informDataLoaded(_fieldTableModel.getFieldArray(),
 515                         _fileExtractTableModel.getData(), altitudeFormat,
 516                         _file.getName());
 517                 // clear up file cacher
 518                 _fileCacher.clear();
 519                 // dispose of dialog
 520                 _dialog.dispose();
 521         }
 522
 523
 524         /**
 525          * Make a panel with a label and a component
 526          * @param inLabelKey label key to use
 527          * @param inComponent component for main area of panel
 528          * @return labelled Panel
 529          */
 530         private static JPanel makeLabelledPanel(String inLabelKey, JComponent inComponent)
 531         {
 532                 JPanel panel = new JPanel();
 533                 panel.setLayout(new BorderLayout());
 534                 panel.add(new JLabel(I18nManager.getText(inLabelKey)), BorderLayout.NORTH);
 535                 panel.add(inComponent, BorderLayout.CENTER);
 536                 return panel;
 537         }
 538
 539
 540         /**
 541          * An entry in the field list has been selected
 542          * @param inFieldNum index of field, starting with 0
 543          */
 544         private void selectField(int inFieldNum)
 545         {
 546                 if (inFieldNum == -1 || inFieldNum != _selectedField)
 547                 {
 548                         _selectedField = inFieldNum;
 549                         _moveUpButton.setEnabled(inFieldNum > 0);
 550                         _moveDownButton.setEnabled(inFieldNum >= 0
 551                                 && inFieldNum < (_fieldTableModel.getRowCount()-1));
 552                 }
 553         }
 554
 555
 556         /**
 557          * @return the last delimiter character used for a load
 558          */
 559         public char getLastUsedDelimiter()
 560         {
 561                 return _lastUsedDelimiter;
 562         }
 563 }