tim/prune/load/TextFileLoader.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 import tim.prune.data.SourceInfo;
  25
  26
  27 /**
  28  * Class to handle loading of text files including GUI options,
  29  * and passing loaded data back to App object
  30  */
  31 public class TextFileLoader
  32 {
  33         private File _file = null;
  34         private App _app = null;
  35         private JFrame _parentFrame = null;
  36         private JDialog _dialog = null;
  37         private JPanel _cardPanel = null;
  38         private CardLayout _layout = null;
  39         private JButton _backButton = null, _nextButton = null;
  40         private JButton _finishButton = null;
  41         private JButton _moveUpButton = null, _moveDownButton = null;
  42         private JRadioButton[] _delimiterRadios = null;
  43         private JTextField _otherDelimiterText = null;
  44         private JLabel _statusLabel = null;
  45         private DelimiterInfo[] _delimiterInfos = 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 Field[] _lastSelectedFields = null;
  58         private Altitude.Format _lastAltitudeFormat = Altitude.Format.NO_FORMAT;
  59
  60         // constants
  61         private static final int SNIPPET_SIZE = 6;
  62         private static final int MAX_SNIPPET_WIDTH = 80;
  63         private static final char[] DELIMITERS = {',', '\t', ';', ' '};
  64
  65
  66         /**
  67          * Inner class to listen for delimiter change operations
  68          */
  69         private class DelimListener implements ActionListener, DocumentListener
  70         {
  71                 public void actionPerformed(ActionEvent e)
  72                 {
  73                         informDelimiterSelected();
  74                 }
  75                 public void changedUpdate(DocumentEvent e)
  76                 {
  77                         informDelimiterSelected();
  78                 }
  79                 public void insertUpdate(DocumentEvent e)
  80                 {
  81                         informDelimiterSelected();
  82                 }
  83                 public void removeUpdate(DocumentEvent e)
  84                 {
  85                         informDelimiterSelected();
  86                 }
  87         }
  88
  89
  90         /**
  91          * Constructor
  92          * @param inApp Application object to inform of track load
  93          * @param inParentFrame parent frame to reference for dialogs
  94          */
  95         public TextFileLoader(App inApp, JFrame inParentFrame)
  96         {
  97                 _app = inApp;
  98                 _parentFrame = inParentFrame;
  99         }
 100
 101
 102         /**
 103          * Open the selected file and show the GUI dialog to select load options
 104          * @param inFile file to open
 105          */
 106         public void openFile(File inFile)
 107         {
 108                 _file = inFile;
 109                 if (preCheckFile(_file))
 110                 {
 111                         _dialog = new JDialog(_parentFrame, I18nManager.getText("dialog.openoptions.title"), true);
 112                         _dialog.setLocationRelativeTo(_parentFrame);
 113                         _dialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
 114                         _dialog.getContentPane().add(makeDialogComponents());
 115
 116                         // select best separator according to row counts (more is better)
 117                         int bestDelim = getBestOption(_delimiterInfos[0].getNumWinningRecords(),
 118                                 _delimiterInfos[1].getNumWinningRecords(), _delimiterInfos[2].getNumWinningRecords(),
 119                                 _delimiterInfos[3].getNumWinningRecords());
 120                         if (bestDelim >= 0)
 121                                 _delimiterRadios[bestDelim].setSelected(true);
 122                         else
 123                                 _delimiterRadios[_delimiterRadios.length-1].setSelected(true);
 124                         informDelimiterSelected();
 125                         _dialog.pack();
 126                         _dialog.setVisible(true);
 127                 }
 128                 else {
 129                         // Didn't pass pre-check
 130                         _app.showErrorMessage("error.load.dialogtitle", "error.load.noread");
 131                         _app.informNoDataLoaded();
 132                 }
 133         }
 134
 135
 136         /**
 137          * Check the given file for readability and funny characters,
 138          * and count the fields for the various separators
 139          * @param inFile file to check
 140          */
 141         private boolean preCheckFile(File inFile)
