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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 */
#if !defined(AutoplayPolicy_h_)
# define AutoplayPolicy_h_
# include "mozilla/NotNull.h"
class nsIPrincipal;
namespace mozilla {
namespace dom {
class HTMLMediaElement;
class AudioContext;
class Document;
enum class DocumentAutoplayPolicy : uint8_t;
* AutoplayPolicy is used to manage autoplay logic for all kinds of media,
* including MediaElement, Web Audio and Web Speech.
* Autoplay could be disable by setting the pref "media.autoplay.default"
* to anything but nsIAutoplay::Allowed. Once user disables autoplay, media
* could only be played if one of following conditions is true.
* 1) Owner document is activated by user gestures
* We restrict user gestures to "mouse click", "keyboard press" and "touch".
* 2) Muted media content or video without audio content.
* 3) Document's origin has the "autoplay-media" permission.
class AutoplayPolicy {
// Returns a DocumentAutoplayPolicy for given document.
static DocumentAutoplayPolicy IsAllowedToPlay(const Document& aDocument);
// Returns whether a given media element is allowed to play.
static bool IsAllowedToPlay(const HTMLMediaElement& aElement);
// Returns whether a given AudioContext is allowed to play.
static bool IsAllowedToPlay(const AudioContext& aContext);
// Return the value of the autoplay permissin for given principal. The return
// value can be 0=unknown, 1=allow, 2=block audio, 5=block audio and video.
static uint32_t GetSiteAutoplayPermission(nsIPrincipal* aPrincipal);
* This class contains helper funtions which could be used in AutoplayPolicy
* for determing Telemetry use-only result. They shouldn't represent the final
* result of blocking autoplay.
class AutoplayPolicyTelemetryUtils {
// Returns true if a given AudioContext would be allowed to play
// if block autoplay was enabled. If this returns false, it means we would
// either block or ask for permission.
// Note: this is for telemetry purposes, and doesn't check the prefs
// which enable/disable block autoplay. Do not use for blocking logic!
static bool WouldBeAllowedToPlayIfAutoplayDisabled(
const AudioContext& aContext);
} // namespace dom
} // namespace mozilla