[Presentation API] Add support for multiple URLs in PresentationRequest on Media Router UI side

chrome/browser/ui/webui/media_router/query_result_manager.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_WEBUI_MEDIA_ROUTER_QUERY_RESULT_MANAGER_H_
 #define CHROME_BROWSER_UI_WEBUI_MEDIA_ROUTER_QUERY_RESULT_MANAGER_H_
 
 #include <map>
 #include <memory>
 #include <set>
+#include <unordered_set>
 #include <vector>
 
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/observer_list.h"
 #include "chrome/browser/media/router/media_routes_observer.h"
 #include "chrome/browser/media/router/media_sink.h"
 #include "chrome/browser/media/router/media_source.h"
 #include "chrome/browser/ui/webui/media_router/media_cast_mode.h"
 #include "chrome/browser/ui/webui/media_router/media_sink_with_cast_modes.h"
 
 namespace media_router {
 
 class MediaRouter;
 class MediaSinksObserver;
 struct RoutesQueryResult;
 struct SinksQueryResult;
 
 // The Media Router dialog allows the user to initiate casting using one of
 // several actions (each represented by a cast mode).  Each cast mode is
-// associated with a media source.  This class allows the dialog to receive
-// lists of MediaSinks compatible with the cast modes available through the
-// dialog.
+// associated with a vector of media sources.  This class allows the dialog to
+// receive lists of MediaSinks compatible with the cast modes available through
+// the dialog.
 //
 // Typical use:
 //
 //   GURL origin("https://origin.com");
 //   QueryResultManager::Observer* observer = ...;
 //   QueryResultManager result_manager(router);
 //   result_manager.AddObserver(observer);
 //   result_manager.StartSinksQuery(MediaCastMode::DEFAULT,
-//       MediaSourceForPresentationUrl("http://google.com"), origin);
+//       {MediaSourceForPresentationUrl("http://google.com")}, origin);
 //   result_manager.StartSinksQuery(MediaCastMode::TAB_MIRROR,
-//       MediaSourceForTab(123), origin);
+//       {MediaSourceForTab(123)}, origin);
 //   ...
 //   [Updates will be received by observer via OnResultsUpdated()]
 //   ...
 //   [When info on MediaSource is needed, i.e. when requesting route for a mode]
 //   CastModeSet cast_modes = result_manager.GetSupportedCastModes();
 //   [Logic to select a MediaCastMode from the set]
-//   MediaSource source = result_manager.GetSourceForCastMode(
-//       MediaCastMode::TAB_MIRROR);
+//   MediaSource source = result_manager.GetSourceForCastModeAndSink(
+//       MediaCastMode::TAB_MIRROR, sink_of_interest);
 //   if (!source.Empty()) {
 //     ...
 //   }
 //
 // Not thread-safe.  Must be used on the UI thread.
 class QueryResultManager {
  public:
   class Observer {
    public:
     virtual ~Observer() {}
 
     // Updated results have been received.
     // |sinks|: List of sinks and the cast modes they are compatible with.
     virtual void OnResultsUpdated(
         const std::vector<MediaSinkWithCastModes>& sinks) = 0;
   };
 
   explicit QueryResultManager(MediaRouter* media_router);
   ~QueryResultManager();
 
   // Adds/removes an observer that is notified with query results.
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);
 
-  // Requests a list of MediaSinks compatible with |source| for |cast_mode|
-  // from |origin|.
+  // Requests a list of MediaSinks compatible with |sources| for |cast_mode|
+  // from |origin|. |sources| should be in descending order of priority.
   // Results are sent to all observers registered with AddObserver().
   //
-  // May start a new query in the Media Router for the registered source if
-  // there is no existing query for it.  If there is an existing query for
-  // |cast_mode|, it is stopped.
+  // May start new queries in the Media Router for the registered sources if
+  // there are no existing queries for it.  If there are existing queries for
+  // |cast_mode|, they are stopped.
   //
-  // If |source| is empty, no new queries are begun.
+  // If |sources| is empty, no new queries are begun.
   void StartSinksQuery(MediaCastMode cast_mode,
-                       const MediaSource& source,
+                       const std::vector<MediaSource>& sources,
                        const GURL& origin);
 
   // Stops notifying observers for |cast_mode|.
   void StopSinksQuery(MediaCastMode cast_mode);
 
   // Gets the set of cast modes that are being actively queried.
   CastModeSet GetSupportedCastModes() const;
 
-  // Returns the MediaSource registered for |cast_mode|.  Returns an empty
-  // MediaSource if there is none.
-  MediaSource GetSourceForCastMode(MediaCastMode cast_mode) const;
+  // Gets the highest-priority source for the cast mode that is supported by
+  // the sink. Returns an empty MediaSource if there isn't any.
+  MediaSource GetSourceForCastModeAndSink(
+      MediaCastMode cast_mode, MediaSink::Id sink_id) const;
+
+  // Returns all the sources registered for |cast_mode|.  Returns an empty
+  // vector if there is none.
+  std::vector<MediaSource> GetSourcesForCastMode(MediaCastMode cast_mode) const;
 
  private:
   class CastModeMediaSinksObserver;
 
