feat(detect): add active layout detection on Gnome (wayland)

espanso-detect/src/layout/gnome.rs

@@ -0,0 +1,56 @@
+/*
+ * This file is part of espanso.
+ *
+ * Copyright (C) 2019-2021 Federico Terzi
+ *
+ * espanso is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * espanso is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with espanso.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+use std::process::Command;
+
+use log::error;
+use regex::Regex;
+use std::path::PathBuf;
+
+lazy_static! {
+  static ref LAYOUT_EXTRACT_REGEX: Regex = Regex::new(r"^\[\('.*?', '(.*?)'\)").unwrap();
+}
+
+pub fn get_active_layout() -> Option<String> {
+  match Command::new("gsettings")
+    .arg("get")
+    .arg("org.gnome.desktop.input-sources")
+    .arg("mru-sources")
+    .output()
+  {
+    Ok(output) => {
+      let output_str = String::from_utf8_lossy(&output.stdout);
+      let captures = LAYOUT_EXTRACT_REGEX.captures(&output_str)?;
+      let layout = captures.get(1)?.as_str();
+      Some(layout.to_string())
+    }
+    Err(err) => {
+      error!(
+        "unable to retrieve current keyboard layout with 'gsettings': {}",
+        err
+      );
+      None
+    }
+  }
+}
+
+pub fn is_gnome() -> bool {
+  let target_session_file = PathBuf::from("/usr/bin/gnome-session");
+  target_session_file.exists()
+}

espanso-detect/src/layout/mod.rs

@@ -21,6 +21,10 @@
 #[cfg(not(feature = "wayland"))]
 mod x11;
 
+#[cfg(target_os = "linux")]
+#[cfg(feature = "wayland")]
+mod gnome;
+
 #[cfg(target_os = "linux")]
 #[cfg(not(feature = "wayland"))]
 pub fn get_active_layout() -> Option<String> {
@@ -30,7 +34,12 @@ pub fn get_active_layout() -> Option<String> {
 #[cfg(target_os = "linux")]
 #[cfg(feature = "wayland")]
 pub fn get_active_layout() -> Option<String> {
-  todo!()
+  if gnome::is_gnome() {
+    gnome::get_active_layout()
+  } else {
+    log::warn!("unable to determine the currently active layout, you might need to explicitly specify the layout in the config for espanso to work correctly.");
+    None
+  }
 }
 
 #[cfg(not(target_os = "linux"))]