observed properties

src/mpv.rs

@@ -9,5 +9,5 @@ pub use format::SetProperty;
 mod handle;
 pub use handle::Handle;
 
-mod event;
+pub mod event;
-pub use event::{EndFileEvent, EndFileReason, Event, LogMessageEvent, StartFileEvent};
+pub use event::Event;

src/mpv/event.rs

@@ -1,6 +1,7 @@
 use super::Error;
+use std::borrow::Cow;
 
-#[derive(Copy, Clone, Debug)]
+#[derive(Clone, Debug)]
 pub enum Event<'a> {
     Shutdown,
     LogMessage(LogMessageEvent<'a>),
@@ -15,18 +16,18 @@ pub enum Event<'a> {
     AudioReconfig,
     //Seek,
     PlaybackRestart,
-    //PropertyChange,
+    PropertyChange(PropertyEvent<'a>),
     //QueueOverflow,
     //Hook,
     Unknown(u32),
 }
 
-#[derive(Copy, Clone, Debug)]
+#[derive(Clone, Debug)]
 pub struct StartFileEvent {
     pub playlist_entry_id: i64,
 }
 
-#[derive(Copy, Clone, Debug)]
+#[derive(Clone, Debug)]
 pub enum EndFileReason {
     Eof,
     Stop,
@@ -35,7 +36,7 @@ pub enum EndFileReason {
     Unknown(u32),
 }
 
-#[derive(Copy, Clone, Debug)]
+#[derive(Clone, Debug)]
 pub struct EndFileEvent {
     pub reason: Result<EndFileReason, Error>,
     pub playlist_entry_id: i64,
@@ -43,10 +44,27 @@ pub struct EndFileEvent {
     pub playlist_insert_num_entries: i32,
 }
 
-#[derive(Copy, Clone, Debug)]
+#[derive(Clone, Debug)]
 pub struct LogMessageEvent<'a> {
     pub prefix: &'a str,
     pub level: &'a str,
     pub text: &'a str,
     //log_level: i32,
 }
+
+#[derive(Clone, Debug)]
+pub struct PropertyEvent<'a> {
+    pub reply_userdata: u64,
+    pub name: &'a str,
+    pub value: PropertyEventValue<'a>,
+}
+
+#[derive(Clone, Debug)]
+pub enum PropertyEventValue<'a> {
+    None,
+    String(Cow<'a, str>),
+    OsdString(&'a str),
+    Flag(bool),
+    Int64(i64),
+    Double(f64),
+}

src/mpv/handle.rs

@@ -1,6 +1,6 @@
-use super::{
+use super::{event, ffi, Error, Event as MpvEvent, SetProperty};
-    ffi, EndFileEvent, EndFileReason, Error, Event as MpvEvent, LogMessageEvent, SetProperty,
+use event::{
-    StartFileEvent,
+    EndFileEvent, EndFileReason, LogMessageEvent, PropertyEvent, PropertyEventValue, StartFileEvent,
 };
 use event_listener::{Event, EventListener, IntoNotification};
 use std::ffi::{c_char, c_void, CStr, CString};
@@ -99,6 +99,24 @@ impl Handle {
         Error::from_return_code(unsafe { ffi::mpv_command(self.inner.as_ptr(), args) })
     }
 
+    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) };
+        Error::from_return_code(rc).map(|()| rc as u32)
+    }
+
     // should take listener before we drain the event queue, so we don't miss any notifications
     pub fn wakeup_listener(&self) -> EventListener {
         self.wakeup.listen()
@@ -156,6 +174,21 @@ impl Handle {
                 }))
             }
 
+            ffi::mpv_event_id_MPV_EVENT_PROPERTY_CHANGE => {
+                let data = unsafe { &*(event.data as *mut ffi::mpv_event_property) };
+                Some(MpvEvent::PropertyChange(PropertyEvent {
+                    reply_userdata: event.reply_userdata,
+                    name: unsafe { CStr::from_ptr(data.name) }.to_str().unwrap(),
+                    value: match data.format {
+                        ffi::mpv_format_MPV_FORMAT_NONE => PropertyEventValue::None,
+                        ffi::mpv_format_MPV_FORMAT_INT64 => {
+                            PropertyEventValue::Int64(*unsafe { &*(data.data as *mut i64) })
+                        }
+                        _ => todo!("{:?}", data.format),
+                    },
+                }))
+            }
+
             11 => Some(MpvEvent::Unknown(event.event_id)),
 
             _ => todo!("event {}", event.event_id),

src/ui/window.rs

@@ -59,7 +59,7 @@ mod imp {
             mpv.set_property("video", false).unwrap();
             mpv.set_property("prefetch-playlist", true).unwrap();
             mpv.set_property("gapless-audio", true).unwrap();
-            // TODO: observe properties
+            mpv.observe_property_i64(0, "duration").unwrap();
 
             mpv.command(["loadfile", "https://www.youtube.com/watch?v=19y8YTbvri8"])
                 .unwrap();