locale: Add translations for layout names

Pulled in some Unix-specific code from https://github.com/rust-locale/locale_config to reduce dependencies.

First reason to reduce dependencies: gettext-rs is not in Debian. Copying gettext-sys might have made sense, but the interface is somewhat confusing.

For translating a couple identifiers, detection and some hand-rolled hash map is all that is needed, and the option to move to gettext later remains.

locale_config has been stripped of the lazy_static dependency, which, messing with the strtup sequence, might be a source of debugging woes. Plus setting language once in the beginning is somewhat inflexible regarding runtime changes.

Cargo.lock

@@ -1,5 +1,13 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+[[package]]
+name = "aho-corasick"
+version = "0.7.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "memchr 2.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "atk-sys"
 version = "0.7.0"
@@ -234,6 +242,11 @@ name = "maplit"
 version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "memchr"
+version = "2.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "memmap"
 version = "0.7.0"
@@ -289,6 +302,23 @@ dependencies = [
  "proc-macro2 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "regex"
+version = "1.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "aho-corasick 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "memchr 2.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex-syntax 0.6.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "thread_local 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "utf8-ranges 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.6.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "rs"
 version = "0.1.0"
@@ -300,6 +330,7 @@ dependencies = [
  "gtk 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "gtk-sys 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "maplit 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex 1.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.101 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_yaml 0.8.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "xkbcommon 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -344,11 +375,24 @@ dependencies = [
  "unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "thread_local"
+version = "0.3.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "unicode-xid"
 version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "utf8-ranges"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "winapi"
 version = "0.3.8"
@@ -386,6 +430,7 @@ dependencies = [
 ]
 
 [metadata]
+"checksum aho-corasick 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)" = "58fb5e95d83b38284460a5fda7d6470aa0b8844d283a0b614b8535e880800d2d"
 "checksum atk-sys 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c7017e53393e713212aed7aea336b6553be4927f58c37070a56c2fe3d107e489"
 "checksum bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "228047a76f468627ca71776ecdebd732a3423081fcf5125585bcd7c49886ce12"
 "checksum cairo-rs 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "dd940f0d609699e343ef71c4af5f66423afbf30d666f796dabd8fd15229cf5b6"
@@ -408,17 +453,22 @@ dependencies = [
 "checksum libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)" = "34fcd2c08d2f832f376f4173a231990fa5aef4e99fb569867318a227ef4c06ba"
 "checksum linked-hash-map 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)" = "ae91b68aebc4ddb91978b11a1b02ddd8602a05ec19002801c5666000e05e0f83"
 "checksum maplit 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "3e2e65a1a2e43cfcb47a895c4c8b10d1f4a61097f9f254f183aee60cad9c651d"
+"checksum memchr 2.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "88579771288728879b57485cc7d6b07d648c9f0141eb955f8ab7f9d45394468e"
 "checksum memmap 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "6585fd95e7bb50d6cc31e20d4cf9afb4e2ba16c5846fc76793f11218da9c475b"
 "checksum pango 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "4c2cb169402a3eb1ba034a7cc7d95b8b1c106e9be5ba4be79a5a93dc1a2795f4"
 "checksum pango-sys 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d6eb49268e69dd0c1da5d3001a61aac08e2e9d2bfbe4ae4b19b9963c998f6453"
 "checksum pkg-config 0.3.16 (registry+https://github.com/rust-lang/crates.io-index)" = "72d5370d90f49f70bd033c3d75e87fc529fbfff9d6f7cccef07d6170079d91ea"
 "checksum proc-macro2 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "afdc77cc74ec70ed262262942ebb7dac3d479e9e5cfa2da1841c0806f6cdabcc"
 "checksum quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "053a8c8bcc71fcce321828dc897a98ab9760bef03a4fc36693c231e5b3216cfe"
+"checksum regex 1.1.9 (registry+https://github.com/rust-lang/crates.io-index)" = "d9d8297cc20bbb6184f8b45ff61c8ee6a9ac56c156cec8e38c3e5084773c44ad"
+"checksum regex-syntax 0.6.12 (registry+https://github.com/rust-lang/crates.io-index)" = "11a7e20d1cce64ef2fed88b66d347f88bd9babb82845b2b858f3edbf59a4f716"
 "checksum serde 1.0.101 (registry+https://github.com/rust-lang/crates.io-index)" = "9796c9b7ba2ffe7a9ce53c2287dfc48080f4b2b362fcc245a259b3a7201119dd"
 "checksum serde_derive 1.0.101 (registry+https://github.com/rust-lang/crates.io-index)" = "4b133a43a1ecd55d4086bd5b4dc6c1751c68b1bfbeba7a5040442022c7e7c02e"
 "checksum serde_yaml 0.8.9 (registry+https://github.com/rust-lang/crates.io-index)" = "38b08a9a90e5260fe01c6480ec7c811606df6d3a660415808c3c3fa8ed95b582"
 "checksum syn 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "66850e97125af79138385e9b88339cbcd037e3f28ceab8c5ad98e64f0f1f80bf"
+"checksum thread_local 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "c6b53e329000edc2b34dbe8545fd20e55a333362d0a321909685a19bd28c3f1b"
 "checksum unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "826e7639553986605ec5979c7dd957c7895e93eabed50ab2ffa7f6128a75097c"
+"checksum utf8-ranges 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "b4ae116fef2b7fea257ed6440d3cfcff7f190865f170cdad00bb6465bf18ecba"
 "checksum winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)" = "8093091eeb260906a183e6ae1abdba2ef5ef2257a21801128899c3fc699229c6"
 "checksum winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
 "checksum winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"

