dom/media/autoplay/AutoplayPolicy.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim:set ts=2 sw=2 sts=2 et cindent: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #if !defined(AutoplayPolicy_h_)
   8 #  define AutoplayPolicy_h_
   9
  10 #  include "mozilla/NotNull.h"
  11
  12 class nsIPrincipal;
  13
  14 namespace mozilla::dom {
  15
  16 class HTMLMediaElement;
  17 class AudioContext;
  18 class Document;
  19 enum class AutoplayPolicy : uint8_t;
  20 enum class AutoplayPolicyMediaType : uint8_t;
  21
  22 }  // namespace mozilla::dom
  23
  24 namespace mozilla::media {
  25 /**
  26  * AutoplayPolicy is used to manage autoplay logic for all kinds of media,
  27  * including MediaElement, Web Audio and Web Speech.
  28  *
  29  * Autoplay could be disable by setting the pref "media.autoplay.default"
  30  * to anything but nsIAutoplay::Allowed. Once user disables autoplay, media
  31  * could only be played if one of following conditions is true.
  32  * 1) Owner document is activated by user gestures
  33  *    We restrict user gestures to "mouse click", "keyboard press" and "touch".
  34  * 2) Muted media content or video without audio content.
  35  * 3) Document's origin has the "autoplay-media" permission.
  36  */
  37 class AutoplayPolicy {
  38  public:
  39   // Returns whether a given media element is allowed to play.
  40   static bool IsAllowedToPlay(const dom::HTMLMediaElement& aElement);
  41
  42   // Returns whether a given AudioContext is allowed to play.
  43   static bool IsAllowedToPlay(const dom::AudioContext& aContext);
  44
  45   // Return the value of the autoplay permission for given principal. The return
  46   // value can be 0=unknown, 1=allow, 2=block audio, 5=block audio and video.
  47   static uint32_t GetSiteAutoplayPermission(nsIPrincipal* aPrincipal);
  48
  49   // Following methods are used for the internal implementation for the Autoplay
  50   // Policy Detection API, the public JS interfaces are in exposed on Navigator.
  51   // https://w3c.github.io/autoplay/#autoplay-detection-methods
  52   static dom::AutoplayPolicy GetAutoplayPolicy(
  53       const dom::HTMLMediaElement& aElement);
  54
  55   static dom::AutoplayPolicy GetAutoplayPolicy(
  56       const dom::AudioContext& aContext);
  57
  58   static dom::AutoplayPolicy GetAutoplayPolicy(
  59       const dom::AutoplayPolicyMediaType& aType, const dom::Document& aDoc);
  60 };
  61
  62 }  // namespace mozilla::media
  63
  64 #endif