 142         {
 143                 // Check file exists and is readable
 144                 if (inFile == null || !inFile.exists() || !inFile.canRead())
 145                 {
 146                         return false;
 147                 }
 148                 // Use a FileCacher to read the file into an array
 149                 _fileCacher = new FileCacher(inFile);
 150
 151                 // Check each line of the file
 152                 String[] fileContents = _fileCacher.getContents();
 153                 boolean fileOK = true;
 154                 _delimiterInfos = new DelimiterInfo[5];
 155                 for (int i=0; i<4; i++) _delimiterInfos[i] = new DelimiterInfo(DELIMITERS[i]);
 156
 157                 String currLine = null;
 158                 String[] splitFields = null;
 159                 int commaFields = 0, semicolonFields = 0, tabFields = 0, spaceFields = 0;
 160                 for (int lineNum=0; lineNum<fileContents.length && fileOK; lineNum++)
 161                 {
 162                         currLine = fileContents[lineNum];
 163                         // check for invalid characters
 164                         if (currLine.indexOf('\0') >= 0) {fileOK = false;}
 165                         // check for commas
 166                         splitFields = currLine.split(",");
 167                         commaFields = splitFields.length;
 168                         if (commaFields > 1) _delimiterInfos[0].incrementNumRecords();
 169                         _delimiterInfos[0].updateMaxFields(commaFields);
 170                         // check for tabs
 171                         splitFields = currLine.split("\t");
 172                         tabFields = splitFields.length;
 173                         if (tabFields > 1) _delimiterInfos[1].incrementNumRecords();
 174                         _delimiterInfos[1].updateMaxFields(tabFields);
 175                         // check for semicolons
 176                         splitFields = currLine.split(";");
 177                         semicolonFields = splitFields.length;
 178                         if (semicolonFields > 1) _delimiterInfos[2].incrementNumRecords();
 179                         _delimiterInfos[2].updateMaxFields(semicolonFields);
 180                         // check for spaces
 181                         splitFields = currLine.split(" ");
 182                         spaceFields = splitFields.length;
 183                         if (spaceFields > 1) _delimiterInfos[3].incrementNumRecords();
 184                         _delimiterInfos[3].updateMaxFields(spaceFields);
 185                         // increment counters
 186                         int bestScorer = getBestOption(commaFields, tabFields, semicolonFields, spaceFields);
 187                         if (bestScorer >= 0)
 188                                 _delimiterInfos[bestScorer].incrementNumWinningRecords();
 189                 }
 190                 return fileOK;
 191         }
 192
 193
 194         /**
 195          * Get the index of the best one in the list
 196          * @return the index of the maximum of the four given values
 197          */
 198         private static int getBestOption(int inOpt0, int inOpt1, int inOpt2, int inOpt3)
 199         {
 200                 int bestIndex = -1;
 201                 int maxScore = 1;
 202                 if (inOpt0 > maxScore) {bestIndex = 0; maxScore = inOpt0;}
 203                 if (inOpt1 > maxScore) {bestIndex = 1; maxScore = inOpt1;}
 204                 if (inOpt2 > maxScore) {bestIndex = 2; maxScore = inOpt2;}
 205                 if (inOpt3 > maxScore) {bestIndex = 3; maxScore = inOpt3;}
 206                 return bestIndex;
 207         }
 208
 209
 210         /**
 211          * Make the components for the open options dialog
 212          * @return Component for all options
 213          */
 214         private Component makeDialogComponents()
 215         {
 216                 JPanel wholePanel = new JPanel();
 217                 wholePanel.setLayout(new BorderLayout());
 218
 219                 // add buttons to south
 220                 JPanel buttonPanel = new JPanel();
 221                 buttonPanel.setLayout(new FlowLayout(FlowLayout.CENTER));
 222                 _backButton = new JButton(I18nManager.getText("button.back"));
 223                 _backButton.addActionListener(new ActionListener() {
 224                         public void actionPerformed(ActionEvent e)
 225                         {
 226                                 _layout.previous(_cardPanel);
 227                                 _backButton.setEnabled(false);
 228                                 _nextButton.setEnabled(true);
 229                                 _finishButton.setEnabled(false);