Cargo.toml

@@ -5,6 +5,7 @@ version = "0.1.0"
 [dependencies]
 bitflags = "1.0.*"
 maplit = "1.0.*"
+regex = "1.1.*"
 serde = { version = "1.0.*", features = ["derive"] }
 serde_yaml = "0.8.*"
 xkbcommon = { version = "0.4.*", features = ["wayland"] }

data/langs/en-US.txt

@@ -0,0 +1,8 @@
+us English (US)
+de German
+el Greek
+es Spanish
+it Italian
+jp+kana Japanese (kana)
+nb Norwegian
+

debian/control

@@ -18,6 +18,7 @@ Build-Depends:
  librust-gtk+v3-22-dev (>= 0.5),
  librust-gtk-sys-dev,
  librust-maplit-1-dev (>= 1.0),
+ librust-regex-1-dev (>= 1.1),
  librust-serde-derive-1-dev (>= 1.0),
  librust-serde-yaml-0.8-dev (>= 0.8),
  librust-xkbcommon-0.4+wayland-dev (>= 0.4),

src/lib.rs

@@ -8,6 +8,7 @@ extern crate gtk_sys;
 #[allow(unused_imports)]
 #[macro_use] // only for tests
 extern crate maplit;
+extern crate regex;
 extern crate serde;
 extern crate xkbcommon;
 
@@ -17,6 +18,8 @@ pub mod float_ord;
 pub mod imservice;
 mod keyboard;
 mod layout;
+mod locale;
+mod locale_config;
 mod outputs;
 mod popover;
 mod resources;

src/locale.rs

@@ -0,0 +1,39 @@
+/*! Locale-specific functions */
+
+use std::cmp;
+use std::ffi::CString;
+
+mod c {
+    use std::os::raw::c_char;
+
+    #[allow(non_camel_case_types)]
+    pub type c_int = i32;
+
+    #[no_mangle]
+    extern "C" {
+        // from libc
+        pub fn strcoll(cs: *const c_char, ct: *const c_char) -> c_int;
+    }
+}
+
+fn cstring_safe(s: &str) -> CString {
+    CString::new(s)
+        .unwrap_or(CString::new("").unwrap())
+}
+
+pub fn compare_current_locale(a: &str, b: &str) -> cmp::Ordering {
+    let a = cstring_safe(a);
+    let b = cstring_safe(b);
+    let a = a.as_ptr();
+    let b = b.as_ptr();
+    let result = unsafe { c::strcoll(a, b) };
+    if result == 0 {
+        cmp::Ordering::Equal
+    } else if result > 0 {
+        cmp::Ordering::Greater
+    } else if result < 0 {
+        cmp::Ordering::Less
+    } else {
+        unreachable!()
+    }
+}

