///////////////////////////////////////////////////////////////////////////// // Name: translation.h // Purpose: wxTranslation class // Author: wxWidgets team // Licence: wxWindows licence ///////////////////////////////////////////////////////////////////////////// /** This class allows to get translations for strings. In wxWidgets this class manages message catalogs which contain the translations of the strings used to the current language. Unlike wxLocale, it isn't bound to locale. It can be used either independently of, or in conjunction with wxLocale. In the latter case, you should initialize wxLocale (which creates wxTranslations instance) first; in the former, you need to create a wxTranslations object and Set() it manually. Only one wxTranslations instance is active at a time; it is set with the Set() method and obtained using Get(). Unlike wxLocale, wxTranslations' primary mean of identifying language is by its "canonical name", i.e. ISO 639 code, possibly combined with ISO 3166 country code and additional modifiers (examples include "fr", "en_GB" or "ca@valencia"; see wxLocale::GetCanonicalName() for more information). This allows apps using wxTranslations API to use even languages not recognized by the operating system or not listed in wxLanguage enum. @since 2.9.1 @see wxLocale, wxTranslationsLoader, wxFileTranslationsLoader */ class wxTranslations { public: /// Constructor wxTranslations(); /** Returns current translations object, may return NULL. You must either call this early in app initialization code, or let wxLocale do it for you. */ static wxTranslations *Get(); /** Sets current translations object. Deletes previous translation object and takes ownership of @a t. */ static void Set(wxTranslations *t); /** Changes loader use to read catalogs to a non-default one. Deletes previous loader and takes ownership of @a loader. @see wxTranslationsLoader, wxFileTranslationsLoader, wxResourceTranslationsLoader */ void SetLoader(wxTranslationsLoader *loader); /** Sets translations language to use. wxLANGUAGE_DEFAULT has special meaning: best suitable translation, given user's preference and available translations, will be used. */ void SetLanguage(wxLanguage lang); /** Sets translations language to use. Empty @a lang string has the same meaning as wxLANGUAGE_DEFAULT in SetLanguage(wxLanguage): best suitable translation, given user's preference and available translations, will be used. */ void SetLanguage(const wxString& lang); /** Returns list of all translations of @a domain that were found. This method can be used e.g. to populate list of application's translations offered to the user. To do this, pass the app's main catalog as @a domain. @see GetBestTranslation() */ wxArrayString GetAvailableTranslations(const wxString& domain) const; /** Returns the best UI language for the @a domain. The language is determined from the preferred UI language or languages list the user configured in the OS. Notice that this may or may not correspond to the default @em locale as obtained from wxLocale::GetSystemLanguage(); modern operation systems (Windows Vista+, OS X) have separate language and regional (= locale) settings. @param domain The catalog domain to look for. @param msgIdLanguage Specifies the language of "msgid" strings in source code (i.e. arguments to GetString(), wxGetTranslation() and the _() macro). @return Language code if a suitable match was found, empty string otherwise. @since 2.9.5 */ wxString GetBestTranslation(const wxString& domain, wxLanguage msgIdLanguage); /** Returns the best UI language for the @a domain. The language is determined from the preferred UI language or languages list the user configured in the OS. Notice that this may or may not correspond to the default @em locale as obtained from wxLocale::GetSystemLanguage(); modern operation systems (Windows Vista+, OS X) have separate language and regional (= locale) settings. @param domain The catalog domain to look for. @param msgIdLanguage Specifies the language of "msgid" strings in source code (i.e. arguments to GetString(), wxGetTranslation() and the _() macro). @return Language code if a suitable match was found, empty string otherwise. @since 2.9.5 */ wxString GetBestTranslation(const wxString& domain, const wxString& msgIdLanguage = "en"); /** Add standard wxWidgets catalogs ("wxstd" and possible port-specific catalogs). @return @true if a suitable catalog was found, @false otherwise @see AddCatalog() */ bool AddStdCatalog(); /** Add a catalog for use with the current locale. By default, it is searched for in standard places (see wxFileTranslationsLoader), but you may also prepend additional directories to the search path with wxFileTranslationsLoader::AddCatalogLookupPathPrefix(). All loaded catalogs will be used for message lookup by GetString() for the current locale. Bu default, i.e. if @a msgIdLanguage is not given, @c msgid strings are assumed to be in English and written only using 7-bit ASCII characters. If you have to deal with non-English strings or 8-bit characters in the source code, see the instructions in @ref overview_nonenglish. @param domain The catalog domain to add. @param msgIdLanguage Specifies the language of "msgid" strings in source code (i.e. arguments to GetString(), wxGetTranslation() and the _() macro). It is used if AddCatalog() cannot find any catalog for current language: if the language is same as source code language, then strings from source code are used instead. @return @true if catalog was successfully loaded, @false otherwise (which might mean that the catalog is not found or that it isn't in the correct format). */ bool AddCatalog(const wxString& domain, wxLanguage msgIdLanguage = wxLANGUAGE_ENGLISH_US); /** Same as AddCatalog(const wxString&, wxLanguage), but takes two additional arguments, @a msgIdLanguage and @a msgIdCharset. This overload