[Presentation API] 1-UA presentation support + presenter APIs.

content/public/browser/presentation_service_delegate.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 CONTENT_PUBLIC_BROWSER_PRESENTATION_SERVICE_DELEGATE_H_
 #define CONTENT_PUBLIC_BROWSER_PRESENTATION_SERVICE_DELEGATE_H_
 
 #include <string>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/presentation_session.h"
 #include "content/public/browser/presentation_session_message.h"
 
 namespace content {
 
 class PresentationScreenAvailabilityListener;
 class PresentationSessionStateListener;
 
 // Param #0: a vector of messages that are received.
 // Param #1: tells the callback handler that it may reuse strings or buffers
 //           in the messages contained within param #0.
 using PresentationSessionMessageCallback = base::Callback<
     void(const ScopedVector<content::PresentationSessionMessage>&, bool)>;
 
+using PresentationReceiverSessionAvailableCallback =
+    base::Callback<void(const content::PresentationSessionInfo*)>;
+
+using SendMessageCallback = base::Callback<void(bool)>;
+
 // An interface implemented by embedders to handle presentation API calls
 // forwarded from PresentationServiceImpl.
 class CONTENT_EXPORT PresentationServiceDelegate {
  public:
   // Observer interface to listen for changes to PresentationServiceDelegate.
   class CONTENT_EXPORT Observer {
    public:
     // Called when the PresentationServiceDelegate is being destroyed.
     virtual void OnDelegateDestroyed() = 0;
 
     // Called when the default presentation has been started outside of a
     // Presentation API context (e.g., browser action). This will not be called
     // if the session was created as a result of Presentation API's
     // StartSession()/JoinSession().
     virtual void OnDefaultPresentationStarted(
         const PresentationSessionInfo& session) = 0;
 
    protected:
     virtual ~Observer() {}
   };
 
   using PresentationSessionSuccessCallback =
       base::Callback<void(const PresentationSessionInfo&)>;
   using PresentationSessionErrorCallback =
       base::Callback<void(const PresentationError&)>;
-  using SendMessageCallback = base::Callback<void(bool)>;
 
   virtual ~PresentationServiceDelegate() {}
 
   // Registers an observer associated with frame with |render_process_id|
   // and |render_frame_id| with this class to listen for updates.
   // This class does not own the observer.
   // It is an error to add an observer if there is already an observer for that
   // frame.
   virtual void AddObserver(int render_process_id,
                            int render_frame_id,
@@ skipping 107 matching lines @@
   // Continuously listen for presentation session state changes for a session.
   // Returns true if |listener| is sucessfully registered.
   // |render_process_id|, |render_frame_id|: ID of frame.
   // |session|: Presentation session to listen for state changes.
   // |listener|: The listener to be invoked whenever there is a state change.
   //             Not owned by this class.
   virtual bool ListenForSessionStateChange(
       int render_process_id,
       int render_frame_id,
       content::PresentationSessionStateListener* listener) = 0;
+
+  // Gets a receiver presentation session for the offscreen presentation hosted
+  // on the offscreen tab containing this frame, or waits until one is
+  // available.

[mark a. foltz, 2015/10/12 21:56:10]

Registers a callback to be notified when the offscreen presentation
corresponding to the frame is available.

[miu, 2015/10/14 01:54:57]

I'm not sure "register" is the right verb here, though.  This is a one-time
callback, not a repeat callback.

+  // Runs |callback| once the receiver becomes available.  |callback| will be
+  // run during this method call if the receiver is already available, or at
+  // some later time when a receiver presentation session becomes available.
+  // It is possible that |callback| will never be run if a receiver never
+  // becomes available.
+  // If |render_process_id| and |render_frame_id| do not refer to the main
+  // render frame of this WebContents, |callback| will be immediately invoked
+  // with null.
+  virtual void NotifyWhenReceiverSessionIsAvailable(
+      int render_process_id,
+      int render_frame_id,
+      const PresentationReceiverSessionAvailableCallback& callback) = 0;
+
+  // Gets all receiver presentation sessions for the offscreen presentation
+  // hosted on the offscreen tab containing this frame.

[mark a. foltz, 2015/10/12 21:56:10]

Returns all presentation sessions for the offscreen presentation corresponding
to the given frame (if any).

[imcheng, 2015/10/17 01:00:24]

Done.

+  // Unlike |GetPresentationReceiverSession|, this method immediately returns

[miu, 2015/10/14 01:54:57]

This part of the comment is stale now (GetPresentationReceiverSession was
renamed).  Suggest you just delete it since the new naming makes things clear.

[imcheng, 2015/10/17 01:00:24]

Done.

+  // all receiver sessions that are currently available.
+  // If |render_process_id| and |render_frame_id| do not refer to the main
+  // render frame of this WebContents, an empty vector will be returned.
+  virtual std::vector<content::PresentationSessionInfo>

[miu, 2015/10/14 01:54:57]

style: Per style guide, consider having the caller provide the vector via an
output argument instead:

  virtual bool GetPresentationReceiverSessions(int, int,
      std::vector<PresSessInfo>* sessions);

(Then you can return false if |render_process_id| and |render_frame_id| are bad
references.)

[imcheng, 2015/10/17 01:00:24]

Done.

+  GetPresentationReceiverSessions(int render_process_id,
+                                  int render_frame_id) = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_PRESENTATION_SERVICE_DELEGATE_H_