src/locale_config.rs

@@ -0,0 +1,541 @@
+/*! Locale detection and management.
+ * Based on https://github.com/rust-locale/locale_config
+ * 
+ * Ready for deletion/replacement once Debian starts packaging this,
+ * although this version doesn't need lazy_static.
+ * 
+ * Copyright (c) 2016–2019 Jan Hudec <bulb@ucw.cz>
+   Copyright (c) 2016 A.J. Gardner <aaron.j.gardner@gmail.com>
+   Copyright (c) 2019, Bastien Orivel <eijebong@bananium.fr>
+   Copyright (c) 2019, Igor Gnatenko <i.gnatenko.brain@gmail.com>
+   Copyright (c) 2019, Sophie Tauchert <999eagle@999eagle.moe>
+ */
+
+use regex::Regex;
+use std::borrow::Cow;
+use std::env;
+
+/// Errors that may be returned by `locale_config`.
+#[derive(Copy,Clone,Debug,PartialEq,Eq)]
+pub enum Error {
+    /// Provided definition was not well formed.
+    ///
+    /// This is returned when provided configuration string does not match even the rather loose
+    /// definition for language range from [RFC4647] or the composition format used by `Locale`.
+    ///
+    /// [RFC4647]: https://www.rfc-editor.org/rfc/rfc4647.txt
+    NotWellFormed,
+    /// Placeholder for adding more errors in future. **Do not match!**.
+    __NonExhaustive,
+}
+
+impl ::std::fmt::Display for Error {
+    fn fmt(&self, out: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        use ::std::error::Error;
+        out.write_str(self.description())
+    }
+}
+
+impl ::std::error::Error for Error {
+    fn description(&self) -> &str {
+        match self {
+            &Error::NotWellFormed => "Language tag is not well-formed.",
+            // this is exception: here we do want exhaustive match so we don't publish version with
+            // missing descriptions by mistake.
+            &Error::__NonExhaustive => panic!("Placeholder error must not be instantiated!"),
+        }
+    }
+}
+
+/// Convenience Result alias.
+type Result<T> = ::std::result::Result<T, Error>;
+
+/// Iterator over `LanguageRange`s for specific category in a `Locale`
+///
+/// Returns `LanguageRange`s in the `Locale` that are applicable to provided category. The tags
+/// are returned in order of preference, which means the category-specific ones first and then
+/// the generic ones.
+///
+/// The iterator is guaranteed to return at least one value.
+pub struct TagsFor<'a, 'c> {
+    src: &'a str,
+    tags: std::str::Split<'a, &'static str>,
+    category: Option<&'c str>,
+}
+
+impl<'a, 'c> Iterator for TagsFor<'a, 'c> {
+    type Item = LanguageRange<'a>;
+    fn next(&mut self) -> Option<Self::Item> {
+        if let Some(cat) = self.category {
+            while let Some(s) = self.tags.next() {
+                if s.starts_with(cat) && s[cat.len()..].starts_with("=") {
+                    return Some(
+                        LanguageRange { language: Cow::Borrowed(&s[cat.len()+1..]) });
+                }
+            }
+            self.category = None;
+            self.tags = self.src.split(",");
+        }
+        while let Some(s) = self.tags.next() {
+            if s.find('=').is_none() {
+                return Some(
+                    LanguageRange{ language: Cow::Borrowed(s) });
+            }
+        }
+        return None;
+    }
+}
+
+/// Language and culture identifier.
+///
+/// This object holds a [RFC4647] extended language range.
+///
+/// The internal data may be owned or shared from object with lifetime `'a`. The lifetime can be
+/// extended using the `into_static()` method, which internally clones the data as needed.
+///
+/// # Syntax
+///
+/// The range is composed of `-`-separated alphanumeric subtags, possibly replaced by `*`s. It
+/// might be empty.
+///
+/// In agreement with [RFC4647], this object only requires that the tag matches:
+///
+/// ```ebnf
+/// language_tag = (alpha{1,8} | "*")
+///                ("-" (alphanum{1,8} | "*"))*
+/// ```
+///
+/// The exact interpretation is up to the downstream localization provider, but it expected that
+/// it will be matched against a normalized [RFC5646] language tag, which has the structure:
+///
+/// ```ebnf
+/// language_tag    = language
+///                   ("-" script)?
+///                   ("-" region)?
+///                   ("-" variant)*
+///                   ("-" extension)*
+///                   ("-" private)?
+///