 230                         }
 231                 });
 232                 _backButton.setEnabled(false);
 233                 buttonPanel.add(_backButton);
 234                 _nextButton = new JButton(I18nManager.getText("button.next"));
 235                 _nextButton.addActionListener(new ActionListener() {
 236                         public void actionPerformed(ActionEvent e)
 237                         {
 238                                 prepareSecondPanel();
 239                                 _layout.next(_cardPanel);
 240                                 _nextButton.setEnabled(false);
 241                                 _backButton.setEnabled(true);
 242                                 _finishButton.setEnabled(_fieldTableModel.getRowCount() > 1);
 243                         }
 244                 });
 245                 buttonPanel.add(_nextButton);
 246                 _finishButton = new JButton(I18nManager.getText("button.finish"));
 247                 _finishButton.addActionListener(new ActionListener() {
 248                         public void actionPerformed(ActionEvent e)
 249                         {
 250                                 finished();
 251                         }
 252                 });
 253                 _finishButton.setEnabled(false);
 254                 buttonPanel.add(_finishButton);
 255                 JButton cancelButton = new JButton(I18nManager.getText("button.cancel"));
 256                 cancelButton.addActionListener(new ActionListener() {
 257                         public void actionPerformed(ActionEvent e)
 258                         {
 259                                 _dialog.dispose();
 260                                 _app.informNoDataLoaded();
 261                         }
 262                 });
 263                 buttonPanel.add(cancelButton);
 264                 wholePanel.add(buttonPanel, BorderLayout.SOUTH);
 265
 266                 // Make the two cards, for delimiter and fields
 267                 _cardPanel = new JPanel();
 268                 _layout = new CardLayout();
 269                 _cardPanel.setLayout(_layout);
 270                 JPanel firstCard = new JPanel();
 271                 firstCard.setLayout(new BorderLayout());
 272                 firstCard.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 15));
 273
 274                 JPanel delimsPanel = new JPanel();
 275                 delimsPanel.setLayout(new GridLayout(0, 2));
 276                 delimsPanel.add(new JLabel(I18nManager.getText("dialog.delimiter.label")));
 277                 delimsPanel.add(new JLabel("")); // blank label to go to next grid row
 278                 // radio buttons
 279                 _delimiterRadios = new JRadioButton[5];
 280                 _delimiterRadios[0] = new JRadioButton(I18nManager.getText("dialog.delimiter.comma"));
 281                 delimsPanel.add(_delimiterRadios[0]);
 282                 _delimiterRadios[1] = new JRadioButton(I18nManager.getText("dialog.delimiter.tab"));
 283                 delimsPanel.add(_delimiterRadios[1]);
 284                 _delimiterRadios[2] = new JRadioButton(I18nManager.getText("dialog.delimiter.semicolon"));
 285                 delimsPanel.add(_delimiterRadios[2]);
 286                 _delimiterRadios[3] = new JRadioButton(I18nManager.getText("dialog.delimiter.space"));
 287                 delimsPanel.add(_delimiterRadios[3]);
 288                 JPanel otherPanel = new JPanel();
 289                 otherPanel.setLayout(new FlowLayout(FlowLayout.LEFT, 0, 0));
 290                 _delimiterRadios[4] = new JRadioButton(I18nManager.getText("dialog.delimiter.other"));
 291                 otherPanel.add(_delimiterRadios[4]);
 292                 _otherDelimiterText = new JTextField(new OneCharDocument(), null, 2);
 293                 otherPanel.add(_otherDelimiterText);
 294                 // Group radio buttons
 295                 ButtonGroup delimGroup = new ButtonGroup();
 296                 DelimListener delimListener = new DelimListener();
 297                 for (int i=0; i<_delimiterRadios.length; i++)
 298                 {
 299                         delimGroup.add(_delimiterRadios[i]);
 300                         _delimiterRadios[i].addActionListener(delimListener);
 301                 }
 302                 _otherDelimiterText.getDocument().addDocumentListener(delimListener);
 303                 delimsPanel.add(new JLabel(""));
 304                 delimsPanel.add(otherPanel);
 305                 _statusLabel = new JLabel("");
 306                 delimsPanel.add(_statusLabel);
 307                 firstCard.add(delimsPanel, BorderLayout.SOUTH);
 308                 // load snippet to show first few lines
