translations: Use gnome-desktop's xkb info database for layout names

debian/control

@@ -9,6 +9,7 @@ Build-Depends:
  ninja-build,
  pkg-config,
  libglib2.0-dev,
+ libgnome-desktop-3-dev,
  libgtk-3-dev,
  libcroco3-dev,
  librust-bitflags-1-dev (>= 1.0),

src/locale.rs

@@ -1,24 +1,93 @@
-/*! Locale-specific functions */
+/*! Locale-specific functions. */
 
 use std::cmp;
-use std::ffi::CString;
+use std::ffi::{ CStr, CString };
+use std::os::raw::c_char;
+use std::ptr;
+use std::str::Utf8Error;
 
 mod c {
-    use std::os::raw::c_char;
+    use super::*;
+    use std::os::raw::c_void;
 
     #[allow(non_camel_case_types)]
     pub type c_int = i32;
 
+    #[derive(Clone, Copy)]
+    #[repr(C)]
+    pub struct GnomeXkbInfo(*const c_void);
+
     #[no_mangle]
     extern "C" {
         // from libc
         pub fn strcoll(cs: *const c_char, ct: *const c_char) -> c_int;
+        // from gnome-desktop3
+        pub fn gnome_xkb_info_new() -> GnomeXkbInfo;
+        pub fn gnome_xkb_info_get_layout_info (
+            info: GnomeXkbInfo,
+            id: *const c_char,
+            display_name: *mut *const c_char,
+            short_name: *const *const c_char,
+            xkb_layout: *const *const c_char,
+            xkb_variant: *const *const c_char
+        ) -> c_int;
+        pub fn g_object_unref(o: GnomeXkbInfo);
+    }
+}
+
+#[derive(Debug)]
+pub enum Error {
+    StringConversion(Utf8Error),
+    NoInfo,
+}
+
+pub struct XkbInfo(c::GnomeXkbInfo);
+
+impl XkbInfo {
+    pub fn new() -> XkbInfo {
+        XkbInfo(unsafe { c::gnome_xkb_info_new() })
+    }
+    pub fn get_display_name(&self, id: &str) -> Result<String, Error> {
+        let id = cstring_safe(id);
+        let id_ref = id.as_ptr();
+        let mut display_name: *const c_char = ptr::null();
+        let found = unsafe {
+            c::gnome_xkb_info_get_layout_info(
+                self.0,
+                id_ref,
+                &mut display_name as *mut *const c_char,
+                ptr::null(), ptr::null(), ptr::null(),
+            )
+        };
+        if found != 0 && !display_name.is_null() {
+            let display_name = unsafe { CStr::from_ptr(display_name) };
+            display_name.to_str()
+                .map(str::to_string)
+                .map_err(Error::StringConversion)
+        } else {
+            Err(Error::NoInfo)
+        }
+    }
+}
+
+impl Drop for XkbInfo {
+    fn drop(&mut self) {
+        unsafe { c::g_object_unref(self.0) }
     }
 }
 
 #[derive(Clone, Debug, PartialEq)]
 pub struct Translation<'a>(pub &'a str);
 
+impl<'a> Translation<'a> {
+    pub fn to_owned(&'a self) -> OwnedTranslation {
+        OwnedTranslation(self.0.to_owned())
+    }
+}
+
+#[derive(Clone, Debug, PartialEq)]
+pub struct OwnedTranslation(pub String);
+
 fn cstring_safe(s: &str) -> CString {
     CString::new(s)
         .unwrap_or(CString::new("").unwrap())

src/meson.build

@@ -39,6 +39,7 @@ cc = meson.get_compiler('c')
 deps = [
 #  dependency('glib-2.0', version: '>=2.26.0'),
   dependency('gio-2.0', version: '>=2.26.0'),
+  dependency('gnome-desktop-3.0', version: '>=3.0'),
   dependency('gtk+-3.0', version: '>=3.0'),
   dependency('libcroco-0.6'),
   dependency('wayland-client', version: '>=1.14'),

src/popover.rs

@@ -4,7 +4,8 @@ use gio;
 use gtk;
 use std::ffi::CString;
 use ::layout::c::{ Bounds, EekGtkKeyboard };
-use ::locale::{ Translation, compare_current_locale };
+use ::locale;
+use ::locale::{ OwnedTranslation, Translation, compare_current_locale };
 use ::locale_config::system_locale;
 use ::manager;
 use ::resources;
@@ -94,7 +95,7 @@ mod variants {
     }
 }
 
