[MediaRouter] Add implementation of PresentationServiceDelegate

chrome/browser/media/router/presentation_service_delegate_impl.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_MEDIA_ROUTER_PRESENTATION_SERVICE_DELEGATE_IMPL_H_
+#define CHROME_BROWSER_MEDIA_ROUTER_PRESENTATION_SERVICE_DELEGATE_IMPL_H_
+
+#include <map>
+#include <string>
+#include <utility>
+
+#include "base/gtest_prod_util.h"
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "base/observer_list.h"
+#include "chrome/browser/media/router/media_router.h"
+#include "chrome/browser/media/router/media_source.h"
+#include "chrome/browser/media/router/presentation_frame_map.h"
+#include "content/public/browser/presentation_service_delegate.h"
+#include "content/public/browser/web_contents_observer.h"
+#include "content/public/browser/web_contents_user_data.h"
+
+namespace content {
+class RenderFrameHost;
+class PresentationScreenAvailabilityListener;
+class WebContents;
+struct PresentationSessionInfo;
+}
+
+namespace media_router {
+
+class MediaRoute;
+class MediaSinksObserver;
+
+// Implementation of PresentationServiceDelegate that that interfaces an
+// instance of WebContents with the Chrome Media Router.
+// In addition to fulfilling Presentation requests, it also
+// provide tab-level information that is required for creating
+// browser-initiated sessions.
+class PresentationServiceDelegateImpl
+    : public content::WebContentsUserData<PresentationServiceDelegateImpl>,
+      public content::PresentationServiceDelegate {
+ public:
+  using RenderFrameHostId =
+      content::PresentationServiceDelegate::RenderFrameHostId;
+
+  ~PresentationServiceDelegateImpl() override;
+
+  // content::PresentationServiceDelegate implementation.
+  // PresentationScreenAvailabilityListener is one per
+  // (frame, presentation URL), while PresentationServiceDelegate::Observer
+  // is one per frame.
+  void AddObserver(
+      int render_process_id,
+      int render_frame_id,
+      content::PresentationServiceDelegate::Observer* observer) override;
+  void RemoveObserver(int render_process_id, int render_frame_id) override;
+  bool AddScreenAvailabilityListener(
+      int render_process_id,
+      int render_frame_id,
+      content::PresentationScreenAvailabilityListener* listener) override;
+  void RemoveScreenAvailabilityListener(
+      int render_process_id,
+      int render_frame_id,
+      content::PresentationScreenAvailabilityListener* listener) override;
+  void Reset(int render_process_id, int render_frame_id) override;
+  void SetDefaultPresentationUrl(
+      int render_process_id,
+      int render_frame_id,
+      const std::string& default_presentation_url,
+      const std::string& default_presentation_id) override;
+  void StartSession(int render_process_id,
+                    int render_frame_id,
+                    const std::string& presentation_url,
+                    const std::string& presentation_id,
+                    const PresentationSessionSuccessCallback& success_cb,
+                    const PresentationSessionErrorCallback& error_cb) override;
+  void JoinSession(int render_process_id,
+                   int render_frame_id,
+                   const std::string& presentation_url,
+                   const std::string& presentation_id,
+                   const PresentationSessionSuccessCallback& success_cb,
+                   const PresentationSessionErrorCallback& error_cb) override;
+  void ListenForSessionMessages(
+      int render_process_id,
+      int render_frame_id,
+      const PresentationSessionMessageCallback& message_cb) override;
+
+  // Notifies this object that |route| has been created or joined outside of a
+  // Presentation API request. The route could be due to
+  // browser action (e.g., browser initiated media router dialog) or
+  // a media route provider (e.g., autojoin).
+  void OnRouteCreated(const MediaRoute& route);
+
+  // Returns the default MediaSource for this tab if there is one.
+  // Returns an empty MediaSource otherwise.
+  MediaSource GetDefaultMediaSource() const;
+
+  // Observer interface for listening to default MediaSource changes for the
+  // WebContents.
+  class DefaultMediaSourceObserver {
+   public:
+    virtual ~DefaultMediaSourceObserver() {}
+
+    // Called when default media source for the corresponding WebContents has
+    // changed.
+    // |source|: New default MediaSource, or empty if default was removed.
+    // |source_host|: Host name of the frame that contains the default media
+    // source, or empty if there is no default media source.
+    virtual void OnDefaultMediaSourceChanged(
+        const MediaSource& source,
+        const std::string& source_host) = 0;
+  };
+
+  // Adds / removes an observer for listening to default MediaSource changes.
+  void AddDefaultMediaSourceObserver(DefaultMediaSourceObserver* observer);
+  void RemoveDefaultMediaSourceObserver(DefaultMediaSourceObserver* observer);
+
+  base::WeakPtr<PresentationServiceDelegateImpl> GetWeakPtr();
+
+ private:
+  explicit PresentationServiceDelegateImpl(content::WebContents* web_contents);
+  friend class content::WebContentsUserData<PresentationServiceDelegateImpl>;
+
+  friend class PresentationServiceDelegateImplTest;
+  friend class PresentationServiceDelegateImplBrowserTest;
+  FRIEND_TEST_ALL_PREFIXES(PresentationServiceDelegateImplTest,
+                           AddScreenAvailabilityListener);
+  FRIEND_TEST_ALL_PREFIXES(PresentationServiceDelegateImplTest,
+                           MaxNumObservers);
+  FRIEND_TEST_ALL_PREFIXES(PresentationServiceDelegateImplTest,
+                           AddListenerSameUrlTwice);
+  FRIEND_TEST_ALL_PREFIXES(PresentationServiceDelegateImplTest, Reset);
+  FRIEND_TEST_ALL_PREFIXES(PresentationServiceDelegateImplBrowserTest,
+                           RemoveObserversOnNavigation);
+
+  // Returns |listener|'s presentation URL as a MediaSource. If |listener| does
+  // not have a persentation URL, default to tab mirroring.
+  MediaSource GetMediaSourceFromListener(
+      content::PresentationScreenAvailabilityListener* listener);
+
+  // Returns the presentation ID to use for frame |rfh_id|.
+  // If |presentation_id| is non-empty, return it.
+  // Otherwise, check if a default presentation ID is set for that frame, and
+  // return it.
+  // Otherwise, returns a randomly generated string.
+  std::string GetOrGeneratePresentationId(

