Add media controls to MediaSession in Blink

third_party/WebKit/Source/modules/mediasession/MediaSession.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "modules/mediasession/MediaSession.h"
 
 #include "bindings/core/v8/ScriptState.h"
 #include "core/dom/Document.h"
 #include "core/dom/ExecutionContext.h"
 #include "core/frame/LocalFrame.h"
+#include "modules/EventTargetModules.h"
 #include "modules/mediasession/MediaMetadata.h"
 #include "modules/mediasession/MediaMetadataSanitizer.h"
 #include "public/platform/InterfaceProvider.h"
 #include <memory>
 
 namespace blink {
 
-MediaSession::MediaSession() = default;
+MediaSession::MediaSession(ScriptState* scriptState)
+    : m_scriptState(scriptState) {}
 
-MediaSession* MediaSession::create() {
-  return new MediaSession();
+MediaSession* MediaSession::create(ScriptState* scriptState) {
+  return new MediaSession(scriptState);
 }
 
-void MediaSession::setMetadata(ScriptState* scriptState,
-                               MediaMetadata* metadata) {
-  if (getService(scriptState)) {
-    getService(scriptState)
-        ->SetMetadata(
-            MediaMetadataSanitizer::sanitizeAndConvertToMojo(metadata));
+void MediaSession::setMetadata(MediaMetadata* metadata) {
+  if (mojom::blink::MediaSessionService* service =
+          getService(m_scriptState.get())) {
+    service->SetMetadata(
+        MediaMetadataSanitizer::sanitizeAndConvertToMojo(metadata));
   }
 }
 
-MediaMetadata* MediaSession::metadata(ScriptState*) const {
+MediaMetadata* MediaSession::metadata() const {
   return m_metadata;
 }
 
+const WTF::AtomicString& MediaSession::interfaceName() const {
+  return EventTargetNames::MediaSession;
+}
+
+ExecutionContext* MediaSession::getExecutionContext() const {
+  return m_scriptState->getExecutionContext();
+}
+
 mojom::blink::MediaSessionService* MediaSession::getService(
     ScriptState* scriptState) {
   if (!m_service) {
     InterfaceProvider* interfaceProvider = nullptr;
     DCHECK(scriptState->getExecutionContext()->isDocument())
         << "MediaSession::getService() is only available from a frame";
     Document* document = toDocument(scriptState->getExecutionContext());
     if (document->frame())
       interfaceProvider = document->frame()->interfaceProvider();
 
     if (interfaceProvider)
       interfaceProvider->getInterface(mojo::GetProxy(&m_service));
   }
   return m_service.get();
 }
 
+// TODO(zqzhang): register listener to MediaSessionService. See
+// https://crbug.com/xxxxxx

[whywhat, 2016/10/17 15:32:34]

The link gives me 404.

[Zhiqiang Zhang (Slow), 2016/10/17 17:19:08]

Fixed.

+#define DEFINE_MEDIA_SESSION_ATTRIBUTE_EVENT_LISTENER(attribute)    \

[whywhat, 2016/10/17 15:32:35]

Ditto in the header.

[Zhiqiang Zhang (Slow), 2016/10/17 17:19:08]

Done.

+  EventListener* MediaSession::on##attribute() {                    \
+    return getAttributeEventListener(EventTypeNames::attribute);    \
+  }                                                                 \
+  void MediaSession::setOn##attribute(EventListener* listener) {    \
+    setAttributeEventListener(EventTypeNames::attribute, listener); \
+  }
+
+DEFINE_MEDIA_SESSION_ATTRIBUTE_EVENT_LISTENER(play);
+DEFINE_MEDIA_SESSION_ATTRIBUTE_EVENT_LISTENER(pause);
+DEFINE_MEDIA_SESSION_ATTRIBUTE_EVENT_LISTENER(playpause);
+DEFINE_MEDIA_SESSION_ATTRIBUTE_EVENT_LISTENER(previoustrack);
+DEFINE_MEDIA_SESSION_ATTRIBUTE_EVENT_LISTENER(nexttrack);
+DEFINE_MEDIA_SESSION_ATTRIBUTE_EVENT_LISTENER(seekforward);
+DEFINE_MEDIA_SESSION_ATTRIBUTE_EVENT_LISTENER(seekbackward);
+
 DEFINE_TRACE(MediaSession) {
   visitor->trace(m_metadata);
+  EventTargetWithInlineData::trace(visitor);
 }
 
 }  // namespace blink