MediaSession: refactor embedder API. Fix Android build

components/embedder_traits/lib.rs

@@ -219,10 +219,11 @@ pub struct MediaMetadata {
 }
 
 /// https://w3c.github.io/mediasession/#enumdef-mediasessionplaybackstate
+#[repr(i32)]
 #[derive(Clone, Debug, Deserialize, Serialize)]
 pub enum MediaSessionPlaybackState {
     /// The browsing context does not specify whether it’s playing or paused.
-    None_,
+    None_ = 1,
     /// The browsing context has paused media and it can be resumed.
     Playing,
     /// The browsing context is currently playing media and it can be paused.

ports/glutin/browser.rs

@@ -449,9 +449,9 @@ where
                         error!("Failed to store profile: {}", e);
                     }
                 },
-                EmbedderMsg::MediaSession(_) => {
-                    debug!("MediaSession received");
-                    // TODO(ferjm)
+                EmbedderMsg::MediaSessionEvent(_) => {
+                    debug!("MediaSessionEvent received");
+                    // TODO(ferjm): MediaSession support for Glutin based browsers.
                 },
             }
         }

ports/libsimpleservo/api/src/lib.rs

@@ -15,7 +15,7 @@ use servo::compositing::windowing::{
     WindowMethods,
 };
 use servo::embedder_traits::resources::{self, Resource, ResourceReaderMethods};
-use servo::embedder_traits::EmbedderMsg;
+use servo::embedder_traits::{EmbedderMsg, MediaSessionEvent};
 use servo::euclid::{Point2D, Rect, Scale, Size2D, Vector2D};
 use servo::keyboard_types::{Key, KeyState, KeyboardEvent};
 use servo::msg::constellation_msg::TraversalDirection;
@@ -42,7 +42,6 @@ thread_local! {
 /// It will be called to notify embedder that some events are available,
 /// and that perform_updates need to be called
 pub use servo::embedder_traits::EventLoopWaker;
-pub use servo::embedder_traits::MediaSessionEvent;
 
 pub struct InitOptions {
     pub args: Vec<String>,
@@ -127,12 +126,19 @@ pub trait HostTrait {
     fn on_shutdown_complete(&self);
     /// A text input is focused.
     fn on_ime_state_changed(&self, show: bool);
-    /// Gets sytem clipboard contents
+    /// Gets sytem clipboard contents.
     fn get_clipboard_contents(&self) -> Option<String>;
-    /// Sets system clipboard contents
+    /// Sets system clipboard contents.
     fn set_clipboard_contents(&self, contents: String);
-    /// Called when there is a new media session event.
-    fn on_media_session_event(&self, event: MediaSessionEvent);
+    /// Called when we get the media session metadata/
+    fn on_media_session_metadata(
+        &self,
+        title: String,
+        artist: Option<String>,
+        album: Option<String>,
+    );
+    /// Called when the media sessoin playback state changes.
+    fn on_media_session_playback_state_change(&self, state: i32);
 }
 
 pub struct ServoGlue {
@@ -585,7 +591,19 @@ impl ServoGlue {
                     self.callbacks.host_callbacks.on_ime_state_changed(false);
                 },
                 EmbedderMsg::MediaSessionEvent(event) => {
-                    self.callbacks.host_callbacks.on_media_session_event(event);
+                    match event {
+                        MediaSessionEvent::SetMetadata(metadata) => {
+                            self.callbacks.host_callbacks.on_media_session_metadata(
+                                metadata.title,
+                                metadata.artist,
+                                metadata.album,
+                            )
+                        },
+                        MediaSessionEvent::PlaybackStateChange(state) => self
+                            .callbacks
+                            .host_callbacks
+                            .on_media_session_playback_state_change(state as i32),
+                    };
                 },
                 EmbedderMsg::Status(..) |
                 EmbedderMsg::SelectFiles(..) |

ports/libsimpleservo/capi/src/lib.rs

@@ -216,8 +216,9 @@ pub struct CHostCallbacks {
     pub on_ime_state_changed: extern "C" fn(show: bool),
     pub get_clipboard_contents: extern "C" fn() -> *const c_char,
     pub set_clipboard_contents: extern "C" fn(contents: *const c_char),
-    // TODO(ferjm) pass C representation of media event.
-    pub on_media_session_event: extern "C" fn(),
+    pub on_media_session_metadata:
+        extern "C" fn(title: *const c_char, album: *const c_char, artist: *const c_char),
+    pub on_media_session_playback_state_change: extern "C" fn(state: i32),
 }
 
 /// Servo options
@@ -711,8 +712,24 @@ impl HostTrait for HostCallbacks {
         (self.0.set_clipboard_contents)(contents.as_ptr());
     }
 
-    fn on_media_session_event(&self, event: MediaSessionEvent) {
-        debug!("on_media_session_event (event: {:?})", event);
-        (self.0.on_media_session_event)();
+    fn on_media_session_metadata(
+        &self,
+        title: String,
+        artist: Option<String>,
+        album: Option<String>,
+    ) {
+        debug!(
+            "on_media_session_metadata ({:?} {:?} {:?})",
+            title, artist, album
+        );
+        let title = CString::new(title).expect("Can't create string");
+        let artist = CString::new(artist.unwrap_or(String::new())).expect("Can't create string");
+        let album = CString::new(album.unwrap_or(String::new())).expect("Can't create string");
+        (self.0.on_media_session_metadata)(title.as_ptr(), artist.as_ptr(), album.as_ptr());
+    }
+
+    fn on_media_session_playback_state_change(&self, state: i32) {
+        debug!("on_media_session_playback_state_change {:?}", state);
+        (self.0.on_media_session_playback_state_change)(state);
     }
 }

ports/libsimpleservo/jniapi/src/lib.rs

@@ -15,7 +15,9 @@ use jni::{errors, JNIEnv, JavaVM};
 use libc::{dup2, pipe, read};
 use log::Level;
 use simpleservo::{self, gl_glue, ServoGlue, SERVO};
-use simpleservo::{Coordinates, EventLoopWaker, HostTrait, InitOptions, VRInitOptions};
+use simpleservo::{
+    Coordinates, EventLoopWaker, HostTrait, InitOptions, MediaSessionEvent, VRInitOptions,
+};
 use std::os::raw::{c_char, c_int, c_void};
 use std::ptr::{null, null_mut};
 use std::sync::Arc;
@@ -508,6 +510,16 @@ impl HostTrait for HostCallbacks {
     }
 
     fn set_clipboard_contents(&self, _contents: String) {}
+
+    fn on_media_session_metadata(
+        &self,
+        _title: String,
+        _artist: Option<String>,
+        _album: Option<String>,
+    ) {
+    }
+
+    fn on_media_session_playback_state_change(&self, state: i32) {}
 }
 
 fn initialize_android_glue(env: &JNIEnv, activity: JObject) {