sousa-gecko/layout/style/nsDOMCSSDeclaration.cpp

/* 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 "mozAutoDocUpdate.h"
#include "mozilla/CSSPropertyId.h"
#include "mozilla/DeclarationBlock.h"
#include "mozilla/ProfilerLabels.h"
#include "mozilla/StyleSheetInlines.h"
#include "mozilla/Try.h"
#include "mozilla/css/Rule.h"
#include "mozilla/dom/BindingUtils.h"
#include "mozilla/dom/CSSStylePropertiesBinding.h"
#include "nsCSSProps.h"

using namespace mozilla;
using namespace mozilla::dom;

nsDOMCSSDeclaration::~nsDOMCSSDeclaration() = default;

/* virtual */
JSObject* nsDOMCSSDeclaration::WrapObject(JSContext* aCx,
                                          JS::Handle<JSObject*> aGivenProto) {
  return CSSStyleProperties_Binding::Wrap(aCx, this, aGivenProto);
}

NS_IMPL_QUERY_INTERFACE(nsDOMCSSDeclaration, nsICSSDeclaration)

void nsDOMCSSDeclaration::GetPropertyValue(const CSSPropertyId& aPropertyId,
                                           nsACString& aValue) {
  MOZ_ASSERT(aPropertyId.IsValid(), "Should pass a valid CSSPropertyId");
  MOZ_ASSERT(aValue.IsEmpty());

  if (Block* decl = GetOrCreateCSSDeclaration(Operation::Read, nullptr)) {
    Servo_DeclarationBlock_GetPropertyValueById(decl, &aPropertyId, &aValue);
  }
}

void nsDOMCSSDeclaration::GetPropertyValue(const NonCustomCSSPropertyId aPropId,
                                           nsACString& aValue) {
  MOZ_ASSERT(aPropId != eCSSProperty_UNKNOWN,
             "Should never pass eCSSProperty_UNKNOWN around");

  GetPropertyValue(CSSPropertyId(aPropId), aValue);
}

void nsDOMCSSDeclaration::SetPropertyValue(const NonCustomCSSPropertyId aPropId,
                                           const nsACString& aValue,
                                           nsIPrincipal* aSubjectPrincipal,
                                           ErrorResult& aRv) {
  if (IsReadOnly()) {
    return;
  }

  if (aValue.IsEmpty()) {
    // If the new value of the property is an empty string we remove the
    // property.
    return RemoveProperty(CSSPropertyId(aPropId), aRv);
  }

  aRv = ParsePropertyValue(aPropId, aValue, false, aSubjectPrincipal);
}

void nsDOMCSSDeclaration::SetPropertyTypedValue(
    const mozilla::CSSPropertyId& aPropId, const nsACString& aValue,
    mozilla::ErrorResult& aRv) {
  MOZ_ASSERT(!aValue.IsEmpty());

  if (IsReadOnly()) {
    return;
  }

  nsresult rv = SetPropertyTypedValue(aPropId, aValue);
  if (NS_FAILED(rv)) {
    if (rv == NS_ERROR_DOM_SYNTAX_ERR) {
      aRv.ThrowTypeError("Invalid values");
    } else {
      aRv.Throw(rv);
    }
  }
}

void nsDOMCSSDeclaration::GetCssText(nsACString& aCssText) {
  MOZ_ASSERT(aCssText.IsEmpty());

  if (auto* decl = GetOrCreateCSSDeclaration(Operation::Read, nullptr)) {
    Servo_DeclarationBlock_GetCssText(decl, &aCssText);
  }
}

void nsDOMCSSDeclaration::SetCssText(const nsACString& aCssText,
                                     nsIPrincipal* aSubjectPrincipal,
                                     ErrorResult& aRv) {
  if (IsReadOnly()) {
    return;
  }

  // We don't need to *do* anything with the old declaration, but we need
  // to ensure that it exists, or else SetCSSDeclaration may crash.
  RefPtr<Block> created;
  Block* olddecl =
      GetOrCreateCSSDeclaration(Operation::Modify, getter_AddRefs(created));
  if (!olddecl) {
    aRv.Throw(NS_ERROR_NOT_AVAILABLE);
    return;
  }

  // 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).
  mozAutoDocUpdate autoUpdate(DocToUpdate(), true);
  DeclarationBlockMutationClosure closure = {};
  MutationClosureData closureData;
  GetPropertyChangeClosure(&closure, &closureData);

  ParsingEnvironment servoEnv = GetParsingEnvironment(aSubjectPrincipal);
  if (!servoEnv.mUrlExtraData) {
    aRv.Throw(NS_ERROR_NOT_AVAILABLE);
    return;
  }

  // Need to special case closure calling here, since parsing css text
  // doesn't modify any existing declaration and that is why the callback isn't
  // called implicitly.
  if (closure.function && !closureData.mWasCalled) {
    closure.function(&closureData, eCSSProperty_UNKNOWN);
  }