 309                 _snippetBox = new JList(_fileCacher.getSnippet(SNIPPET_SIZE, MAX_SNIPPET_WIDTH));
 310                 _snippetBox.setEnabled(false);
 311                 firstCard.add(makeLabelledPanel("dialog.openoptions.filesnippet", _snippetBox), BorderLayout.CENTER);
 312
 313                 // Second screen, for field order selection
 314                 JPanel secondCard = new JPanel();
 315                 secondCard.setLayout(new BorderLayout());
 316                 secondCard.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 15));
 317                 // table for file contents
 318                 _fileExtractTableModel = new FileExtractTableModel();
 319                 JTable extractTable = new JTable(_fileExtractTableModel);
 320                 JScrollPane tableScrollPane = new JScrollPane(extractTable);
 321                 extractTable.setPreferredScrollableViewportSize(new Dimension(350, 80));
 322                 extractTable.getTableHeader().setReorderingAllowed(false);
 323                 secondCard.add(makeLabelledPanel("dialog.openoptions.filesnippet", tableScrollPane), BorderLayout.NORTH);
 324                 JPanel innerPanel2 = new JPanel();
 325                 innerPanel2.setLayout(new BorderLayout());
 326                 innerPanel2.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
 327
 328                 _fieldTable = new JTable(new FieldSelectionTableModel());
 329                 _fieldTable.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
 330                 // add listener for selected table row
 331                 _fieldTable.getSelectionModel().addListSelectionListener(
 332                         new ListSelectionListener() {
 333                                 public void valueChanged(ListSelectionEvent e) {
 334                                         ListSelectionModel lsm = (ListSelectionModel) e.getSource();
 335                                         if (lsm.isSelectionEmpty()) {
 336                                                 //no rows are selected
 337                                                 selectField(-1);
 338                                         } else {
 339                                                 selectField(lsm.getMinSelectionIndex());
 340                                         }
 341                                 }
 342                         });
 343                 JPanel tablePanel = new JPanel();
 344                 tablePanel.setLayout(new BorderLayout());
 345                 tablePanel.add(_fieldTable.getTableHeader(), BorderLayout.NORTH);
 346                 tablePanel.add(_fieldTable, BorderLayout.CENTER);
 347                 innerPanel2.add(tablePanel, BorderLayout.CENTER);
 348
 349                 JPanel innerPanel3 = new JPanel();
 350                 innerPanel3.setLayout(new BoxLayout(innerPanel3, BoxLayout.Y_AXIS));
 351                 _moveUpButton = new JButton(I18nManager.getText("button.moveup"));
 352                 _moveUpButton.addActionListener(new ActionListener() {
 353                         public void actionPerformed(ActionEvent e)
 354                         {
 355                                 int currRow = _fieldTable.getSelectedRow();
 356                                 closeTableComboBox(currRow);
 357                                 _fieldTableModel.moveUp(currRow);
 358                                 _fieldTable.setRowSelectionInterval(currRow-1, currRow-1);
 359                         }
 360                 });
 361                 innerPanel3.add(_moveUpButton);
 362                 _moveDownButton = new JButton(I18nManager.getText("button.movedown"));
 363                 _moveDownButton.addActionListener(new ActionListener() {
 364                         public void actionPerformed(ActionEvent e)
 365                         {
 366                                 int currRow = _fieldTable.getSelectedRow();
 367                                 closeTableComboBox(currRow);
 368                                 _fieldTableModel.moveDown(currRow);
 369                                 _fieldTable.setRowSelectionInterval(currRow+1, currRow+1);
 370                         }
 371                 });
 372                 innerPanel3.add(_moveDownButton);
 373                 innerPanel3.add(Box.createVerticalStrut(60));
 374                 JButton guessButton = new JButton(I18nManager.getText("button.guessfields"));
 375                 guessButton.addActionListener(new ActionListener() {
 376                         public void actionPerformed(ActionEvent e)
 377                         {
 378                                 _lastSelectedFields = null;
 379                                 prepareSecondPanel();
 380                         }
 381                 });