+/// language        = alpha{2,3} ("-" alpha{3}){0,3}
+///
+/// script          = aplha{4}
+///
+/// region          = alpha{2}
+///                 | digit{3}
+///
+/// variant         = alphanum{5,8}
+///                 | digit alphanum{3}
+///
+/// extension       = [0-9a-wyz] ("-" alphanum{2,8})+
+///
+/// private         = "x" ("-" alphanum{1,8})+
+/// ```
+///
+///  * `language` is an [ISO639] 2-letter or, where not defined, 3-letter code. A code for
+///     macro-language might be followed by code of specific dialect.
+///  * `script` is an [ISO15924] 4-letter code.
+///  * `region` is either an [ISO3166] 2-letter code or, for areas other than countries, [UN M.49]
+///    3-digit numeric code.
+///  * `variant` is a string indicating variant of the language.
+///  * `extension` and `private` define additional options. The private part has same structure as
+///    the Unicode [`-u-` extension][u_ext]. Available options are documented for the facets that
+///    use them.
+///
+/// The values obtained by inspecting the system are normalized according to those rules.
+///
+/// The content will be case-normalized as recommended in [RFC5646] §2.1.1, namely:
+///
+///  * `language` is written in lowercase,
+///  * `script` is written with first capital,
+///  * `country` is written in uppercase and
+///  * all other subtags are written in lowercase.
+///
+/// When detecting system configuration, additional options that may be generated under the
+/// [`-u-` extension][u_ext] currently are:
+///
+/// * `cf` — Currency format (`account` for parenthesized negative values, `standard` for minus
+///   sign).
+/// * `fw` — First day of week (`mon` to `sun`).
+/// * `hc` — Hour cycle (`h12` for 1–12, `h23` for 0–23).
+/// * `ms` — Measurement system (`metric` or `ussystem`).
+/// * `nu` — Numbering system—only decimal systems are currently used.
+/// * `va` — Variant when locale is specified in Unix format and the tag after `@` does not
+///   correspond to any variant defined in [Language subtag registry].
+///
+/// And under the `-x-` extension, following options are defined:
+///
+/// * `df` — Date format:
+///
+///     * `iso`: Short date should be in ISO format of `yyyy-MM-dd`.
+///
+///     For example `-df-iso`.
+///
+/// * `dm` — Decimal separator for monetary:
+///
+///     Followed by one or more Unicode codepoints in hexadecimal. For example `-dm-002d` means to
+///     use comma.
+///
+/// * `ds` — Decimal separator for numbers:
+///
+///     Followed by one or more Unicode codepoints in hexadecimal. For example `-ds-002d` means to
+///     use comma.
+///
+/// * `gm` — Group (thousand) separator for monetary:
+///
+///     Followed by one or more Unicode codepoints in hexadecimal. For example `-dm-00a0` means to
+///     use non-breaking space.
+///
+/// * `gs` — Group (thousand) separator for numbers:
+///
+///     Followed by one or more Unicode codepoints in hexadecimal. For example `-ds-00a0` means to
+///     use non-breaking space.
+///
+/// * `ls` — List separator:
+///
+///     Followed by one or more Unicode codepoints in hexadecimal. For example, `-ds-003b` means to
+///     use a semicolon.
+///
+/// [RFC5646]: https://www.rfc-editor.org/rfc/rfc5646.txt
+/// [RFC4647]: https://www.rfc-editor.org/rfc/rfc4647.txt
+/// [ISO639]: https://en.wikipedia.org/wiki/ISO_639
+/// [ISO15924]: https://en.wikipedia.org/wiki/ISO_15924
+/// [ISO3166]: https://en.wikipedia.org/wiki/ISO_3166
+/// [UN M.49]: https://en.wikipedia.org/wiki/UN_M.49
+/// [u_ext]: http://www.unicode.org/reports/tr35/#u_Extension
+/// [Language subtag registry]: https://www.iana.org/assignments/language-subtag-registry/language-subtag-registry
+#[derive(Clone,Debug,Eq,Hash,PartialEq)]
+pub struct LanguageRange<'a> {
+    language: Cow<'a, str>
+}
+
+impl<'a> LanguageRange<'a> {
+    /// Return LanguageRange for the invariant locale.
+    ///
+    /// Invariant language is identified simply by empty string.
+    pub fn invariant() -> LanguageRange<'static> {
+        LanguageRange { language: Cow::Borrowed("") }
+    }
+
+    /// Create language tag from Unix/Linux/GNU locale tag.
+    ///
+    /// Unix locale tags have the form
+    ///
+    /// > *language* [ `_` *region* ] [ `.` *encoding* ] [ `@` *variant* ]
+    ///
+    /// The *language* and *region* have the same format as RFC5646. *Encoding* is not relevant
