diff -r 000000000000 -r 6474c204b198 layout/style/nsDOMCSSDeclaration.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/style/nsDOMCSSDeclaration.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,454 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+/* base class for DOM objects for element.style and cssStyleRule.style */
+
+#include "nsDOMCSSDeclaration.h"
+
+#include "nsCSSParser.h"
+#include "nsCSSStyleSheet.h"
+#include "mozilla/css/Rule.h"
+#include "mozilla/css/Declaration.h"
+#include "mozilla/dom/CSS2PropertiesBinding.h"
+#include "nsCSSProps.h"
+#include "nsCOMPtr.h"
+#include "mozAutoDocUpdate.h"
+#include "nsIURI.h"
+#include "mozilla/dom/BindingUtils.h"
+#include "nsContentUtils.h"
+
+using namespace mozilla;
+
+nsDOMCSSDeclaration::~nsDOMCSSDeclaration()
+{
+}
+
+/* virtual */ JSObject*
+nsDOMCSSDeclaration::WrapObject(JSContext* aCx)
+{
+  return dom::CSS2PropertiesBinding::Wrap(aCx, this);
+}
+
+NS_INTERFACE_TABLE_HEAD(nsDOMCSSDeclaration)
+  NS_INTERFACE_TABLE(nsDOMCSSDeclaration,
+                     nsICSSDeclaration,
+                     nsIDOMCSSStyleDeclaration)
+  NS_INTERFACE_TABLE_TO_MAP_SEGUE
+NS_INTERFACE_MAP_END
+
+NS_IMETHODIMP
+nsDOMCSSDeclaration::GetPropertyValue(const nsCSSProperty aPropID,
+                                      nsAString& aValue)
+{
+  NS_PRECONDITION(aPropID != eCSSProperty_UNKNOWN,
+                  "Should never pass eCSSProperty_UNKNOWN around");
+
+  css::Declaration* decl = GetCSSDeclaration(false);
+
+  aValue.Truncate();
+  if (decl) {
+    decl->GetValue(aPropID, aValue);
+  }
+  return NS_OK;
+}
+
+void
+nsDOMCSSDeclaration::GetCustomPropertyValue(const nsAString& aPropertyName,
+                                            nsAString& aValue)
+{
+  MOZ_ASSERT(Substring(aPropertyName, 0,
+                       CSS_CUSTOM_NAME_PREFIX_LENGTH).EqualsLiteral("--"));
+
+  css::Declaration* decl = GetCSSDeclaration(false);
+  if (!decl) {
+    aValue.Truncate();
+    return;
+  }
+
+  decl->GetVariableDeclaration(Substring(aPropertyName,
+                                         CSS_CUSTOM_NAME_PREFIX_LENGTH),
+                               aValue);
+}
+
+NS_IMETHODIMP
+nsDOMCSSDeclaration::SetPropertyValue(const nsCSSProperty aPropID,
+                                      const nsAString& aValue)
+{
+  if (aValue.IsEmpty()) {
+    // If the new value of the property is an empty string we remove the
+    // property.
+    return RemoveProperty(aPropID);
+  }
+
+  return ParsePropertyValue(aPropID, aValue, false);
+}
+
+
+NS_IMETHODIMP
+nsDOMCSSDeclaration::GetCssText(nsAString& aCssText)
+{
+  css::Declaration* decl = GetCSSDeclaration(false);
+  aCssText.Truncate();
+
+  if (decl) {
+    decl->ToString(aCssText);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDOMCSSDeclaration::SetCssText(const nsAString& aCssText)
+{
+  // We don't need to *do* anything with the old declaration, but we need
+  // to ensure that it exists, or else SetCSSDeclaration may crash.
+  css::Declaration* olddecl = GetCSSDeclaration(true);
+  if (!olddecl) {
+    return NS_ERROR_FAILURE;
+  }
+
+  CSSParsingEnvironment env;
+  GetCSSParsingEnvironment(env);
+  if (!env.mPrincipal) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // For nsDOMCSSAttributeDeclaration, SetCSSDeclaration will lead to
+  // Attribute setting code, which leads in turn to BeginUpdate.  We
+  // need to start the update now so that the old rule doesn't get used
+  // between when we mutate the declaration and when we set the new
+  // rule (see stack in bug 209575).
