add feature flag for song notifications

enables users/distributions to ship without dbus dependency

Cargo.toml

@@ -28,7 +28,7 @@ librespot-core = "0.1.3"
 librespot-playback = "0.1.3"
 librespot-protocol = "0.1.3"
 log = "0.4.0"
-notify-rust = "4"
+notify-rust = { version = "4", optional = true }
 rspotify = { version = "0.10.0", features = ["blocking"] }
 serde = "1.0"
 serde_json = "1.0"
@@ -57,4 +57,5 @@ rodio_backend = ["librespot-playback/rodio-backend"]
 portaudio_backend = ["librespot-playback/portaudio-backend"]
 termion_backend = ["cursive/termion-backend"]
 mpris = ["dbus"]
-default = ["share_clipboard", "pulseaudio_backend", "mpris", "cursive/pancurses-backend"]
+notify = ["notify-rust"]
+default = ["share_clipboard", "pulseaudio_backend", "mpris", "notify", "cursive/pancurses-backend"]

src/queue.rs

@@ -1,7 +1,9 @@
 use std::cmp::Ordering;
 use std::sync::{Arc, RwLock};
 
+#[cfg(feature = "notify")]
 use notify_rust::Notification;
+
 use rand::prelude::*;
 use strum_macros::Display;
 
@@ -221,6 +223,7 @@ impl Queue {
             current.replace(index);
             self.spotify.update_track();
             if self.spotify.cfg.notify.unwrap_or(false) {
+                #[cfg(feature = "notify")]
                 if let Err(e) = Notification::new().summary(&track.to_string()).show() {
                     error!("error showing notification: {:?}", e);
                 }