/* -*- 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/. */ /* * the container for the style sheets that apply to a presentation, and * the internal API that the style system exposes for creating (and * potentially re-creating) style contexts */ #ifndef nsStyleSet_h_ #define nsStyleSet_h_ #include "mozilla/Attributes.h" #include "mozilla/StyleSheetInlines.h" #include "mozilla/EnumeratedArray.h" #include "mozilla/LinkedList.h" #include "mozilla/MemoryReporting.h" #include "mozilla/SheetType.h" #include "nsIStyleRuleProcessor.h" #include "nsBindingManager.h" #include "nsRuleNode.h" #include "nsTArray.h" #include "nsCOMArray.h" #include "nsIStyleRule.h" class gfxFontFeatureValueSet; class nsCSSKeyframesRule; class nsCSSFontFeatureValuesRule; class nsCSSPageRule; class nsCSSCounterStyleRule; class nsICSSPseudoComparator; class nsRuleWalker; struct ElementDependentRuleProcessorData; struct nsFontFaceRuleContainer; struct TreeMatchContext; namespace mozilla { class CSSStyleSheet; class EventStates; enum class CSSPseudoElementType : uint8_t; } // namespace mozilla class nsEmptyStyleRule final : public nsIStyleRule { private: ~nsEmptyStyleRule() {} public: NS_DECL_ISUPPORTS virtual void MapRuleInfoInto(nsRuleData* aRuleData) override; virtual bool MightMapInheritedStyleData() override; virtual bool GetDiscretelyAnimatedCSSValue(nsCSSPropertyID aProperty, nsCSSValue* aValue) override; #ifdef DEBUG virtual void List(FILE* out = stdout, int32_t aIndent = 0) const override; #endif }; class nsInitialStyleRule final : public nsIStyleRule { private: ~nsInitialStyleRule() {} public: NS_DECL_ISUPPORTS virtual void MapRuleInfoInto(nsRuleData* aRuleData) override; virtual bool MightMapInheritedStyleData() override; virtual bool GetDiscretelyAnimatedCSSValue(nsCSSPropertyID aProperty, nsCSSValue* aValue) override; #ifdef DEBUG virtual void List(FILE* out = stdout, int32_t aIndent = 0) const override; #endif }; class nsDisableTextZoomStyleRule final : public nsIStyleRule { private: ~nsDisableTextZoomStyleRule() {} public: NS_DECL_ISUPPORTS virtual void MapRuleInfoInto(nsRuleData* aRuleData) override; virtual bool MightMapInheritedStyleData() override; virtual bool GetDiscretelyAnimatedCSSValue(nsCSSPropertyID aProperty, nsCSSValue* aValue) override; #ifdef DEBUG virtual void List(FILE* out = stdout, int32_t aIndent = 0) const override; #endif }; // The style set object is created by the document viewer and ownership is // then handed off to the PresShell. Only the PresShell should delete a // style set. class nsStyleSet final { public: nsStyleSet(); ~nsStyleSet(); size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const; void Init(nsPresContext *aPresContext); nsRuleNode* GetRuleTree() { return mRuleTree; } // get a style context for a non-pseudo frame. already_AddRefed<nsStyleContext> ResolveStyleFor(mozilla::dom::Element* aElement, nsStyleContext* aParentContext); already_AddRefed<nsStyleContext> ResolveStyleFor(mozilla::dom::Element* aElement, nsStyleContext* aParentContext, TreeMatchContext& aTreeMatchContext); // Get a style context (with the given parent) for the // sequence of style rules in the |aRules| array. already_AddRefed<nsStyleContext> ResolveStyleForRules(nsStyleContext* aParentContext, const nsTArray< nsCOMPtr<nsIStyleRule> > &aRules); // Get a style context that represents aBaseContext, but as though // it additionally matched the rules in the aRules array (in that // order, as more specific than any other rules). // // One of the following must hold: // 1. The resulting style context must be used only on a temporary // basis, and it must never be put into the style context tree // (and, in particular, we must never call // ResolveStyleWithReplacement with it as the old context, which // might happen if it is put in the style context tree), or // 2. The additional rules must be appropriate for the transitions // level of the cascade, which is the highest level of the cascade. // (This is the case for one current caller, the cover rule used // for CSS transitions.) already_AddRefed<nsStyleContext> ResolveStyleByAddingRules(nsStyleContext* aBaseContext, const nsCOMArray<nsIStyleRule> &aRules); // Resolve style by making replacements in the list of style rules as // described by