  RefPtr<Block> newdecl =
      Servo_ParseStyleAttribute(&aCssText, servoEnv.mUrlExtraData,
                                servoEnv.mCompatMode, servoEnv.mLoader,
                                servoEnv.mRuleType)
          .Consume();
  aRv = SetCSSDeclaration(newdecl, &closureData);
}

uint32_t nsDOMCSSDeclaration::Length() {
  Block* decl = GetOrCreateCSSDeclaration(Operation::Read, nullptr);
  if (decl) {
    return Servo_DeclarationBlock_Count(decl);
  }
  return 0;
}

void nsDOMCSSDeclaration::IndexedGetter(uint32_t aIndex, bool& aFound,
                                        nsACString& aPropName) {
  Block* decl = GetOrCreateCSSDeclaration(Operation::Read, nullptr);
  CSSPropertyId id{eCSSProperty_UNKNOWN};
  if ((aFound = decl && Servo_DeclarationBlock_GetAt(decl, aIndex, &id))) {
    id.ToString(aPropName);
  }
}

void nsDOMCSSDeclaration::GetPropertyValue(const nsACString& aPropertyName,
                                           nsACString& aReturn) {
  MOZ_ASSERT(aReturn.IsEmpty());
  if (auto* decl = GetOrCreateCSSDeclaration(Operation::Read, nullptr)) {
    Servo_DeclarationBlock_GetPropertyValue(decl, &aPropertyName, &aReturn);
  }
}

bool nsDOMCSSDeclaration::HasLonghandProperty(const nsACString& aPropertyName) {
  if (auto* decl = GetOrCreateCSSDeclaration(Operation::Read, nullptr)) {
    return Servo_DeclarationBlock_HasLonghandProperty(decl, &aPropertyName);
  }

  return false;
}

void nsDOMCSSDeclaration::GetPropertyPriority(const nsACString& aPropertyName,
                                              nsACString& aPriority) {
  MOZ_ASSERT(aPriority.IsEmpty());
  auto* decl = GetOrCreateCSSDeclaration(Operation::Read, nullptr);
  if (decl &&
      Servo_DeclarationBlock_GetPropertyIsImportant(decl, &aPropertyName)) {
    aPriority.AssignLiteral("important");
  }
}

void nsDOMCSSDeclaration::SetProperty(const nsACString& aPropertyName,
                                      const nsACString& aValue,
                                      const nsACString& aPriority,
                                      nsIPrincipal* aSubjectPrincipal,
                                      ErrorResult& aRv) {
  if (IsReadOnly()) {
    return;
  }

  // In the common (and fast) cases we can use the property id
  CSSPropertyId propertyId = CSSPropertyId::Parse(aPropertyName);
  if (!propertyId.IsValid()) {
    return;
  }

  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?
    return RemoveProperty(propertyId, aRv);
  }

  bool important;
  if (aPriority.IsEmpty()) {
    important = false;
  } else if (aPriority.LowerCaseEqualsASCII("important")) {
    important = true;
  } else {
    // XXX silent failure?
    return;
  }

  if (propertyId.IsCustom()) {
    aRv = ParseCustomPropertyValue(aPropertyName, aValue, important,
                                   aSubjectPrincipal);
    return;
  }
  aRv =
      ParsePropertyValue(propertyId.mId, aValue, important, aSubjectPrincipal);
}

void nsDOMCSSDeclaration::RemoveProperty(const nsACString& aPropertyName,
                                         nsACString& aReturn,
                                         ErrorResult& aRv) {
  if (IsReadOnly()) {
    return;
  }

  CSSPropertyId propertyId = CSSPropertyId::Parse(aPropertyName);
  if (!propertyId.IsValid()) {
    return;
  }

  GetPropertyValue(propertyId, aReturn);

  RemoveProperty(propertyId, aRv);
}

void nsDOMCSSDeclaration::RemoveProperty(const CSSPropertyId& aPropertyId,
                                         mozilla::ErrorResult& aRv) {
  if (IsReadOnly()) {
    return;
  }

  Block* olddecl =
      GetOrCreateCSSDeclaration(Operation::RemoveProperty, nullptr);
  if (!olddecl) {
    return;  // no decl, so nothing to remove
  }

  mozAutoDocUpdate autoUpdate(DocToUpdate(), true);

  DeclarationBlockMutationClosure closure = {};
  MutationClosureData closureData;
  GetPropertyChangeClosure(&closure, &closureData);

  RefPtr<Block> decl = EnsureBlockMutable(olddecl);
  if (!Servo_DeclarationBlock_RemovePropertyById(decl, &aPropertyId, closure)) {
    return;
  }
  aRv = SetCSSDeclaration(decl, &closureData);
}

/* static */ nsDOMCSSDeclaration::ParsingEnvironment
nsDOMCSSDeclaration::GetParsingEnvironmentForRule(const css::Rule* aRule,
                                                  StyleCssRuleType aRuleType) {
  if (!aRule) {
    return {};
  }

