Default media session actions

components/script/dom/htmlmediaelement.rs

@@ -1913,6 +1913,15 @@ impl HTMLMediaElement {
             self.media_element_load_algorithm();
         }
     }
+
+    fn send_media_session_event(&self, event: MediaSessionEvent) {
+        let global = self.global();
+        let media_session = global.as_window().Navigator().MediaSession();
+
+        media_session.register_media_instance(&self);
+
+        media_session.send_event(event);
+    }
 }
 
 // XXX Placeholder for [https://github.com/servo/servo/issues/22293]

components/script/dom/mediasession.rs

@@ -2,8 +2,10 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
+use crate::compartments::{AlreadyInCompartment, InCompartment};
 use crate::dom::bindings::callback::ExceptionHandling;
 use crate::dom::bindings::cell::DomRefCell;
+use crate::dom::bindings::codegen::Bindings::HTMLMediaElementBinding::HTMLMediaElementMethods;
 use crate::dom::bindings::codegen::Bindings::MediaSessionBinding;
 use crate::dom::bindings::codegen::Bindings::MediaSessionBinding::MediaSessionAction;
 use crate::dom::bindings::codegen::Bindings::MediaSessionBinding::MediaSessionActionHandler;
@@ -61,15 +63,38 @@ impl MediaSession {
         )
     }
 
+    pub fn register_media_instance(&self, media_instance: &HTMLMediaElement) {
+        self.media_instance.set(Some(media_instance));
+    }
+
     pub fn handle_action(&self, action: MediaSessionActionType) {
-        println!("HANDLE ACTION {:?}", action);
+        debug!("Handle media session action {:?} {:?}", action);
         if let Some(handler) = self.action_handlers.borrow().get(&action) {
             if handler.Call__(ExceptionHandling::Report).is_err() {
                 warn!("Error calling MediaSessionActionHandler callback");
             }
             return;
         }
-        // TODO default action.
+
+        // Default action.
+        if let Some(media) = self.media_instance.get() {
+            match action {
+                MediaSessionActionType::Play => {
+                    let in_compartment_proof = AlreadyInCompartment::assert(&self.global());
+                    media.Play(InCompartment::Already(&in_compartment_proof));
+                },
+                MediaSessionActionType::Pause => {
+                    media.Pause();
+                },
+                MediaSessionActionType::SeekBackward => {},
+                MediaSessionActionType::SeekForward => {},
+                MediaSessionActionType::PreviousTrack => {},
+                MediaSessionActionType::NextTrack => {},
+                MediaSessionActionType::SkipAd => {},
+                MediaSessionActionType::Stop => {},
+                MediaSessionActionType::SeekTo => {},
+            }
+        }
     }
 
     pub fn send_event(&self, event: MediaSessionEvent) {

components/script_traits/script_msg.rs

@@ -256,7 +256,7 @@ pub enum ScriptMsg {
     GetScreenAvailSize(IpcSender<DeviceIntSize>),
     /// Notifies the constellation about media session events
     /// (i.e. when there is metadata for the active media session, playback state changes...).
-    MediaSessionEvent(BrowsingContextId, MediaSessionEvent)
+    MediaSessionEvent(BrowsingContextId, MediaSessionEvent),
 }
 
 impl fmt::Debug for ScriptMsg {