   FRIEND_TEST_ALL_PREFIXES(QueryResultManagerTest, Observers);
   FRIEND_TEST_ALL_PREFIXES(QueryResultManagerTest, StartRoutesDiscovery);
   FRIEND_TEST_ALL_PREFIXES(QueryResultManagerTest, MultipleQueries);
+  FRIEND_TEST_ALL_PREFIXES(QueryResultManagerTest, MultipleUrls);
 
-  // Sets the media source for |cast_mode|.
-  void SetSourceForCastMode(MediaCastMode cast_mode, const MediaSource& source);
+  // Sets the media sources for |cast_mode|.
+  void SetSourcesForCastMode(

[mark a. foltz, 2016/08/23 20:46:47]

Doesn't this depend on the sink?  Or is this to keep track of which sources we
need to register observers for?

[takumif, 2016/08/23 22:13:09]

It's the latter.

+      MediaCastMode cast_mode, const std::vector<MediaSource>& source);
 
-  // Stops and destroys the MediaSinksObserver for |cast_mode|.
-  void RemoveObserverForCastMode(MediaCastMode cast_mode);
+  // Stops and destroys the MediaSinksObservers for |cast_mode|.
+  void RemoveObserversForCastMode(MediaCastMode cast_mode);
 
-  // Returns true if the |entry|'s sink is compatible with at least one cast
-  // mode.
-  bool IsValid(const MediaSinkWithCastModes& entry) const;
+  // Set all the sinks to not support the cast mode.
+  void ResetSinkCompatibilityForCastMode(MediaCastMode cast_mode);
 
   // Modifies the current set of results with |result| associated with
-  // |cast_mode|.
+  // |cast_mode| and |source|.
   void UpdateWithSinksQueryResult(MediaCastMode cast_mode,
-                                  const std::vector<MediaSink>& result);
+                                  const MediaSource source,
+                                  const std::vector<MediaSink>& result_sinks);
 
   // Notifies observers that results have been updated.
   void NotifyOnResultsUpdated();
 
+  // Returns the first source on the vector supported by the sink. Returns an
+  // empty |MediaSource| if none exists.
+  MediaSource GetFirstSourceSupportedBySink(

[mark a. foltz, 2016/08/23 20:46:47]

Doesn't this depend on the cast mode?

Also, this could be a method on MediaSinkWithCastModes.

+    std::vector<MediaSource> sources, MediaSink::Id sink_id) const;
+
+  // Returns true if the source is in the set of sources supported by the sink.
+  bool SinkSupportsSource(MediaSink sink, MediaSource source) const;

[mark a. foltz, 2016/08/23 20:46:47]

This could be a method on MediaSinkWithCastModes.

+
+  // Creates a MediaSinkWithCastModes that contains the sink and the cast modes
+  // it supports.
+  MediaSinkWithCastModes GetMediaSinkWithCastModes(const MediaSink& sink);

[mark a. foltz, 2016/08/23 20:46:47]

return const ref

+
   // MediaSinksObservers that listens for compatible MediaSink updates.
   // Each observer is associated with a MediaCastMode. Results received by
   // observers are propagated back to this class.
-  std::map<MediaCastMode, std::unique_ptr<MediaSinksObserver>> sinks_observers_;
+  std::map<MediaCastMode, std::vector<std::unique_ptr<MediaSinksObserver>>>
+  sinks_observers_;
 
   // Holds registrations of MediaSources for cast modes.
-  std::map<MediaCastMode, MediaSource> cast_mode_sources_;
+  std::map<MediaCastMode, std::vector<MediaSource>> cast_mode_sources_;
 
-  // Holds all known sinks and their associated cast modes.
-  std::map<MediaSink::Id, MediaSinkWithCastModes> all_sinks_;
+  // Holds all known sinks along with the cast modes and sources they support.
+  std::map<MediaSink, std::map<MediaCastMode,

[mark a. foltz, 2016/08/23 20:46:47]

These nested data structures are really hard to understand.  It seems like this
value could be folded into MediaSinkWithCastModes by having MSWCM be an ordered
map of CastMode -> MediaSource.

[takumif, 2016/08/23 22:13:09]

This could be a map from sink to unordered set of sources. I believe we'll still
need per-sink set(s) of supported sources, as I mentioned in my reply.

+      std::unordered_set<MediaSource::Id>>, MediaSink::Compare> all_sinks_;
 
   // Registered observers.
   base::ObserverList<Observer> observers_;
 
   // Not owned by this object.
   MediaRouter* const router_;
 
   DISALLOW_COPY_AND_ASSIGN(QueryResultManager);
 };
 
 }  // namespace media_router
 
 #endif  // CHROME_BROWSER_UI_WEBUI_MEDIA_ROUTER_QUERY_RESULT_MANAGER_H_