+  mozAutoDocConditionalContentUpdateBatch autoUpdate(DocToUpdate(), true);
+
+  nsAutoPtr<css::Declaration> decl(new css::Declaration());
+  decl->InitializeEmpty();
+  nsCSSParser cssParser(env.mCSSLoader);
+  bool changed;
+  nsresult result = cssParser.ParseDeclarations(aCssText, env.mSheetURI,
+                                                env.mBaseURI,
+                                                env.mPrincipal, decl, &changed);
+  if (NS_FAILED(result) || !changed) {
+    return result;
+  }
+
+  return SetCSSDeclaration(decl.forget());
+}
+
+NS_IMETHODIMP
+nsDOMCSSDeclaration::GetLength(uint32_t* aLength)
+{
+  css::Declaration* decl = GetCSSDeclaration(false);
+
+  if (decl) {
+    *aLength = decl->Count();
+  } else {
+    *aLength = 0;
+  }
+
+  return NS_OK;
+}
+
+already_AddRefed<dom::CSSValue>
+nsDOMCSSDeclaration::GetPropertyCSSValue(const nsAString& aPropertyName, ErrorResult& aRv)
+{
+  // We don't support CSSValue yet so we'll just return null...
+
+  return nullptr;
+}
+
+void
+nsDOMCSSDeclaration::IndexedGetter(uint32_t aIndex, bool& aFound, nsAString& aPropName)
+{
+  css::Declaration* decl = GetCSSDeclaration(false);
+  aFound = decl && decl->GetNthProperty(aIndex, aPropName);
+}
+
+NS_IMETHODIMP
+nsDOMCSSDeclaration::GetPropertyValue(const nsAString& aPropertyName,
+                                      nsAString& aReturn)
+{
+  const nsCSSProperty propID =
+    nsCSSProps::LookupProperty(aPropertyName,
+                               nsCSSProps::eEnabledForAllContent);
+  if (propID == eCSSProperty_UNKNOWN) {
+    aReturn.Truncate();
+    return NS_OK;
+  }
+
+  if (propID == eCSSPropertyExtra_variable) {
+    GetCustomPropertyValue(aPropertyName, aReturn);
+    return NS_OK;
+  }
+
+  return GetPropertyValue(propID, aReturn);
+}
+
+NS_IMETHODIMP
+nsDOMCSSDeclaration::GetAuthoredPropertyValue(const nsAString& aPropertyName,
+                                              nsAString& aReturn)
+{
+  const nsCSSProperty propID =
+    nsCSSProps::LookupProperty(aPropertyName,
+                               nsCSSProps::eEnabledForAllContent);
+  if (propID == eCSSProperty_UNKNOWN) {
+    aReturn.Truncate();
+    return NS_OK;
+  }
+
+  if (propID == eCSSPropertyExtra_variable) {
+    GetCustomPropertyValue(aPropertyName, aReturn);
+    return NS_OK;
+  }
+
+  css::Declaration* decl = GetCSSDeclaration(false);
+  if (!decl) {
+    return NS_ERROR_FAILURE;
+  }
+
+  decl->GetAuthoredValue(propID, aReturn);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDOMCSSDeclaration::GetPropertyPriority(const nsAString& aPropertyName,
+                                         nsAString& aReturn)
+{
+  css::Declaration* decl = GetCSSDeclaration(false);
+
+  aReturn.Truncate();
+  if (decl && decl->GetValueIsImportant(aPropertyName)) {
+    aReturn.AssignLiteral("important");
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDOMCSSDeclaration::SetProperty(const nsAString& aPropertyName,
+                                 const nsAString& aValue,
+                                 const nsAString& aPriority)
+{
+  // In the common (and fast) cases we can use the property id
+  nsCSSProperty propID =
+    nsCSSProps::LookupProperty(aPropertyName,
+                               nsCSSProps::eEnabledForAllContent);
+  if (propID == eCSSProperty_UNKNOWN) {
+    return NS_OK;
+  }
+
+  if (aValue.IsEmpty()) {
+    // If the new value of the property is an empty string we remove the
+    // property.
+    // XXX this ignores the priority string, should it?
