tim/prune/load/NmeaFileLoader.java

   1 package tim.prune.load;
   2
   3 import java.io.BufferedReader;
   4 import java.io.File;
   5 import java.io.FileReader;
   6 import java.io.IOException;
   7 import java.util.ArrayList;
   8
   9 import tim.prune.App;
  10 import tim.prune.data.Altitude;
  11 import tim.prune.data.Field;
  12
  13 /**
  14  * Class to handle the loading of Nmea files
  15  */
  16 public class NmeaFileLoader
  17 {
  18         /** App for callback of file loading */
  19         private App _app = null;
  20
  21         /**
  22          * Constructor
  23          * @param inApp App object
  24          */
  25         public NmeaFileLoader(App inApp)
  26         {
  27                 _app = inApp;
  28         }
  29
  30         /**
  31          * Open the selected file
  32          * @param inFile File to open
  33          */
  34         public void openFile(File inFile)
  35         {
  36                 BufferedReader reader = null;
  37                 ArrayList<NmeaMessage> messages = new ArrayList<NmeaMessage>();
  38                 try
  39                 {
  40                         reader = new BufferedReader(new FileReader(inFile));
  41                         String currLine = reader.readLine();
  42                         boolean newSegment = true;
  43                         while (currLine != null)
  44                         {
  45                                 // Try to make an NmeaMessage object for each line of file
  46                                 if (currLine.trim().length() > 0)
  47                                 {
  48                                         NmeaMessage message = processLine(currLine);
  49                                         if (message != null)
  50                                         {
  51                                                 if (message.hasFix()) {
  52                                                         message.setSegment(newSegment);
  53                                                         // add message to list
  54                                                         messages.add(message);
  55                                                 }
  56                                                 // Start a new segment if fix lost
  57                                                 newSegment = !message.hasFix();
  58                                         }
  59                                 }
  60                                 // Read next line, if any
  61                                 currLine = reader.readLine();
  62                         }
  63                 }
  64                 catch (IOException ioe) {
  65                         _app.showErrorMessage("error.load.dialogtitle", "error.load.noread");
  66                 }
  67                 finally
  68                 {
  69                         // close file ignoring errors
  70                         try
  71                         {
  72                                 if (reader != null) reader.close();
  73                         }
  74                         catch (Exception e) {}
  75                 }
  76                 if (messages.size() > 0)
  77                 {
  78                         _app.informDataLoaded(getFieldArray(), makeDataArray(messages),
  79                                 Altitude.Format.METRES, inFile.getName());
  80                 }
  81         }
  82
  83         /**
  84          * Process the given NMEA line and return the message
  85          * @param inLine line to process
  86          * @return message object
  87          */
  88         private static NmeaMessage processLine(String inLine)
  89         {
  90                 // Only consider lines which are long enough and begin with the GPS position sentence
  91                 if (inLine == null || inLine.length() < 20 || !inLine.startsWith("$GPGGA")) {
  92                         return null;
  93                 }
  94                 // TODO: May be possible to pull date out of GPRMC messages, but then need to back-populate
  95                 // Assume comma delimiter, split into array
  96                 String[] splitLine = inLine.split(",");
  97                 if (splitLine != null && splitLine.length >= 10)
  98                 {
  99                         return new NmeaMessage(splitLine[2] + splitLine[3], // latitude
 100                                 splitLine[4] + splitLine[5], // longitude
 101                                 splitLine[9], // altitude
 102                                 splitLine[1], // timestamp
 103                                 splitLine[6]); // fix
 104                 }
 105                 // Couldn't parse it, return null
 106                 return null;
 107         }
 108
 109         /**
 110          * Make an object array from the data list
 111          * @param inList list of messages
 112          * @return object array for loading
 113          */
 114         private static Object[][] makeDataArray(ArrayList<NmeaMessage> inList)
 115         {
 116                 Object[][] result = new Object[inList.size()][];
 117                 for (int i=0; i<inList.size(); i++) {
 118                         result[i] = inList.get(i).getStrings();
 119                 }
 120                 return result;
 121         }
 122
 123         /**
 124          * @see tim.prune.load.xml.XmlHandler#getFieldArray()
 125          */
 126         public Field[] getFieldArray()
 127         {
 128                 final Field[] fields = {Field.LATITUDE, Field.LONGITUDE, Field.ALTITUDE,
 129                         Field.TIMESTAMP, Field.NEW_SEGMENT};
 130                 return fields;
 131         }
 132 }