tim/prune/function/charts/Charter.java

   1 package tim.prune.function.charts;
   2
   3 import java.awt.BorderLayout;
   4 import java.awt.FlowLayout;
   5 import java.awt.GridLayout;
   6 import java.awt.event.ActionEvent;
   7 import java.awt.event.ActionListener;
   8 import java.io.File;
   9 import java.io.FileWriter;
  10 import java.io.IOException;
  11 import java.io.OutputStreamWriter;
  12
  13 import javax.swing.BorderFactory;
  14 import javax.swing.BoxLayout;
  15 import javax.swing.ButtonGroup;
  16 import javax.swing.JButton;
  17 import javax.swing.JCheckBox;
  18 import javax.swing.JDialog;
  19 import javax.swing.JFileChooser;
  20 import javax.swing.JLabel;
  21 import javax.swing.JOptionPane;
  22 import javax.swing.JPanel;
  23 import javax.swing.JRadioButton;
  24 import javax.swing.JTextField;
  25 import javax.swing.SwingConstants;
  26
  27 import tim.prune.App;
  28 import tim.prune.ExternalTools;
  29 import tim.prune.GenericFunction;
  30 import tim.prune.I18nManager;
  31 import tim.prune.config.Config;
  32 import tim.prune.data.DataPoint;
  33 import tim.prune.data.Distance;
  34 import tim.prune.data.Field;
  35 import tim.prune.data.Timestamp;
  36 import tim.prune.data.Track;
  37 import tim.prune.gui.profile.SpeedData;
  38 import tim.prune.gui.profile.VerticalSpeedData;
  39 import tim.prune.load.GenericFileFilter;
  40
  41 /**
  42  * Class to manage the generation of charts using gnuplot
  43  */
  44 public class Charter extends GenericFunction
  45 {
  46         /** dialog object, cached */
  47         private JDialog _dialog = null;
  48         /** radio button for distance axis */
  49         private JRadioButton _distanceRadio = null;
  50         /** radio button for time axis */
  51         private JRadioButton _timeRadio = null;
  52         /** array of checkboxes for specifying y axes */
  53         private JCheckBox[] _yAxesBoxes = null;
  54         /** radio button for svg output */
  55         private JRadioButton _svgRadio = null;
  56         /** file chooser for saving svg file */
  57         private JFileChooser _fileChooser = null;
  58         /** text field for svg width */
  59         private JTextField _svgWidthField = null;
  60         /** text field for svg height */
  61         private JTextField _svgHeightField = null;
  62
  63         /** Default dimensions of Svg file */
  64         private static final String DEFAULT_SVG_WIDTH  = "800";
  65         private static final String DEFAULT_SVG_HEIGHT = "400";
  66
  67
  68         /**
  69          * Constructor from superclass
  70          * @param inApp app object
  71          */
  72         public Charter(App inApp)
  73         {
  74                 super(inApp);
  75         }
  76
  77         /**
  78          * @return key for function name
  79          */
  80         public String getNameKey()
  81         {
  82                 return "function.charts";
  83         }
  84
  85         /**
  86          * Show the dialog
  87          */
  88         public void begin()
  89         {
  90                 // First check if gnuplot is available
  91                 if (!ExternalTools.isToolInstalled(ExternalTools.TOOL_GNUPLOT))
  92                 {
  93                         _app.showErrorMessage(getNameKey(), "dialog.charts.gnuplotnotfound");
  94                         return;
  95                 }
  96                 // Make dialog window
  97                 if (_dialog == null)
  98                 {
  99                         _dialog = new JDialog(_parentFrame, I18nManager.getText(getNameKey()), true);
 100                         _dialog.setLocationRelativeTo(_parentFrame);
 101                         _dialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
 102                         _dialog.getContentPane().add(makeDialogComponents());
 103                         _dialog.pack();
 104                 }
 105                 if (setupDialog(_app.getTrackInfo().getTrack())) {
 106                         _dialog.setVisible(true);
 107                 }
 108                 else {
 109                         _app.showErrorMessage(getNameKey(), "dialog.charts.needaltitudeortimes");
 110                 }
 111         }
 112
 113
 114         /**
 115          * Make the dialog components
 116          * @return panel containing gui elements
 117          */
