sigh. alright, cache playlist-pos locally

src/mpv/event.rs

@@ -55,7 +55,12 @@ pub struct LogMessageEvent {
 pub struct PropertyEvent {
     pub reply_userdata: u64,
     pub name: String,
-    //pub value: PropertyEventValue,
+    pub value: Option<PropertyEventValue>,
+}
+
+#[derive(Clone, Debug)]
+pub enum PropertyEventValue {
+    Int64(i64),
 }
 
 #[derive(Clone, Debug)]

src/mpv/handle.rs

@@ -1,5 +1,6 @@
 use super::event::{
-    EndFileEvent, EndFileReason, HookEvent, LogMessageEvent, PropertyEvent, StartFileEvent,
+    EndFileEvent, EndFileReason, HookEvent, LogMessageEvent, PropertyEvent, PropertyEventValue,
+    StartFileEvent,
 };
 use super::{ffi, Error, Event as MpvEvent, GetProperty, SetProperty};
 use event_listener::{Event, EventListener, IntoNotification};
@@ -140,6 +141,18 @@ impl Handle {
         })
     }
 
+    pub fn observe_property_i64(&self, reply_userdata: u64, name: &str) -> Result<(), Error> {
+        let name = CString::new(name).expect("null bytes in property name");
+        Error::from_return_code(unsafe {
+            ffi::mpv_observe_property(
+                self.inner.as_ptr(),
+                reply_userdata,
+                name.as_ptr(),
+                ffi::mpv_format_MPV_FORMAT_INT64,
+            )
+        })
+    }
+
     pub fn unobserve_property(&self, registered_reply_userdata: u64) -> Result<u32, Error> {
         let rc =
             unsafe { ffi::mpv_unobserve_property(self.inner.as_ptr(), registered_reply_userdata) };
@@ -244,6 +257,15 @@ impl Handle {
                     name: unsafe { CStr::from_ptr(data.name) }
                         .to_string_lossy()
                         .into(),
+                    value: match data.format {
+                        ffi::mpv_format_MPV_FORMAT_NONE => None,
+                        ffi::mpv_format_MPV_FORMAT_INT64 => {
+                            Some(PropertyEventValue::Int64(unsafe {
+                                *(data.data as *mut i64)
+                            }))
+                        }
+                        _ => todo!(),
+                    },
                 }))
             }
 

src/ui/window.rs

@@ -61,8 +61,8 @@ mod imp {
         _mute: (),
         #[property(type = bool, get = Self::pause, set = Self::set_pause)]
         _pause: (),
-        #[property(type = i64, get = Self::playlist_pos)]
+        #[property(get)]
-        _playlist_pos: (),
+        playlist_pos: Cell<i64>,
         #[property(type = f64, get = Self::time_pos)]
         _time_pos: (),
         #[property(type = f64, get = Self::duration)]
@@ -97,7 +97,7 @@ mod imp {
             mpv.set_property("vid", false).unwrap();
             mpv.set_property("prefetch-playlist", true).unwrap();
 
-            mpv.observe_property(3, "playlist-pos").unwrap();
+            mpv.observe_property_i64(3, "playlist-pos").unwrap();
             mpv.observe_property(4, "idle-active").unwrap();
             mpv.observe_property(6, "playlist-count").unwrap();
             mpv.observe_property(7, "duration").unwrap();
@@ -126,7 +126,7 @@ mod imp {
                 _volume: (),
                 _mute: (),
                 _pause: (),
-                _playlist_pos: (),
+                playlist_pos: Cell::new(-1),
                 _time_pos: (),
                 _duration: (),
                 _idle_active: (),
@@ -468,10 +468,6 @@ mod imp {
             self.mpv.set_property("pause", pause).unwrap();
         }
 
-        fn playlist_pos(&self) -> i64 {
-            self.mpv.get_property("playlist-pos").unwrap()
-        }
-
         fn time_pos(&self) -> f64 {
             if let Some(queued_seek) = self.queued_seek.get() {
                 // counterfeit time-pos while the seek is ongoing
@@ -556,9 +552,17 @@ mod imp {
         }
 
         fn on_property_change(&self, event: crate::mpv::event::PropertyEvent) {
+            use crate::mpv::event::PropertyEventValue;
+
             match event.reply_userdata {
                 3 => {
                     assert_eq!(event.name, "playlist-pos");
+                    let value = match event.value {
+                        Some(PropertyEventValue::Int64(i)) => i,
+                        _ => unreachable!(),
+                    };
+                    self.playlist_pos.set(value);
+                    event!(Level::TRACE, "playlist-pos is now {value}");
                     self.obj().notify("playlist-pos");
                 }