 382                 innerPanel3.add(guessButton);
 383
 384                 innerPanel2.add(innerPanel3, BorderLayout.EAST);
 385                 secondCard.add(innerPanel2, BorderLayout.CENTER);
 386                 JPanel altUnitsPanel = new JPanel();
 387                 altUnitsPanel.setLayout(new FlowLayout(FlowLayout.LEFT));
 388                 altUnitsPanel.add(new JLabel(I18nManager.getText("dialog.openoptions.altitudeunits")));
 389                 String[] units = {I18nManager.getText("units.metres"), I18nManager.getText("units.feet")};
 390                 _unitsDropDown = new JComboBox(units);
 391                 altUnitsPanel.add(_unitsDropDown);
 392                 secondCard.add(altUnitsPanel, BorderLayout.SOUTH);
 393                 _cardPanel.add(firstCard, "card1");
 394                 _cardPanel.add(secondCard, "card2");
 395
 396                 wholePanel.add(_cardPanel, BorderLayout.CENTER);
 397                 return wholePanel;
 398         }
 399
 400
 401         /**
 402          * Close the combo box on the selected row of the field table
 403          * @param inRow currently selected row number
 404          */
 405         private void closeTableComboBox(int inRow)
 406         {
 407                 TableCellEditor editor = _fieldTable.getCellEditor(inRow, 1);
 408                 if (editor != null)
 409                 {
 410                         editor.stopCellEditing();
 411                 }
 412         }
 413
 414
 415         /**
 416          * change the status based on selection of a delimiter
 417          */
 418         protected void informDelimiterSelected()
 419         {
 420                 int fields = 0;
 421                 // Loop through radios to see which one is selected
 422                 for (int i=0; i<(_delimiterRadios.length-1); i++)
 423                 {
 424                         if (_delimiterRadios[i].isSelected())
 425                         {
 426                                 // Set label text to describe records and fields
 427                                 int numRecords = _delimiterInfos[i].getNumRecords();
 428                                 if (numRecords == 0)
 429                                 {
 430                                         _statusLabel.setText(I18nManager.getText("dialog.openoptions.deliminfo.norecords"));
 431                                 }
 432                                 else
 433                                 {
 434                                         fields = _delimiterInfos[i].getMaxFields();
 435                                         _statusLabel.setText("" + numRecords + " " + I18nManager.getText("dialog.openoptions.deliminfo.records")
 436                                                 + " " + fields + " " + I18nManager.getText("dialog.openoptions.deliminfo.fields"));
 437                                 }
 438                         }
 439                 }
 440                 // Don't show label if "other" delimiter is chosen (as records, fields are unknown)
 441                 if (_delimiterRadios[_delimiterRadios.length-1].isSelected())
 442                 {
 443                         _statusLabel.setText("");
 444                 }
 445                 // enable/disable next button
 446                 _nextButton.setEnabled((_delimiterRadios[4].isSelected() == false && fields > 1)
 447                         || _otherDelimiterText.getText().length() == 1);
 448         }
 449
 450
 451         /**
 452          * Get the delimiter info from the first step
 453          * @return delimiter information object for the selected delimiter
 454          */
 455         public DelimiterInfo getSelectedDelimiterInfo()
 456         {
 457                 for (int i=0; i<4; i++)
 458                         if (_delimiterRadios[i].isSelected()) return _delimiterInfos[i];
 459                 // must be "other" - build info if necessary
 460                 if (_delimiterInfos[4] == null)
 461                         _delimiterInfos[4] = new DelimiterInfo(_otherDelimiterText.getText().charAt(0));
 462                 return _delimiterInfos[4];
 463         }
 464
 465
 466         /**
 467          * Use the delimiter selected to determine the fields in the file
 468          * and prepare the second panel accordingly
 469          */
 470         private void prepareSecondPanel()
 471         {
 472                 DelimiterInfo info = getSelectedDelimiterInfo();
 473                 FileSplitter splitter = new FileSplitter(_fileCacher);
 474                 // Check info makes sense - num fields > 0, num records > 0
 475                 // set "Finished" button to disabled if not ok
 476                 // Add data to GUI elements