[mark a. foltz, 2015/05/14 22:20:46]

This is an odd method - it seems like it would be cleaner to have

GetDefaultPresentationId(rfh_id)

and 

GeneratePresentationId()

and have the calling code implement the correct logic, according to whether we
were starting presentation from a default URL/id or a URL/id passed with
StartSession().

[haibinlu, 2015/05/15 23:32:30]

removed the method for now. will split when adding requestRoute

+      RenderFrameHostId rfh_id,
+      const std::string& presentation_id) const;
+
+  // Returns |true| is frame |rfh_id| is the main frame of |web_contents_|.
+  bool IsMainFrame(RenderFrameHostId rfh_id) const;

[mark a. foltz, 2015/05/14 22:20:46]

This is to determine whether the frame's DPU has been chosen for browser
intitiated presentation?
Can we call this IsFrameForDefaultPresentation()?

[haibinlu, 2015/05/15 23:32:30]

This is for checking the main frame.

+
+  // Updates tab-level default MediaSource and source host name. If either
+  // changed, notify the observers.
+  void UpdateDefaultMediaSourceAndNotifyObservers(
+      const MediaSource& new_default_source,
+      const std::string& new_default_source_host);
+
+  void SetMediaRouterForTest(MediaRouter* router);
+
+  PresentationFrameMap frame_map_;

[mark a. foltz, 2015/05/14 22:20:46]

Add docstrings for class members.

[haibinlu, 2015/05/15 23:32:30]

Done.

+
+  MediaSource default_source_;
+  std::string default_source_host_;

[mark a. foltz, 2015/05/14 22:20:46]

Can this be derived from default_source_?

+
+  content::WebContents* web_contents_;
+
+  // Observers listening for changes to default media source. Not owned by
+  // this class.
+  ObserverList<DefaultMediaSourceObserver> default_media_source_observers_;
+
+  // Does not own this object.
+  MediaRouter* router_;
+
+  // NOTE: All WeakPtrs must be invalidated before member variables.
+  base::WeakPtrFactory<PresentationServiceDelegateImpl> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(PresentationServiceDelegateImpl);
+};
+
+}  // namespace media_router
+
+#endif  // CHROME_BROWSER_MEDIA_ROUTER_PRESENTATION_SERVICE_DELEGATE_IMPL_H_