  MOZ_ASSERT(aRule->Type() == aRuleType);
  MOZ_ASSERT(aRuleType != StyleCssRuleType::NestedDeclarations);

  StyleSheet* sheet = aRule->GetStyleSheet();
  if (!sheet) {
    return {};
  }

  if (Document* document = sheet->GetAssociatedDocument()) {
    return {
        sheet->URLData(),
        document->GetCompatibilityMode(),
        document->GetExistingCSSLoader(),
        aRuleType,
    };
  }

  return {
      sheet->URLData(),
      eCompatibility_FullStandards,
      nullptr,
      aRuleType,
  };
}

template <typename Func>
nsresult nsDOMCSSDeclaration::ModifyDeclaration(
    nsIPrincipal* aSubjectPrincipal, MutationClosureData* aClosureData,
    Func aFunc) {
  RefPtr<Block> created;
  Block* olddecl =
      GetOrCreateCSSDeclaration(Operation::Modify, getter_AddRefs(created));
  if (!olddecl) {
    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).
  mozAutoDocUpdate autoUpdate(DocToUpdate(), true);
  ParsingEnvironment servoEnv = GetParsingEnvironment(aSubjectPrincipal);
  if (!servoEnv.mUrlExtraData) {
    return NS_ERROR_NOT_AVAILABLE;
  }

  RefPtr<Block> decl = EnsureBlockMutable(olddecl);
  bool changed = MOZ_TRY(aFunc(decl, servoEnv));
  if (!changed) {
    return NS_OK;
  }

  return SetCSSDeclaration(decl, aClosureData);
}

nsresult nsDOMCSSDeclaration::ParsePropertyValue(
    const NonCustomCSSPropertyId aPropId, const nsACString& aPropValue,
    bool aIsImportant, nsIPrincipal* aSubjectPrincipal) {
  AUTO_PROFILER_LABEL_CATEGORY_PAIR_RELEVANT_FOR_JS(LAYOUT_CSSParsing);
  MOZ_ASSERT(!IsReadOnly());

  DeclarationBlockMutationClosure closure = {};
  MutationClosureData closureData;
  GetPropertyChangeClosure(&closure, &closureData);

  return ModifyDeclaration(aSubjectPrincipal, &closureData,
                           [&](Block* decl, ParsingEnvironment& env) {
                             bool ok = Servo_DeclarationBlock_SetPropertyById(
                                 decl, aPropId, &aPropValue, aIsImportant,
                                 env.mUrlExtraData, StyleParsingMode::DEFAULT,
                                 env.mCompatMode, env.mLoader, env.mRuleType,
                                 closure);

                             // Don't propagate parsing failures as nsresult
                             // errors. Instead, treat treat them as "no
                             // change".
                             return Result<bool, nsresult>(ok);
                           });
}

nsresult nsDOMCSSDeclaration::ParseCustomPropertyValue(
    const nsACString& aPropertyName, const nsACString& aPropValue,
    bool aIsImportant, nsIPrincipal* aSubjectPrincipal) {
  MOZ_ASSERT(nsCSSProps::IsCustomPropertyName(aPropertyName));
  MOZ_ASSERT(!IsReadOnly());

  DeclarationBlockMutationClosure closure = {};
  MutationClosureData closureData;
  GetPropertyChangeClosure(&closure, &closureData);

  return ModifyDeclaration(aSubjectPrincipal, &closureData,
                           [&](Block* decl, ParsingEnvironment& env) {
                             bool ok = Servo_DeclarationBlock_SetProperty(
                                 decl, &aPropertyName, &aPropValue,
                                 aIsImportant, env.mUrlExtraData,
                                 StyleParsingMode::DEFAULT, env.mCompatMode,
                                 env.mLoader, env.mRuleType, closure);

                             // Don't propagate parsing failures as nsresult
                             // errors. Instead, treat treat them as "no
                             // change".
                             return Result<bool, nsresult>(ok);
                           });
}

nsresult nsDOMCSSDeclaration::SetPropertyTypedValue(
    const CSSPropertyId& aPropId, const nsACString& aPropValue) {
  MOZ_ASSERT(!IsReadOnly());

  DeclarationBlockMutationClosure closure = {};
  MutationClosureData closureData;
  GetPropertyChangeClosure(&closure, &closureData);

  return ModifyDeclaration(
      nullptr, &closureData,
      [&](Block* decl, ParsingEnvironment& env) -> Result<bool, nsresult> {
        bool changed;
        MOZ_TRY(Servo_DeclarationBlock_SetPropertyTypedValue(
            decl, &aPropId, &aPropValue, env.mUrlExtraData, closure, &changed));
        return changed;
      });
}

already_AddRefed<StyleLockedDeclarationBlock>
nsDOMCSSDeclaration::EnsureBlockMutable(Block* aBlock) {
  if (Servo_DeclarationBlock_IsImmutable(aBlock)) {
    return Servo_DeclarationBlock_Clone(aBlock).Consume();
  }
  return do_AddRef(aBlock);
}