 477                 String[][] tableData = splitter.splitFieldData(info.getDelimiter());
 478                 // possible to ignore blank columns here
 479                 _currentDelimiter = info.getDelimiter();
 480                 _fileExtractTableModel.updateData(tableData);
 481                 _fieldTableModel = new FieldSelectionTableModel();
 482
 483                 // Check number of fields and use last ones if count matches
 484                 Field[] startFieldArray = null;
 485                 if (_lastSelectedFields != null && splitter.getNumColumns() == _lastSelectedFields.length)
 486                 {
 487                         startFieldArray = _lastSelectedFields;
 488                 }
 489                 else
 490                 {
 491                         // Take first full row of file and use it to guess fields
 492                         startFieldArray = FieldGuesser.guessFields(splitter.getFirstFullRow());
 493                 }
 494
 495                 _fieldTableModel.updateData(startFieldArray);
 496                 _fieldTable.setModel(_fieldTableModel);
 497                 // add dropdowns to second column
 498                 JComboBox fieldTypesBox = new JComboBox();
 499                 String[] fieldNames = Field.getFieldNames();
 500                 for (int i=0; i<fieldNames.length; i++)
 501                 {
 502                         fieldTypesBox.addItem(fieldNames[i]);
 503                 }
 504                 _fieldTable.getColumnModel().getColumn(1).setCellEditor(new DefaultCellEditor(fieldTypesBox));
 505
 506                 // Set altitude format to same as last time if available
 507                 if (_lastAltitudeFormat == Altitude.Format.METRES)
 508                         _unitsDropDown.setSelectedIndex(0);
 509                 else if (_lastAltitudeFormat == Altitude.Format.FEET)
 510                         _unitsDropDown.setSelectedIndex(1);
 511                 // no selection on field list
 512                 selectField(-1);
 513         }
 514
 515
 516         /**
 517          * All options have been selected, so load file
 518          */
 519         private void finished()
 520         {
 521                 // Save delimiter, field array and altitude format for later use
 522                 _lastUsedDelimiter = _currentDelimiter;
 523                 _lastSelectedFields = _fieldTableModel.getFieldArray();
 524                 Altitude.Format altitudeFormat = Altitude.Format.METRES;
 525                 if (_unitsDropDown.getSelectedIndex() == 1)
 526                 {
 527                         altitudeFormat = Altitude.Format.FEET;
 528                 }
 529                 _lastAltitudeFormat = altitudeFormat;
 530                 // give data to App
 531                 SourceInfo sourceInfo = new SourceInfo(_file, SourceInfo.FILE_TYPE.TEXT);
 532                 _app.informDataLoaded(_fieldTableModel.getFieldArray(),
 533                         _fileExtractTableModel.getData(), altitudeFormat, sourceInfo);
 534                 // clear up file cacher
 535                 _fileCacher.clear();
 536                 // dispose of dialog
 537                 _dialog.dispose();
 538         }
 539
 540
 541         /**
 542          * Make a panel with a label and a component
 543          * @param inLabelKey label key to use
 544          * @param inComponent component for main area of panel
 545          * @return labelled Panel
 546          */
 547         private static JPanel makeLabelledPanel(String inLabelKey, JComponent inComponent)
 548         {
 549                 JPanel panel = new JPanel();
 550                 panel.setLayout(new BorderLayout());
 551                 panel.add(new JLabel(I18nManager.getText(inLabelKey)), BorderLayout.NORTH);
 552                 panel.add(inComponent, BorderLayout.CENTER);
 553                 return panel;
 554         }
 555
 556
 557         /**
 558          * An entry in the field list has been selected
 559          * @param inFieldNum index of field, starting with 0
 560          */
 561         private void selectField(int inFieldNum)
 562         {
 563                 if (inFieldNum == -1 || inFieldNum != _selectedField)
 564                 {
 565                         _selectedField = inFieldNum;
 566                         _moveUpButton.setEnabled(inFieldNum > 0);
 567                         _moveDownButton.setEnabled(inFieldNum >= 0
 568                                 && inFieldNum < (_fieldTableModel.getRowCount()-1));
 569                 }
 570         }
 571
 572
 573         /**
 574          * @return the last delimiter character used for a load
 575          */
 576         public char getLastUsedDelimiter()
 577         {
 578                 return _lastUsedDelimiter;
 579         }
 580 }