Fix for #3492 - DateField should have an option to show week numbers

svn changeset:12004/svn branch:6.3

1 files changed, 31 insertions, 0 deletions

diff --git a/src/com/vaadin/terminal/gwt/client/DateTimeService.java b/src/com/vaadin/terminal/gwt/client/DateTimeService.java
index e16d9b078d..7bc8e8eba4 100644
--- a/src/com/vaadin/terminal/gwt/client/DateTimeService.java
+++ b/src/com/vaadin/terminal/gwt/client/DateTimeService.java
@@ -234,4 +234,35 @@ public class DateTimeService {
         return ((y + 1900) * 10000 + m * 100 + d) * 1000000000;

     }

 

+    /**

+     * Returns the ISO-8601 week number of the given date.

+     * 

+     * @param date

+     *            The date for which the week number should be resolved

+     * @return The ISO-8601 week number for {@literal date}

+     */

+    public static int getISOWeekNumber(Date date) {

+        final long MILLISECONDS_PER_DAY = 24 * 3600 * 1000;

+        int dayOfWeek = date.getDay(); // 0 == sunday

+

+        // ISO 8601 use weeks that start on monday so we use

+        // mon=1,tue=2,...sun=7;

+        if (dayOfWeek == 0) {

+            dayOfWeek = 7;

+        }

+        // Find nearest thursday (defines the week in ISO 8601). The week number

+        // for the nearest thursday is the same as for the target date.

+        int nearestThursdayDiff = 4 - dayOfWeek; // 4 is thursday

+        Date nearestThursday = new Date(date.getTime() + nearestThursdayDiff

+                * MILLISECONDS_PER_DAY);

+

+        Date firstOfJanuary = new Date(nearestThursday.getYear(), 0, 1);

+        long timeDiff = nearestThursday.getTime() - firstOfJanuary.getTime();

+        int daysSinceFirstOfJanuary = (int) (timeDiff / MILLISECONDS_PER_DAY);

+

+        int weekNumber = (daysSinceFirstOfJanuary) / 7 + 1;

+

+        return weekNumber;

+    }

+

 }