gpui: Introduce PlatformKeyboardLayout trait for human-friendly keyboard layout names (#29049)

This PR adds a new `PlatformKeyboardLayout` trait with two methods:
`id(&self) -> &str` and `name(&self) -> &str`. The `id()` method returns
a unique identifier for the keyboard layout, while `name()` provides a
human-readable name. This distinction is especially important on
Windows, where the `id` and `name` can be quite different. For example,
the French layout has an `id` of `0000040C`, which is not
human-readable, whereas the `name` would simply be `French`. Currently,
the existing `keyboard_layout()` method returns what's essentially the
same as `id()` in this new design.

This PR implements the `name()` method for both Windows and macOS. On
Linux, for now, `name()` still returns the same value as `id()`.

Release Notes:

- N/A

crates/gpui/src/platform/linux/headless/client.rs

@@ -9,7 +9,8 @@ use util::ResultExt;
 use crate::platform::linux::LinuxClient;
 use crate::platform::{LinuxCommon, PlatformWindow};
 use crate::{
-    AnyWindowHandle, CursorStyle, DisplayId, PlatformDisplay, ScreenCaptureSource, WindowParams,
+    AnyWindowHandle, CursorStyle, DisplayId, LinuxKeyboardLayout, PlatformDisplay,
+    PlatformKeyboardLayout, ScreenCaptureSource, WindowParams,
 };
 
 pub struct HeadlessClientState {
@@ -50,8 +51,8 @@ impl LinuxClient for HeadlessClient {
         f(&mut self.0.borrow_mut().common)
     }
 
-    fn keyboard_layout(&self) -> String {
-        "unknown".to_string()
+    fn keyboard_layout(&self) -> Box<dyn PlatformKeyboardLayout> {
+        Box::new(LinuxKeyboardLayout::new("unknown".to_string()))
     }
 
     fn displays(&self) -> Vec<Rc<dyn PlatformDisplay>> {

crates/gpui/src/platform/linux/platform.rs

@@ -25,8 +25,8 @@ use xkbcommon::xkb::{self, Keycode, Keysym, State};
 use crate::{
     Action, AnyWindowHandle, BackgroundExecutor, ClipboardItem, CursorStyle, DisplayId,
     ForegroundExecutor, Keymap, LinuxDispatcher, Menu, MenuItem, OwnedMenu, PathPromptOptions,
-    Pixels, Platform, PlatformDisplay, PlatformTextSystem, PlatformWindow, Point, Result,
-    ScreenCaptureSource, Task, WindowAppearance, WindowParams, px,
+    Pixels, Platform, PlatformDisplay, PlatformKeyboardLayout, PlatformTextSystem, PlatformWindow,
+    Point, Result, ScreenCaptureSource, Task, WindowAppearance, WindowParams, px,
 };
 
 #[cfg(any(feature = "wayland", feature = "x11"))]
@@ -46,7 +46,7 @@ const FILE_PICKER_PORTAL_MISSING: &str =
 pub trait LinuxClient {
     fn compositor_name(&self) -> &'static str;
     fn with_common<R>(&self, f: impl FnOnce(&mut LinuxCommon) -> R) -> R;
-    fn keyboard_layout(&self) -> String;
+    fn keyboard_layout(&self) -> Box<dyn PlatformKeyboardLayout>;
     fn displays(&self) -> Vec<Rc<dyn PlatformDisplay>>;
     #[allow(unused)]
     fn display(&self, id: DisplayId) -> Option<Rc<dyn PlatformDisplay>>;
@@ -138,7 +138,7 @@ impl<P: LinuxClient + 'static> Platform for P {
         self.with_common(|common| common.text_system.clone())
     }
 
-    fn keyboard_layout(&self) -> String {
+    fn keyboard_layout(&self) -> Box<dyn PlatformKeyboardLayout> {
         self.keyboard_layout()
     }
 
@@ -858,6 +858,26 @@ impl crate::Modifiers {
     }
 }
 
+pub(crate) struct LinuxKeyboardLayout {
+    id: String,
+}
+
+impl PlatformKeyboardLayout for LinuxKeyboardLayout {
+    fn id(&self) -> &str {
+        &self.id
+    }
+
+    fn name(&self) -> &str {
+        &self.id
+    }
+}
+
+impl LinuxKeyboardLayout {
+    pub(crate) fn new(id: String) -> Self {
+        Self { id }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

crates/gpui/src/platform/linux/wayland/client.rs

@@ -66,8 +66,10 @@ use wayland_protocols_plasma::blur::client::{org_kde_kwin_blur, org_kde_kwin_blu
 use xkbcommon::xkb::ffi::XKB_KEYMAP_FORMAT_TEXT_V1;
 use xkbcommon::xkb::{self, KEYMAP_COMPILE_NO_FLAGS, Keycode};
 
