Code for language pack support

2 files changed, 136 insertions, 4 deletions

diff --git a/src/sugar/activity/i18n.py b/src/sugar/activity/i18n.py
new file mode 100644
index 0000000..0963ffa
--- /dev/null
+++ b/src/sugar/activity/i18n.py
@@ -0,0 +1,134 @@
+# Copyright (C) 2010 One Laptop Per Child
+#
+# Author: Sayamindu Dasgupta <sayamindu@laptop.org>
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the
+# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+# Boston, MA 02111-1307, USA.
+
+import gconf
+
+import locale
+import os
+import struct
+import sys
+
+import dateutil.parser
+import time
+
+_MO_BIG_ENDIAN    = 0xde120495
+_MO_LITTLE_ENDIAN = 0x950412de
+
+def _readbin(handle, fmt, bytecount):
+    read_bytes = handle.read(bytecount)
+    retvalue = struct.unpack(fmt, read_bytes)
+    if len(retvalue) == 1:
+        return retvalue[0]
+    else:
+        return retvalue
+
+def _extract_header(filepath):
+    header = ''
+    handle = open(filepath, 'rb')
+    magic_number = _readbin(handle, '<I', 4)
+
+    if magic_number == _MO_BIG_ENDIAN:
+        fmt = '>II'
+    elif magic_number == _MO_LITTLE_ENDIAN:
+        fmt = '<II'
+    else:
+        raise IOError ('File does not seem to be valid MO file')
+
+    version, numofstrings = _readbin(handle, fmt, 8)
+
+    msgids_hash_offset, msgstrs_hash_offset = _readbin(handle, fmt, 8)
+    handle.seek(msgids_hash_offset)
+
+    msgids_index = []
+    for i in range(numofstrings):
+        msgids_index.append(_readbin(handle, fmt, 8))
+    handle.seek(msgstrs_hash_offset)
+
+    msgstrs_index = []
+    for i in range(numofstrings):
+        msgstrs_index.append(_readbin(handle, fmt, 8))
+
+    for i in range(numofstrings):
+        handle.seek(msgids_index[i][1])
+        msgid = handle.read(msgids_index[i][0])
+        if msgid == '':
+            handle.seek(msgstrs_index[i][1])
+            msgstr = handle.read(msgstrs_index[i][0])
+            header = msgstr
+            break
+        else:
+            continue
+
+    handle.close()
+    return header
+
+def _extract_modification_time(filepath):
+    header = _extract_header(filepath)
+    items = header.split('\n')
+    for item in items:
+        if item.startswith('PO-Revision-Date:'):
+            timestr = item.split(': ')[1]
+            parsedtime = dateutil.parser.parse(timestr)
+            return time.mktime(parsedtime.timetuple())
+
+    raise ValueError ('Could not find revision date')
+    return -1
+
+
+def get_locale_path(bundle_id):
+    """ Gets the locale path, the directory where the preferred 
+        MO file is located.
+        The preferred MO file is the one with the latest 
+        translation.
+    """
+    
+    # Note: We pre-assign weights to the directories so that if no translations
+    # exist, the appropriate fallbacks (eg: bn for bn_BD) can be loaded
+    # The directory with the highest weight is returned, and if a MO file is
+    # found, the weight of the directory is set to the MO's modification time
+    # (as described in the MO header, and _not_ the filesystem mtime)
+    
+    candidate_dirs = {}
+
+    if 'SUGAR_LOCALEDIR' in os.environ:
+        candidate_dirs[os.environ['SUGAR_LOCALEDIR']] = 2
+    
+    gconf_client = gconf.client_get_default()
+    packdir = gconf_client.get_string("/desktop/sugar/i18n/langpackdir")
+    if packdir is not None or packdir is not '':
+        candidate_dirs[packdir] = 1
+    
+    candidate_dirs[os.path.join(sys.prefix, 'share', 'locale')] = 0
+
+    for candidate_dir in candidate_dirs.keys():
+        if os.path.exists(candidate_dir):
+            fullpath = os.path.join(candidate_dir, \
+                locale.getdefaultlocale()[0], 'LC_MESSAGES', \
+                bundle_id + '.mo')
+            if os.path.exists(fullpath):
+                try:
+                    candidate_dirs[candidate_dir] = \
+                        _extract_modification_time(fullpath)
+                except (IOError, ValueError):
+                    # The mo file is damaged or has not been initialized
+                    # Set lowest priority
+                    candidate_dirs[candidate_dir] = -1
+
+    return sorted(candidate_dirs.iteritems(), key=lambda (k, v): (v, k), \
+        reverse = True)[0][0]
diff --git a/src/sugar/activity/main.py b/src/sugar/activity/main.py
index ef4d001..b03272b 100644
--- a/src/sugar/activity/main.py
+++ b/src/sugar/activity/main.py
@@ -26,7 +26,7 @@ import dbus.service
 import dbus.glib
 
 import sugar
-from sugar.activity import activityhandle
+from sugar.activity import activityhandle, i18n
 from sugar.bundle.activitybundle import ActivityBundle
 from sugar.graphics import style
 from sugar import logger
@@ -103,9 +103,7 @@ def main():
     settings.set_property('gtk-font-name',
                           '%s %f' % (style.FONT_FACE, style.FONT_SIZE))
 
-    locale_path = None
-    if 'SUGAR_LOCALEDIR' in os.environ:
-        locale_path = os.environ['SUGAR_LOCALEDIR']
+    locale_path = i18n.get_locale_path(bundle.get_bundle_id())
 
     gettext.bindtextdomain(bundle.get_bundle_id(), locale_path)
     gettext.bindtextdomain('sugar-toolkit', sugar.locale_path)