gecko-dev/dom/media/BackgroundVideoDecodingPermissionObserver.h

/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* 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/. */

#if !defined(BackgroundVideoDecodingPermissionObserver_h_)
#  define BackgroundVideoDecodingPermissionObserver_h_

#  include "nsIObserver.h"
#  include "nsISupportsImpl.h"

class nsISupports;
class nsPIDOMWindowOuter;

namespace mozilla {

namespace dom {
class Document;
}

class MediaDecoder;

class BackgroundVideoDecodingPermissionObserver final : public nsIObserver {
 public:
  NS_DECL_ISUPPORTS

  explicit BackgroundVideoDecodingPermissionObserver(MediaDecoder* aDecoder);

  NS_IMETHOD Observe(nsISupports* aSubject, const char* aTopic,
                     const char16_t* aData) override;
  void RegisterEvent();
  void UnregisterEvent();

 private:
  ~BackgroundVideoDecodingPermissionObserver();
  void EnableEvent() const;
  void DisableEvent() const;
  already_AddRefed<nsPIDOMWindowOuter> GetOwnerWindow() const;
  dom::Document* GetOwnerDoc() const;
  bool IsValidEventSender(nsISupports* aSubject) const;

  // The life cycle of observer would always be shorter than decoder, so we
  // use raw pointer here.
  MediaDecoder* mDecoder;
  bool mIsRegisteredForEvent;
};

}  // namespace mozilla

#endif  // BackgroundVideoDecodingPermissionObserver_h_