-fn make_menu_builder(inputs: Vec<(&str, Translation)>) -> gtk::Builder {
+fn make_menu_builder(inputs: Vec<(&str, OwnedTranslation)>) -> gtk::Builder {
     let mut xml: Vec<u8> = Vec::new();
     writeln!(
         xml,
@@ -227,37 +228,73 @@ pub fn show(
         )
         .and_then(|lang| resources::get_layout_names(lang.as_str()));
 
+    // The actual translation procedure attempts to take all xkb names
+    // from gnome-desktop's xkb info.
+    // Remaining names are translated using the internal database,
+    // which is only available if the locale is set.
+    // The result is a rather ugly and verbose translation procedure...
+    enum Status {
+        /// xkb names should get all translated here
+        Translated(OwnedTranslation),
+        /// Builtin names need builtin translations
+        Remaining(String),
+    }
+    
+    let xkb_translator = locale::XkbInfo::new();
+
     let translated_names = all_layouts.iter()
-        .map(LayoutId::get_name);
-    let translated_names: Vec<Translation> = match translations {
+        .map(|id| match id {
+            LayoutId::System { name, kind: _ } => {
+                xkb_translator.get_display_name(name)
+                    .map(|s| Status::Translated(OwnedTranslation(s)))
+                    .unwrap_or_else(|e| {
+                        eprintln!(
+                            "No display name for xkb layout {}: {:?}",
+                            name,
+                            e,
+                        );
+                        Status::Remaining(name.clone())
+                    })
+            },
+            LayoutId::Local(name) => Status::Remaining(name.clone()),
+        });
+
+    let translated_names: Vec<OwnedTranslation> = match translations {
         Some(translations) => {
             translated_names
-                .map(move |name| {
-                    translations.get(name)
-                        .map(|translation| translation.clone())
-                        .unwrap_or(Translation(name))
+                .map(|status| match status {
+                    Status::Remaining(name) => {
+                        translations.get(name.as_str())
+                            .unwrap_or(&Translation(name.as_str()))
+                            .to_owned()
+                    },
+                    Status::Translated(t) => t,
                 })
                 .collect()
         },
         None => {
-            translated_names.map(|name| Translation(name))
+            translated_names
+                .map(|status| match status {
+                    Status::Remaining(name) => OwnedTranslation(name),
+                    Status::Translated(t) => t,
+                })
                 .collect()
         },
     };
 
     // sorted collection of human and machine names
-    let mut human_names: Vec<(Translation, LayoutId)> = translated_names
+    let mut human_names: Vec<(OwnedTranslation, LayoutId)> = translated_names
         .into_iter()
         .zip(all_layouts.clone().into_iter())
         .collect();
 
     human_names.sort_unstable_by(|(tr_a, _), (tr_b, _)| {
-        compare_current_locale(tr_a.0, tr_b.0)
+        compare_current_locale(&tr_a.0, &tr_b.0)
     });
 
     // GVariant doesn't natively support `enum`s,
     // so the `choices` vector will serve as a lookup table.
-    let choices_with_translations: Vec<(String, (Translation, LayoutId))>
+    let choices_with_translations: Vec<(String, (OwnedTranslation, LayoutId))>
         = human_names.into_iter()
             .enumerate()
                 .map(|(i, human_entry)| {(
@@ -268,7 +305,7 @@ pub fn show(
 
     let builder = make_menu_builder(
         choices_with_translations.iter()
-            .map(|(id, (translation, _))| (id.as_str(), translation.clone()))
+            .map(|(id, (translation, _))| (id.as_str(), (*translation).clone()))
             .collect()
     );