is only available in non-Unicode build. @param domain The catalog domain to add. @param msgIdLanguage Specifies the language of "msgid" strings in source code (i.e. arguments to GetString(), wxGetTranslation() and the _() macro). It is used if AddCatalog() cannot find any catalog for current language: if the language is same as source code language, then strings from source code are used instead. @param msgIdCharset Lets you specify the charset used for msgids in sources in case they use 8-bit characters (e.g. German or French strings). @return @true if catalog was successfully loaded, @false otherwise (which might mean that the catalog is not found or that it isn't in the correct format). */ bool AddCatalog(const wxString& domain, wxLanguage msgIdLanguage, const wxString& msgIdCharset); /** Check if the given catalog is loaded, and returns @true if it is. According to GNU gettext tradition, each catalog normally corresponds to 'domain' which is more or less the application name. @see AddCatalog() */ bool IsLoaded(const wxString& domain) const; /** Retrieves the translation for a string in all loaded domains unless the @a domain parameter is specified (and then only this catalog/domain is searched). Returns @NULL if translation is not available. This function is thread-safe. @remarks Domains are searched in the last to first order, i.e. catalogs added later override those added before. @since 3.0 */ const wxString *GetTranslatedString(const wxString& origString, const wxString& domain = wxEmptyString) const; /** Retrieves the translation for a string in all loaded domains unless the @a domain parameter is specified (and then only this catalog/domain is searched). Returns @NULL if translation is not available. This form is used when retrieving translation of string that has different singular and plural form in English or different plural forms in some other language. @param origString The singular form of the string to be converted. @param n The number on which the plural form choice depends on. (In some languages, there are different plural forms for e.g. n=2 and n=3 etc., in addition to the singular form (n=1) being different.) @param domain The only domain (i.e. message catalog) to search if specified. By default this parameter is empty, indicating that all loaded catalogs should be searched. See GNU gettext manual for additional information on plural forms handling. This method is called by the wxGetTranslation() function and _() macro. This function is thread-safe. @remarks Domains are searched in the last to first order, i.e. catalogs added later override those added before. @since 3.0 */ const wxString *GetTranslatedString(const wxString& origString, unsigned n, const wxString& domain = wxEmptyString) const; /** Returns the header value for header @a header. The search for @a header is case sensitive. If an @a domain is passed, this domain is searched. Else all domains will be searched until a header has been found. The return value is the value of the header if found. Else this will be empty. */ wxString GetHeaderValue(const wxString& header, const wxString& domain = wxEmptyString) const; }; /** Abstraction of translations discovery and loading. This interface makes it possible to override wxWidgets' default catalogs loading mechanism and load MO files from locations other than the filesystem (e.g. embed them in executable). Implementations must implement the LoadCatalog() method. @see wxFileTranslationsLoader, wxResourceTranslationsLoader @since 2.9.1 */ class wxTranslationsLoader { public: /// Trivial default constructor. wxTranslationsLoader(); /** Called to load requested catalog. If the catalog is found, LoadCatalog() should create wxMsgCatalog instance with its data and return it. The caller will take ownership of the catalog. @param domain Domain to load. @param lang Language to look for. This is "canonical name" (see wxLocale::GetCanonicalName()), i.e. ISO 639 code, possibly combined with country code or additional modifiers (e.g. "fr", "en_GB" or "ca@valencia"). @return Loaded catalog or NULL on failure. */ virtual wxMsgCatalog *LoadCatalog(const wxString& domain, const wxString& lang) = 0; /** Implements wxTranslations::GetAvailableTranslations(). */ virtual wxArrayString GetAvailableTranslations(const wxString& domain) const = 0; }; /** Standard wxTranslationsLoader implementation. This finds catalogs in the filesystem, using the standard Unix layout. This is the default unless you change the loader with wxTranslations::SetLoader(). Catalogs are searched for in standard places (system locales directory, `LC_PATH` on Unix systems, Resources subdirectory of the application bundle on OS X, executable's directory on Windows), but you may also prepend additional directories to the search path with AddCatalogLookupPathPrefix(). @since 2.9.1 */ class wxFileTranslationsLoader : public wxTranslationsLoader { public: /** Add a prefix to the catalog lookup path: the message catalog files will be looked up under prefix/lang/LC_MESSAGES and prefix/lang directories (in this order). This only applies to subsequent invocations of wxTranslations::AddCatalog(). */ static void AddCatalogLookupPathPrefix(const wxString& prefix); }; /** This loader makes it possible to load translations from Windows resources. If you wish to store translation MO files in resources, you have to enable this loader before calling wxTranslations::AddCatalog() or wxLocale::AddCatalog(): @code wxTranslations::Get()->SetLoader(new wxResourceTranslationsLoader); @endcode Translations are stored in resources as compiled MO files, with type set to "MOFILE" (unless you override GetResourceType()) and name consisting of the domain, followed by underscore, followed by language identification. For example, the relevant part of .rc file would look like this: @code myapp_de MOFILE "catalogs/de/myapp.mo" myapp_fr