dom/animation/AnimationUtils.cpp
author Tim Huang <tihuang@mozilla.com>
Thu, 31 Aug 2017 11:14:14 +0800
changeset 453921 b2f55468b241f28678dc5e35e19eb3b5781a1c5c
parent 446915 b828f7a6c2bf49b0d6d1161190b9b80f0ba78418
child 459313 c3f16a179c93d9b75dd4581280967fa6ef364cc3
permissions -rw-r--r--
Bug 1222285 - Part 2: Making the keyboard events of modifier keys been suppressed when 'privacy.resistFingerprinting' is true. r=arthuredelstein,masayuki This patch makes 'Shift', 'Alt', 'Contorl' and 'AltGraph' been suppressed for content when fingerprinting resistance is enabled. Chrome can still get these events. The reason behind this is that websites can still observe key combinations to tell which keyboard layout is using even we spoof the keyboardEvent.code, keyboardEvent.keyCode and modifier states. For example, the AZERTY France keyboard, the digit keys of it requires the user press the Shift key. So, it is easy to differentiate AZERTY and QWERTY keyboard by observing whether a Shift key generates its own before the digit keys. There are similar issues for 'Alt' and 'AltGraph' as well. MozReview-Commit-ID: 3CwCgvey4lK

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=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/. */

#include "AnimationUtils.h"

#include "nsDebug.h"
#include "nsAtom.h"
#include "nsIContent.h"
#include "nsIDocument.h"
#include "nsGlobalWindow.h"
#include "nsString.h"
#include "xpcpublic.h" // For xpc::NativeGlobal
#include "mozilla/EffectSet.h"
#include "mozilla/dom/KeyframeEffectReadOnly.h"
#include "mozilla/Preferences.h"

namespace mozilla {

/* static */ void
AnimationUtils::LogAsyncAnimationFailure(nsCString& aMessage,
                                         const nsIContent* aContent)
{
  if (aContent) {
    aMessage.AppendLiteral(" [");
    aMessage.Append(nsAtomCString(aContent->NodeInfo()->NameAtom()));

    nsAtom* id = aContent->GetID();
    if (id) {
      aMessage.AppendLiteral(" with id '");
      aMessage.Append(nsAtomCString(aContent->GetID()));
      aMessage.Append('\'');
    }
    aMessage.Append(']');
  }
  aMessage.Append('\n');
  printf_stderr("%s", aMessage.get());
}

/* static */ nsIDocument*
AnimationUtils::GetCurrentRealmDocument(JSContext* aCx)
{
  nsGlobalWindowInner* win = xpc::CurrentWindowOrNull(aCx);
  if (!win) {
    return nullptr;
  }
  return win->GetDoc();
}

/* static */ bool
AnimationUtils::IsOffscreenThrottlingEnabled()
{
  static bool sOffscreenThrottlingEnabled;
  static bool sPrefCached = false;

  if (!sPrefCached) {
    sPrefCached = true;
    Preferences::AddBoolVarCache(&sOffscreenThrottlingEnabled,
                                 "dom.animations.offscreen-throttling");
  }

  return sOffscreenThrottlingEnabled;
}

/* static */ bool
AnimationUtils::EffectSetContainsAnimatedScale(EffectSet& aEffects,
                                               const nsIFrame* aFrame)
{
  for (const dom::KeyframeEffectReadOnly* effect : aEffects) {
    if (effect->ContainsAnimatedScale(aFrame)) {
      return true;
    }
  }

  return false;
}

} // namespace mozilla