Add a function for sending desktop notifications

src/plugin/utils.cpp

@@ -391,3 +391,15 @@ Configuration load_config_for(const fs::path& yabridge_path) {
 
     return Configuration(*config_file, yabridge_path);
 }
+
+bool send_notification(const std::string& title, const std::string body) {
+    try {
+        return bp::system(bp::search_path("notify-send"), "--urgency=critical",
+                          "--expire-time=20000", "--app-name=yabridge", title,
+                          body) == EXIT_SUCCESS;
+    } catch (const boost::process::process_error&) {
+        // We will have printed the message to the terminal anyways, so if the
+        // user doesn't have libnotify installed we'll just fail silently
+        return false;
+    }
+}

src/plugin/utils.h

@@ -264,6 +264,21 @@ boost::filesystem::path get_this_file_location();
  */
 Configuration load_config_for(const boost::filesystem::path& yabridge_path);
 
+/**
+ * Send a desktop notification using `notify-send`. Used for diagnostics when a
+ * plugin fails to load since the user may not be checking the output in a
+ * terminal.
+ *
+ * @param title The title (or technically, summary) of the notification.
+ * @param body The message to display. This can contain line feeds and also
+ *   basic HTML-like formatting, so special characters may need to be escaped.
+ *   The message can also be empty.
+ *
+ * @return Whether the notification was sent. This will be false if
+ *   `notify-send` is not available.
+ */
+bool send_notification(const std::string& title, const std::string body);
+
 /**
  * Starting from the starting file or directory, go up in the directory
  * hierarchy until we find a file named `filename`.