aReplacements, but otherwise maintaining the status // quo. // aPseudoElement must follow the same rules as for // ResolvePseudoElementStyle, and be null for non-pseudo-element cases enum { // flags for aFlags // Skip starting CSS animations that result from the style. eSkipStartingAnimations = (1<<0), }; already_AddRefed<nsStyleContext> ResolveStyleWithReplacement(mozilla::dom::Element* aElement, mozilla::dom::Element* aPseudoElement, nsStyleContext* aNewParentContext, nsStyleContext* aOldStyleContext, nsRestyleHint aReplacements, uint32_t aFlags = 0); // Resolve style by returning a style context with the specified // animation data removed. It is allowable to remove all animation // data with eRestyle_AllHintsWithAnimations, or by using any other // hints that are allowed by ResolveStyleWithReplacement. already_AddRefed<nsStyleContext> ResolveStyleWithoutAnimation(mozilla::dom::Element* aElement, nsStyleContext* aStyleContext, nsRestyleHint aWhichToRemove); // Get a style context for a text node (which no rules will match). // // The returned style context will have nsCSSAnonBoxes::mozText as its pseudo. // // (Perhaps mozText should go away and we shouldn't even create style // contexts for such content nodes, when text-combine-upright is not // present. However, not doing any rule matching for them is a first step.) already_AddRefed<nsStyleContext> ResolveStyleForText(nsIContent* aTextNode, nsStyleContext* aParentContext); // Get a style context for a non-element (which no rules will match) // other than a text node, such as placeholder frames, and the // nsFirstLetterFrame for everything after the first letter. // // The returned style context will have nsCSSAnonBoxes::mozOtherNonElement as // its pseudo. // // (Perhaps mozOtherNonElement should go away and we shouldn't even // create style contexts for such content nodes. However, not doing // any rule matching for them is a first step.) already_AddRefed<nsStyleContext> ResolveStyleForOtherNonElement(nsStyleContext* aParentContext); // Get a style context for a pseudo-element. aParentElement must be // non-null. aPseudoID is the CSSPseudoElementType for the // pseudo-element. aPseudoElement must be non-null if the pseudo-element // type is one that allows user action pseudo-classes after it or allows // style attributes; otherwise, it is ignored. already_AddRefed<nsStyleContext> ResolvePseudoElementStyle(mozilla::dom::Element* aParentElement, mozilla::CSSPseudoElementType aType, nsStyleContext* aParentContext, mozilla::dom::Element* aPseudoElement); // This functions just like ResolvePseudoElementStyle except that it will // return nullptr if there are no explicit style rules for that // pseudo element. already_AddRefed<nsStyleContext> ProbePseudoElementStyle(mozilla::dom::Element* aParentElement, mozilla::CSSPseudoElementType aType, nsStyleContext* aParentContext); already_AddRefed<nsStyleContext> ProbePseudoElementStyle(mozilla::dom::Element* aParentElement, mozilla::CSSPseudoElementType aType, nsStyleContext* aParentContext, TreeMatchContext& aTreeMatchContext, mozilla::dom::Element* aPseudoElement = nullptr); /** * Bit-flags that can be passed to ResolveAnonymousBoxStyle and GetContext * in their parameter 'aFlags'. */ enum { eNoFlags = 0, eIsLink = 1 << 0, eIsVisitedLink = 1 << 1, eDoAnimation = 1 << 2, // Indicates that we should skip the flex/grid item specific chunk of // ApplyStyleFixups(). This is useful if our parent has "display: flex" // or "display: grid" but we can tell we're not going to honor that (e.g. if // it's the outer frame of a button widget, and we're the inline frame for // the button's label). eSkipParentDisplayBasedStyleFixup = 1 << 3 }; // Get a style context for an anonymous box. aPseudoTag is the // pseudo-tag to use and must be non-null. aFlags will be forwarded // to a GetContext call internally. already_AddRefed<nsStyleContext> ResolveAnonymousBoxStyle(nsIAtom* aPseudoTag, nsStyleContext* aParentContext, uint32_t aFlags = eNoFlags); #ifdef MOZ_XUL // Get a style context for a XUL tree pseudo. aPseudoTag is the // pseudo-tag to use and must be non-null. aParentContent must be // non-null. aComparator must be