 118         private JPanel makeDialogComponents()
 119         {
 120                 JPanel dialogPanel = new JPanel();
 121                 dialogPanel.setLayout(new BorderLayout());
 122
 123                 JPanel mainPanel = new JPanel();
 124                 mainPanel.setLayout(new BoxLayout(mainPanel, BoxLayout.Y_AXIS));
 125                 // x axis choice
 126                 JPanel axisPanel = new JPanel();
 127                 axisPanel.setBorder(BorderFactory.createTitledBorder(I18nManager.getText("dialog.charts.xaxis")));
 128                 _distanceRadio = new JRadioButton(I18nManager.getText("fieldname.distance"));
 129                 _distanceRadio.setSelected(true);
 130                 _timeRadio = new JRadioButton(I18nManager.getText("fieldname.time"));
 131                 ButtonGroup axisGroup = new ButtonGroup();
 132                 axisGroup.add(_distanceRadio); axisGroup.add(_timeRadio);
 133                 axisPanel.add(_distanceRadio); axisPanel.add(_timeRadio);
 134                 mainPanel.add(axisPanel);
 135
 136                 // y axis choices
 137                 JPanel yPanel = new JPanel();
 138                 yPanel.setBorder(BorderFactory.createTitledBorder(I18nManager.getText("dialog.charts.yaxis")));
 139                 _yAxesBoxes = new JCheckBox[4]; // dist altitude speed vertspeed (time not available on y axis)
 140                 _yAxesBoxes[0] = new JCheckBox(I18nManager.getText("fieldname.distance"));
 141                 _yAxesBoxes[1] = new JCheckBox(I18nManager.getText("fieldname.altitude"));
 142                 _yAxesBoxes[1].setSelected(true);
 143                 _yAxesBoxes[2] = new JCheckBox(I18nManager.getText("fieldname.speed"));
 144                 _yAxesBoxes[3] = new JCheckBox(I18nManager.getText("fieldname.verticalspeed"));
 145                 for (int i=0; i<4; i++) {
 146                         yPanel.add(_yAxesBoxes[i]);
 147                 }
 148                 mainPanel.add(yPanel);
 149
 150                 // Add validation to prevent choosing invalid (ie dist/dist) combinations
 151                 ActionListener xAxisListener = new ActionListener() {
 152                         public void actionPerformed(ActionEvent e) {
 153                                 enableYbox(0, _timeRadio.isSelected());
 154                         }
 155                 };
 156                 _timeRadio.addActionListener(xAxisListener);
 157                 _distanceRadio.addActionListener(xAxisListener);
 158
 159                 // output buttons
 160                 JPanel outputPanel = new JPanel();
 161                 outputPanel.setBorder(BorderFactory.createTitledBorder(I18nManager.getText("dialog.charts.output")));
 162                 outputPanel.setLayout(new BorderLayout());
 163                 JPanel radiosPanel = new JPanel();
 164                 JRadioButton screenRadio = new JRadioButton(I18nManager.getText("dialog.charts.screen"));
 165                 screenRadio.setSelected(true);
 166                 _svgRadio = new JRadioButton(I18nManager.getText("dialog.charts.svg"));
 167                 ButtonGroup outputGroup = new ButtonGroup();
 168                 outputGroup.add(screenRadio); outputGroup.add(_svgRadio);
 169                 radiosPanel.add(screenRadio); radiosPanel.add(_svgRadio);
 170                 outputPanel.add(radiosPanel, BorderLayout.NORTH);
 171                 // panel for svg width, height
 172                 JPanel sizePanel = new JPanel();
 173                 sizePanel.setLayout(new GridLayout(2, 2, 10, 1));
 174                 JLabel widthLabel = new JLabel(I18nManager.getText("dialog.charts.svgwidth"));
 175                 widthLabel.setHorizontalAlignment(SwingConstants.RIGHT);
 176                 sizePanel.add(widthLabel);
 177                 _svgWidthField = new JTextField(DEFAULT_SVG_WIDTH, 5);
 178                 sizePanel.add(_svgWidthField);
 179                 JLabel heightLabel = new JLabel(I18nManager.getText("dialog.charts.svgheight"));
 180                 heightLabel.setHorizontalAlignment(SwingConstants.RIGHT);
 181                 sizePanel.add(heightLabel);
 182                 _svgHeightField = new JTextField(DEFAULT_SVG_HEIGHT, 5);
 183                 sizePanel.add(_svgHeightField);
 184
 185                 outputPanel.add(sizePanel, BorderLayout.EAST);
