Feature #567

- added a calendar offset that effectively changes the first
  month to be displayed in the calendar report (thanks to
  Michelle Crane)
- calendar.offset turns the featue off or on
- calendar.offset.value controls the number of month to be
  applied for the offset

src/Config.cpp

@@ -97,6 +97,8 @@ std::string Config::defaults =
   "calendar.legend=yes                            # Display the legend on calendar\n"
   "calendar.details=sparse                        # Calendar shows information for tasks w/due dates: full, sparse or none\n"
   "calendar.details.report=list                   # Report to use when showing task information in cal\n"
+  "calendar.offset=no                             # Apply an offset value to control the first month of the calendar\n"
+  "calendar.offset.value=-1                       # The number of months the first month of the calendar is moved\n"
   "calendar.holidays=none                         # Show public holidays on calendar:full, sparse or none\n"
   "#monthsperline=3                               # Number of calendar months on a line\n"
   "\n"

src/command.cpp

@@ -891,8 +891,8 @@ int handleShow (std::string& outs)
     // Note that there is a leading and trailing space, to make it easier to
     // search for whole words.
     std::string recognized =
-      " annotations blanklines bulk burndown.bias calendar.details "
-      "calendar.details.report calendar.holidays calendar.legend color "
+      " annotations blanklines bulk burndown.bias calendar.details calendar.details.report "
+      "calendar.holidays calendar.legend color calendar.offset calendar.offset.value "
       "color.active color.due color.due.today color.blocked color.burndown.done "
       "color.burndown.pending color.burndown.started color.overdue color.pri.H "
       "color.pri.L color.pri.M color.pri.none color.recurring color.tagged "

src/report.cpp

@@ -1477,10 +1477,29 @@ int handleReportCalendar (std::string& outs)
       yFrom = oldest.year();
     }
 
+    if (context.config.getBoolean ("calendar.offset"))
+    {
+      int moffset = context.config.getInteger ("calendar.offset.value") % 12;
+      int yoffset = context.config.getInteger ("calendar.offset.value") / 12;
+      mFrom += moffset;
+      yFrom += yoffset;
+      if (mFrom < 1)
+      {
+        mFrom += 12;
+        yFrom--;
+      }
+      else if (mFrom > 12)
+      {
+        mFrom -= 12;
+        yFrom++;
+      }
+    }
+
     mTo = mFrom + monthsToDisplay - 1;
     yTo = yFrom;
-    if (mTo > 12) {
-      mTo -=12;
+    if (mTo > 12)
+    {
+      mTo -= 12;
       yTo++;
     }
 

src/tests/cal.t

@@ -30,7 +30,7 @@
 
 use strict;
 use warnings;
-use Test::More tests => 76;
+use Test::More tests => 87;
 
 # Create the rc file.
 if (open my $fh, '>', 'cal.rc')
@@ -54,6 +54,7 @@ my $day         = $nday;
 my $prevmonth   = $months[($nmon-1) % 12];
 my $month       = $months[($nmon) % 12];
 my $nextmonth   = $months[($nmon+1) % 12];
+my $prevyear    = $nyear + 1899;
 my $year        = $nyear + 1900;
 my $nextyear    = $nyear + 1901;
 
@@ -137,6 +138,23 @@ unlike ($output, qr/March 2010/,     'March 2010 is not displayed');
 like   ($output, qr/April 2010/,     'April 2010 is displayed');
 unlike ($output, qr/May 2010/,       'May 2010 is not displayed');
 
+# calendar offsets
+$output = qx{../task rc:cal.rc rc.calendar.offset:on rc.monthsperline:1 cal 1 2011};
+unlike ($output, qr/November 2010/,  'November 2010 is not displayed');
+like   ($output, qr/December 2010/,  'December 2010 is displayed');
+unlike ($output, qr/January 2011/,   'January  2011 is not displayed');
+$output = qx{../task rc:cal.rc rc.calendar.offset:on rc.calendar.offset.value:2 rc.monthsperline:1 cal 1 2011};
+unlike ($output, qr/January 2011/,   'January  2011 is not displayed');
+unlike ($output, qr/February 2011/,  'February 2011 is not displayed');
+like   ($output, qr/March 2011/,     'March 2011 is displayed');
+unlike ($output, qr/April 2011/,     'April 2011 is not displayed');
+$output = qx{../task rc:cal.rc rc.calendar.offset:on rc.calendar.offset.value:-12 rc.monthsperline:1 cal};
+like   ($output, qr/$month\S*?\s+?$prevyear/, 'Current month and year ahead are displayed');
+unlike ($output, qr/$month\S*?\s+?$year/,     'Current month and year are not displayed');
+$output = qx{../task rc:cal.rc rc.calendar.offset:on rc.calendar.offset.value:12 rc.monthsperline:1 cal};
+unlike ($output, qr/$month\S*?\s+?$year/,     'Current month and year are not displayed');
+like   ($output, qr/$month\S*?\s+?$nextyear/, 'Current month and year ahead are displayed');
+
 # Cleanup.
 unlink 'pending.data';
 ok (!-r 'pending.data', 'Removed pending.data');