diff --git a/Cargo.toml b/Cargo.toml
index bbe4019..4491829 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -40,7 +40,7 @@ reqwest-middleware = { version = "0.4.0", features = [
 ] }
 serde = { version = "1.0.214", features = ["derive"] }
 serde_json = "1.0.133"
-tokio = { version = "1", features = ["parking_lot", "rt-multi-thread"] }
+tokio = { version = "1", features = ["parking_lot", "rt-multi-thread", "sync"] }
 tracing = { version = "0.1.40", default-features = false, features = [
   "attributes",
   "std",
diff --git a/src/application.rs b/src/application.rs
index 40a0951..0195919 100644
--- a/src/application.rs
+++ b/src/application.rs
@@ -56,7 +56,7 @@ glib::wrapper! {
 
 impl Default for Application {
     fn default() -> Self {
-        glib::Object::builder::<Application>()
+        glib::Object::builder::<Self>()
             .property("application-id", crate::APP_ID)
             .property("flags", gio::ApplicationFlags::default())
             .build()
diff --git a/src/model/song.rs b/src/model/song.rs
index eb88071..027805a 100644
--- a/src/model/song.rs
+++ b/src/model/song.rs
@@ -76,7 +76,7 @@ glib::wrapper! {
 impl Song {
     pub fn from_child(window: &crate::ui::Window, song: &subsonic::schema::Child) -> Self {
         let api = window.api();
-        let song: Song = Object::builder()
+        let song: Self = Object::builder()
             .property("id", &song.id)
             .property("title", &song.title)
             .property("artist", &song.artist)
diff --git a/src/mpris.rs b/src/mpris.rs
index d65db7d..619024f 100644
--- a/src/mpris.rs
+++ b/src/mpris.rs
@@ -20,8 +20,6 @@ impl Mpris {
 
         object_server.at("/org/mpris/MediaPlayer2", mpris).await?;
 
-        //let _mpris = object_server.interface::<_, Self>("/org/mpris/MediaPlayer2").await?;
-
         Ok(())
     }
 }
@@ -43,34 +41,34 @@ impl Mpris {
     }
 
     #[zbus(property)]
-    fn can_quit(&self) -> bool {
+    const fn can_quit(&self) -> bool {
         true
     }
 
     #[zbus(property)]
-    fn fullscreen(&self) -> bool {
+    const fn fullscreen(&self) -> bool {
         false
     }
 
     #[zbus(property)]
     // TODO: report that if the argument is just _ the attribute panics
     // TODO: why can't this return zbus::fdo::Result??
-    fn set_fullscreen(&self, _fullscreen: bool) -> zbus::Result<()> {
+    const fn set_fullscreen(&self, _fullscreen: bool) -> zbus::Result<()> {
         Err(zbus::Error::Unsupported)
     }
 
     #[zbus(property)]
-    fn can_set_fullscreen(&self) -> bool {
+    const fn can_set_fullscreen(&self) -> bool {
         false
     }
 
     #[zbus(property)]
-    fn can_raise(&self) -> bool {
+    const fn can_raise(&self) -> bool {
         true
     }
 
     #[zbus(property)]
-    fn has_track_list(&self) -> bool {
+    const fn has_track_list(&self) -> bool {
         false // TODO?
     }
 
@@ -85,12 +83,12 @@ impl Mpris {
     }
 
     #[zbus(property)]
-    fn supported_uri_schemes(&self) -> Vec<String> {
+    const fn supported_uri_schemes(&self) -> Vec<String> {
         vec![]
     }
 
     #[zbus(property)]
-    fn supported_mime_types(&self) -> Vec<String> {
+    const fn supported_mime_types(&self) -> Vec<String> {
         vec![]
     }
 }
diff --git a/src/mpris/player.rs b/src/mpris/player.rs
index 5a03cbd..2f59010 100644
--- a/src/mpris/player.rs
+++ b/src/mpris/player.rs
@@ -16,7 +16,7 @@ impl Player {
     pub async fn new(
         object_server: &zbus::ObjectServer,
         playbin: &Window,
-    ) -> Result<InterfaceRef<Player>, zbus::Error> {
+    ) -> Result<InterfaceRef<Self>, zbus::Error> {
         let player = Self {
             window: playbin.downgrade().into(),
         };
@@ -131,7 +131,7 @@ impl Player {
     }
 
     #[zbus(property)]
-    fn rate(&self) -> zbus::fdo::Result<f64> {
+    const fn rate(&self) -> zbus::fdo::Result<f64> {
         Ok(1.0)
     }
 
@@ -173,6 +173,7 @@ impl Player {
                     (url::Url::from_file_path(path).unwrap().to_string()).into(),
                 );
             }
+            drop(mpris_art_path);
             map.insert("xesam:album", song.album().into());
             // TODO: use the right opensubsonic data
             map.insert("xesam:artist", vec![song.artist()].into());
@@ -201,12 +202,12 @@ impl Player {
     }
 
