state machine

src/ui/window.rs

@@ -11,10 +11,22 @@ mod imp {
     use tracing::{event, span, Level};
     use zbus::object_server::InterfaceRef;
 
+    #[derive(Debug, Copy, Clone)]
+    enum State {
+        Idle,
+        FileLoading,
+        FileLoaded,
+        Active,
+        FileEnded,
+        Seeking,
+    }
+
     #[derive(gtk::CompositeTemplate, glib::Properties)]
     #[template(resource = "/eu/callcc/audrey/window.ui")]
     #[properties(wrapper_type = super::Window)]
     pub struct Window {
+        state: Cell<State>,
+
         #[template_child]
         pub(super) playbar: TemplateChild<crate::ui::Playbar>,
 
@@ -92,6 +104,8 @@ mod imp {
             mpv.add_hook(0, "on_before_start_file", 0).unwrap();
 
             Self {
+                state: Cell::new(State::Idle),
+
                 playbar: Default::default(),
                 play_queue: Default::default(),
                 can_click_shuffle_all: Cell::new(false),
@@ -427,6 +441,9 @@ mod imp {
                 4 => {
                     assert_eq!(event.name, "idle-active");
                     self.obj().notify("idle-active");
+                    if self.obj().idle_active() {
+                        self.on_idle_active();
+                    }
                 }
 
                 6 => {
@@ -487,7 +504,25 @@ mod imp {
             };
         }
 
+        fn on_idle_active(&self) {
+            match self.state.get() {
+                State::Idle => {}
+                State::FileEnded => {}
+
+                other => panic!("invalid state transition: IdleActive from {other:?}"),
+            }
+            self.state.set(State::Idle);
+        }
+
         fn on_start_file(&self) {
+            match self.state.get() {
+                State::Idle => {}
+                State::FileEnded => {}
+
+                other => panic!("invalid state transition: StartFile from {other:?}"),
+            }
+            self.state.set(State::FileLoading);
+
             event!(Level::INFO, "StartFile");
             self.obj().notify("song");
             self.buffering_start();
@@ -526,6 +561,13 @@ mod imp {
         }
 
         fn on_file_loaded(&self) {
+            match self.state.get() {
+                State::FileLoading => {}
+
+                other => panic!("invalid state transition: FileLoaded from {other:?}"),
+            }
+            self.state.set(State::FileLoaded);
+
             event!(Level::INFO, "FileLoaded");
             // sanity check
             // i think "path" is only available after this event is dispatched
@@ -537,10 +579,27 @@ mod imp {
 
         fn on_seek(&self) {
             event!(Level::INFO, "Seek");
+
+            match self.state.get() {
+                State::Active => {}
+                State::Seeking => {}
+
+                other => panic!("invalid state transition: Seek from {other:?}"),
+            }
+            self.state.set(State::Seeking);
+
             self.buffering_start();
         }
 
         fn on_playback_restart(&self) {
+            match self.state.get() {
+                State::FileLoaded => {}
+                State::Seeking => {}
+
+                other => panic!("invalid state transition: PlaybackRestart from {other:?}"),
+            }
+            self.state.set(State::Active);
+
             event!(Level::INFO, "PlaybackRestart");
             self.buffering_end();
             self.obj().notify("time-pos");
@@ -554,6 +613,16 @@ mod imp {
 
         fn on_end_file(&self, event: crate::mpv::event::EndFileEvent) {
             event!(Level::INFO, "EndFile: {event:?}");
+
+            match self.state.get() {
+                State::Active => {}
+                State::FileLoading => {}
+                State::Seeking => {}
+
+                other => panic!("invalid state transition: EndFile from {other:?}"),
+            }
+            self.state.set(State::FileEnded);
+
             self.obj().notify("song");
             self.buffering_end();