 186                 mainPanel.add(outputPanel);
 187                 dialogPanel.add(mainPanel, BorderLayout.CENTER);
 188
 189                 // button panel on bottom
 190                 JPanel buttonPanel = new JPanel();
 191                 buttonPanel.setLayout(new FlowLayout(FlowLayout.RIGHT));
 192                 // ok button
 193                 JButton okButton = new JButton(I18nManager.getText("button.ok"));
 194                 okButton.addActionListener(new ActionListener() {
 195                         public void actionPerformed(ActionEvent e) {
 196                                 showChart(_app.getTrackInfo().getTrack());
 197                                 _dialog.setVisible(false);
 198                         }
 199                 });
 200                 buttonPanel.add(okButton);
 201                 // Cancel button
 202                 JButton cancelButton = new JButton(I18nManager.getText("button.cancel"));
 203                 cancelButton.addActionListener(new ActionListener() {
 204                         public void actionPerformed(ActionEvent e) {
 205                                 _dialog.setVisible(false);
 206                         }
 207                 });
 208                 buttonPanel.add(cancelButton);
 209                 dialogPanel.add(buttonPanel, BorderLayout.SOUTH);
 210                 return dialogPanel;
 211         }
 212
 213
 214         /**
 215          * Set up the dialog according to the track contents
 216          * @param inTrack track object
 217          * @return true if it's all ok
 218          */
 219         private boolean setupDialog(Track inTrack)
 220         {
 221                 boolean hasTimes = inTrack.hasData(Field.TIMESTAMP);
 222                 boolean hasAltitudes = inTrack.hasAltitudeData();
 223                 _timeRadio.setEnabled(hasTimes);
 224
 225                 // Add checks to prevent choosing unavailable combinations
 226                 if (!hasTimes) {
 227                         _distanceRadio.setSelected(true);
 228                 }
 229                 enableYbox(0, !_distanceRadio.isSelected());
 230                 enableYbox(1, hasAltitudes);
 231                 enableYbox(2, hasTimes);
 232                 enableYbox(3, hasTimes && hasAltitudes);
 233                 return (hasTimes || hasAltitudes);
 234         }
 235
 236
 237         /**
 238          * Enable or disable the given y axis checkbox
 239          * @param inIndex index of checkbox
 240          * @param inFlag true to enable
 241          */
 242         private void enableYbox(int inIndex, boolean inFlag)
 243         {
 244                 _yAxesBoxes[inIndex].setEnabled(inFlag);
 245                 if (!inFlag) {
 246                         _yAxesBoxes[inIndex].setSelected(inFlag);
 247                 }
 248         }
 249
 250         /**
 251          * Show the chart for the specified track
 252          * @param inTrack track object containing data
 253          */
 254         private void showChart(Track inTrack)
 255         {
 256                 int numCharts = 0;
 257                 for (int i=0; i<_yAxesBoxes.length; i++) {
 258                         if (_yAxesBoxes[i].isSelected()) {
 259                                 numCharts++;
 260                         }
 261                 }
 262                 // Select default chart if none selected
 263                 if (numCharts == 0) {
 264                         _yAxesBoxes[1].setSelected(true);
 265                         numCharts = 1;
 266                 }
 267                 int[] heights = getHeights(numCharts);
 268
 269                 boolean showSvg = _svgRadio.isSelected();
 270                 File svgFile = null;
 271                 if (showSvg) {
 272                         svgFile = selectSvgFile();
 273                         if (svgFile == null) {showSvg = false;}
 274                 }
 275                 OutputStreamWriter writer = null;
 276                 try
 277                 {
 278                         final String gnuplotPath = Config.getConfigString(Config.KEY_GNUPLOT_PATH);
 279                         Process process = Runtime.getRuntime().exec(gnuplotPath + " -persist");
 280                         writer = new OutputStreamWriter(process.getOutputStream());
 281                         if (showSvg)
 282                         {
