Python i18n API. Many thanks to Campbell and Brecht for the reviews and suggestions!

This commit adds:
* A new bpy.app.translations module giving some info about locales/translation stuff (current active locale, all locales currently known by blender, all translation contexts currently defined, etc.).

* The ability for addons to feature translations, using the (un)register functions of above module.

* Also cleans up "translate py string when storing into RNA prop" by removing "PROP_TRANSLATE" string's subtype, and adding a PROP_STRING_PY_TRANSLATE flag instead (this way it is no more exposed to python...).

Addon translations work with py dictionaries: each addon features a dict {lang: {(context, message): translation, ...}, ...}, which is registered when the addon is enabled (and unregistered when disabled). 

Then, when a key (context, message) is not found in regular mo catalog, a cache dict for current locale is built from all registered addon translations, and key is searched in it.

Note: currently addons writers have to do all the work by hand, will add something (probably extend "edit translation" addon) to automate messages extraction from addons soon(ish)! To get a look to expected behavior from addons, have a look at render_copy_settings/__init__.py and render_copy_settings/translations.py (rather stupid example currently, but...). Once we have a complete process, I'll also update relevant wiki pages.

1 files changed, 4 insertions, 3 deletions

diff --git a/source/blender/makesrna/intern/rna_define.c b/source/blender/makesrna/intern/rna_define.c
index b94d7eb691f..ac307139860 100644
--- a/source/blender/makesrna/intern/rna_define.c
+++ b/source/blender/makesrna/intern/rna_define.c
@@ -2534,13 +2534,14 @@ PropertyRNA *RNA_def_string_file_name(StructOrFunctionRNA *cont_, const char *id
 	return prop;
 }
 
-PropertyRNA *RNA_def_string_translate(StructOrFunctionRNA *cont_, const char *identifier, const char *default_value,
-                                      int maxlen, const char *ui_name, const char *ui_description)
+PropertyRNA *RNA_def_string_py_translate(StructOrFunctionRNA *cont_, const char *identifier, const char *default_value,
+                                         int maxlen, const char *ui_name, const char *ui_description)
 {
 	ContainerRNA *cont = cont_;
 	PropertyRNA *prop;
 
-	prop = RNA_def_property(cont, identifier, PROP_STRING, PROP_TRANSLATE);
+	prop = RNA_def_property(cont, identifier, PROP_STRING, PROP_NONE);
+	RNA_def_property_flag(prop, PROP_STRING_PY_TRANSLATE);
 	if (maxlen != 0) RNA_def_property_string_maxlength(prop, maxlen);
 	if (default_value) RNA_def_property_string_default(prop, default_value);
 	RNA_def_property_ui_text(prop, ui_name, ui_description);