/* -*- Mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 40 -*- */
/* vim: set ts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_dom_audiochannelservice_h__
#define mozilla_dom_audiochannelservice_h__

#include "nsAutoPtr.h"
#include "nsISupports.h"

#include "AudioChannelCommon.h"
#include "nsHTMLMediaElement.h"

namespace mozilla {
namespace dom {

class AudioChannelService : public nsISupports
{
public:
  NS_DECL_ISUPPORTS

  /**
   * Returns the AudioChannelServce singleton. Only to be called from main thread.
   * @return NS_OK on proper assignment, NS_ERROR_FAILURE otherwise.
   */
  static AudioChannelService*
  GetAudioChannelService();

  /**
   * Shutdown the singleton.
   */
  static void Shutdown();

  /**
   * Any MediaElement that starts playing should register itself to
   * this service, sharing the AudioChannelType.
   */
  void RegisterMediaElement(nsHTMLMediaElement* aMediaElement,
                            AudioChannelType aType);

  /**
   * Any MediaElement that stops playing should unregister itself to
   * this service.
   */
  void UnregisterMediaElement(nsHTMLMediaElement* aMediaElement);

  /**
   * Return true if this type should be muted.
   */
  virtual bool GetMuted(AudioChannelType aType, bool aElementHidden);

  void Notify();

protected:
  AudioChannelService();
  virtual ~AudioChannelService();

  bool ChannelsActiveWithHigherPriorityThan(AudioChannelType aType);

  nsDataHashtable< nsPtrHashKey<nsHTMLMediaElement>, AudioChannelType > mMediaElements;

  int32_t* mChannelCounters;
};

} // namespace dom
} // namespace mozilla

#endif