config: Add keymap_from_names for RMLVO keymaps

jay-config/src/_private/client.rs

@@ -19,7 +19,7 @@ use {
             acceleration::AccelProfile, capability::Capability, clickmethod::ClickMethod,
         },
         keyboard::{
-            Keymap,
+            Group, Keymap,
             mods::{Modifiers, RELEASE},
             syms::KeySym,
         },
@@ -1385,6 +1385,23 @@ impl ConfigClient {
         keymap
     }
 
+    pub fn keymap_from_names(
+        &self,
+        rules: Option<&str>,
+        model: Option<&str>,
+        groups: Option<&[Group<'_>]>,
+        options: Option<&[&str]>,
+    ) -> Keymap {
+        let res = self.send_with_response(&ClientMessage::KeymapFromNames {
+            rules,
+            model,
+            groups: groups.map(|v| v.to_vec()),
+            options: options.map(|v| v.to_vec()),
+        });
+        get_response!(res, Keymap(0), KeymapFromNames { keymap });
+        keymap
+    }
+
     pub fn set_ei_socket_enabled(&self, enabled: bool) {
         self.send(&ClientMessage::SetEiSocketEnabled { enabled })
     }

jay-config/src/_private/ipc.rs

@@ -7,7 +7,7 @@ use {
             FocusFollowsMouseMode, InputDevice, LayerDirection, Seat, SwitchEvent, Timeline,
             acceleration::AccelProfile, capability::Capability, clickmethod::ClickMethod,
         },
-        keyboard::{Keymap, mods::Modifiers, syms::KeySym},
+        keyboard::{Group, Keymap, mods::Modifiers, syms::KeySym},
         logging::LogLevel,
         theme::{BarPosition, Color, colors::Colorable, sized::Resizable},
         timer::Timer,
@@ -820,6 +820,12 @@ pub enum ClientMessage<'a> {
         connector: Connector,
         use_native_gamut: bool,
     },
+    KeymapFromNames {
+        rules: Option<&'a str>,
+        model: Option<&'a str>,
+        groups: Option<Vec<Group<'a>>>,
+        options: Option<Vec<&'a str>>,
+    },
 }
 
 #[derive(Serialize, Deserialize, Debug)]
@@ -1067,6 +1073,9 @@ pub enum Response {
     GetBarPosition {
         position: BarPosition,
     },
+    KeymapFromNames {
+        keymap: Keymap,
+    },
 }
 
 #[derive(Serialize, Deserialize, Debug)]

jay-config/src/keyboard/mod.rs

@@ -70,6 +70,15 @@ impl Keymap {
     }
 }
 
+/// An RMLVO group consisting of a layout and a variant.
+#[derive(Serialize, Deserialize, Copy, Clone, Debug, Eq, PartialEq, Hash)]
+pub struct Group<'a> {
+    /// The layout of the group.
+    pub layout: &'a str,
+    /// The variant of the group. Can be an empty string.
+    pub variant: &'a str,
+}
+
 /// Parses a keymap.
 ///
 /// The returned keymap can later be used to set the keymap of a seat. If the keymap cannot
@@ -109,3 +118,39 @@ impl Keymap {
 pub fn parse_keymap(keymap: &str) -> Keymap {
     get!(Keymap::INVALID).parse_keymap(keymap)
 }
+
+/// Creates a keymap from RMLVO names.
+///
+/// If a parameter is not given, a value from the environment or a default is used:
+///
+/// | name                   | default                |
+/// | ---------------------- | ---------------------- |
+/// | `XKB_DEFAULT_RULES`    | `evdev`                |
+/// | `XKB_DEFAULT_MODEL`    | `pc105`                |
+/// | `XKB_DEFAULT_LAYOUT`   | `us`                   |
+/// | `XKB_DEFAULT_VARIANTS` |                        |
+/// | `XKB_DEFAULT_OPTIONS`  |                        |
+///
+/// `XKB_DEFAULT_LAYOUT` and `XKB_DEFAULT_VARIANTS` are parsed into the `groups` parameter like this example:
+/// ```
+/// XKB_DEFAULT_LAYOUT = "us,il,ru,de,jp"
+/// XKB_DEFAULT_VARIANTS = ",,phonetic,neo"
+/// ```
+/// produces:
+/// ```
+/// [
+///     Group { layout: "us", variant: "" },
+///     Group { layout: "il", variant: "" },
+///     Group { layout: "ru", variant: "phonetic" },
+///     Group { layout: "de", variant: "neo" },
+///     Group { layout: "jp", variant: "" },
+/// ]
+/// ```
+pub fn keymap_from_names(
+    rules: Option<&str>,
+    model: Option<&str>,
+    groups: Option<&[Group<'_>]>,
+    options: Option<&[&str]>,
+) -> Keymap {
+    get!(Keymap::INVALID).keymap_from_names(rules, model, groups, options)
+}