Background service (#43)

better handling of background-service: lan-mouse can now be run without a gui by specifying --daemon as an argument.
Otherwise the servic will be run as a child process and correctly terminate when the window is closed / frontend exits.

Closes #38

src/frontend/cli.rs

@@ -1,10 +1,10 @@
 use anyhow::{anyhow, Result, Context};
-use std::{thread::{self, JoinHandle}, io::{Write, Read, ErrorKind}, str::SplitWhitespace};
+use std::{thread, io::{Write, Read, ErrorKind}, str::SplitWhitespace};
 #[cfg(windows)]
 use std::net::SocketAddrV4;
 
 #[cfg(unix)]
-use std::{os::unix::net::UnixStream, path::Path, env};
+use std::os::unix::net::UnixStream;
 #[cfg(windows)]
 use std::net::TcpStream;
 
@@ -12,9 +12,9 @@ use crate::{client::Position, config::DEFAULT_PORT};
 
 use super::{FrontendEvent, FrontendNotify};
 
-pub fn start() -> Result<(JoinHandle<()>, JoinHandle<()>)> {
+pub fn run() -> Result<()> {
     #[cfg(unix)]
-    let socket_path = Path::new(env::var("XDG_RUNTIME_DIR")?.as_str()).join("lan-mouse-socket.sock");
+    let socket_path = super::FrontendListener::socket_path()?;
 
     #[cfg(unix)]
     let Ok(mut tx) = UnixStream::connect(&socket_path) else {
@@ -50,7 +50,7 @@ pub fn start() -> Result<(JoinHandle<()>, JoinHandle<()>)> {
                                 log::error!("error sending message: {e}");
                             };
                             if *event == FrontendEvent::Shutdown() {
-                                break;
+                                return;
                             }
                         }
                         // prompt is printed after the server response is received
@@ -126,7 +126,29 @@ pub fn start() -> Result<(JoinHandle<()>, JoinHandle<()>)> {
                 prompt();
             }
         })?;
-    Ok((reader, writer))
+    match reader.join() {
+        Ok(_) => (),
+        Err(e) => {
+            let msg = match (e.downcast_ref::<&str>(), e.downcast_ref::<String>()) {
+                (Some(&s), _) => s,
+                (_, Some(s)) => s,
+                _ => "no panic info"
+            };
+            log::error!("reader thread paniced: {msg}");
+        },
+    }
+    match writer.join() {
+        Ok(_) => (),
+        Err(e) => {
+            let msg = match (e.downcast_ref::<&str>(), e.downcast_ref::<String>()) {
+                (Some(&s), _) => s,
+                (_, Some(s)) => s,
+                _ => "no panic info"
+            };
+            log::error!("writer thread paniced: {msg}");
+        },
+    }
+    Ok(())
 }
 
 fn prompt() {

src/frontend/gtk.rs

@@ -2,7 +2,7 @@ mod window;
 mod client_object;
 mod client_row;
 
-use std::{io::{Result, Read, ErrorKind}, thread::{self, JoinHandle}, env, process, path::Path, os::unix::net::UnixStream, str};
+use std::{io::{Read, ErrorKind}, env, process, str};
 
 use crate::{frontend::gtk::window::Window, config::DEFAULT_PORT};
 
@@ -14,11 +14,11 @@ use self::client_object::ClientObject;
 
 use super::FrontendNotify;
 
-pub fn start() -> Result<JoinHandle<glib::ExitCode>> {
-    log::debug!("starting gtk frontend");
-    thread::Builder::new()
-        .name("gtk-thread".into())
-        .spawn(gtk_main)
+pub fn run() -> glib::ExitCode {
+    log::debug!("running gtk frontend");
+    let ret = gtk_main();
+    log::debug!("frontend exited");
+    ret
 }
 
 fn gtk_main() -> glib::ExitCode {
@@ -33,7 +33,8 @@ fn gtk_main() -> glib::ExitCode {
     app.connect_startup(|_| load_css());
     app.connect_activate(build_ui);
 
-    app.run()
+    let args: Vec<&'static str> = vec![];
+    app.run_with_args(&args)
 }
 
 fn load_css() {
@@ -52,20 +53,14 @@ fn load_icons() {
 }
 
 fn build_ui(app: &Application) {
-    let xdg_runtime_dir = match env::var("XDG_RUNTIME_DIR") {
-        Ok(v) => v,
+    log::debug!("connecting to lan-mouse-socket");
+    let mut rx = match super::wait_for_service() {
+        Ok(stream) => stream,
         Err(e) => {
-            log::error!("{e}");
+            log::error!("could not connect to lan-mouse-socket: {e}");
             process::exit(1);
         }
     };
-    log::debug!("connecting to lan-mouse-socket ... ");
-    let socket_path = Path::new(xdg_runtime_dir.as_str())
-        .join("lan-mouse-socket.sock");
-    let Ok(mut rx) = UnixStream::connect(&socket_path) else {
-        log::error!("Could not connect to lan-mouse-socket @ {socket_path:?}");
-        process::exit(1);
-    };
     let tx = match rx.try_clone() {
         Ok(sock) => sock,
         Err(e) => {

src/frontend/gtk/window/imp.rs

@@ -15,8 +15,6 @@ pub struct Window {
     #[template_child]
     pub port_edit_cancel: TemplateChild<Button>,
     #[template_child]
-    pub add_client_button: TemplateChild<Button>,
-    #[template_child]
     pub client_list: TemplateChild<ListBox>,
     #[template_child]
     pub client_placeholder: TemplateChild<ActionRow>,