[Blink,RemotePlayback] Use PresentationController for availability

third_party/WebKit/Source/modules/remoteplayback/RemotePlayback.h

 // Copyright 2016 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.
 
 #ifndef RemotePlayback_h
 #define RemotePlayback_h
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "core/dom/ExecutionContext.h"
 #include "core/events/EventTarget.h"
 #include "modules/ModulesExport.h"
 #include "platform/bindings/ActiveScriptWrappable.h"
 #include "platform/bindings/TraceWrapperMember.h"
 #include "platform/heap/Handle.h"
 #include "platform/wtf/Compiler.h"
 #include "platform/wtf/text/AtomicString.h"
 #include "platform/wtf/text/WTFString.h"
+#include "public/platform/WebURL.h"
+#include "public/platform/WebVector.h"
+#include "public/platform/modules/presentation/WebPresentationAvailabilityObserver.h"
 #include "public/platform/modules/remoteplayback/WebRemotePlaybackAvailability.h"
 #include "public/platform/modules/remoteplayback/WebRemotePlaybackClient.h"
 #include "public/platform/modules/remoteplayback/WebRemotePlaybackState.h"
 
 namespace blink {
 
 class AvailabilityCallbackWrapper;
 class HTMLMediaElement;
 class RemotePlaybackAvailabilityCallback;
 class ScriptPromiseResolver;
 class ScriptState;
 
 class MODULES_EXPORT RemotePlayback final
     : public EventTargetWithInlineData,
       public ActiveScriptWrappable<RemotePlayback>,
-      NON_EXPORTED_BASE(public WebRemotePlaybackClient) {
+      NON_EXPORTED_BASE(public WebRemotePlaybackClient),
+      public WebPresentationAvailabilityObserver {
   DEFINE_WRAPPERTYPEINFO();
   USING_GARBAGE_COLLECTED_MIXIN(RemotePlayback);
 
  public:
   static RemotePlayback* Create(HTMLMediaElement&);
 
   // Notifies this object that disableRemotePlayback attribute was set on the
   // corresponding media element.
   void RemotePlaybackDisabled();
 
@@ skipping 22 matching lines @@
 
   // The implementation of prompt(). Used by the native remote playback button.
   void PromptInternal();
 
   // The implementation of watchAvailability() and cancelWatchAvailability().
   int WatchAvailabilityInternal(AvailabilityCallbackWrapper*);
   bool CancelWatchAvailabilityInternal(int id);
 
   WebRemotePlaybackState GetState() const { return state_; }
 
+  // WebPresentationAvailabilityObserver implementation.
+  void AvailabilityChanged(bool) override;
+  const WebVector<WebURL>& Urls() const override;

[mark a. foltz, 2017/05/31 21:16:41]

Can this method have a more specific name?

+
   // WebRemotePlaybackClient implementation.
   void StateChanged(WebRemotePlaybackState) override;
   void AvailabilityChanged(WebRemotePlaybackAvailability) override;
   void PromptCancelled() override;
   bool RemotePlaybackAvailable() const override;
+  void SourceChanged(const WebURL&) override;
 
   // ScriptWrappable implementation.
   bool HasPendingActivity() const final;
 
   DEFINE_ATTRIBUTE_EVENT_LISTENER(connecting);
   DEFINE_ATTRIBUTE_EVENT_LISTENER(connect);
   DEFINE_ATTRIBUTE_EVENT_LISTENER(disconnect);
 
   DECLARE_VIRTUAL_TRACE();
   DECLARE_VIRTUAL_TRACE_WRAPPERS();
 
  private:
   friend class V8RemotePlayback;
   friend class RemotePlaybackTest;
   friend class MediaControlsImplTest;
 
   explicit RemotePlayback(HTMLMediaElement&);
 
   // Calls the specified availability callback with the current availability.
   // Need a void() method to post it as a task.
   void NotifyInitialAvailability(int callback_id);
 
+  // Starts or stops listening if there're both
+  // registered availability callbacks and a valid source set.
+  void UpdateListeningState();
+
+  // Fills |availability_urls_| with the info about the given source.
+  // TODO(avayvod): support extra info fetched by the video stack and multiple
+  // sources.
+  void UpdateAvailabilityUrls(const WebURL& source);
+
   WebRemotePlaybackState state_;
   WebRemotePlaybackAvailability availability_;
   HeapHashMap<int, TraceWrapperMember<AvailabilityCallbackWrapper>>
       availability_callbacks_;
   Member<HTMLMediaElement> media_element_;
   Member<ScriptPromiseResolver> prompt_promise_resolver_;
+  WebVector<WebURL> availability_urls_;

[mark a. foltz, 2017/05/31 21:16:41]

Only one element here seems to be used at any one time.

+  bool is_listening_;
 };
 
 }  // namespace blink
 
 #endif  // RemotePlayback_h