+    /// here, since Rust always uses Utf-8. That leaves *variant*, which is unfortunately rather
+    /// free-form. So this function will translate known variants to corresponding RFC5646 subtags
+    /// and represent anything else with Unicode POSIX variant (`-u-va-`) extension.
+    ///
+    /// Note: This function is public here for benefit of applications that may come across this
+    /// kind of tags from other sources than system configuration.
+    pub fn from_unix(s: &str) -> Result<LanguageRange<'static>> {
+        let unix_tag_regex = Regex::new(r"(?ix) ^
+            (?P<language> [[:alpha:]]{2,3} )
+            (?: _  (?P<region> [[:alpha:]]{2} | [[:digit:]]{3} ))?
+            (?: \. (?P<encoding> [0-9a-zA-Z-]{1,20} ))?
+            (?: @  (?P<variant> [[:alnum:]]{1,20} ))?
+        $ ").unwrap();
+        
+        let unix_invariant_regex = Regex::new(r"(?ix) ^
+            (?: c | posix )
+            (?: \. (?: [0-9a-zA-Z-]{1,20} ))?
+        $ ").unwrap();
+        
+        if let Some(caps) = unix_tag_regex.captures(s) {
+            let src_variant = caps.name("variant").map(|m| m.as_str()).unwrap_or("").to_ascii_lowercase();
+            let mut res = caps.name("language").map(|m| m.as_str()).unwrap().to_ascii_lowercase();
+            let region = caps.name("region").map(|m| m.as_str()).unwrap_or("");
+            let mut script = "";
+            let mut variant = "";
+            let mut uvariant = "";
+            match src_variant.as_ref() {
+            // Variants seen in the wild in GNU LibC (via http://lh.2xlibre.net/) or in Debian
+            // GNU/Linux Stretch system. Treatment of things not found in RFC5646 subtag registry
+            // (http://www.iana.org/assignments/language-subtag-registry/language-subtag-registry)
+            // or CLDR according to notes at https://wiki.openoffice.org/wiki/LocaleMapping.
+            // Dialects:
+                // aa_ER@saaho - NOTE: Can't be found under that name in RFC5646 subtag registry,
+                // but there is language Saho with code ssy, which is likely that thing.
+                "saaho" if res == "aa" => res = String::from("ssy"),
+            // Scripts:
+                // @arabic
+                "arabic" => script = "Arab",
+                // @cyrillic
+                "cyrl" => script = "Cyrl",
+                "cyrillic" => script = "Cyrl",
+                // @devanagari
+                "devanagari" => script = "Deva",
+                // @hebrew
+                "hebrew" => script = "Hebr",
+                // tt@iqtelif
+                // Neither RFC5646 subtag registry nor CLDR knows anything about this, but as best
+                // as I can tell it is Tatar name for Latin (default is Cyrillic).
+                "iqtelif" => script = "Latn",
+                // @Latn
+                "latn" => script = "Latn",
+                // @latin
+                "latin" => script = "Latn",
+                // en@shaw
+                "shaw" => script = "Shaw",
+            // Variants:
+                // sr@ijekavianlatin
+                "ijekavianlatin" => {
+                    script = "Latn";
+                    variant = "ijekavsk";
+                },
+                // sr@ije
+                "ije" => variant = "ijekavsk",
+                // sr@ijekavian
+                "ijekavian" => variant = "ijekavsk",
+                // ca@valencia
+                "valencia" => variant = "valencia",
+            // Currencies:
+                // @euro - NOTE: We follow suite of Java and Openoffice and ignore it, because it
+                // is default for all locales where it sometimes appears now, and because we use
+                // explicit currency in monetary formatting anyway.
+                "euro" => {},
+            // Collation:
+                // gez@abegede - NOTE: This is collation, but CLDR does not have any code for it,
+                // so we for the moment leave it fall through as -u-va- instead of -u-co-.
+            // Anything else:
+                // en@boldquot, en@quot, en@piglatin - just randomish stuff
+                // @cjknarrow - beware, it's gonna end up as -u-va-cjknarro due to lenght limit
+                s if s.len() <= 8 => uvariant = &*s,
+                s => uvariant = &s[0..8], // the subtags are limited to 8 chars, but some are longer
+            };
+            if script != "" {
+                res.push('-');
+                res.push_str(script);
+            }
+            if region != "" {
+                res.push('-');
+                res.push_str(&*region.to_ascii_uppercase());
+            }
+            if variant != "" {
+                res.push('-');
+                res.push_str(variant);
+            }
+            if uvariant != "" {
+                res.push_str("-u-va-");
+                res.push_str(uvariant);
+            }
+            return Ok(LanguageRange {
+                language: Cow::Owned(res)
+            });
+        } else if unix_invariant_regex.is_match(s) {
+            return Ok(LanguageRange::invariant())
+        } else {
+            return Err(Error::NotWellFormed);
+        }
+    }
+}
+
+impl<'a> AsRef<str> for LanguageRange<'a> {
+    fn as_ref(&self) -> &str {
+        self.language.as_ref()
+    }
+}
+
+/// Locale configuration.
+///
+/// Users may accept several languages in some order of preference and may want to use rules from
+/// different culture for some particular aspect of the program behaviour, and operating systems
+/// allow them to specify this (to various extent).
+///
+/// The `Locale` objects represent the user configuration. They contain:
+///
+///  - The primary `LanguageRange`.
+///  - Optional category-specific overrides.
+///  - Optional fallbacks in case data (usually translations) for the primary language are not
+///    available.
+///
+/// The set of categories is open-ended. The `locale` crate uses five well-known categories
+/// `messages`, `numeric`, `time`, `collate` and `monetary`, but some systems define additional
+/// ones (GNU Linux has additionally `paper`, `name`, `address`, `telephone` and `measurement`) and
+/// these are provided in the user default `Locale` and other libraries can use them.
+///
+/// `Locale` is represented by a `,`-separated sequence of tags in `LanguageRange` syntax, where
+/// all except the first one may be preceded by category name and `=` sign.
+///
+/// The first tag indicates the default locale, the tags prefixed by category names indicate
+/// _overrides_ for those categories and the remaining tags indicate fallbacks.
+///
+/// Note that a syntactically valid value of HTTP `Accept-Language` header is a valid `Locale`. Not
+/// the other way around though due to the presence of category selectors.
+// TODO: Interning
+#[derive(Clone,Debug,Eq,Hash,PartialEq)]
+pub struct Locale {
+    // TODO: Intern the string for performance reasons
+    // XXX: Store pre-split to LanguageTags?
+    inner: String,
+}
+
+impl Locale {
+    /// Construct invariant locale.
+    ///
+    /// Invariant locale is represented simply with empty string.
+    pub fn invariant() -> Locale {
+        Locale::from(LanguageRange::invariant())
+    }
+
+    /// Append fallback language tag.
+    ///
+    /// Adds fallback to the end of the list.
+    pub fn add(&mut self, tag: &LanguageRange) {
+        for i in self.inner.split(',') {
+            if i == tag.as_ref() {
+                return; // don't add duplicates
+            }
+        }
+        self.inner.push_str(",");
+        self.inner.push_str(tag.as_ref());
+    }
+
+    /// Append category override.
+    ///
+    /// Appending new override for a category that already has one will not replace the existing
+    /// override. This might change in future.
+    pub fn add_category(&mut self, category: &str, tag: &LanguageRange) {
+        if self.inner.split(',').next().unwrap() == tag.as_ref() {
+            return; // don't add useless override equal to the primary tag
+        }
+        for i in self.inner.split(',') {
+            if i.starts_with(category) &&
+                    i[category.len()..].starts_with("=") &&
+                    &i[category.len() + 1..] == tag.as_ref() {
+                return; // don't add duplicates
+            }
+        }
+        self.inner.push_str(",");
+        self.inner.push_str(category);
+        self.inner.push_str("=");
+        self.inner.push_str(tag.as_ref());
+    }
+
+    /// Iterate over `LanguageRange`s in this `Locale` applicable to given category.
+    ///