+    if (propID == eCSSPropertyExtra_variable) {
+      return RemoveCustomProperty(aPropertyName);
+    }
+    return RemoveProperty(propID);
+  }
+
+  bool important;
+  if (aPriority.IsEmpty()) {
+    important = false;
+  } else if (aPriority.EqualsLiteral("important")) {
+    important = true;
+  } else {
+    // XXX silent failure?
+    return NS_OK;
+  }
+
+  if (propID == eCSSPropertyExtra_variable) {
+    return ParseCustomPropertyValue(aPropertyName, aValue, important);
+  }
+  return ParsePropertyValue(propID, aValue, important);
+}
+
+NS_IMETHODIMP
+nsDOMCSSDeclaration::RemoveProperty(const nsAString& aPropertyName,
+                                    nsAString& aReturn)
+{
+  const nsCSSProperty propID =
+    nsCSSProps::LookupProperty(aPropertyName,
+                               nsCSSProps::eEnabledForAllContent);
+  if (propID == eCSSProperty_UNKNOWN) {
+    aReturn.Truncate();
+    return NS_OK;
+  }
+
+  if (propID == eCSSPropertyExtra_variable) {
+    RemoveCustomProperty(aPropertyName);
+    return NS_OK;
+  }
+
+  nsresult rv = GetPropertyValue(propID, aReturn);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return RemoveProperty(propID);
+}
+
+/* static */ void
+nsDOMCSSDeclaration::GetCSSParsingEnvironmentForRule(css::Rule* aRule,
+                                                     CSSParsingEnvironment& aCSSParseEnv)
+{
+  nsIStyleSheet* sheet = aRule ? aRule->GetStyleSheet() : nullptr;
+  nsRefPtr<nsCSSStyleSheet> cssSheet(do_QueryObject(sheet));
+  if (!cssSheet) {
+    aCSSParseEnv.mPrincipal = nullptr;
+    return;
+  }
+
+  nsIDocument* document = sheet->GetOwningDocument();
+  aCSSParseEnv.mSheetURI = sheet->GetSheetURI();
+  aCSSParseEnv.mBaseURI = sheet->GetBaseURI();
+  aCSSParseEnv.mPrincipal = cssSheet->Principal();
+  aCSSParseEnv.mCSSLoader = document ? document->CSSLoader() : nullptr;
+}
+
+nsresult
+nsDOMCSSDeclaration::ParsePropertyValue(const nsCSSProperty aPropID,
+                                        const nsAString& aPropValue,
+                                        bool aIsImportant)
+{
+  css::Declaration* olddecl = GetCSSDeclaration(true);
+  if (!olddecl) {
+    return NS_ERROR_FAILURE;
+  }
+
+  CSSParsingEnvironment env;
+  GetCSSParsingEnvironment(env);
+  if (!env.mPrincipal) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // For nsDOMCSSAttributeDeclaration, SetCSSDeclaration will lead to
+  // Attribute setting code, which leads in turn to BeginUpdate.  We
+  // need to start the update now so that the old rule doesn't get used
+  // between when we mutate the declaration and when we set the new
+  // rule (see stack in bug 209575).
+  mozAutoDocConditionalContentUpdateBatch autoUpdate(DocToUpdate(), true);
+  css::Declaration* decl = olddecl->EnsureMutable();
+
+  nsCSSParser cssParser(env.mCSSLoader);
+  bool changed;
+  nsresult result = cssParser.ParseProperty(aPropID, aPropValue, env.mSheetURI,
+                                            env.mBaseURI, env.mPrincipal, decl,
+                                            &changed, aIsImportant);
+  if (NS_FAILED(result) || !changed) {
+    if (decl != olddecl) {
+      delete decl;
+    }
+    return result;
+  }
+
+  return SetCSSDeclaration(decl);
+}
+
+nsresult
+nsDOMCSSDeclaration::ParseCustomPropertyValue(const nsAString& aPropertyName,
+                                              const nsAString& aPropValue,
+                                              bool aIsImportant)
+{
+  MOZ_ASSERT(nsCSSProps::IsCustomPropertyName(aPropertyName));
+
+  css::Declaration* olddecl = GetCSSDeclaration(true);
+  if (!olddecl) {
+    return NS_ERROR_FAILURE;
+  }
+
+  CSSParsingEnvironment env;
+  GetCSSParsingEnvironment(env);
+  if (!env.mPrincipal) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // For nsDOMCSSAttributeDeclaration, SetCSSDeclaration will lead to
+  // Attribute setting code, which leads in turn to BeginUpdate.  We
+  // need to start the update now so that the old rule doesn't get used
+  // between when we mutate the declaration and when we set the new
+  // rule (see stack in bug 209575).
