From 04d976ceee07b9f4df76a538fb285485ce38ff53 Mon Sep 17 00:00:00 2001
From: Vassilii Khachaturov <vassilii@tarunz.org>
Date: Thu, 30 Jan 2014 16:35:13 +0200
Subject: [PATCH] 7117: disallow new year unless Julian or like cal

---
 gramps/gen/lib/date.py         |  3 +++
 gramps/gui/editors/editdate.py | 22 ++++++++++++++++++----
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/gramps/gen/lib/date.py b/gramps/gen/lib/date.py
index 587797c6f..939508c21 100644
--- a/gramps/gen/lib/date.py
+++ b/gramps/gen/lib/date.py
@@ -1925,3 +1925,6 @@ def gregorian(date):
         date.convert_calendar(Date.CAL_GREGORIAN)
     return date
 
+def calendar_has_fixed_newyear(cal):
+    """Does the given calendar have a fixed new year, or may it be reset?"""
+    return cal not in (Date.CAL_GREGORIAN, Date.CAL_JULIAN, Date.CAL_SWEDISH)
diff --git a/gramps/gui/editors/editdate.py b/gramps/gui/editors/editdate.py
index 43c20b396..607fcaa1c 100644
--- a/gramps/gui/editors/editdate.py
+++ b/gramps/gui/editors/editdate.py
@@ -64,7 +64,7 @@ from gi.repository import Gtk
 #-------------------------------------------------------------------------
 from gramps.gen.const import GRAMPS_LOCALE as glocale
 _ = glocale.translation.sgettext
-from gramps.gen.lib.date import Date, DateError
+from gramps.gen.lib.date import Date, DateError, calendar_has_fixed_newyear
 from gramps.gen.datehandler import displayer
 from gramps.gen.const import URL_MANUAL_PAGE
 from ..display import display_help
@@ -135,7 +135,12 @@ class EditDate(ManagedWindow):
         for name in Date.ui_calendar_names:
             self.calendar_box.get_model().append([name])
 
-        self.calendar_box.set_active(self.date.get_calendar())
+        self.new_year = self.top.get_object('newyear')
+        self.new_year.set_text(self.date.newyear_to_str())
+
+        cal = self.date.get_calendar()
+        self.calendar_box.set_active(cal)
+        self.align_newyear_ui_with_calendar(cal)
         self.calendar_box.connect('changed', self.switch_calendar)
 
         self.quality_box = self.top.get_object('quality_box')
@@ -171,8 +176,6 @@ class EditDate(ManagedWindow):
         self.stop_year.set_value(self.date.get_stop_year())
         
         self.dual_dated = self.top.get_object('dualdated')
-        self.new_year = self.top.get_object('newyear')
-        self.new_year.set_text(self.date.newyear_to_str())
 
         # Disable second date controls if not compound date
         if not self.date.is_compound():
@@ -358,6 +361,15 @@ class EditDate(ManagedWindow):
         else:
             self.calendar_box.set_sensitive(1)
 
+    def align_newyear_ui_with_calendar(self, cal):
+        if calendar_has_fixed_newyear(cal):
+            LOG.debug("new year disabled for cal {0}".format(cal))
+            self.new_year.set_sensitive(0)
+            self.new_year.set_text('')
+        else:
+            LOG.debug("new year enabled for cal {0}".format(cal))
+            self.new_year.set_sensitive(1)
+
     def switch_calendar(self, obj):
         """
         Change month names and convert the date based on the calendar 
@@ -369,6 +381,8 @@ class EditDate(ManagedWindow):
         LOG.debug(">>>switch_calendar: {0} changed, {1} -> {2}".format(
             obj, old_cal, new_cal))
 
+        self.align_newyear_ui_with_calendar(new_cal)
+
         (the_quality, the_modifier, the_calendar, 
          the_value, the_text, the_newyear) = self.build_date_from_ui()
         try: