// Copyright 2014 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 MEDIA_BASE_PLAYER_TRACKER_H_
#define MEDIA_BASE_PLAYER_TRACKER_H_

#include "base/basictypes.h"
#include "base/callback.h"
#include "media/base/media_export.h"

namespace media {

// An interface for players to register to be notified when a new decryption key
// becomes available or when the CDM is unset.
class MEDIA_EXPORT PlayerTracker {
 public:
  virtual ~PlayerTracker();

  // Registers player callbacks with the CDM.
  // - |new_key_cb| is fired when a new decryption key becomes available.
  // - |cdm_unset_cb| is fired when the CDM is detached from the player.
  // Returns a registration ID which can be used to unregister a player.
  virtual int RegisterPlayer(const base::Closure& new_key_cb,
                             const base::Closure& cdm_unset_cb) = 0;

  // Unregisters a previously registered player. This should be called when
  // the CDM is detached from the player (e.g. setMediaKeys(0)), or when the
  // player is destroyed.
  virtual void UnregisterPlayer(int registration_id) = 0;

 protected:
  PlayerTracker();

 private:
  DISALLOW_COPY_AND_ASSIGN(PlayerTracker);
};

}  // namespace media

#endif  // MEDIA_BASE_PLAYER_TRACKER_H_