+    /// Returns `LanguageRange`s in the `Locale` that are applicable to provided category. The tags
+    /// are returned in order of preference, which means the category-specific ones first and then
+    /// the generic ones.
+    ///
+    /// The iterator is guaranteed to return at least one value.
+    pub fn tags_for<'a, 'c>(&'a self, category: &'c str) -> TagsFor<'a, 'c> {
+        let mut tags = self.inner.split(",");
+        while let Some(s) = tags.clone().next() {
+            if s.starts_with(category) && s[category.len()..].starts_with("=") {
+                return TagsFor {
+                    src: self.inner.as_ref(),
+                    tags: tags,
+                    category: Some(category),
+                };
+            }
+            tags.next();
+        }
+        return TagsFor {
+            src: self.inner.as_ref(),
+            tags: self.inner.split(","),
+            category: None,
+        };
+    }
+}
+
+/// Locale is specified by a string tag. This is the way to access it.
+// FIXME: Do we want to provide the full string representation? We would have it as single string
+// then.
+impl AsRef<str> for Locale {
+    fn as_ref(&self) -> &str {
+        self.inner.as_ref()
+    }
+}
+
+impl<'a> From<LanguageRange<'a>> for Locale {
+    fn from(t: LanguageRange<'a>) -> Locale {
+        Locale {
+            inner: t.language.into_owned(),
+        }
+    }
+}
+
+fn tag(s: &str) -> Result<LanguageRange> {
+    LanguageRange::from_unix(s)
+}
+
+// TODO: Read /etc/locale.alias
+fn tag_inv(s: &str) -> LanguageRange {
+    tag(s).unwrap_or(LanguageRange::invariant())
+}
+
+pub fn system_locale() -> Option<Locale> {
+    // LC_ALL overrides everything
+    if let Ok(all) = env::var("LC_ALL") {
+        if let Ok(t) = tag(all.as_ref()) {
+            return Some(Locale::from(t));
+        }
+    }
+    // LANG is default
+    let mut loc =
+        if let Ok(lang) = env::var("LANG") {
+            Locale::from(tag_inv(lang.as_ref()))
+        } else {
+            Locale::invariant()
+        };
+    // category overrides
+    for &(cat, var) in [
+        ("ctype",       "LC_CTYPE"),
+        ("numeric",     "LC_NUMERIC"),
+        ("time",        "LC_TIME"),
+        ("collate",     "LC_COLLATE"),
+        ("monetary",    "LC_MONETARY"),
+        ("messages",    "LC_MESSAGES"),
+        ("paper",       "LC_PAPER"),
+        ("name",        "LC_NAME"),
+        ("address",     "LC_ADDRESS"),
+        ("telephone",   "LC_TELEPHONE"),
+        ("measurement", "LC_MEASUREMENT"),
+    ].iter() {
+        if let Ok(val) = env::var(var) {
+            if let Ok(tag) = tag(val.as_ref())
+            {
+                loc.add_category(cat, &tag);
+            }
+        }
+    }
+    // LANGUAGE defines fallbacks
+    if let Ok(langs) = env::var("LANGUAGE") {
+        for i in langs.split(':') {
+            if i != "" {
+                if let Ok(tag) = tag(i) {
+                    loc.add(&tag);
+                }
+            }
+        }
+    }
+    if loc.as_ref() != "" {
+        return Some(loc);
+    } else {
+        return None;
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::LanguageRange;
+
+    #[test]
+    fn unix_tags() {
+        assert_eq!("cs-CZ", LanguageRange::from_unix("cs_CZ.UTF-8").unwrap().as_ref());
+        assert_eq!("sr-RS-ijekavsk", LanguageRange::from_unix("sr_RS@ijekavian").unwrap().as_ref());
+        assert_eq!("sr-Latn-ijekavsk", LanguageRange::from_unix("sr.UTF-8@ijekavianlatin").unwrap().as_ref());
+        assert_eq!("en-Arab", LanguageRange::from_unix("en@arabic").unwrap().as_ref());
+        assert_eq!("en-Arab", LanguageRange::from_unix("en.UTF-8@arabic").unwrap().as_ref());
+        assert_eq!("de-DE", LanguageRange::from_unix("DE_de.UTF-8@euro").unwrap().as_ref());
+        assert_eq!("ssy-ER", LanguageRange::from_unix("aa_ER@saaho").unwrap().as_ref());
+        assert!(LanguageRange::from_unix("foo_BAR").is_err());
+        assert!(LanguageRange::from_unix("en@arabic.UTF-8").is_err());
+        assert_eq!("", LanguageRange::from_unix("C").unwrap().as_ref());
+        assert_eq!("", LanguageRange::from_unix("C.UTF-8").unwrap().as_ref());
+        assert_eq!("", LanguageRange::from_unix("C.ISO-8859-1").unwrap().as_ref());
+        assert_eq!("", LanguageRange::from_unix("POSIX").unwrap().as_ref());
+    }
+}

src/popover.rs

@@ -3,6 +3,9 @@
 use gio;
 use gtk;
 use ::layout::c::EekGtkKeyboard;
+use ::locale::compare_current_locale;
+use ::locale_config::system_locale;
+use ::resources;
 
 use gio::ActionExt;
 use gio::ActionMapExt;
@@ -48,7 +51,7 @@ mod variants {
     }
 }
 
-fn make_menu_builder(inputs: Vec<&str>) -> gtk::Builder {
+fn make_menu_builder(inputs: Vec<(&str, &str)>) -> gtk::Builder {
     let mut xml: Vec<u8> = Vec::new();
     writeln!(
         xml,
@@ -57,16 +60,17 @@ fn make_menu_builder(inputs: Vec<&str>) -> gtk::Builder {
   <menu id=\"app-menu\">
     <section>"
     ).unwrap();
-    for input in inputs {
+    for (input_name, human_name) in inputs {
         writeln!(
             xml,
             "
         <item>
             <attribute name=\"label\" translatable=\"yes\">{}</attribute>
             <attribute name=\"action\">layout</attribute>
-            <attribute name=\"target\">{0}</attribute>
+            <attribute name=\"target\">{}</attribute>
         </item>",
-            input,
+            human_name,
+            input_name,
         ).unwrap();
     }
     writeln!(
@@ -106,7 +110,35 @@ pub fn show(window: EekGtkKeyboard, position: ::layout::c::Bounds) {
         .map(|(_kind, name)| name.as_str())
         .collect();
 
-    let builder = make_menu_builder(input_names.clone());
+    let translations = system_locale()
+        .map(|locale|
+            locale.tags_for("messages")
+                .next().unwrap() // guaranteed to exist
+                .as_ref()
+                .to_owned()
+        )
+        .and_then(|lang| resources::get_layout_names(lang.as_str()));
+
+    // sorted collection of human and machine names
+    let mut human_names: Vec<(&str, &str)> = match translations {
+        Some(translations) => {
+            input_names.iter()
+                .map(|name| (*name, *translations.get(name).unwrap_or(name)))
+                .collect()
+        },
+        // display bare codes
+        None => {
+            input_names.iter()
+                .map(|n| (*n, *n)) // turns &&str into &str
+                .collect()
+        }
+    };
+
+    human_names.sort_unstable_by(|(_, human_label_a), (_, human_label_b)| {
+        compare_current_locale(human_label_a, human_label_b)
+    });
+
+    let builder = make_menu_builder(human_names);
     // Much more debuggable to populate the model & menu
     // from a string representation
     // than add items imperatively

src/resources.rs

@@ -2,6 +2,13 @@
  * This could be done using GResource, but that would need additional work.
  */
 
+use std::collections::HashMap;
+
+use std::iter::FromIterator;
+
+// TODO: keep a list of what is a language layout,
+// and what a convenience layout. "_wide" is not a layout,
+// neither is "number"
 const KEYBOARDS: &[(*const str, *const str)] = &[
     ("us", include_str!("../data/keyboards/us.yaml")),
     ("us_wide", include_str!("../data/keyboards/us_wide.yaml")),
@@ -27,3 +34,76 @@ pub fn get_keyboard(needle: &str) -> Option<&'static str> {
             unsafe { &*value }
         })
 }
+
+/// Translations of the layout identifier strings
+const LAYOUT_NAMES: &[(*const str, *const str)] = &[
+    ("en-US", include_str!("../data/langs/en-US.txt")),
+    ("pl-PL", include_str!("../data/langs/pl-PL.txt")),
+];
+
+pub fn get_layout_names(lang: &str)
+    -> Option<HashMap<&'static str, &'static str>>
+{
+    let translations = LAYOUT_NAMES.iter()
+        .find(|(name, _data)| {
+            let name: *const str = *name;
+            (unsafe { &*name }) == lang
+        })
+        .map(|(_name, data)| {
+            let data: *const str = *data;
+            unsafe { &*data }
+        });
+    translations.map(make_mapping)
+}
+
+fn parse_line(line: &str) -> Option<(&str, &str)> {
+    let comment = line.trim().starts_with("#");
+    if comment {
+        None
+    } else {
+        let mut iter = line.splitn(2, " ");
+        let name = iter.next().unwrap();
+        // will skip empty and unfinished lines
+        iter.next().map(|tr| (name, tr.trim()))
+    }
+}
+
+fn make_mapping(data: &str) -> HashMap<&str, &str> {
+    HashMap::from_iter(
+        data.split("\n")
+            .filter_map(parse_line)
+    )
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn mapping_line() {
+        assert_eq!(
+            Some(("name", "translation")),
+            parse_line("name translation")
+        );
+    }
+
+    #[test]
+    fn mapping_bad() {
+        assert_eq!(None, parse_line("bad"));
+    }
+
+    #[test]
+    fn mapping_empty() {
+        assert_eq!(None, parse_line(""));
+    }
+
+    #[test]
+    fn mapping_comment() {
+        assert_eq!(None, parse_line("# comment"));
+    }
+
+    #[test]
+    fn mapping_comment_offset() {
+        assert_eq!(None, parse_line("  # comment"));
+    }
+}