 283                                 writer.write("set terminal svg size " + getSvgValue(_svgWidthField, DEFAULT_SVG_WIDTH) + " "
 284                                         + getSvgValue(_svgHeightField, DEFAULT_SVG_HEIGHT) + "\n");
 285                                 writer.write("set out '" + svgFile.getAbsolutePath() + "'\n");
 286                         }
 287                         if (numCharts > 1) {
 288                                 writer.write("set multiplot layout " + numCharts + ",1\n");
 289                         }
 290                         // Loop over possible charts
 291                         int chartNum = 0;
 292                         for (int c=0; c<_yAxesBoxes.length; c++)
 293                         {
 294                                 if (_yAxesBoxes[c].isSelected())
 295                                 {
 296                                         writer.write("set size 1," + (0.01*heights[chartNum*2+1]) + "\n");
 297                                         writer.write("set origin 0," + (0.01*heights[chartNum*2]) + "\n");
 298                                         writeChart(writer, inTrack, _distanceRadio.isSelected(), c);
 299                                         chartNum++;
 300                                 }
 301                         }
 302                         // Close multiplot if open
 303                         if (numCharts > 1) {
 304                                 writer.write("unset multiplot\n");
 305                         }
 306                 }
 307                 catch (Exception e) {
 308                         _app.showErrorMessageNoLookup(getNameKey(), e.getMessage());
 309                 }
 310                 finally {
 311                         try {
 312                                 // Close writer
 313                                 if (writer != null) writer.close();
 314                         }
 315                         catch (Exception e) {} // ignore
 316                 }
 317         }
 318
 319
 320         /**
 321          * Parse the given text field's value and return as string
 322          * @param inField text field to read from
 323          * @param inDefault default value if not valid
 324          * @return value of svg dimension as string
 325          */
 326         private static String getSvgValue(JTextField inField, String inDefault)
 327         {
 328                 int value = 0;
 329                 try {
 330                         value = Integer.parseInt(inField.getText());
 331                 }
 332                 catch (Exception e) {} // ignore, value stays zero
 333                 if (value > 0) {
 334                         return "" + value;
 335                 }
 336                 return inDefault;
 337         }
 338
 339
 340         /**
 341          * Write out the selected chart to the given Writer object
 342          * @param inWriter writer object
 343          * @param inTrack Track containing data
 344          * @param inDistance true if x axis is distance
 345          * @param inYaxis index of y axis
 346          * @throws IOException if writing error occurred
 347          */
 348         private static void writeChart(OutputStreamWriter inWriter, Track inTrack, boolean inDistance, int inYaxis)
 349         throws IOException
 350         {
 351                 ChartSeries xValues = null, yValues = null;
 352                 ChartSeries distValues = getDistanceValues(inTrack);
 353                 // Choose x values according to axis
 354                 if (inDistance) {
 355                         xValues = distValues;
 356                 }
 357                 else {
 358                         xValues = getTimeValues(inTrack);
 359                 }
 360                 // Choose y values according to axis
 361                 switch (inYaxis)
 362                 {
 363                 case 0: // y axis is distance
 364                         yValues = distValues;
 365                         break;
 366                 case 1: // y axis is altitude
 367                         yValues = getAltitudeValues(inTrack);
 368                         break;
 369                 case 2: // y axis is speed
 370                         yValues = getSpeedValues(inTrack);
 371                         break;
 372                 case 3: // y axis is vertical speed
