The Tor Browser: layout/style/nsRuleProcessorData.h@8bccb770b82d (annotated)

layout/style/nsRuleProcessorData.h@8bccb770b82d (annotated)

layout/style/nsRuleProcessorData.h

Wed, 31 Dec 2014 13:27:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 13:27:57 +0100
branch: TOR_BUG_3246
changeset 6: 8bccb770b82d
permissions: -rw-r--r--

Ignore runtime configuration files generated during quality assurance.

 /* -*- 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/. */
 /*
  * data structures passed to nsIStyleRuleProcessor methods (to pull loop
  * invariant computations out of the loop)
  */
 #ifndef nsRuleProcessorData_h_
 #define nsRuleProcessorData_h_
 #include "nsPresContext.h" // for nsCompatibility
 #include "nsString.h"
 #include "nsChangeHint.h"
 #include "nsCSSPseudoElements.h"
 #include "nsRuleWalker.h"
 #include "nsNthIndexCache.h"
 #include "nsILoadContext.h"
 #include "nsIDocument.h"
 #include "mozilla/AutoRestore.h"
 #include "mozilla/BloomFilter.h"
 #include "mozilla/EventStates.h"
 #include "mozilla/GuardObjects.h"
 class nsAttrValue;
 class nsIAtom;
 class nsIContent;
 class nsICSSPseudoComparator;
 class nsIStyleSheet;
 struct TreeMatchContext;
 /**
  * An AncestorFilter is used to keep track of ancestors so that we can
  * quickly tell that a particular selector is not relevant to a given
  * element.
  */
 class MOZ_STACK_CLASS AncestorFilter {
   friend struct TreeMatchContext;
  public:
   /* Maintenance of our ancestor state */
   void PushAncestor(mozilla::dom::Element *aElement);
   void PopAncestor();
   /* Check whether we might have an ancestor matching one of the given
      atom hashes.  |hashes| must have length hashListLength */
   template<size_t hashListLength>
     bool MightHaveMatchingAncestor(const uint32_t* aHashes) const
   {
     MOZ_ASSERT(mFilter);
     for (size_t i = 0; i < hashListLength && aHashes[i]; ++i) {
       if (!mFilter->mightContain(aHashes[i])) {
         return false;
       }
     }
     return true;
   }
   bool HasFilter() const { return mFilter; }
 #ifdef DEBUG
   void AssertHasAllAncestors(mozilla::dom::Element *aElement) const;
 #endif
  private:
   // Using 2^12 slots makes the Bloom filter a nice round page in
   // size, so let's do that.  We get a false positive rate of 1% or
   // less even with several hundred things in the filter.  Note that
   // we allocate the filter lazily, because not all tree match
   // contexts can use one effectively.
   typedef mozilla::BloomFilter<12, nsIAtom> Filter;
   nsAutoPtr<Filter> mFilter;
   // Stack of indices to pop to.  These are indices into mHashes.
   nsTArray<uint32_t> mPopTargets;
   // List of hashes; this is what we pop using mPopTargets.  We store
   // hashes of our ancestor element tag names, ids, and classes in
   // here.
   nsTArray<uint32_t> mHashes;
   // A debug-only stack of Elements for use in assertions
 #ifdef DEBUG
   nsTArray<mozilla::dom::Element*> mElements;
 #endif
 };
 /**
  * A |TreeMatchContext| has data about a matching operation.  The
  * data are not node-specific but are invariants of the DOM tree the
  * nodes being matched against are in.
  *
  * Most of the members are in parameters to selector matching.  The
  * one out parameter is mHaveRelevantLink.  Consumers that use a
  * TreeMatchContext for more than one matching operation and care
  * about :visited and mHaveRelevantLink need to
  * ResetForVisitedMatching() and ResetForUnvisitedMatching() as
  * needed.
  */
 struct MOZ_STACK_CLASS TreeMatchContext {
   // Reset this context for matching for the style-if-:visited.
   void ResetForVisitedMatching() {
     NS_PRECONDITION(mForStyling, "Why is this being called?");
     mHaveRelevantLink = false;
     mVisitedHandling = nsRuleWalker::eRelevantLinkVisited;
   }
   void ResetForUnvisitedMatching() {
     NS_PRECONDITION(mForStyling, "Why is this being called?");
     mHaveRelevantLink = false;
     mVisitedHandling = nsRuleWalker::eRelevantLinkUnvisited;
   }
   void SetHaveRelevantLink() { mHaveRelevantLink = true; }
   bool HaveRelevantLink() const { return mHaveRelevantLink; }
   nsRuleWalker::VisitedHandlingType VisitedHandling() const
   {
     return mVisitedHandling;
   }
   void AddScopeElement(mozilla::dom::Element* aElement) {
     NS_PRECONDITION(mHaveSpecifiedScope,
                     "Should be set before calling AddScopeElement()");
     mScopes.AppendElement(aElement);
   }
   bool IsScopeElement(mozilla::dom::Element* aElement) const {
     return mScopes.Contains(aElement);
   }
   void SetHasSpecifiedScope() {
     mHaveSpecifiedScope = true;
   }
   bool HasSpecifiedScope() const {
     return mHaveSpecifiedScope;
   }
   /**
    * Initialize the ancestor filter and list of style scopes.  If aElement is
    * not null, it and all its ancestors will be passed to
    * mAncestorFilter.PushAncestor and PushStyleScope, starting from the root and
    * going down the tree.  Must only be called for elements in a document.
    */
   void InitAncestors(mozilla::dom::Element *aElement);
   /**
    * Like InitAncestors, but only initializes the style scope list, not the
    * ancestor filter.  May be called for elements outside a document.
    */
   void InitStyleScopes(mozilla::dom::Element* aElement);
   void PushStyleScope(mozilla::dom::Element* aElement)
   {