non-null. already_AddRefed<nsStyleContext> ResolveXULTreePseudoStyle(mozilla::dom::Element* aParentElement, nsIAtom* aPseudoTag, nsStyleContext* aParentContext, nsICSSPseudoComparator* aComparator); #endif // Append all the currently-active font face rules to aArray. Return // true for success and false for failure. bool AppendFontFaceRules(nsTArray<nsFontFaceRuleContainer>& aArray); // Return the winning (in the cascade) @keyframes rule for the given name. nsCSSKeyframesRule* KeyframesRuleForName(const nsString& aName); // Return the winning (in the cascade) @counter-style rule for the given name. nsCSSCounterStyleRule* CounterStyleRuleForName(const nsAString& aName); // Fetch object for looking up font feature values already_AddRefed<gfxFontFeatureValueSet> GetFontFeatureValuesLookup(); // Append all the currently-active font feature values rules to aArray. // Return true for success and false for failure. bool AppendFontFeatureValuesRules( nsTArray<nsCSSFontFeatureValuesRule*>& aArray); // Append all the currently-active page rules to aArray. Return // true for success and false for failure. bool AppendPageRules(nsTArray<nsCSSPageRule*>& aArray); // Begin ignoring style context destruction, to avoid lots of unnecessary // work on document teardown. void BeginShutdown(); // Free all of the data associated with this style set. void Shutdown(); // Get a new style context that lives in a different parent // The new context will be the same as the old if the new parent is the // same as the old parent. // aElement should be non-null if this is a style context for an // element or pseudo-element; in the latter case it should be the // real element the pseudo-element is for. already_AddRefed<nsStyleContext> ReparentStyleContext(nsStyleContext* aStyleContext, nsStyleContext* aNewParentContext, mozilla::dom::Element* aElement); // Test if style is dependent on a document state. bool HasDocumentStateDependentStyle(nsIContent* aContent, mozilla::EventStates aStateMask); // Test if style is dependent on content state nsRestyleHint HasStateDependentStyle(mozilla::dom::Element* aElement, mozilla::EventStates aStateMask); nsRestyleHint HasStateDependentStyle(mozilla::dom::Element* aElement, mozilla::CSSPseudoElementType aPseudoType, mozilla::dom::Element* aPseudoElement, mozilla::EventStates aStateMask); // Test if style is dependent on the presence of an attribute. nsRestyleHint HasAttributeDependentStyle(mozilla::dom::Element* aElement, int32_t aNameSpaceID, nsIAtom* aAttribute, int32_t aModType, bool aAttrHasChanged, const nsAttrValue* aOtherValue, mozilla::RestyleHintData& aRestyleHintDataResult); /* * Do any processing that needs to happen as a result of a change in * the characteristics of the medium, and return whether style rules * may have changed as a result. */ bool MediumFeaturesChanged(); // APIs for registering objects that can supply additional // rules during processing. void SetBindingManager(nsBindingManager* aBindingManager) { mBindingManager = aBindingManager; } // APIs to manipulate the style sheet lists. The sheets in each // list are stored with the most significant sheet last. nsresult AppendStyleSheet(mozilla::SheetType aType, mozilla::CSSStyleSheet* aSheet); nsresult PrependStyleSheet(mozilla::SheetType aType, mozilla::CSSStyleSheet* aSheet); nsresult RemoveStyleSheet(mozilla::SheetType aType, mozilla::CSSStyleSheet* aSheet); nsresult ReplaceSheets(mozilla::SheetType aType, const nsTArray<RefPtr<mozilla::CSSStyleSheet>>& aNewSheets); nsresult InsertStyleSheetBefore(mozilla::SheetType aType, mozilla::CSSStyleSheet* aNewSheet, mozilla::CSSStyleSheet* aReferenceSheet); // Enable/Disable entire author style level (Doc, ScopedDoc & PresHint levels) bool GetAuthorStyleDisabled() const; nsresult SetAuthorStyleDisabled(bool aStyleDisabled); int32_t SheetCount(mozilla::SheetType aType) const { return mSheets[aType].Length(); } mozilla::CSSStyleSheet* StyleSheetAt(mozilla::SheetType aType, int32_t aIndex) const { return mSheets[aType][aIndex]; } void AppendAllXBLStyleSheets(nsTArray<mozilla::CSSStyleSheet*>& aArray) const; nsresult RemoveDocStyleSheet(mozilla::CSSStyleSheet* aSheet); nsresult AddDocStyleSheet(mozilla::CSSStyleSheet* aSheet, nsIDocument* aDocument); void BeginUpdate(); nsresult EndUpdate(); // Methods for reconstructing the tree; BeginReconstruct basically moves