+  mozAutoDocConditionalContentUpdateBatch autoUpdate(DocToUpdate(), true);
+  css::Declaration* decl = olddecl->EnsureMutable();
+
+  nsCSSParser cssParser(env.mCSSLoader);
+  bool changed;
+  nsresult result =
+    cssParser.ParseVariable(Substring(aPropertyName,
+                                      CSS_CUSTOM_NAME_PREFIX_LENGTH),
+                            aPropValue, env.mSheetURI,
+                            env.mBaseURI, env.mPrincipal, decl,
+                            &changed, aIsImportant);
+  if (NS_FAILED(result) || !changed) {
+    if (decl != olddecl) {
+      delete decl;
+    }
+    return result;
+  }
+
+  return SetCSSDeclaration(decl);
+}
+
+nsresult
+nsDOMCSSDeclaration::RemoveProperty(const nsCSSProperty aPropID)
+{
+  css::Declaration* decl = GetCSSDeclaration(false);
+  if (!decl) {
+    return NS_OK; // no decl, so nothing to remove
+  }
+
+  // For nsDOMCSSAttributeDeclaration, SetCSSDeclaration will lead to
+  // Attribute setting code, which leads in turn to BeginUpdate.  We
+  // need to start the update now so that the old rule doesn't get used
+  // between when we mutate the declaration and when we set the new
+  // rule (see stack in bug 209575).
+  mozAutoDocConditionalContentUpdateBatch autoUpdate(DocToUpdate(), true);
+
+  decl = decl->EnsureMutable();
+  decl->RemoveProperty(aPropID);
+  return SetCSSDeclaration(decl);
+}
+
+nsresult
+nsDOMCSSDeclaration::RemoveCustomProperty(const nsAString& aPropertyName)
+{
+  MOZ_ASSERT(Substring(aPropertyName, 0,
+                       CSS_CUSTOM_NAME_PREFIX_LENGTH).EqualsLiteral("--"));
+
+  css::Declaration* decl = GetCSSDeclaration(false);
+  if (!decl) {
+    return NS_OK; // no decl, so nothing to remove
+  }
+
+  // For nsDOMCSSAttributeDeclaration, SetCSSDeclaration will lead to
+  // Attribute setting code, which leads in turn to BeginUpdate.  We
+  // need to start the update now so that the old rule doesn't get used
+  // between when we mutate the declaration and when we set the new
+  // rule (see stack in bug 209575).
+  mozAutoDocConditionalContentUpdateBatch autoUpdate(DocToUpdate(), true);
+
+  decl = decl->EnsureMutable();
+  decl->RemoveVariableDeclaration(Substring(aPropertyName,
+                                            CSS_CUSTOM_NAME_PREFIX_LENGTH));
+  return SetCSSDeclaration(decl);
+}
+
+bool IsCSSPropertyExposedToJS(nsCSSProperty aProperty, JSContext* cx, JSObject* obj)
+{
+  nsCSSProps::EnabledState enabledState = nsCSSProps::eEnabledForAllContent;
+
+  // Optimization: we skip checking properties of the JSContext
+  // in the majority case where the property does not have the
+  // CSS_PROPERTY_ALWAYS_ENABLED_IN_PRIVILEGED_CONTENT flag.
+  bool isEnabledInChromeOrCertifiedApp
+    = nsCSSProps::PropHasFlags(aProperty,
+                               CSS_PROPERTY_ALWAYS_ENABLED_IN_CHROME_OR_CERTIFIED_APP);
+
+  if (isEnabledInChromeOrCertifiedApp) {
+    if (dom::IsInCertifiedApp(cx, obj) ||
+        nsContentUtils::ThreadsafeIsCallerChrome())
+    {
+      enabledState |= nsCSSProps::eEnabledInChromeOrCertifiedApp;
+    }
+  }
+  return nsCSSProps::IsEnabled(aProperty, enabledState);
+}