From f8246801ba47f66d205dae142d4d3498a304220e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fernando=20Jim=C3=A9nez=20Moreno?= <ferjmoreno@gmail.com>
Date: Fri, 4 Oct 2019 12:27:16 +0200
Subject: [PATCH] MediaSession registration

---
 components/script/dom/mediasession.rs | 33 +++++++++++++++++++++------
 components/script/script_thread.rs    | 27 ++++++++++++++++++++++
 2 files changed, 53 insertions(+), 7 deletions(-)

diff --git a/components/script/dom/mediasession.rs b/components/script/dom/mediasession.rs
index bb33c523374..6d9afa592e0 100644
--- a/components/script/dom/mediasession.rs
+++ b/components/script/dom/mediasession.rs
@@ -8,11 +8,13 @@ use crate::dom::bindings::codegen::Bindings::MediaSessionBinding::MediaSessionAc
 use crate::dom::bindings::codegen::Bindings::MediaSessionBinding::MediaSessionActionHandler;
 use crate::dom::bindings::codegen::Bindings::MediaSessionBinding::MediaSessionMethods;
 use crate::dom::bindings::codegen::Bindings::MediaSessionBinding::MediaSessionPlaybackState;
-use crate::dom::bindings::reflector::{reflect_dom_object, Reflector};
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
 use crate::dom::bindings::root::{DomRoot, MutNullableDom};
 use crate::dom::mediametadata::MediaMetadata;
 use crate::dom::window::Window;
+use crate::script_thread::ScriptThread;
 use dom_struct::dom_struct;
+use msg::constellation_msg::PipelineId;
 use std::rc::Rc;
 
 #[dom_struct]
@@ -25,18 +27,24 @@ pub struct MediaSession {
 }
 
 impl MediaSession {
-    fn new_inherited() -> MediaSession {
-        MediaSession {
+    #[allow(unrooted_must_root)]
+    fn new_inherited(pipeline_id: PipelineId) -> MediaSession {
+        let media_session = MediaSession {
             reflector_: Reflector::new(),
             metadata: Default::default(),
             playback_state: DomRefCell::new(MediaSessionPlaybackState::None),
-        }
+        };
+        ScriptThread::register_media_session(&media_session, pipeline_id);
+        media_session
     }
 
-    pub fn new(global: &Window) -> DomRoot<MediaSession> {
+    pub fn new(window: &Window) -> DomRoot<MediaSession> {
+        let pipeline_id = window
+            .pipeline_id()
+            .expect("Cannot create MediaSession without a PipelineId");
         reflect_dom_object(
-            Box::new(MediaSession::new_inherited()),
-            global,
+            Box::new(MediaSession::new_inherited(pipeline_id)),
+            window,
             MediaSessionBinding::Wrap,
         )
     }
@@ -71,3 +79,14 @@ impl MediaSessionMethods for MediaSession {
     ) {
     }
 }
+
+impl Drop for MediaSession {
+    fn drop(&mut self) {
+        let global = self.global();
+        let pipeline_id = global
+            .as_window()
+            .pipeline_id()
+            .expect("No PipelineId while dropping MediaSession");
+        ScriptThread::remove_media_session(pipeline_id);
+    }
+}
diff --git a/components/script/script_thread.rs b/components/script/script_thread.rs
index dbc4f0fb444..5aec6a8a57d 100644
--- a/components/script/script_thread.rs
+++ b/components/script/script_thread.rs
@@ -51,6 +51,7 @@ use crate::dom::event::{Event, EventBubbles, EventCancelable};
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::htmlanchorelement::HTMLAnchorElement;
 use crate::dom::htmliframeelement::{HTMLIFrameElement, NavigationType};
+use crate::dom::mediasession::MediaSession;
 use crate::dom::mutationobserver::MutationObserver;
 use crate::dom::node::{
     from_untrusted_node_address, window_from_node, Node, NodeDamage, ShadowIncluding,
@@ -696,6 +697,11 @@ pub struct ScriptThread {
 
     /// Code is running as a consequence of a user interaction
     is_user_interacting: Cell<bool>,
+
+    /// The MediaSessions registered for this Pipeline, if any.
+    /// There can only be one active MediaSession. The constellation
+    /// has the PipelineId of the active MediaSession, if any.
+    media_sessions: DomRefCell<HashMap<PipelineId, Dom<MediaSession>>>,
 }
 
 /// In the event of thread panic, all data on the stack runs its destructor. However, there
@@ -1365,6 +1371,7 @@ impl ScriptThread {
 
             node_ids: Default::default(),
             is_user_interacting: Cell::new(false),
+            media_sessions: DomRefCell::new(HashMap::new()),
         }
     }
 
@@ -3948,6 +3955,26 @@ impl ScriptThread {
             globals,
         )
     }
+
+    pub fn register_media_session(media_session: &MediaSession, pipeline_id: PipelineId) {
+        SCRIPT_THREAD_ROOT.with(|root| {
+            let script_thread = unsafe { &*root.get().unwrap() };
+            script_thread
+                .media_sessions
+                .borrow_mut()
+                .insert(pipeline_id, Dom::from_ref(media_session));
+        })
+    }
+
+    pub fn remove_media_session(pipeline_id: PipelineId) {
+        SCRIPT_THREAD_ROOT.with(|root| {
+            let script_thread = unsafe { &*root.get().unwrap() };
+            script_thread
+                .media_sessions
+                .borrow_mut()
+                .remove(&pipeline_id);
+        })
+    }
 }
 
 impl Drop for ScriptThread {