MOFILE "catalogs/fr/myapp.mo" myapp_en_GB MOFILE "catalogs/en_GB/myapp.mo" @endcode This class is only available on Windows. @since 2.9.1 */ class wxResourceTranslationsLoader : public wxTranslationsLoader { protected: /** Returns resource type to use for translations. Default type is "MOFILE". */ virtual wxString GetResourceType() const; /** Returns handle of the module to load resources from. By default, the main executable is used. */ virtual WXHINSTANCE GetModule() const; }; /** Represents a loaded translations message catalog. This class should only be used directly by wxTranslationsLoader implementations. @since 2.9.1 */ class wxMsgCatalog { public: /** Creates catalog loaded from a MO file. @param filename Path to the MO file to load. @param domain Catalog's domain. This typically matches the @a filename. @return Successfully loaded catalog or NULL on failure. */ static wxMsgCatalog *CreateFromFile(const wxString& filename, const wxString& domain); /** Creates catalog from MO file data in memory buffer. @param data Data in MO file format. @param domain Catalog's domain. This typically matches the @a filename. @return Successfully loaded catalog or NULL on failure. */ static wxMsgCatalog *CreateFromData(const wxScopedCharBuffer& data, const wxString& domain); }; // ============================================================================ // Global functions/macros // ============================================================================ /** @addtogroup group_funcmacro_string */ //@{ /** This macro is identical to _() but for the plural variant of wxGetTranslation(). @return A const wxString. @header{wx/intl.h} */ #define wxPLURAL(string, plural, n) /** This macro doesn't do anything in the program code -- it simply expands to the value of its argument. However it does have a purpose which is to mark the literal strings for the extraction into the message catalog created by @c xgettext program. Usually this is achieved using _() but that macro not only marks the string for extraction but also expands into a wxGetTranslation() call which means that it cannot be used in some situations, notably for static array initialization. Here is an example which should make it more clear: suppose that you have a static array of strings containing the names of chemical elements, which have to be translated. If you write: @code static const char * const elements[] = { _("Hydrogen"), _("Helium"), ... }; ... // use elements[n] as usual @endcode The code would compile and run, but there would be no translations for the strings because static variables are initialized at a very early stage of program execution; that is, before the locale and paths to message catalog files have been set up. So instead you should do this: @code static const char * const elements[] = { wxTRANSLATE("Hydrogen"), wxTRANSLATE("Helium"), ... }; ... // use wxGetTranslation(elements[n]) @endcode Note that if you simply omit wxTRANSLATE() above, those strings would not be marked for translation, and would therefore not be included in the message catalog. Consequently, wxGetTranslation() would not find translations for them. @return A const wxChar*. @header{wx/intl.h} */ #define wxTRANSLATE(string) /** This function returns the translation of @a string in the current @c locale(). If the string is not found in any of the loaded message catalogs (see @ref overview_i18n), the original string is returned. If you enable logging of trace messages with "i18n" mask (using wxLog::AddTraceMask()) and debug logging is enabled (see @ref overview_debugging), a message is also logged in this case -- which helps to find the strings which were not yet translated. If @a domain is specified then only that domain/catalog is searched for a matching string. As this function is used very often, an alternative (and also common in Unix world) syntax is provided: the _() macro is defined to do the same thing as wxGetTranslation(). This function is thread-safe. @note This function is not suitable for literal strings using wxT() macro since this macro is not recognised by @c xgettext, and so such strings are not extracted to the message catalog. Instead, use the _() and wxPLURAL() macro for all literal strings. @see wxGetTranslation(const wxString&, const wxString&, unsigned, const wxString&) @header{wx/intl.h} */ const wxString& wxGetTranslation(const wxString& string, const wxString& domain = wxEmptyString); /** This is an overloaded version of wxGetTranslation(const wxString&, const wxString&), please see its documentation for general information. This version is used when retrieving translation of string that has different singular and plural forms in English or different plural forms in some other language. Like wxGetTranslation(const wxString&,const wxString&), the @a string parameter must contain the singular form of the string to be converted and is used as the key for the search in the catalog. The @a plural parameter is the plural form (in English). The parameter @a n is used to determine the plural form. If no message catalog is found, @a string is returned if "n == 1", otherwise @a plural is returned. See GNU gettext Manual for additional information on plural forms handling: For a shorter alternative see the wxPLURAL() macro. This function is thread-safe. @header{wx/intl.h} */ const wxString& wxGetTranslation(const wxString& string, const wxString& plural, unsigned n, const wxString& domain = wxEmptyString); /** Macro to be used around all literal strings that should be translated. This macro expands into a call to wxGetTranslation(), so it marks the message for the extraction by @c xgettext just as wxTRANSLATE() does, but also returns the translation of the string for the current locale during execution. This macro is thread-safe. @header{wx/intl.h} */ const wxString& _(const wxString& string); //@}