tim/prune/gui/colour/DateColourer.java

   1 package tim.prune.gui.colour;
   2
   3 import java.awt.Color;
   4 import java.text.DateFormat;
   5 import java.util.Calendar;
   6 import java.util.HashMap;
   7 import java.util.TimeZone;
   8
   9 import tim.prune.config.Config;
  10 import tim.prune.data.DataPoint;
  11 import tim.prune.data.Timestamp;
  12 import tim.prune.data.Track;
  13 import tim.prune.data.TrackInfo;
  14
  15 /**
  16  * Point colourer giving a different colour to each date.
  17  * Uses the currently selected timezone, so the results
  18  * may be different when selecting a different timezone
  19  */
  20 public class DateColourer extends DiscretePointColourer
  21 {
  22         // Doesn't really matter what format is used here, as long as dates are different
  23         private static final DateFormat DEFAULT_DATE_FORMAT = DateFormat.getDateInstance();
  24         // Selected timezone for deciding which date a timestamp falls on
  25         private TimeZone _selectedTimezone = null;
  26
  27         /**
  28          * Constructor
  29          * @param inStartColour start colour of scale
  30          * @param inEndColour end colour of scale
  31          * @param inWrapLength number of unique colours before wrap
  32          */
  33         public DateColourer(Color inStartColour, Color inEndColour, int inWrapLength)
  34         {
  35                 super(inStartColour, inEndColour, inWrapLength);
  36         }
  37
  38         /**
  39          * Calculate the colours for each of the points in the given track
  40          * @param inTrackInfo track info object
  41          */
  42         @Override
  43         public synchronized void calculateColours(TrackInfo inTrackInfo)
  44         {
  45                 // Note, this method needs to be synchronized because otherwise the
  46                 // Calendar objects in the different threads get confused and the
  47                 // wrong colours are generated.
  48
  49                 // TODO: Move this timezone-selection into a helper for use by others?
  50                 // Select the current timezone
  51                 final String zoneId = Config.getConfigString(Config.KEY_TIMEZONE_ID);
  52                 if (zoneId == null || zoneId.equals("")) {
  53                         _selectedTimezone = TimeZone.getDefault();
  54                 }
  55                 else {
  56                         _selectedTimezone = TimeZone.getTimeZone(zoneId);
  57                 }
  58                 // initialise the array to the right size
  59                 Track track = inTrackInfo == null ? null : inTrackInfo.getTrack();
  60                 final int numPoints = track == null ? 0 : track.getNumPoints();
  61                 init(numPoints);
  62                 // Make a hashmap of the already-used dates
  63                 HashMap<String, Integer> usedDates = new HashMap<String, Integer>(20);
  64                 // Also store the previous one, because they're probably consecutive
  65                 String prevDate = null;
  66                 int prevIndex = -1;
  67
  68                 // loop over track points
  69                 int dayIndex = -1;
  70                 for (int i=0; i<numPoints; i++)
  71                 {
  72                         DataPoint p = track.getPoint(i);
  73                         if (p != null && !p.isWaypoint())
  74                         {
  75                                 dayIndex = 0; // default index 0 will be used if no date found
  76                                 String date = getDate(p.getTimestamp());
  77                                 if (date != null)
  78                                 {
  79                                         // Check if it's the previous one
  80                                         if (prevDate != null && date.equals(prevDate)) {
  81                                                 dayIndex = prevIndex;
  82                                         }
  83                                         else
  84                                         {
  85                                                 // Look up in the hashmap to see if it's been used before
  86                                                 Integer foundIndex = usedDates.get(date);
  87                                                 if (foundIndex == null)
  88                                                 {
  89                                                         // not been used before, so add it
  90                                                         dayIndex = usedDates.size() + 1;
  91                                                         usedDates.put(date, dayIndex);
  92                                                 }
  93                                                 else
  94                                                 {
  95                                                         // found it
  96                                                         dayIndex = foundIndex;
  97                                                 }
  98                                                 // Remember what we've got for the next point
  99                                                 prevDate = date;
 100                                                 prevIndex = dayIndex;
 101                                         }
 102                                 }
 103                                 // if date is null (no timestamp or invalid) then dayIndex remains 0
 104                                 setColour(i, dayIndex);
 105                         }
 106                 }
 107
 108                 // generate the colours needed
 109                 generateDiscreteColours(usedDates.size() + 1);
 110         }
 111
 112
 113         /**
 114          * Find which date (in the currently selected timezone) the given timestamp falls on
 115          * @param inTimestamp timestamp
 116          * @return String containing description of date, or null
 117          */
 118         private String getDate(Timestamp inTimestamp)
 119         {
 120                 if (inTimestamp == null || !inTimestamp.isValid()) {
 121                         return null;
 122                 }
 123                 Calendar cal = inTimestamp.getCalendar(null);
 124                 // use selected time zone, not system one
 125                 DEFAULT_DATE_FORMAT.setTimeZone(_selectedTimezone);
 126                 return DEFAULT_DATE_FORMAT.format(cal.getTime());
 127         }
 128 }