dom/canvas/nsICanvasRenderingContextInternal.cpp

   1 /* -*- Mode: C++; tab-width: 40; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "nsICanvasRenderingContextInternal.h"
   7
   8 #include "mozilla/dom/CanvasUtils.h"
   9 #include "mozilla/dom/Document.h"
  10 #include "mozilla/dom/WorkerCommon.h"
  11 #include "mozilla/dom/WorkerPrivate.h"
  12 #include "mozilla/PresShell.h"
  13 #include "nsPIDOMWindow.h"
  14 #include "nsRefreshDriver.h"
  15
  16 nsICanvasRenderingContextInternal::nsICanvasRenderingContextInternal() =
  17     default;
  18
  19 nsICanvasRenderingContextInternal::~nsICanvasRenderingContextInternal() =
  20     default;
  21
  22 mozilla::PresShell* nsICanvasRenderingContextInternal::GetPresShell() {
  23   if (mCanvasElement) {
  24     return mCanvasElement->OwnerDoc()->GetPresShell();
  25   }
  26   return nullptr;
  27 }
  28
  29 nsIGlobalObject* nsICanvasRenderingContextInternal::GetParentObject() const {
  30   if (mCanvasElement) {
  31     return mCanvasElement->OwnerDoc()->GetScopeObject();
  32   }
  33   if (mOffscreenCanvas) {
  34     return mOffscreenCanvas->GetParentObject();
  35   }
  36   return nullptr;
  37 }
  38
  39 nsIPrincipal* nsICanvasRenderingContextInternal::PrincipalOrNull() const {
  40   if (mCanvasElement) {
  41     return mCanvasElement->NodePrincipal();
  42   }
  43   if (mOffscreenCanvas) {
  44     nsIGlobalObject* global = mOffscreenCanvas->GetParentObject();
  45     if (global) {
  46       return global->PrincipalOrNull();
  47     }
  48   }
  49   return nullptr;
  50 }
  51
  52 nsICookieJarSettings* nsICanvasRenderingContextInternal::GetCookieJarSettings()
  53     const {
  54   if (mCanvasElement) {
  55     return mCanvasElement->OwnerDoc()->CookieJarSettings();
  56   }
  57
  58   // If there is an offscreen canvas, attempt to retrieve its owner window
  59   // and return the cookieJarSettings for the window's document, if available.
  60   if (mOffscreenCanvas) {
  61     nsCOMPtr<nsPIDOMWindowInner> win =
  62         do_QueryInterface(mOffscreenCanvas->GetOwnerGlobal());
  63
  64     if (win) {
  65       return win->GetExtantDoc()->CookieJarSettings();
  66     }
  67
  68     // If the owner window cannot be retrieved, check if there is a current
  69     // worker and return its cookie jar settings if available.
  70     mozilla::dom::WorkerPrivate* worker =
  71         mozilla::dom::GetCurrentThreadWorkerPrivate();
  72
  73     if (worker) {
  74       return worker->CookieJarSettings();
  75     }
  76   }
  77
  78   return nullptr;
  79 }
  80
  81 void nsICanvasRenderingContextInternal::RemovePostRefreshObserver() {
  82   if (mRefreshDriver) {
  83     mRefreshDriver->RemovePostRefreshObserver(this);
  84     mRefreshDriver = nullptr;
  85   }
  86 }
  87
  88 void nsICanvasRenderingContextInternal::AddPostRefreshObserverIfNecessary() {
  89   if (!GetPresShell() || !GetPresShell()->GetPresContext() ||
  90       !GetPresShell()->GetPresContext()->RefreshDriver()) {
  91     return;
  92   }
  93   mRefreshDriver = GetPresShell()->GetPresContext()->RefreshDriver();
  94   mRefreshDriver->AddPostRefreshObserver(this);
  95 }
  96
  97 void nsICanvasRenderingContextInternal::DoSecurityCheck(
  98     nsIPrincipal* aPrincipal, bool aForceWriteOnly, bool aCORSUsed) {
  99   if (mCanvasElement) {
 100     mozilla::CanvasUtils::DoDrawImageSecurityCheck(mCanvasElement, aPrincipal,
 101                                                    aForceWriteOnly, aCORSUsed);
 102   } else if (mOffscreenCanvas) {
 103     mozilla::CanvasUtils::DoDrawImageSecurityCheck(mOffscreenCanvas, aPrincipal,
 104                                                    aForceWriteOnly, aCORSUsed);
 105   }
 106 }
 107
 108 bool nsICanvasRenderingContextInternal::ShouldResistFingerprinting(
 109     mozilla::RFPTarget aTarget) const {
 110   if (mCanvasElement) {
 111     return mCanvasElement->OwnerDoc()->ShouldResistFingerprinting(aTarget);
 112   }
 113   if (mOffscreenCanvas) {
 114     return mOffscreenCanvas->ShouldResistFingerprinting(aTarget);
 115   }
 116   // Last resort, just check the global preference
 117   return nsContentUtils::ShouldResistFingerprinting("Fallback", aTarget);
 118 }