dom/base/nsScreen.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   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 #include "nsContentUtils.h"
   8 #include "nsScreen.h"
   9 #include "mozilla/dom/Document.h"
  10 #include "nsGlobalWindowInner.h"
  11 #include "nsGlobalWindowOuter.h"
  12 #include "nsIDocShell.h"
  13 #include "nsPresContext.h"
  14 #include "nsCOMPtr.h"
  15 #include "nsIDocShellTreeItem.h"
  16 #include "nsLayoutUtils.h"
  17 #include "nsDeviceContext.h"
  18 #include "mozilla/widget/ScreenManager.h"
  19
  20 using namespace mozilla;
  21 using namespace mozilla::dom;
  22
  23 nsScreen::nsScreen(nsPIDOMWindowInner* aWindow)
  24     : DOMEventTargetHelper(aWindow),
  25       mScreenOrientation(new ScreenOrientation(aWindow, this)) {}
  26
  27 nsScreen::~nsScreen() = default;
  28
  29 // QueryInterface implementation for nsScreen
  30 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsScreen)
  31 NS_INTERFACE_MAP_END_INHERITING(DOMEventTargetHelper)
  32
  33 NS_IMPL_ADDREF_INHERITED(nsScreen, DOMEventTargetHelper)
  34 NS_IMPL_RELEASE_INHERITED(nsScreen, DOMEventTargetHelper)
  35
  36 NS_IMPL_CYCLE_COLLECTION_INHERITED(nsScreen, DOMEventTargetHelper,
  37                                    mScreenOrientation)
  38
  39 int32_t nsScreen::PixelDepth() {
  40   // Return 24 to prevent fingerprinting.
  41   if (ShouldResistFingerprinting(RFPTarget::ScreenPixelDepth)) {
  42     return 24;
  43   }
  44   nsDeviceContext* context = GetDeviceContext();
  45   if (NS_WARN_IF(!context)) {
  46     return 24;
  47   }
  48   return context->GetDepth();
  49 }
  50
  51 nsPIDOMWindowOuter* nsScreen::GetOuter() const {
  52   if (nsPIDOMWindowInner* inner = GetOwner()) {
  53     return inner->GetOuterWindow();
  54   }
  55   return nullptr;
  56 }
  57
  58 nsDeviceContext* nsScreen::GetDeviceContext() const {
  59   return nsLayoutUtils::GetDeviceContextForScreenInfo(GetOuter());
  60 }
  61
  62 CSSIntRect nsScreen::GetRect() {
  63   // Return window inner rect to prevent fingerprinting.
  64   if (ShouldResistFingerprinting(RFPTarget::ScreenRect)) {
  65     return GetWindowInnerRect();
  66   }
  67
  68   // Here we manipulate the value of aRect to represent the screen size,
  69   // if in RDM.
  70   if (nsPIDOMWindowInner* owner = GetOwner()) {
  71     if (Document* doc = owner->GetExtantDoc()) {
  72       Maybe<CSSIntSize> deviceSize =
  73           nsGlobalWindowOuter::GetRDMDeviceSize(*doc);
  74       if (deviceSize.isSome()) {
  75         const CSSIntSize& size = deviceSize.value();
  76         return {0, 0, size.width, size.height};
  77       }
  78     }
  79   }
  80
  81   nsDeviceContext* context = GetDeviceContext();
  82   if (NS_WARN_IF(!context)) {
  83     return {};
  84   }
  85
  86   nsRect r;
  87   context->GetRect(r);
  88   return CSSIntRect::FromAppUnitsRounded(r);
  89 }
  90
  91 CSSIntRect nsScreen::GetAvailRect() {
  92   // Return window inner rect to prevent fingerprinting.
  93   if (ShouldResistFingerprinting(RFPTarget::ScreenAvailRect)) {
  94     return GetWindowInnerRect();
  95   }
  96
  97   // Here we manipulate the value of aRect to represent the screen size,
  98   // if in RDM.
  99   if (nsPIDOMWindowInner* owner = GetOwner()) {
 100     if (Document* doc = owner->GetExtantDoc()) {
 101       Maybe<CSSIntSize> deviceSize =
 102           nsGlobalWindowOuter::GetRDMDeviceSize(*doc);
 103       if (deviceSize.isSome()) {
 104         const CSSIntSize& size = deviceSize.value();
 105         return {0, 0, size.width, size.height};
 106       }
 107     }
 108   }
 109
 110   nsDeviceContext* context = GetDeviceContext();
 111   if (NS_WARN_IF(!context)) {
 112     return {};
 113   }
 114
 115   nsRect r;
 116   context->GetClientRect(r);
 117   return CSSIntRect::FromAppUnitsRounded(r);
 118 }
 119
 120 uint16_t nsScreen::GetOrientationAngle() const {
 121   nsDeviceContext* context = GetDeviceContext();
 122   if (context) {
 123     return context->GetScreenOrientationAngle();
 124   }
 125   RefPtr<widget::Screen> s =
 126       widget::ScreenManager::GetSingleton().GetPrimaryScreen();
 127   return s->GetOrientationAngle();
 128 }
 129
 130 hal::ScreenOrientation nsScreen::GetOrientationType() const {
 131   nsDeviceContext* context = GetDeviceContext();
 132   if (context) {
 133     return context->GetScreenOrientationType();
 134   }
 135   RefPtr<widget::Screen> s =
 136       widget::ScreenManager::GetSingleton().GetPrimaryScreen();
 137   return s->GetOrientationType();
 138 }
 139
 140 ScreenOrientation* nsScreen::Orientation() const { return mScreenOrientation; }
 141
 142 void nsScreen::GetMozOrientation(nsString& aOrientation,
 143                                  CallerType aCallerType) const {
 144   switch (mScreenOrientation->DeviceType(aCallerType)) {
 145     case OrientationType::Portrait_primary:
 146       aOrientation.AssignLiteral("portrait-primary");
 147       break;
 148     case OrientationType::Portrait_secondary:
 149       aOrientation.AssignLiteral("portrait-secondary");
 150       break;
 151     case OrientationType::Landscape_primary:
 152       aOrientation.AssignLiteral("landscape-primary");
 153       break;
 154     case OrientationType::Landscape_secondary:
 155       aOrientation.AssignLiteral("landscape-secondary");
 156       break;
 157     default:
 158       MOZ_CRASH("Unacceptable screen orientation type.");
 159   }
 160 }
 161
 162 /* virtual */
 163 JSObject* nsScreen::WrapObject(JSContext* aCx,
 164                                JS::Handle<JSObject*> aGivenProto) {
 165   return Screen_Binding::Wrap(aCx, this, aGivenProto);
 166 }
 167
 168 CSSIntRect nsScreen::GetWindowInnerRect() {
 169   nsCOMPtr<nsPIDOMWindowInner> win = GetOwner();
 170   if (!win) {
 171     return {};
 172   }
 173   double width;
 174   double height;
 175   if (NS_FAILED(win->GetInnerWidth(&width)) ||
 176       NS_FAILED(win->GetInnerHeight(&height))) {
 177     return {};
 178   }
 179   return {0, 0, int32_t(std::round(width)), int32_t(std::round(height))};
 180 }
 181
 182 bool nsScreen::ShouldResistFingerprinting(RFPTarget aTarget) const {
 183   nsCOMPtr<nsPIDOMWindowInner> owner = GetOwner();
 184   return owner &&
 185          nsGlobalWindowInner::Cast(owner)->ShouldResistFingerprinting(aTarget);
 186 }