XtSetLanguageProc() XtSetLanguageProc()
Name
XtSetLanguageProc - register the language procedure called to set the locale.
Synopsis
XtLanguageProc XtSetLanguageProc(app_context, proc, client_data)
XtAppContext app_context;
XtLanguageProc proc;
XtPointer client_data;
Inputs
app_context
Specifies the application context in which the language procedure is to be used, or NULL.
proc Specifies the language procedure.
client_data
Specifies additional data to be passed to the language procedure when it is called.
Returns
The previously registered language procedure.
Availability
Release 5 and later.
Description
XtSetLanguageProc() registers proc as the language procedure that will be called (with client_data) from XtDisplayInitialize() for all sub-
sequent displays initialized in the application context app_context. The language procedure is called by XtDisplayInitialize() (in Release
5) in order to determine the language string and perform whatever localization is required by an internationalized application.
If app_context is NULL, the specified language procedure is registered in all application contexts created by the calling process, includ-
ing any future application contexts that may be created. If proc is NULL a default language procedure is registered.
XtSetLanguageProc() returns the previously registered language procedure. If a language procedure has not yet been registered, the return
value is unspecified but if it is used in a subsequent call to XtSetLanguageProc(), it will cause the default language procedure to be reg-
istered.
Note that the "default" language procedure is not registered by default; you must call XtSetLanguageProc() with a proc of NULL to register
this default procedure. If XtSetLanguageProc() is never called, XtDisplayInitialize() determines the language string by the same procedure
it used prior to Release 5. See XtDisplayInitialize() for more information.
See the "Background" section below for a description of the default language procedure. See XtLanguageProc(2) for an explanation of how to
write a language procedure.
Usage
Most internationalized applications should call XtSetLanguageProc() directly before calling XtAppInitialize(). The default language proce-
dure should be adequate for applications that use only the internationalization facilities provided by ANSI-C and Xlib.
Example
A client wishing to use this default procedure to establish locale can do so as in following example:
Widget top;
XtSetLanguageProc(NULL, NULL, NULL);
top = XtAppInitialize( ... );
Background
The default language procedure does the following:
o Sets the locale according to the environment. On ANSI C-based systems this is done by calling setlocale(LC_ALL, language). If an error
is encountered a warning message is issued with XtWarning(), where language is the language string determined by XtDisplayInitialize()
and passed to the default language procedure.
o Calls XSupportsLocale() to verify that the current locale is supported. If the locale is not supported, a warning message is issued
with XtWarning() and the locale is set to "C."
o Calls XSetLocaleModifiers() specifying the empty string.
o Returns the value of the current locale. On ANSI-C-based systems this is the return value from a final call to setlocale(LC_ALL, NULL).
See Also
XtDisplayInitialize(1),
XtLanguageProc(2).
Xt - Locale Management XtSetLanguageProc()