the // old rule tree root and style context roots out of the way, // and EndReconstruct destroys the old rule tree when we're done nsresult BeginReconstruct(); // Note: EndReconstruct should not be called if BeginReconstruct fails void EndReconstruct(); bool IsInRuleTreeReconstruct() const { return mInReconstruct; } void RootStyleContextAdded() { ++mRootStyleContextCount; } void RootStyleContextRemoved() { MOZ_ASSERT(mRootStyleContextCount > 0); --mRootStyleContextCount; } // Return whether the rule tree has cached data such that we need to // do dynamic change handling for changes that change the results of // media queries or require rebuilding all style data. // We don't care whether we have cached rule processors or whether // they have cached rule cascades; getting the rule cascades again in // order to do rule matching will get the correct rule cascade. bool HasCachedStyleData() const { return (mRuleTree && mRuleTree->TreeHasCachedData()) || mRootStyleContextCount > 0; } // Notify the style set that a rulenode is no longer in use, or was // just created and is not in use yet. static const uint32_t kGCInterval = 300; void RuleNodeUnused(nsRuleNode* aNode, bool aMayGC) { ++mUnusedRuleNodeCount; mUnusedRuleNodeList.insertBack(aNode); if (aMayGC && mUnusedRuleNodeCount >= kGCInterval && !mInGC && !mInReconstruct) { GCRuleTrees(); } } // Notify the style set that a rulenode that wasn't in use now is void RuleNodeInUse(nsRuleNode* aNode) { MOZ_ASSERT(mUnusedRuleNodeCount > 0); --mUnusedRuleNodeCount; aNode->removeFrom(mUnusedRuleNodeList); } // Returns true if a restyle of the document is needed due to cloning // sheet inners. bool EnsureUniqueInnerOnCSSSheets(); // Called by CSSStyleSheet::EnsureUniqueInner to let us know it cloned // its inner. void SetNeedsRestyleAfterEnsureUniqueInner() { mNeedsRestyleAfterEnsureUniqueInner = true; } nsIStyleRule* InitialStyleRule(); bool HasRuleProcessorUsedByMultipleStyleSets(mozilla::SheetType aSheetType); // Tells the RestyleManager for the document using this style set // to drop any nsCSSSelector pointers it has. void ClearSelectors(); // Returns whether aSheetType represents a level of the cascade that uses // CSSStyleSheets. See gCSSSheetTypes in nsStyleSet.cpp for the list // of CSS sheet types. static bool IsCSSSheetType(mozilla::SheetType aSheetType); private: nsStyleSet(const nsStyleSet& aCopy) = delete; nsStyleSet& operator=(const nsStyleSet& aCopy) = delete; // Free all the rules with reference-count zero. This continues iterating // over the free list until it is empty, which allows immediate collection // of nodes whose reference-count drops to zero during the destruction of // a child node. This allows the collection of entire trees at once, since // children hold their parents alive. void GCRuleTrees(); nsresult DirtyRuleProcessors(mozilla::SheetType aType); // Update the rule processor list after a change to the style sheet list. nsresult GatherRuleProcessors(mozilla::SheetType aType); void AddImportantRules(nsRuleNode* aCurrLevelNode, nsRuleNode* aLastPrevLevelNode, nsRuleWalker* aRuleWalker); // Move aRuleWalker forward by the appropriate rule if we need to add // a rule due to property restrictions on pseudo-elements. void WalkRestrictionRule(mozilla::CSSPseudoElementType aPseudoType, nsRuleWalker* aRuleWalker); void WalkDisableTextZoomRule(mozilla::dom::Element* aElement, nsRuleWalker* aRuleWalker); #ifdef DEBUG // Just like AddImportantRules except it doesn't actually add anything; it // just asserts that there are no important rules between aCurrLevelNode and // aLastPrevLevelNode. void AssertNoImportantRules(nsRuleNode* aCurrLevelNode, nsRuleNode* aLastPrevLevelNode); // Just like AddImportantRules except it doesn't actually add anything; it // just asserts that there are no CSS rules between aCurrLevelNode and // aLastPrevLevelNode. Mostly useful for the preshint level. void AssertNoCSSRules(nsRuleNode* aCurrLevelNode, nsRuleNode* aLastPrevLevelNode); #endif // Enumerate the rules in a way that cares about the order of the // rules. // aElement is the element the rules are for. It might be null. aData // is the closure to pass to aCollectorFunc. If aContent is not null, // aData must be a RuleProcessorData* void