Simplify user code by parsing properties ourselves

examples/media_player.rs

@@ -4,6 +4,7 @@ use mpvipc::{
     Event,
     Mpv,
     MpvDataType,
+    Property,
 };
 use std::io::{self, Write};
 
@@ -31,39 +32,17 @@ fn main() -> Result<(), Error> {
     loop {
         let event = mpv.event_listen()?;
         match event {
-            Event::PropertyChange { name, id: _, data } => {
-                match name.as_ref() {
-                    "path" => {
-                        match data {
-                            MpvDataType::String(value) => println!("\nPlaying: {}", value),
-                            MpvDataType::Null => (),
-                            _ => panic!("Wrong data type for 'path' value: {:?}", data),
-                        }
-                    },
-                    "pause" => {
-                        match data {
-                            MpvDataType::Bool(value) => pause = value,
-                            _ => panic!("Wrong data type for 'pause' value: {:?}", data),
-                        }
-                    },
-                    "playback-time" => {
-                        match data {
-                            MpvDataType::Double(value) => playback_time = value,
-                            MpvDataType::Null => (),
-                            _ => panic!("Wrong data type for 'playback-time' value: {:?}", data),
-                        }
-                    },
-                    "duration" => {
-                        match data {
-                            MpvDataType::Double(value) => duration = value,
-                            MpvDataType::Null => (),
-                            _ => panic!("Wrong data type for 'duration' value: {:?}", data),
-                        }
-                    },
-                    "metadata" => {
-                        match data {
-                            MpvDataType::HashMap(value) => {
-                                println!("File tags:");
+            Event::PropertyChange(property) => {
+                match property {
+                    Property::Path(Some(value)) => println!("\nPlaying: {}", value),
+                    Property::Path(None) => (),
+                    Property::Pause(value) => pause = value,
+                    Property::PlaybackTime(Some(value)) => playback_time = value,
+                    Property::PlaybackTime(None) => playback_time = std::f64::NAN,
+                    Property::Duration(Some(value)) => duration = value,
+                    Property::Duration(None) => duration = std::f64::NAN,
+                    Property::Metadata(Some(value)) => {
+                        println!("File tags:");
                         if let Some(MpvDataType::String(value)) = value.get("ARTIST") {
                             println!(" Artist: {}", value);
                         }
@@ -77,11 +56,8 @@ fn main() -> Result<(), Error> {
                             println!(" Track: {}", value);
                         }
                     },
-                            MpvDataType::Null => (),
-                            _ => panic!("Wrong data type for 'metadata' value: {:?}", data),
-                        }
-                    },
-                    _ => panic!("Wrong property changed: {}", name),
+                    Property::Metadata(None) => (),
+                    Property::Unknown { name: _, id: _, data: _ } => (),
                 }
             },
             Event::Shutdown => return Ok(()),

src/ipc.rs

@@ -1,4 +1,4 @@
-use log::debug;
+use log::{debug, warn};
 use serde_json::{self, Value};
 use std::collections::HashMap;
 use std::io::BufReader;
@@ -279,6 +279,40 @@ pub fn observe_mpv_property(instance: &Mpv, id: &isize, property: &str) -> Resul
     }
 }
 
+fn try_convert_property(name: &str, id: isize, data: MpvDataType) -> Event {
+    let property = match name {
+        "path" => match data {
+            MpvDataType::String(value) => Property::Path(Some(value)),
+            MpvDataType::Null => Property::Path(None),
+            _ => unimplemented!(),
+        },
+        "pause" => match data {
+            MpvDataType::Bool(value) => Property::Pause(value),
+            _ => unimplemented!(),
+        },
+        "playback-time" => match data {
+            MpvDataType::Double(value) => Property::PlaybackTime(Some(value)),
+            MpvDataType::Null => Property::PlaybackTime(None),
+            _ => unimplemented!(),
+        },
+        "duration" => match data {
+            MpvDataType::Double(value) => Property::Duration(Some(value)),
+            MpvDataType::Null => Property::Duration(None),
+            _ => unimplemented!(),
+        },
+        "metadata" => match data {
+            MpvDataType::HashMap(value) => Property::Metadata(Some(value)),
+            MpvDataType::Null => Property::Metadata(None),
+            _ => unimplemented!(),
+        },
+        _ => {
+            warn!("Property {} not implemented", name);
+            Property::Unknown { name: name.to_string(), id, data }
+        }
+    };
+    Event::PropertyChange(property)
+}
+
 pub fn listen(instance: &mut Mpv) -> Result<Event, Error> {
     let mut response = String::new();
     instance.reader.read_line(&mut response).unwrap();
@@ -391,7 +425,7 @@ pub fn listen(instance: &mut Mpv) -> Result<Event, Error> {
                             }
                         }
 
-                        event = Event::PropertyChange { name, id, data }
+                        event = try_convert_property(name.as_ref(), id, data);
                     }
                     _ => {
                         event = Event::Unimplemented;

src/lib.rs

@@ -36,13 +36,23 @@ pub enum Event {
     MetadataUpdate,
     Seek,
     PlaybackRestart,
-    PropertyChange {
+    PropertyChange(Property),
+    ChapterChange,
+    Unimplemented,
+}
+
+#[derive(Debug)]
+pub enum Property {
+    Path(Option<String>),
+    Pause(bool),
+    PlaybackTime(Option<f64>),
+    Duration(Option<f64>),
+    Metadata(Option<HashMap<String, MpvDataType>>),
+    Unknown {
         name: String,
         id: isize,
         data: MpvDataType,
     },
-    ChapterChange,
-    Unimplemented,
 }
 
 #[derive(Debug)]