merge from open-source master

Change-Id: If7ae0c5629d1b3c540cacfa517425c2e6b5822d1

Author: The Android Open Source Project

core/java/android/text/format/DateUtils.java

@@ -496,7 +496,7 @@ public static CharSequence getRelativeTimeSpanString(long time, long now, long m
                 }
             }
         } else if (duration < WEEK_IN_MILLIS && minResolution < WEEK_IN_MILLIS) {
-            count = duration / DAY_IN_MILLIS;
+            count = getNumberOfDaysPassed(time, now);
             if (past) {
                 if (abbrevRelative) {
                     resId = com.android.internal.R.plurals.abbrev_num_days_ago;
@@ -520,6 +520,24 @@ public static CharSequence getRelativeTimeSpanString(long time, long now, long m
         return String.format(format, count);
     }
 
+    /**
+     * Returns the number of days passed between two dates.
+     *
+     * @param date1 first date
+     * @param date2 second date
+     * @return number of days passed between to dates.
+     */
+    private synchronized static long getNumberOfDaysPassed(long date1, long date2) {
+        if (sThenTime == null) {
+            sThenTime = new Time();
+        }
+        sThenTime.set(date1);
+        int day1 = Time.getJulianDay(date1, sThenTime.gmtoff);
+        sThenTime.set(date2);
+        int day2 = Time.getJulianDay(date2, sThenTime.gmtoff);
+        return Math.abs(day2 - day1);
+    }
+
     /**
      * Return string describing the elapsed time since startTime formatted like
      * "[relative time/date], [time]".
@@ -1550,40 +1568,45 @@ public static String formatDateTime(Context context, long millis, int flags) {
     public static CharSequence getRelativeTimeSpanString(Context c, long millis,
             boolean withPreposition) {
 
+        String result;
         long now = System.currentTimeMillis();
         long span = now - millis;
 
-        if (sNowTime == null) {
-            sNowTime = new Time();
-            sThenTime = new Time();
-        }
+        synchronized (DateUtils.class) {
+            if (sNowTime == null) {
+                sNowTime = new Time();
+            }
 
-        sNowTime.set(now);
-        sThenTime.set(millis);
+            if (sThenTime == null) {
+                sThenTime = new Time();
+            }
 
-        String result;
-        int prepositionId;
-        if (span < DAY_IN_MILLIS && sNowTime.weekDay == sThenTime.weekDay) {
-            // Same day
-            int flags = FORMAT_SHOW_TIME;
-            result = formatDateRange(c, millis, millis, flags);
-            prepositionId = R.string.preposition_for_time;
-        } else if (sNowTime.year != sThenTime.year) {
-            // Different years
-            int flags = FORMAT_SHOW_DATE | FORMAT_SHOW_YEAR | FORMAT_NUMERIC_DATE;
-            result = formatDateRange(c, millis, millis, flags);
-
-            // This is a date (like "10/31/2008" so use the date preposition)
-            prepositionId = R.string.preposition_for_date;
-        } else {
-            // Default
-            int flags = FORMAT_SHOW_DATE | FORMAT_ABBREV_MONTH;
-            result = formatDateRange(c, millis, millis, flags);
-            prepositionId = R.string.preposition_for_date;
-        }
-        if (withPreposition) {
-            Resources res = c.getResources();
-            result = res.getString(prepositionId, result);
+            sNowTime.set(now);
+            sThenTime.set(millis);
+
+            int prepositionId;
+            if (span < DAY_IN_MILLIS && sNowTime.weekDay == sThenTime.weekDay) {
+                // Same day
+                int flags = FORMAT_SHOW_TIME;
+                result = formatDateRange(c, millis, millis, flags);
+                prepositionId = R.string.preposition_for_time;
+            } else if (sNowTime.year != sThenTime.year) {
+                // Different years
+                int flags = FORMAT_SHOW_DATE | FORMAT_SHOW_YEAR | FORMAT_NUMERIC_DATE;
+                result = formatDateRange(c, millis, millis, flags);
+
+                // This is a date (like "10/31/2008" so use the date preposition)
+                prepositionId = R.string.preposition_for_date;
+            } else {
+                // Default
+                int flags = FORMAT_SHOW_DATE | FORMAT_ABBREV_MONTH;
+                result = formatDateRange(c, millis, millis, flags);
+                prepositionId = R.string.preposition_for_date;
+            }
+            if (withPreposition) {
+                Resources res = c.getResources();
+                result = res.getString(prepositionId, result);
+            }
         }
         return result;
     }