FileRules(nsIStyleRuleProcessor::EnumFunc aCollectorFunc, RuleProcessorData* aData, mozilla::dom::Element* aElement, nsRuleWalker* aRuleWalker); // Enumerate all the rules in a way that doesn't care about the order // of the rules and break out if the enumeration is halted. void WalkRuleProcessors(nsIStyleRuleProcessor::EnumFunc aFunc, ElementDependentRuleProcessorData* aData, bool aWalkAllXBLStylesheets); // Helper for ResolveStyleWithReplacement // aPseudoElement must follow the same rules as for // ResolvePseudoElementStyle, and be null for non-pseudo-element cases nsRuleNode* RuleNodeWithReplacement(mozilla::dom::Element* aElement, mozilla::dom::Element* aPseudoElement, nsRuleNode* aOldRuleNode, mozilla::CSSPseudoElementType aPseudoType, nsRestyleHint aReplacements); already_AddRefed<nsStyleContext> GetContext(nsStyleContext* aParentContext, nsRuleNode* aRuleNode, nsRuleNode* aVisitedRuleNode, nsIAtom* aPseudoTag, mozilla::CSSPseudoElementType aPseudoType, mozilla::dom::Element* aElementForAnimation, uint32_t aFlags); nsPresContext* PresContext() { return mRuleTree->PresContext(); } // The sheets in each array in mSheets are stored with the most significant // sheet last. // The arrays for ePresHintSheet, eStyleAttrSheet, eTransitionSheet, // eAnimationSheet and eSVGAttrAnimationSheet are always empty. // (FIXME: We should reduce the storage needed for them.) mozilla::EnumeratedArray<mozilla::SheetType, mozilla::SheetType::Count, nsTArray<RefPtr<mozilla::CSSStyleSheet>>> mSheets; // mRuleProcessors[eScopedDocSheet] is always null; rule processors // for scoped style sheets are stored in mScopedDocSheetRuleProcessors. mozilla::EnumeratedArray<mozilla::SheetType, mozilla::SheetType::Count, nsCOMPtr<nsIStyleRuleProcessor>> mRuleProcessors; // Rule processors for HTML5 scoped style sheets, one per scope. nsTArray<nsCOMPtr<nsIStyleRuleProcessor> > mScopedDocSheetRuleProcessors; RefPtr<nsBindingManager> mBindingManager; RefPtr<nsRuleNode> mRuleTree; // This is the root of our rule tree. It is a // lexicographic tree of matched rules that style // contexts use to look up properties. uint16_t mBatching; unsigned mInShutdown : 1; unsigned mInGC : 1; unsigned mAuthorStyleDisabled: 1; unsigned mInReconstruct : 1; unsigned mInitFontFeatureValuesLookup : 1; unsigned mNeedsRestyleAfterEnsureUniqueInner : 1; unsigned mDirty : int(mozilla::SheetType::Count); // one bit per sheet type uint32_t mRootStyleContextCount; #ifdef DEBUG // In debug builds, we stash a weak pointer here to the old root during // reconstruction. During GC, we check for this pointer, and null it out // when we encounter it. This allows us to assert that the old root (and // thus all of its subtree) was GCed after reconstruction, which implies // that there are no style contexts holding on to old rule nodes. nsRuleNode* mOldRootNode; #endif // Track our rule nodes with zero refcount. When this hits a threshold, we // sweep and free. Keeping unused rule nodes around for a bit allows us to // reuse them in many cases. mozilla::LinkedList<nsRuleNode> mUnusedRuleNodeList; uint32_t mUnusedRuleNodeCount; // Empty style rules to force things that restrict which properties // apply into different branches of the rule tree. RefPtr<nsEmptyStyleRule> mFirstLineRule, mFirstLetterRule, mPlaceholderRule; // Style rule which sets all properties to their initial values for // determining when context-sensitive values are in use. RefPtr<nsInitialStyleRule> mInitialStyleRule; // Style rule that sets the internal -x-text-zoom property on // <svg:text> elements to disable the effect of text zooming. RefPtr<nsDisableTextZoomStyleRule> mDisableTextZoomStyleRule; // whether font feature values lookup object needs initialization RefPtr<gfxFontFeatureValueSet> mFontFeatureValuesLookup; }; #ifdef MOZILLA_INTERNAL_API inline void nsRuleNode::AddRef() { if (mRefCnt++ == 0) { MOZ_ASSERT(mPresContext->StyleSet()->IsGecko(), "ServoStyleSets should not have rule nodes"); mPresContext->StyleSet()->AsGecko()->RuleNodeInUse(this); } } inline void nsRuleNode::Release() { if (--mRefCnt == 0) { MOZ_ASSERT(mPresContext->StyleSet()->IsGecko(), "ServoStyleSets should not have rule nodes"); mPresContext->StyleSet()->AsGecko()->RuleNodeUnused(this, /* aMayGC = */ true); } } #endif #endif