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/* -*- 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 */
/* base class for all rule types in a CSS style sheet */
#ifndef mozilla_css_Rule_h___
#define mozilla_css_Rule_h___
#include "mozilla/dom/CSSRuleBinding.h"
#include "mozilla/dom/DocumentOrShadowRoot.h"
#include "mozilla/StyleSheet.h"
#include "mozilla/MemoryReporting.h"
#include "nsISupports.h"
#include "nsWrapperCache.h"
template <class T>
struct already_AddRefed;
namespace mozilla {
enum class StyleCssRuleType : uint8_t;
namespace css {
class GroupRule;
class Rule : public nsISupports, public nsWrapperCache {
Rule(StyleSheet* aSheet, Rule* aParentRule, uint32_t aLineNumber,
uint32_t aColumnNumber)
: mSheet(aSheet),
mColumnNumber(aColumnNumber) {
#ifdef DEBUG
#ifdef DEBUG
void AssertParentRuleType();
Rule(const Rule& aCopy)
: mSheet(aCopy.mSheet),
mColumnNumber(aCopy.mColumnNumber) {}
virtual ~Rule() = default;
// Return true if this rule is known to be a cycle collection leaf, in the
// sense that it doesn't have any outgoing owning edges.
virtual bool IsCCLeaf() const MOZ_MUST_OVERRIDE;
virtual bool IsGroupRule() const { return false; }
#ifdef DEBUG
virtual void List(FILE* out = stdout, int32_t aIndent = 0) const = 0;
StyleSheet* GetStyleSheet() const { return mSheet; }
// Clear the mSheet pointer on this rule and descendants.
virtual void DropSheetReference();
// Clear the mParentRule pointer on this rule.
void DropParentRuleReference() { mParentRule = nullptr; }
void DropReferences() {
uint32_t GetLineNumber() const { return mLineNumber; }
uint32_t GetColumnNumber() const { return mColumnNumber; }
// Whether this a rule in a read only style sheet.
bool IsReadOnly() const;
// Whether this rule is an @import rule that hasn't loaded yet (and thus
// doesn't affect the style of the page).
bool IsIncompleteImportRule() const;
// This is pure virtual because all of Rule's data members are non-owning and
// thus measured elsewhere.
virtual size_t SizeOfIncludingThis(MallocSizeOf) const MOZ_MUST_OVERRIDE = 0;
virtual StyleCssRuleType Type() const = 0;
// WebIDL interface
uint16_t TypeForBindings() const {
auto type = uint16_t(Type());
// we return 0.
return type > 15 ? 0 : type;
virtual void GetCssText(nsACString& aCssText) const = 0;
void SetCssText(const nsACString& aCssText);
Rule* GetParentRule() const;
StyleSheet* GetParentStyleSheet() const { return GetStyleSheet(); }
nsINode* GetAssociatedDocumentOrShadowRoot() const {
if (!mSheet) {
return nullptr;
auto* associated = mSheet->GetAssociatedDocumentOrShadowRoot();
return associated ? &associated->AsNode() : nullptr;
nsISupports* GetParentObject() const { return mSheet; }
// True if we're known-live for cycle collection purposes.
bool IsKnownLive() const;
// Hook subclasses can use to properly unlink the nsWrapperCache of
// their declarations.
void UnlinkDeclarationWrapper(nsWrapperCache& aDecl);
// mSheet should only ever be null when we create a synthetic CSSFontFaceRule
// for an InspectorFontFace.
// mSheet and mParentRule will be cleared when they are detached from the
// parent object, either because the rule is removed or the parent is
// destroyed.
StyleSheet* MOZ_NON_OWNING_REF mSheet;
Rule* MOZ_NON_OWNING_REF mParentRule;
// Keep the same type so that MSVC packs them.
uint32_t mLineNumber;
uint32_t mColumnNumber;
} // namespace css
} // namespace mozilla
#endif /* mozilla_css_Rule_h___ */