 373                         yValues = getVertSpeedValues(inTrack);
 374                         break;
 375                 }
 376                 // Make a temporary data file for the output (one per subchart)
 377                 File tempFile = File.createTempFile("prunedata", null);
 378                 tempFile.deleteOnExit();
 379                 // write out values for x and y to temporary file
 380                 FileWriter tempFileWriter = null;
 381                 try {
 382                         tempFileWriter = new FileWriter(tempFile);
 383                         tempFileWriter.write("# Temporary data file for GpsPrune charts\n\n");
 384                         for (int i=0; i<inTrack.getNumPoints(); i++) {
 385                                 if (xValues.hasData(i) && yValues.hasData(i)) {
 386                                         tempFileWriter.write("" + xValues.getData(i) + ", " + yValues.getData(i) + "\n");
 387                                 }
 388                         }
 389                 }
 390                 catch (IOException ioe) { // rethrow
 391                         throw ioe;
 392                 }
 393                 finally {
 394                         try {
 395                                 tempFileWriter.close();
 396                         }
 397                         catch (Exception e) {}
 398                 }
 399
 400                 // Sort out units to use
 401                 final String distLabel = I18nManager.getText(Config.getUnitSet().getDistanceUnit().getShortnameKey());
 402                 final String altLabel  = I18nManager.getText(Config.getUnitSet().getAltitudeUnit().getShortnameKey());
 403                 final String speedLabel = I18nManager.getText(Config.getUnitSet().getSpeedUnit().getShortnameKey());
 404                 final String vertSpeedLabel = I18nManager.getText(Config.getUnitSet().getVerticalSpeedUnit().getShortnameKey());
 405
 406                 // Set x axis label
 407                 if (inDistance) {
 408                         inWriter.write("set xlabel '" + I18nManager.getText("fieldname.distance") + " (" + distLabel + ")'\n");
 409                 }
 410                 else {
 411                         inWriter.write("set xlabel '" + I18nManager.getText("fieldname.time") + " (" + I18nManager.getText("units.hours") + ")'\n");
 412                 }
 413
 414                 // set other labels and plot chart
 415                 String chartTitle = null;
 416                 switch (inYaxis)
 417                 {
 418                 case 0: // y axis is distance
 419                         inWriter.write("set ylabel '" + I18nManager.getText("fieldname.distance") + " (" + distLabel + ")'\n");
 420                         chartTitle = I18nManager.getText("fieldname.distance");
 421                         break;
 422                 case 1: // y axis is altitude
 423                         inWriter.write("set ylabel '" + I18nManager.getText("fieldname.altitude") + " (" + altLabel + ")'\n");
 424                         chartTitle = I18nManager.getText("fieldname.altitude");
 425                         break;
 426                 case 2: // y axis is speed
 427                         inWriter.write("set ylabel '" + I18nManager.getText("fieldname.speed") + " (" + speedLabel + ")'\n");
 428                         chartTitle = I18nManager.getText("fieldname.speed");
 429                         break;
 430                 case 3: // y axis is vertical speed
 431                         inWriter.write("set ylabel '" + I18nManager.getText("fieldname.verticalspeed") + " (" + vertSpeedLabel + ")'\n");
 432                         chartTitle = I18nManager.getText("fieldname.verticalspeed");
 433                         break;
 434                 }
 435                 inWriter.write("set style fill solid 0.5 border -1\n");
 436                 inWriter.write("plot '" + tempFile.getAbsolutePath() + "' title '" + chartTitle + "' with filledcurve y1=0 lt rgb \"#009000\"\n");
 437         }
 438
 439
 440         /**
 441          * Calculate the distance values for each point in the given track
 442          * @param inTrack track object
 443          * @return distance values in a ChartSeries object
 444          */
 445         private static ChartSeries getDistanceValues(Track inTrack)
