diff -r 000000000000 -r 6474c204b198 layout/style/nsStyleSet.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/layout/style/nsStyleSet.h Wed Dec 31 06:09:35 2014 +0100 @@ -0,0 +1,492 @@ +/* -*- 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/MemoryReporting.h" + +#include "nsIStyleRuleProcessor.h" +#include "nsCSSStyleSheet.h" +#include "nsBindingManager.h" +#include "nsRuleNode.h" +#include "nsTArray.h" +#include "nsCOMArray.h" +#include "nsAutoPtr.h" +#include "nsIStyleRule.h" +#include "nsCSSPseudoElements.h" +#include "gfxFontFeatures.h" + +class nsCSSFontFaceRule; +class nsCSSKeyframesRule; +class nsCSSFontFeatureValuesRule; +class nsCSSPageRule; +class nsRuleWalker; +struct ElementDependentRuleProcessorData; +struct TreeMatchContext; + +namespace mozilla { +class EventStates; +} // namespace mozilla + +class nsEmptyStyleRule MOZ_FINAL : public nsIStyleRule +{ + NS_DECL_ISUPPORTS + virtual void MapRuleInfoInto(nsRuleData* aRuleData) MOZ_OVERRIDE; +#ifdef DEBUG + virtual void List(FILE* out = stdout, int32_t aIndent = 0) const MOZ_OVERRIDE; +#endif +}; + +class nsInitialStyleRule MOZ_FINAL : public nsIStyleRule +{ + NS_DECL_ISUPPORTS + virtual void MapRuleInfoInto(nsRuleData* aRuleData) MOZ_OVERRIDE; +#ifdef DEBUG + virtual void List(FILE* out = stdout, int32_t aIndent = 0) const MOZ_OVERRIDE; +#endif +}; + +class nsDisableTextZoomStyleRule MOZ_FINAL : public nsIStyleRule +{ + NS_DECL_ISUPPORTS + virtual void MapRuleInfoInto(nsRuleData* aRuleData) MOZ_OVERRIDE; +#ifdef DEBUG + virtual void List(FILE* out = stdout, int32_t aIndent = 0) const MOZ_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 +{ + public: + nsStyleSet(); + + size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const; + + void Init(nsPresContext *aPresContext); + + nsRuleNode* GetRuleTree() { return mRuleTree; } + + // enable / disable the Quirk style sheet + void EnableQuirkStyleSheet(bool aEnable); + + // get a style context for a non-pseudo frame. + already_AddRefed + ResolveStyleFor(mozilla::dom::Element* aElement, + nsStyleContext* aParentContext); + + already_AddRefed + 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 + ResolveStyleForRules(nsStyleContext* aParentContext, + const nsTArray< nsCOMPtr > &aRules); + + // used in ResolveStyleForRules below + struct RuleAndLevel + { + nsIStyleRule* mRule; + uint8_t mLevel; + }; + + // Get a new style context for aElement for the rules in aRules + // aRules is an array of rules and their levels in reverse order, + // that is from the leaf-most to the root-most rule in the rule tree. + already_AddRefed + ResolveStyleForRules(nsStyleContext* aParentContext, + nsStyleContext* aOldStyle, + const nsTArray& 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). + already_AddRefed + ResolveStyleByAddingRules(nsStyleContext* aBaseContext, + const nsCOMArray &aRules); + + // Get a style context for a non-element (which no rules will match), + // such as text nodes, placeholder frames, and the nsFirstLetterFrame + // for everything after the first letter. + // + // Perhaps this 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 + ResolveStyleForNonElement(nsStyleContext* aParentContext); + + // Get a style context for a pseudo-element. aParentElement must be + // non-null. aPseudoID is the nsCSSPseudoElements::Type for the + // pseudo-element. aPseudoElement must be non-null if the pseudo-element + // type is one that allows user action pseudo-classes after it; otherwise, + // it is ignored. + already_AddRefed + ResolvePseudoElementStyle(mozilla::dom::Element* aParentElement, + nsCSSPseudoElements::Type 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 + ProbePseudoElementStyle(mozilla::dom::Element* aParentElement, + nsCSSPseudoElements::Type aType, + nsStyleContext* aParentContext); + already_AddRefed + ProbePseudoElementStyle(mozilla::dom::Element* aParentElement, + nsCSSPseudoElements::Type aType, + nsStyleContext* aParentContext, + TreeMatchContext& aTreeMatchContext, + mozilla::dom::Element* aPseudoElement = nullptr); + + // Get a style context for an anonymous box. aPseudoTag is the + // pseudo-tag to use and must be non-null. + already_AddRefed + ResolveAnonymousBoxStyle(nsIAtom* aPseudoTag, nsStyleContext* aParentContext); + +#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 + 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(nsPresContext* aPresContext, + nsTArray& aArray); + + // Return the winning (in the cascade) @keyframes rule for the given name. + nsCSSKeyframesRule* KeyframesRuleForName(nsPresContext* aPresContext, + const nsString& aName); + + // Fetch object for looking up font feature values + already_AddRefed GetFontFeatureValuesLookup(); + + // Append all the currently-active font feature values rules to aArray. + // Return true for success and false for failure. + bool AppendFontFeatureValuesRules(nsPresContext* aPresContext, + nsTArray& aArray); + + // Append all the currently-active page rules to aArray. Return + // true for success and false for failure. + bool AppendPageRules(nsPresContext* aPresContext, + nsTArray& aArray); + + // Begin ignoring style context destruction, to avoid lots of unnecessary + // work on document teardown. + void BeginShutdown(nsPresContext* aPresContext); + + // Free all of the data associated with this style set. + void Shutdown(nsPresContext* aPresContext); + + // Notification that a style context is being destroyed. + void NotifyStyleContextDestroyed(nsPresContext* aPresContext, + nsStyleContext* aStyleContext); + + // 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 + ReparentStyleContext(nsStyleContext* aStyleContext, + nsStyleContext* aNewParentContext, + mozilla::dom::Element* aElement); + + // Test if style is dependent on a document state. + bool HasDocumentStateDependentStyle(nsPresContext* aPresContext, + nsIContent* aContent, + mozilla::EventStates aStateMask); + + // Test if style is dependent on content state + nsRestyleHint HasStateDependentStyle(nsPresContext* aPresContext, + mozilla::dom::Element* aElement, + mozilla::EventStates aStateMask); + nsRestyleHint HasStateDependentStyle(nsPresContext* aPresContext, + mozilla::dom::Element* aElement, + nsCSSPseudoElements::Type aPseudoType, + mozilla::dom::Element* aPseudoElement, + mozilla::EventStates aStateMask); + + // Test if style is dependent on the presence of an attribute. + nsRestyleHint HasAttributeDependentStyle(nsPresContext* aPresContext, + mozilla::dom::Element* aElement, + nsIAtom* aAttribute, + int32_t aModType, + bool aAttrHasChanged); + + /* + * 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(nsPresContext* aPresContext); + + // APIs for registering objects that can supply additional + // rules during processing. + void SetBindingManager(nsBindingManager* aBindingManager) + { + mBindingManager = aBindingManager; + } + + // The "origins" of the CSS cascade, from lowest precedence to + // highest (for non-!important rules). + enum sheetType { + eAgentSheet, // CSS + eUserSheet, // CSS + ePresHintSheet, + eDocSheet, // CSS + eScopedDocSheet, + eStyleAttrSheet, + eOverrideSheet, // CSS + eAnimationSheet, + eTransitionSheet, + eSheetTypeCount + // be sure to keep the number of bits in |mDirty| below and in + // NS_RULE_NODE_LEVEL_MASK updated when changing the number of sheet + // types + }; + + // APIs to manipulate the style sheet lists. The sheets in each + // list are stored with the most significant sheet last. + nsresult AppendStyleSheet(sheetType aType, nsIStyleSheet *aSheet); + nsresult PrependStyleSheet(sheetType aType, nsIStyleSheet *aSheet); + nsresult RemoveStyleSheet(sheetType aType, nsIStyleSheet *aSheet); + nsresult ReplaceSheets(sheetType aType, + const nsCOMArray &aNewSheets); + nsresult InsertStyleSheetBefore(sheetType aType, nsIStyleSheet *aNewSheet, + nsIStyleSheet *aReferenceSheet); + + nsresult DirtyRuleProcessors(sheetType aType); + + // Enable/Disable entire author style level (Doc, ScopedDoc & PresHint levels) + bool GetAuthorStyleDisabled(); + nsresult SetAuthorStyleDisabled(bool aStyleDisabled); + + int32_t SheetCount(sheetType aType) const { + return mSheets[aType].Count(); + } + + nsIStyleSheet* StyleSheetAt(sheetType aType, int32_t aIndex) const { + return mSheets[aType].ObjectAt(aIndex); + } + + nsresult RemoveDocStyleSheet(nsIStyleSheet* aSheet); + nsresult