text: // 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 <memory>
  #include <string>
  #include <vector>
  
  #include "base/callback.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"
  
  class GURL;
  
  namespace content {
  
  class PresentationScreenAvailabilityListener;
  
  using PresentationSessionStartedCallback =
      base::Callback<void(const PresentationSessionInfo&)>;
  using PresentationSessionErrorCallback =
      base::Callback<void(const PresentationError&)>;
  
  // 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)>;
  
  struct PresentationConnectionStateChangeInfo {
    explicit PresentationConnectionStateChangeInfo(
        PresentationConnectionState state)
        : state(state),
          close_reason(PRESENTATION_CONNECTION_CLOSE_REASON_CONNECTION_ERROR) {}
    ~PresentationConnectionStateChangeInfo() = default;
  
    PresentationConnectionState state;
  
    // |close_reason| and |messsage| are only used for state change to CLOSED.
    PresentationConnectionCloseReason close_reason;
    std::string message;
  };
  
  using PresentationConnectionStateChangedCallback =
      base::Callback<void(const PresentationConnectionStateChangeInfo&)>;
  
  // 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 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,
                             Observer* observer) = 0;
  
    // Unregisters the observer associated with the frame with |render_process_id|
    // and |render_frame_id|.
    // The observer will no longer receive updates.
    virtual void RemoveObserver(int render_process_id, int render_frame_id) = 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;
  
    // 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 URLs for frame given by |render_process_id|
    // and |render_frame_id|. When the default presentation is started on this
    // frame, |callback| will be invoked with the corresponding
    // PresentationSessionInfo object.
    // If |default_presentation_urls| is empty, the default presentation URLs will
    // be cleared and the previously registered callback (if any) will be removed.
    virtual void SetDefaultPresentationUrls(
        int render_process_id,
        int render_frame_id,
        const std::vector<GURL>& default_presentation_urls,
        const PresentationSessionStartedCallback& callback) = 0;
  
    // Starts a new presentation session. The presentation id of the session will
    // be the default presentation ID if any or a generated one otherwise.
    // Typically, the embedder will allow the user to select a screen to show
    // one of the |presentation_urls|.
    // |render_process_id|, |render_frame_id|: ID of originating frame.
    // |presentation_urls|: Possible URLs for the presentation.
    // |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::vector<GURL>& presentation_urls,
        const PresentationSessionStartedCallback& 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_urls|: Possible URLs of the presentation.
    // |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::vector<GURL>& presentation_urls,
        const std::string& presentation_id,
        const PresentationSessionStartedCallback& success_cb,
        const PresentationSessionErrorCallback& error_cb) = 0;
  
    // Closes an existing presentation connection.
    // |render_process_id|, |render_frame_id|: ID for originating frame.
    // |presentation_id|: The ID of the presentation to close.
    virtual void CloseConnection(int render_process_id,
                                 int render_frame_id,
                                 const std::string& presentation_id) = 0;
  
    // Terminates an existing presentation.
    // |render_process_id|, |render_frame_id|: ID for originating frame.
    // |presentation_id|: The ID of the presentation to terminate.
    virtual void Terminate(int render_process_id,
                           int render_frame_id,
                           const std::string& presentation_id) = 0;
  
    // Listens for messages for a presentation session.
    // |render_process_id|, |render_frame_id|: ID for originating frame.
    // |session|: URL and ID of presentation session to listen for messages.
    // |message_cb|: Invoked with a non-empty list of messages whenever there are
    // messages.
    virtual void ListenForSessionMessages(
        int render_process_id,
        int render_frame_id,
        const content::PresentationSessionInfo& session,
        const PresentationSessionMessageCallback& message_cb) = 0;
  
    // Sends a message (string or binary data) to a presentation session.
    // |render_process_id|, |render_frame_id|: ID of originating frame.
    // |session|: The presentation session to send the message to.
    // |message|: The message to send. The embedder takes ownership of |message|.
    //            Must not be null.
    // |send_message_cb|: Invoked after handling the send message request.
    virtual void SendMessage(int render_process_id,
                             int render_frame_id,
                             const content::PresentationSessionInfo& session,
                             std::unique_ptr<PresentationSessionMessage> message,
                             const SendMessageCallback& send_message_cb) = 0;
  
    // Continuously listen for state changes for a PresentationConnection in a
    // frame.
    // |render_process_id|, |render_frame_id|: ID of frame.
    // |connection|: PresentationConnection to listen for state changes.
    // |state_changed_cb|: Invoked with the PresentationConnection and its new
    // state whenever there is a state change.
    virtual void ListenForConnectionStateChange(
        int render_process_id,
        int render_frame_id,
        const PresentationSessionInfo& connection,
        const PresentationConnectionStateChangedCallback& state_changed_cb) = 0;
  };
  
  }  // namespace content
  
  #endif  // CONTENT_PUBLIC_BROWSER_PRESENTATION_SERVICE_DELEGATE_H_
  