 446         {
 447                 // Calculate distances and fill in in values array
 448                 ChartSeries values = new ChartSeries(inTrack.getNumPoints());
 449                 double totalRads = 0;
 450                 DataPoint prevPoint = null, currPoint = null;
 451                 for (int i=0; i<inTrack.getNumPoints(); i++)
 452                 {
 453                         currPoint = inTrack.getPoint(i);
 454                         if (prevPoint != null && !currPoint.isWaypoint() && !currPoint.getSegmentStart())
 455                         {
 456                                 totalRads += DataPoint.calculateRadiansBetween(prevPoint, currPoint);
 457                         }
 458
 459                         // distance values use currently configured units
 460                         values.setData(i, Distance.convertRadiansToDistance(totalRads));
 461
 462                         prevPoint = currPoint;
 463                 }
 464                 return values;
 465         }
 466
 467         /**
 468          * Calculate the time values for each point in the given track
 469          * @param inTrack track object
 470          * @return time values in a ChartSeries object
 471          */
 472         private static ChartSeries getTimeValues(Track inTrack)
 473         {
 474                 // Calculate times and fill in in values array
 475                 ChartSeries values = new ChartSeries(inTrack.getNumPoints());
 476                 double seconds = 0.0;
 477                 Timestamp prevTimestamp = null;
 478                 DataPoint currPoint = null;
 479                 for (int i=0; i<inTrack.getNumPoints(); i++)
 480                 {
 481                         currPoint = inTrack.getPoint(i);
 482                         if (currPoint.hasTimestamp())
 483                         {
 484                                 if (!currPoint.getSegmentStart() && prevTimestamp != null) {
 485                                         seconds += (currPoint.getTimestamp().getSecondsSince(prevTimestamp));
 486                                 }
 487                                 values.setData(i, seconds / 60.0 / 60.0);
 488                                 prevTimestamp = currPoint.getTimestamp();
 489                         }
 490                 }
 491                 return values;
 492         }
 493
 494         /**
 495          * Calculate the altitude values for each point in the given track
 496          * @param inTrack track object
 497          * @return altitude values in a ChartSeries object
 498          */
 499         private static ChartSeries getAltitudeValues(Track inTrack)
 500         {
 501                 ChartSeries values = new ChartSeries(inTrack.getNumPoints());
 502                 final double multFactor = Config.getUnitSet().getAltitudeUnit().getMultFactorFromStd();
 503                 for (int i=0; i<inTrack.getNumPoints(); i++) {
 504                         if (inTrack.getPoint(i).hasAltitude()) {
 505                                 values.setData(i, inTrack.getPoint(i).getAltitude().getMetricValue() * multFactor);
 506                         }
 507                 }
 508                 return values;
 509         }
 510
 511         /**
 512          * Calculate the speed values for each point in the given track
 513          * @param inTrack track object
 514          * @return speed values in a ChartSeries object
 515          */
 516         private static ChartSeries getSpeedValues(Track inTrack)
 517         {
 518                 // Calculate speeds using the same formula as the profile chart
 519                 SpeedData speeds = new SpeedData(inTrack);
 520                 speeds.init(Config.getUnitSet());
 521
 522                 final int numPoints = inTrack.getNumPoints();
 523                 ChartSeries values = new ChartSeries(numPoints);
 524                 // Loop over collected points
 525                 for (int i=0; i<numPoints; i++)
 526                 {
 527                         if (speeds.hasData(i))
 528                         {
 529                                 values.setData(i, speeds.getData(i));
 530                         }
 531                 }
 532                 return values;
 533         }
 534
 535         /**
 536          * Calculate the vertical speed values for each point in the given track