-use super::display::WaylandDisplay;
-use super::window::{ImeInput, WaylandWindowStatePtr};
+use super::{
+    display::WaylandDisplay,
+    window::{ImeInput, WaylandWindowStatePtr},
+};
 
 use crate::platform::linux::{
     LinuxClient, get_xkb_compose_state, is_within_click_distance, open_uri_internal, read_fd,
@@ -83,11 +85,11 @@ use crate::platform::linux::{
 use crate::platform::{PlatformWindow, blade::BladeContext};
 use crate::{
     AnyWindowHandle, Bounds, CursorStyle, DOUBLE_CLICK_INTERVAL, DevicePixels, DisplayId,
-    FileDropEvent, ForegroundExecutor, KeyDownEvent, KeyUpEvent, Keystroke, LinuxCommon, Modifiers,
-    ModifiersChangedEvent, MouseButton, MouseDownEvent, MouseExitEvent, MouseMoveEvent,
-    MouseUpEvent, NavigationDirection, Pixels, PlatformDisplay, PlatformInput, Point, SCROLL_LINES,
-    ScaledPixels, ScreenCaptureSource, ScrollDelta, ScrollWheelEvent, Size, TouchPhase,
-    WindowParams, point, px, size,
+    FileDropEvent, ForegroundExecutor, KeyDownEvent, KeyUpEvent, Keystroke, LinuxCommon,
+    LinuxKeyboardLayout, Modifiers, ModifiersChangedEvent, MouseButton, MouseDownEvent,
+    MouseExitEvent, MouseMoveEvent, MouseUpEvent, NavigationDirection, Pixels, PlatformDisplay,
+    PlatformInput, PlatformKeyboardLayout, Point, SCROLL_LINES, ScaledPixels, ScreenCaptureSource,
+    ScrollDelta, ScrollWheelEvent, Size, TouchPhase, WindowParams, point, px, size,
 };
 
 /// Used to convert evdev scancode to xkb scancode
@@ -587,9 +589,9 @@ impl WaylandClient {
 }
 
 impl LinuxClient for WaylandClient {
-    fn keyboard_layout(&self) -> String {
+    fn keyboard_layout(&self) -> Box<dyn PlatformKeyboardLayout> {
         let state = self.0.borrow();
-        if let Some(keymap_state) = &state.keymap_state {
+        let id = if let Some(keymap_state) = &state.keymap_state {
             let layout_idx = keymap_state.serialize_layout(xkbcommon::xkb::STATE_LAYOUT_EFFECTIVE);
             keymap_state
                 .get_keymap()
@@ -597,7 +599,8 @@ impl LinuxClient for WaylandClient {
                 .to_string()
         } else {
             "unknown".to_string()
-        }
+        };
+        Box::new(LinuxKeyboardLayout::new(id))
     }
 
     fn displays(&self) -> Vec<Rc<dyn PlatformDisplay>> {

crates/gpui/src/platform/linux/x11/client.rs

@@ -59,9 +59,10 @@ use crate::platform::{
 };
 use crate::{
     AnyWindowHandle, Bounds, ClipboardItem, CursorStyle, DisplayId, FileDropEvent, Keystroke,
-    Modifiers, ModifiersChangedEvent, MouseButton, Pixels, Platform, PlatformDisplay,
-    PlatformInput, Point, RequestFrameOptions, ScaledPixels, ScreenCaptureSource, ScrollDelta,
-    Size, TouchPhase, WindowParams, X11Window, modifiers_from_xinput_info, point, px,
+    LinuxKeyboardLayout, Modifiers, ModifiersChangedEvent, MouseButton, Pixels, Platform,
+    PlatformDisplay, PlatformInput, PlatformKeyboardLayout, Point, RequestFrameOptions,
+    ScaledPixels, ScreenCaptureSource, ScrollDelta, Size, TouchPhase, WindowParams, X11Window,
+    modifiers_from_xinput_info, point, px,
 };
 
 /// Value for DeviceId parameters which selects all devices.
@@ -1282,14 +1283,16 @@ impl LinuxClient for X11Client {
         f(&mut self.0.borrow_mut().common)
     }
 
-    fn keyboard_layout(&self) -> String {
+    fn keyboard_layout(&self) -> Box<dyn PlatformKeyboardLayout> {
         let state = self.0.borrow();
         let layout_idx = state.xkb.serialize_layout(STATE_LAYOUT_EFFECTIVE);
-        state
-            .xkb
-            .get_keymap()
-            .layout_get_name(layout_idx)
-            .to_string()
+        Box::new(LinuxKeyboardLayout::new(
+            state
+                .xkb
+                .get_keymap()
+                .layout_get_name(layout_idx)
+                .to_string(),
+        ))
     }
 
     fn displays(&self) -> Vec<Rc<dyn PlatformDisplay>> {