AddDocStyleSheet(nsIStyleSheet* 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(); + + // Let the style set know that a particular sheet is the quirks sheet. This + // sheet must already have been added to the UA sheets. The pointer must not + // be null. This should only be called once for a given style set. + void SetQuirkStyleSheet(nsIStyleSheet* aQuirkStyleSheet); + + // 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()) || !mRoots.IsEmpty(); + } + + // Notify the style set that a rulenode is no longer in use, or was + // just created and is not in use yet. + void RuleNodeUnused() { + ++mUnusedRuleNodeCount; + } + + // Notify the style set that a rulenode that wasn't in use now is + void RuleNodeInUse() { + --mUnusedRuleNodeCount; + } + + nsCSSStyleSheet::EnsureUniqueInnerResult EnsureUniqueInnerOnCSSSheets(); + + nsIStyleRule* InitialStyleRule(); + + private: + nsStyleSet(const nsStyleSet& aCopy) MOZ_DELETE; + nsStyleSet& operator=(const nsStyleSet& aCopy) MOZ_DELETE; + + // Run mark-and-sweep GC on mRuleTree and mOldRuleTrees, based on mRoots. + void GCRuleTrees(); + + // Update the rule processor list after a change to the style sheet list. + nsresult GatherRuleProcessors(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(nsCSSPseudoElements::Type 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); + + /** + * Bit-flags that can be passed to GetContext() in its parameter 'aFlags'. + */ + enum { + eNoFlags = 0, + eIsLink = 1 << 0, + eIsVisitedLink = 1 << 1, + eDoAnimation = 1 << 2, + + // Indicates that we should skip the flex-item-specific chunk of + // ApplyStyleFixups(). This is useful if our parent has "display: flex" + // but we can tell it's not going to actually be a flex container (e.g. if + // it's the outer frame of a button widget, and we're the inline frame for + // the button's label). + eSkipFlexItemStyleFixup = 1 << 3 + }; + + already_AddRefed + GetContext(nsStyleContext* aParentContext, + nsRuleNode* aRuleNode, + nsRuleNode* aVisitedRuleNode, + nsIAtom* aPseudoTag, + nsCSSPseudoElements::Type 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, + // and eAnimationSheet are always empty. (FIXME: We should reduce + // the storage needed for them.) + nsCOMArray mSheets[eSheetTypeCount]; + + // mRuleProcessors[eScopedDocSheet] is always null; rule processors + // for scoped style sheets are stored in mScopedDocSheetRuleProcessors. + nsCOMPtr mRuleProcessors[eSheetTypeCount]; + + // Rule processors for HTML5 scoped style sheets, one per scope. + nsTArray > mScopedDocSheetRuleProcessors; + + // cached instance for enabling/disabling + nsCOMPtr mQuirkStyleSheet; + + nsRefPtr mBindingManager; + + 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 mAuthorStyleDisabled: 1; + unsigned mInReconstruct : 1; + unsigned mInitFontFeatureValuesLookup : 1; + unsigned mDirty : 9; // one dirty bit is used per sheet type + + uint32_t mUnusedRuleNodeCount; // used to batch rule node GC + nsTArray mRoots; // style contexts with no parent + + // Empty style rules to force things that restrict which properties + // apply into different branches of the rule tree. + nsRefPtr mFirstLineRule, mFirstLetterRule, mPlaceholderRule; + + // Style rule which sets all properties to their initial values for + // determining when context-sensitive values are in use. + nsRefPtr mInitialStyleRule; + + // Style rule that sets the internal -x-text-zoom property on + // elements to disable the effect of text zooming. + nsRefPtr mDisableTextZoomStyleRule; + + // Old rule trees, which should only be non-empty between + // BeginReconstruct and EndReconstruct, but in case of bugs that cause + // style contexts to exist too long, may last longer. + nsTArray mOldRuleTrees; + + // whether font feature values lookup object needs initialization + nsRefPtr mFontFeatureValuesLookup; +}; + +#ifdef MOZILLA_INTERNAL_API +inline +void nsRuleNode::AddRef() +{ + if (mRefCnt++ == 0 && !IsRoot()) { + mPresContext->StyleSet()->RuleNodeInUse(); + } +} + +inline +void nsRuleNode::Release() +{ + if (--mRefCnt == 0 && !IsRoot()) { + mPresContext->StyleSet()->RuleNodeUnused(); + } +} +#endif + +#endif