 537          * @param inTrack track object
 538          * @return vertical speed values in a ChartSeries object
 539          */
 540         private static ChartSeries getVertSpeedValues(Track inTrack)
 541         {
 542                 // Calculate speeds using the same formula as the profile chart
 543                 VerticalSpeedData speeds = new VerticalSpeedData(inTrack);
 544                 speeds.init(Config.getUnitSet());
 545
 546                 final int numPoints = inTrack.getNumPoints();
 547                 ChartSeries values = new ChartSeries(numPoints);
 548                 // Loop over collected points
 549                 for (int i=0; i<numPoints; i++)
 550                 {
 551                         if (speeds.hasData(i))
 552                         {
 553                                 values.setData(i, speeds.getData(i));
 554                         }
 555                 }
 556                 return values;
 557         }
 558
 559
 560         /**
 561          * Select a file to write for the SVG output
 562          * @return selected File object or null if cancelled
 563          */
 564         private File selectSvgFile()
 565         {
 566                 if (_fileChooser == null)
 567                 {
 568                         _fileChooser = new JFileChooser();
 569                         _fileChooser.setDialogType(JFileChooser.SAVE_DIALOG);
 570                         _fileChooser.setFileFilter(new GenericFileFilter("filetype.svg", new String[] {"svg"}));
 571                         _fileChooser.setAcceptAllFileFilterUsed(false);
 572                         // start from directory in config which should be set
 573                         String configDir = Config.getConfigString(Config.KEY_TRACK_DIR);
 574                         if (configDir != null) {_fileChooser.setCurrentDirectory(new File(configDir));}
 575                 }
 576                 boolean chooseAgain = true;
 577                 while (chooseAgain)
 578                 {
 579                         chooseAgain = false;
 580                         if (_fileChooser.showSaveDialog(_parentFrame) == JFileChooser.APPROVE_OPTION)
 581                         {
 582                                 // OK pressed and file chosen
 583                                 File file = _fileChooser.getSelectedFile();
 584                                 // Check file extension
 585                                 if (!file.getName().toLowerCase().endsWith(".svg")) {
 586                                         file = new File(file.getAbsolutePath() + ".svg");
 587                                 }
 588                                 // Check if file exists and if necessary prompt for overwrite
 589                                 Object[] buttonTexts = {I18nManager.getText("button.overwrite"), I18nManager.getText("button.cancel")};
 590                                 if (!file.exists() || (file.canWrite() && JOptionPane.showOptionDialog(_parentFrame,
 591                                                 I18nManager.getText("dialog.save.overwrite.text"),
 592                                                 I18nManager.getText("dialog.save.overwrite.title"), JOptionPane.YES_NO_OPTION,
 593                                                 JOptionPane.WARNING_MESSAGE, null, buttonTexts, buttonTexts[1])
 594                                         == JOptionPane.YES_OPTION))
 595                                 {
 596                                         return file;
 597                                 }
 598                                 chooseAgain = true;
 599                         }
 600                 }
 601                 // Cancel pressed so no file selected
 602                 return null;
 603         }
 604
 605
 606         /**
 607          * @param inNumCharts number of charts to draw
 608          * @return array of ints describing position and height of each subchart
 609          */
 610         private static int[] getHeights(int inNumCharts)
 611         {
 612                 if (inNumCharts <= 1) {return new int[] {0, 100};}
 613                 if (inNumCharts == 2) {return new int[] {25, 75, 0, 25};}
 614                 if (inNumCharts == 3) {return new int[] {40, 60, 20, 20, 0, 20};}
 615                 return new int[] {54, 46, 36, 18, 18, 18, 0, 18};
 616         }
 617 }