gi-pango-1.0.16: Pango bindings

CopyrightWill Thompson Iñaki García Etxebarria and Jonas Platte
MaintainerIñaki García Etxebarria (
Safe HaskellNone




The Language structure is used to represent a language.

Language pointers can be efficiently copied and compared with each other.


Exported types

newtype Language Source #

Memory-managed wrapper type.


Language (ManagedPtr Language) 
BoxedObject Language Source # 
Instance details

Defined in GI.Pango.Structs.Language


boxedType :: Language -> IO GType #

noLanguage :: Maybe Language Source #

A convenience alias for Nothing :: Maybe Language.



languageFromString Source #


:: (HasCallStack, MonadIO m) 
=> Maybe Text

language: a string representing a language tag, or Nothing

-> m (Maybe Language)

Returns: an opaque pointer to a Language structure, or Nothing if language was Nothing. The returned pointer will be valid forever after, and should not be freed.

Take a RFC-3066 format language tag as a string and convert it to a Language pointer that can be efficiently copied (copy the pointer) and compared with other language tags (compare the pointer.)

This function first canonicalizes the string by converting it to lowercase, mapping '_' to '-', and stripping all characters other than letters and '-'.

Use languageGetDefault if you want to get the Language for the current locale of the process.


languageGetDefault Source #


:: (HasCallStack, MonadIO m) 
=> m Language

Returns: the default language as a Language, must not be freed.

Returns the Language for the current locale of the process. Note that this can change over the life of an application.

On Unix systems, this is the return value is derived from <literal>setlocale(LC_CTYPE, NULL)</literal>, and the user can affect this through the environment variables LC_ALL, LC_CTYPE or LANG (checked in that order). The locale string typically is in the form lang_COUNTRY, where lang is an ISO-639 language code, and COUNTRY is an ISO-3166 country code. For instance, sv_FI for Swedish as written in Finland or pt_BR for Portuguese as written in Brazil.

On Windows, the C library does not use any such environment variables, and setting them won't affect the behavior of functions like ctime(). The user sets the locale through the Regional Options in the Control Panel. The C library (in the setlocale() function) does not use country and language codes, but country and language names spelled out in English. However, this function does check the above environment variables, and does return a Unix-style locale string based on either said environment variables or the thread's current locale.

Your application should call <literal>setlocale(LC_ALL, "");</literal> for the user settings to take effect. Gtk+ does this in its initialization functions automatically (by calling gtk_set_locale()). See <literal>man setlocale</literal> for more details.

Since: 1.16


languageGetSampleString Source #


:: (HasCallStack, MonadIO m) 
=> Language

language: a Language, or Nothing

-> m Text

Returns: the sample string. This value is owned by Pango and should not be freed.

Get a string that is representative of the characters needed to render a particular language.

The sample text may be a pangram, but is not necessarily. It is chosen to be demonstrative of normal text in the language, as well as exposing font feature requirements unique to the language. It is suitable for use as sample text in a font selection dialog.

If language is Nothing, the default language as found by languageGetDefault is used.

If Pango does not have a sample string for language, the classic "The quick brown fox..." is returned. This can be detected by comparing the returned pointer value to that returned for (non-existent) language code "xx". That is, compare to: <informalexample><programlisting> pango_language_get_sample_string (pango_language_from_string ("xx")) </programlisting></informalexample>


languageIncludesScript Source #


:: (HasCallStack, MonadIO m) 
=> Language

language: a Language, or Nothing

-> Script

script: a Script

-> m Bool

Returns: True if script is one of the scripts used to write language or if nothing is known about language (including the case that language is Nothing), False otherwise.

Determines if script is one of the scripts used to write language. The returned value is conservative; if nothing is known about the language tag language, True will be returned, since, as far as Pango knows, script might be used to write language.

This routine is used in Pango's itemization process when determining if a supplied language tag is relevant to a particular section of text. It probably is not useful for applications in most circumstances.

This function uses languageGetScripts internally.

Since: 1.4


languageMatches Source #


:: (HasCallStack, MonadIO m) 
=> Language

language: a language tag (see languageFromString), Nothing is allowed and matches nothing but '*'

-> Text

rangeList: a list of language ranges, separated by ';', ':', ',', or space characters. Each element must either be '*', or a RFC 3066 language range canonicalized as by languageFromString

-> m Bool

Returns: True if a match was found.

Checks if a language tag matches one of the elements in a list of language ranges. A language tag is considered to match a range in the list if the range is '*', the range is exactly the tag, or the range is a prefix of the tag, and the character after it in the tag is '-'.


languageToString Source #


:: (HasCallStack, MonadIO m) 
=> Language

language: a language tag.

-> m Text

Returns: a string representing the language tag. This is owned by Pango and should not be freed.

Gets the RFC-3066 format string representing the given language tag.