     #[zbus(property)]
-    fn minimum_rate(&self) -> f64 {
+    const fn minimum_rate(&self) -> f64 {
         1.0
     }
 
     #[zbus(property)]
-    fn maximum_rate(&self) -> f64 {
+    const fn maximum_rate(&self) -> f64 {
         1.0
     }
 
@@ -236,7 +237,7 @@ impl Player {
     }
 
     #[zbus(property(emits_changed_signal = "const"))]
-    fn can_control(&self) -> bool {
+    const fn can_control(&self) -> bool {
         true
     }
 }
diff --git a/src/mpv/error.rs b/src/mpv/error.rs
index bb6bc0e..868d8fc 100644
--- a/src/mpv/error.rs
+++ b/src/mpv/error.rs
@@ -6,7 +6,7 @@ use std::fmt;
 pub struct Error(pub(super) c_int);
 
 impl Error {
-    pub(super) fn from_return_code(rc: c_int) -> Result<(), Self> {
+    pub(super) const fn from_return_code(rc: c_int) -> Result<(), Self> {
         if rc == 0 {
             Ok(())
         } else {
@@ -20,7 +20,7 @@ impl Error {
             .unwrap()
     }
 
-    pub fn is_property_unavailable(self) -> bool {
+    pub const fn is_property_unavailable(self) -> bool {
         self.0 == ffi::mpv_error_MPV_ERROR_PROPERTY_UNAVAILABLE
     }
 }
diff --git a/src/mpv/format.rs b/src/mpv/format.rs
index b8043f7..b37813c 100644
--- a/src/mpv/format.rs
+++ b/src/mpv/format.rs
@@ -66,7 +66,7 @@ impl SetProperty for i64 {
             ctx,
             name,
             ffi::mpv_format_MPV_FORMAT_INT64,
-            std::ptr::from_ref::<i64>(&self) as *mut c_void,
+            std::ptr::from_ref::<Self>(&self) as *mut c_void,
         ))
     }
 }
@@ -81,7 +81,7 @@ impl SetProperty for f64 {
             ctx,
             name,
             ffi::mpv_format_MPV_FORMAT_DOUBLE,
-            std::ptr::from_ref::<f64>(&self) as *mut c_void,
+            std::ptr::from_ref::<Self>(&self) as *mut c_void,
         ))
     }
 }
@@ -111,12 +111,12 @@ impl GetProperty for bool {
 
 impl GetProperty for i64 {
     unsafe fn get_property(ctx: *mut ffi::mpv_handle, name: *const c_char) -> Result<Self, Error> {
-        let mut value: i64 = -1;
+        let mut value: Self = -1;
         Error::from_return_code(ffi::mpv_get_property(
             ctx,
             name,
             ffi::mpv_format_MPV_FORMAT_INT64,
-            std::ptr::from_mut::<i64>(&mut value) as *mut c_void,
+            std::ptr::from_mut::<Self>(&mut value) as *mut c_void,
         ))?;
         Ok(value)
     }
@@ -124,12 +124,12 @@ impl GetProperty for i64 {
 
 impl GetProperty for f64 {
     unsafe fn get_property(ctx: *mut ffi::mpv_handle, name: *const c_char) -> Result<Self, Error> {
-        let mut value: f64 = 0.0;
+        let mut value: Self = 0.0;
         Error::from_return_code(ffi::mpv_get_property(
             ctx,
             name,
             ffi::mpv_format_MPV_FORMAT_DOUBLE,
-            std::ptr::from_mut::<f64>(&mut value) as *mut c_void,
+            std::ptr::from_mut::<Self>(&mut value) as *mut c_void,
         ))?;
         Ok(value)
     }
diff --git a/src/subsonic.rs b/src/subsonic.rs
index c8ec249..437fdf5 100644
--- a/src/subsonic.rs
+++ b/src/subsonic.rs
@@ -146,7 +146,7 @@ impl Client {
             .with(http_cache)
             .build();
 
-        Ok(Client { client, base_url })
+        Ok(Self { client, base_url })
     }
 
     async fn send(
@@ -255,12 +255,10 @@ impl Client {
     }
 
     pub fn cover_art_url(&self, id: &str, size: Option<u32>) -> url::Url {
+        let endpoint = &["rest", "getCoverArt"];
         match size {
-            None => self.url(&["rest", "getCoverArt"], &[("id", id)]),
-            Some(size) => self.url(
-                &["rest", "getCoverArt"],
-                &[("id", id), ("size", &size.to_string())],
-            ),
+            None => self.url(endpoint, &[("id", id)]),
+            Some(size) => self.url(endpoint, &[("id", id), ("size", &size.to_string())]),
         }
     }
 
