[Presentation API] Additional plumbing for PresentationServiceImpl.

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 "base/callback.h"
 #include "content/common/content_export.h"
+#include "content/public/browser/presentation_session.h"
 
 namespace content {
 
 class PresentationScreenAvailabilityListener;
 
 // 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;
 
    protected:
     virtual ~Observer() {}
   };
 
+  using PresentationSessionSuccessCallback =
+      base::Callback<void(const PresentationSessionInfo&)>;
+  using PresentationSessionErrorCallback =
+      base::Callback<void(const PresentationError&)>;
+
   virtual ~PresentationServiceDelegate() {}
 
   // Registers an observer with this class to listen for updates to this class.
   // This class does not own the observer.
   // It is an error to add an observer if it has already been added before.
   virtual void AddObserver(Observer* observer) = 0;
   // Unregisters an observer with this class.
   virtual void RemoveObserver(Observer* observer) = 0;
 
   // Registers |listener| to continuously listen for
   // availability updates for a presentation URL, originated from the frame
   // given by |render_process_id| and |render_frame_id|.
   // This class does not own |listener|.
   // Returns true on success.
   // This call will return false if a listener with the same presentation URL
   // from the same frame is already registered.
   virtual bool AddScreenAvailabilityListener(
       int render_process_id,
       int render_frame_id,
       PresentationScreenAvailabilityListener* listener) = 0;
 
   // Unregisters |listener| originated from the frame given by
   // |render_process_id| and |render_frame_id| from this class. The listener
   // will no longer receive availability updates.
   virtual void RemoveScreenAvailabilityListener(
       int render_process_id,
       int render_frame_id,
       PresentationScreenAvailabilityListener* listener) = 0;
 
-  // Unregisters all listeners associated with the frame given by
-  // |render_process_id| and |render_frame_id|.
-  virtual void RemoveAllScreenAvailabilityListeners(
+  // Resets the presentation state for the frame given by |render_process_id|
+  // and |render_frame_id|.
+  // This unregisters all listeners associated with the given frame, and clears
+  // the default presentation URL and ID set for the frame.
+  virtual void Reset(
       int render_process_id,
       int render_frame_id) = 0;
+
+  // Sets the default presentation URL and ID for frame given by
+  // |render_process_id| and |render_frame_id|.
+  // If |default_presentation_url| is empty, the default presentation URL will
+  // be cleared.
+  virtual void SetDefaultPresentationUrl(
+      int render_process_id,
+      int render_frame_id,
+      const std::string& default_presentation_url,
+      const std::string& default_presentation_id) = 0;
+
+  // Starts a new presentation session.
+  // This brings up a screen list for the user to select a screen to

[mark a. foltz, 2015/03/18 00:10:58]

Actually that's up to the embedder :)

Maybe, "Typically, the embedder will allow the user to select a screen to show
the |presentation_url|."

[imcheng, 2015/03/18 00:56:53]

Done.

+  // establish the presentation session on.
+  // |render_process_id|, |render_frame_id|: ID of originating frame.
+  // |presentation_url|: URL of the presentation. If empty, fall back to

[mark a. foltz, 2015/03/18 00:10:58]

presentation_url should be mandatory for all calls to startSession.
It's optional for querying for screen availability.

[imcheng, 2015/03/18 00:56:53]

Done.

+  // falling back on "1-UA" mode, i.e. offscreen tab rendering.
+  // |presentation_id|: The caller may provide an non-empty string to be used
+  // as the ID of the presentation. If this is an empty string, the embedder
+  // will automatically generate one.
+  // |success_cb|: Invoked with session info, if presentation session started
+  // successfully.
+  // |error_cb|: Invoked with error reason, if presentation session did not
+  // start.
+  virtual 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) = 0;
+
+  // Joins an existing presentation session. Unlike StartSession(), this
+  // does not bring a screen list UI.
+  // |render_process_id|, |render_frame_id|: ID for originating frame.
+  // |presentation_url|: URL of the presentation. If empty, fall back to

[mark a. foltz, 2015/03/18 00:10:58]

Also mandatory for joinSession().

[imcheng, 2015/03/18 00:56:53]

Done.

+  // falling back on "1-UA" mode, i.e. offscreen tab rendering.
+  // |presentation_id|: The ID of the presentation to join.
+  // |success_cb|: Invoked with session info, if presentation session joined
+  // successfully.
+  // |error_cb|: Invoked with error reason, if joining failed.
+  virtual 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) = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_PRESENTATION_SERVICE_DELEGATE_H_