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.data.DataPoint;
  10 import tim.prune.data.Timestamp;
  11 import tim.prune.data.Track;
  12 import tim.prune.data.TrackInfo;
  13
  14 /**
  15  * Point colourer giving a different colour to each date
  16  * Uses the system timezone so may give funny results for
  17  * data from other timezones (eg far-away holidays)
  18  */
  19 public class DateColourer extends DiscretePointColourer
  20 {
  21         // Doesn't really matter what format is used here, as long as dates are different
  22         private static final DateFormat DEFAULT_DATE_FORMAT = DateFormat.getDateInstance();
  23
  24         /**
  25          * Constructor
  26          * @param inStartColour start colour of scale
  27          * @param inEndColour end colour of scale
  28          * @param inWrapLength number of unique colours before wrap
  29          */
  30         public DateColourer(Color inStartColour, Color inEndColour, int inWrapLength)
  31         {
  32                 super(inStartColour, inEndColour, inWrapLength);
  33         }
  34
  35         /**
  36          * Calculate the colours for each of the points in the given track
  37          * @param inTrackInfo track info object
  38          */
  39         @Override
  40         public void calculateColours(TrackInfo inTrackInfo)
  41         {
  42                 // initialise the array to the right size
  43                 Track track = inTrackInfo == null ? null : inTrackInfo.getTrack();
  44                 final int numPoints = track == null ? 0 : track.getNumPoints();
  45                 init(numPoints);
  46                 // Make a hashmap of the already-used dates
  47                 HashMap<String, Integer> usedDates = new HashMap<String, Integer>(20);
  48                 // Also store the previous one, because they're probably consecutive
  49                 String prevDate = null;
  50                 int prevIndex = -1;
  51
  52                 // loop over track points
  53                 int dayIndex = -1;
  54                 for (int i=0; i<numPoints; i++)
  55                 {
  56                         DataPoint p = track.getPoint(i);
  57                         if (p != null && !p.isWaypoint())
  58                         {
  59                                 dayIndex = 0; // default index 0 will be used if no date found
  60                                 String date = getDate(p.getTimestamp());
  61                                 if (date != null)
  62                                 {
  63                                         // Check if it's the previous one
  64                                         if (prevDate != null && date.equals(prevDate)) {
  65                                                 dayIndex = prevIndex;
  66                                         }
  67                                         else
  68                                         {
  69                                                 // Look up in the hashmap to see if it's been used before
  70                                                 Integer foundIndex = usedDates.get(date);
  71                                                 if (foundIndex == null)
  72                                                 {
  73                                                         // not been used before, so add it
  74                                                         dayIndex = usedDates.size() + 1;
  75                                                         usedDates.put(date, dayIndex);
  76                                                 }
  77                                                 else
  78                                                 {
  79                                                         // found it
  80                                                         dayIndex = foundIndex;
  81                                                 }
  82                                                 // Remember what we've got for the next point
  83                                                 prevDate = date;
  84                                                 prevIndex = dayIndex;
  85                                         }
  86                                 }
  87                                 // if date is null (no timestamp or invalid) then dayIndex remains 0
  88                                 setColour(i, dayIndex);
  89                         }
  90                 }
  91                 // generate the colours needed
  92                 generateDiscreteColours(usedDates.size() + 1);
  93         }
  94
  95
  96         /**
  97          * Find which date (in the system timezone) the given timestamp falls on
  98          * @param inTimestamp timestamp
  99          * @return String containing description of date, or null
 100          */
 101         private static String getDate(Timestamp inTimestamp)
 102         {
 103                 if (inTimestamp == null || !inTimestamp.isValid()) {
 104                         return null;
 105                 }
 106                 Calendar cal = inTimestamp.getCalendar();
 107                 // use system time zone
 108                 cal.setTimeZone(TimeZone.getDefault());
 109                 return DEFAULT_DATE_FORMAT.format(cal.getTime());
 110         }
 111 }