diff --git a/src/ui/play_queue.rs b/src/ui/play_queue.rs
index df9f5f1..e305799 100644
--- a/src/ui/play_queue.rs
+++ b/src/ui/play_queue.rs
@@ -50,7 +50,7 @@ mod imp {
     #[gtk::template_callbacks]
     impl PlayQueue {
         #[template_callback]
-        fn visible_child_name(&self, n_items: u32) -> &'static str {
+        const fn visible_child_name(&self, n_items: u32) -> &'static str {
             if n_items > 0 {
                 "not-empty"
             } else {
diff --git a/src/ui/play_queue/song.rs b/src/ui/play_queue/song.rs
index 40154a3..ee00b82 100644
--- a/src/ui/play_queue/song.rs
+++ b/src/ui/play_queue/song.rs
@@ -203,5 +203,5 @@ impl Song {
         song.need_thumbnail(window);
     }
 
-    pub fn unbind(&self) {}
+    pub const fn unbind(&self) {}
 }
diff --git a/src/ui/playbar.rs b/src/ui/playbar.rs
index af5277f..e57db49 100644
--- a/src/ui/playbar.rs
+++ b/src/ui/playbar.rs
@@ -76,7 +76,7 @@ mod imp {
         }
 
         #[template_callback]
-        fn mute_button_icon_name(&self, mute: bool) -> &'static str {
+        const fn mute_button_icon_name(&self, mute: bool) -> &'static str {
             if mute {
                 "audio-volume-muted"
             } else {
@@ -150,17 +150,17 @@ mod imp {
         // updated
         #[template_callback]
         fn song_title(&self, song: Option<&Song>) -> String {
-            song.map(Song::title).unwrap_or("".to_string())
+            song.map(Song::title).unwrap_or_default()
         }
 
         #[template_callback]
         fn song_artist(&self, song: Option<&Song>) -> String {
-            song.map(Song::artist).unwrap_or("".to_string())
+            song.map(Song::artist).unwrap_or_default()
         }
 
         #[template_callback]
         fn song_album(&self, song: Option<&Song>) -> String {
-            song.map(Song::album).unwrap_or("".to_string())
+            song.map(Song::album).unwrap_or_default()
         }
     }
 
diff --git a/src/ui/window.rs b/src/ui/window.rs
index fef2112..8b4121d 100644
--- a/src/ui/window.rs
+++ b/src/ui/window.rs
@@ -243,16 +243,17 @@ mod imp {
             self.time_pos_notify_timeout
                 .replace(Some(glib::timeout_add_local(
                     std::time::Duration::from_millis(100),
-                    move || match window.upgrade() {
-                        None => glib::ControlFlow::Break,
-                        Some(window) => {
-                            match window.imp().state.get() {
-                                State::Idle | State::FileLoading | State::Seeking => {}
-                                State::Active => window.notify("time-pos"),
-                                State::FileEnded => {}
-                            }
-                            glib::ControlFlow::Continue
-                        }
+                    move || {
+                        window
+                            .upgrade()
+                            .map_or(glib::ControlFlow::Break, move |window| {
+                                match window.imp().state.get() {
+                                    State::Idle | State::FileLoading | State::Seeking => {}
+                                    State::Active => window.notify("time-pos"),
+                                    State::FileEnded => {}
+                                }
+                                glib::ControlFlow::Continue
+                            })
                     },
                 )));
 
@@ -522,17 +523,19 @@ mod imp {
         }
 
         fn song(&self) -> Option<Song> {
-            match self.obj().playlist_pos().try_into() {
-                Ok(playlist_pos) => Some(
-                    self.obj()
-                        .playlist_model()
-                        .item(playlist_pos)
-                        .unwrap()
-                        .dynamic_cast()
-                        .unwrap(),
-                ),
-                Err(_) => None,
-            }
+            self.obj().playlist_pos().try_into().map_or_else(
+                move |_| None,
+                move |playlist_pos| {
+                    Some(
+                        self.obj()
+                            .playlist_model()
+                            .item(playlist_pos)
+                            .unwrap()
+                            .dynamic_cast()
+                            .unwrap(),
+                    )
+                },
+            )
         }
 
         fn buffering_start(&self) {
@@ -541,17 +544,16 @@ mod imp {
             if let Some(source) = self.buffering_timeout.replace(Some(glib::timeout_add_local(
                 std::time::Duration::from_millis(100),
                 move || {
-                    match window.upgrade() {
-                        None => glib::ControlFlow::Break,
-                        Some(window) => {
+                    window
+                        .upgrade()
+                        .map_or(glib::ControlFlow::Break, move |window| {
                             // 3 second period from gnome hig
                             if started_buffering.elapsed() > std::time::Duration::from_secs(3) {
                                 window.imp().playbar.set_show_pulse_bar(true);
                                 window.imp().playbar.pulse_bar().pulse();
                             }
                             glib::ControlFlow::Continue
-                        }
-                    }
+                        })
                 },
             ))) {
                 source.remove()