     NS_PRECONDITION(aElement, "aElement must not be null");
     if (aElement->IsScopedStyleRoot()) {
       mStyleScopes.AppendElement(aElement);
     }
   }
   void PopStyleScope(mozilla::dom::Element* aElement)
   {
     NS_PRECONDITION(aElement, "aElement must not be null");
     if (mStyleScopes.SafeLastElement(nullptr) == aElement) {
       mStyleScopes.TruncateLength(mStyleScopes.Length() - 1);
     }
   }
   bool PopStyleScopeForSelectorMatching(mozilla::dom::Element* aElement)
   {
     NS_ASSERTION(mForScopedStyle, "only call PopStyleScopeForSelectorMatching "
                                   "when mForScopedStyle is true");
     if (!mCurrentStyleScope) {
       return false;
     }
     if (mCurrentStyleScope == aElement) {
       mCurrentStyleScope = nullptr;
     }
     return true;
   }
 #ifdef DEBUG
   void AssertHasAllStyleScopes(mozilla::dom::Element* aElement)
   {
     nsINode* cur = aElement->GetParentNode();
     while (cur) {
       if (cur->IsScopedStyleRoot()) {
         MOZ_ASSERT(mStyleScopes.Contains(cur));
       }
       cur = cur->GetParentNode();
     }
   }
 #endif
   bool SetStyleScopeForSelectorMatching(mozilla::dom::Element* aSubject,
                                         mozilla::dom::Element* aScope)
   {
 #ifdef DEBUG
     AssertHasAllStyleScopes(aSubject);
 #endif
     mForScopedStyle = !!aScope;
     if (!aScope) {
       // This is not for a scoped style sheet; return true, as we want
       // selector matching to proceed.
       mCurrentStyleScope = nullptr;
       return true;
     }
     if (aScope == aSubject) {
       // Although the subject is the same element as the scope, as soon
       // as we continue with selector matching up the tree we don't want
       // to match any more elements.  So we return true to indicate that
       // we want to do the initial selector matching, but set
       // mCurrentStyleScope to null so that no ancestor elements will match.
       mCurrentStyleScope = nullptr;
       return true;
     }
     if (mStyleScopes.Contains(aScope)) {
       // mStyleScopes contains all of the scope elements that are ancestors of
       // aSubject, so if aScope is in mStyleScopes, then we do want selector
       // matching to proceed.
       mCurrentStyleScope = aScope;
       return true;
     }
     // Otherwise, we're not in the scope, and we don't want to proceed
     // with selector matching.
     mCurrentStyleScope = nullptr;
     return false;
   }
   bool IsWithinStyleScopeForSelectorMatching() const
   {
     NS_ASSERTION(mForScopedStyle, "only call IsWithinScopeForSelectorMatching "
                                   "when mForScopedStyle is true");
     return mCurrentStyleScope;
   }
   /* Helper class for maintaining the ancestor state */
   class MOZ_STACK_CLASS AutoAncestorPusher {
   public:
     AutoAncestorPusher(TreeMatchContext& aTreeMatchContext
                        MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
       : mPushedAncestor(false)
       , mPushedStyleScope(false)
       , mTreeMatchContext(aTreeMatchContext)
       , mElement(nullptr)
     {
       MOZ_GUARD_OBJECT_NOTIFIER_INIT;
     }
     void PushAncestorAndStyleScope(mozilla::dom::Element* aElement) {
       MOZ_ASSERT(!mElement);
       if (aElement) {
         mElement = aElement;
         mPushedAncestor = true;
         mPushedStyleScope = true;
         mTreeMatchContext.mAncestorFilter.PushAncestor(aElement);
         mTreeMatchContext.PushStyleScope(aElement);
       }
     }
     void PushAncestorAndStyleScope(nsIContent* aContent) {
       if (aContent && aContent->IsElement()) {
         PushAncestorAndStyleScope(aContent->AsElement());
       }
     }
     void PushStyleScope(mozilla::dom::Element* aElement) {
       MOZ_ASSERT(!mElement);
       if (aElement) {
         mElement = aElement;
         mPushedStyleScope = true;
         mTreeMatchContext.PushStyleScope(aElement);
       }
     }
     void PushStyleScope(nsIContent* aContent) {
       if (aContent && aContent->IsElement()) {
         PushStyleScope(aContent->AsElement());
       }
     }
     ~AutoAncestorPusher() {
       if (mPushedAncestor) {
         mTreeMatchContext.mAncestorFilter.PopAncestor();
       }
       if (mPushedStyleScope) {
         mTreeMatchContext.PopStyleScope(mElement);
       }
     }
   private:
     bool mPushedAncestor;
     bool mPushedStyleScope;
     TreeMatchContext& mTreeMatchContext;
     mozilla::dom::Element* mElement;
     MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
   };
   /* Helper class for tracking whether we're skipping the ApplyStyleFixups
    * code for flex items.
    *
    * The optional second parameter aSkipFlexItemStyleFixup allows this
    * class to be instantiated but only conditionally activated (e.g.
    * in cases where we may or may not want to be skipping flex-item
    * style fixup for a particular chunk of code).
    */
   class MOZ_STACK_CLASS AutoFlexItemStyleFixupSkipper {
   public:
     AutoFlexItemStyleFixupSkipper(TreeMatchContext& aTreeMatchContext,
                                   bool aSkipFlexItemStyleFixup = true
                                   MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
       : mAutoRestorer(aTreeMatchContext.mSkippingFlexItemStyleFixup)
     {
       MOZ_GUARD_OBJECT_NOTIFIER_INIT;
       if (aSkipFlexItemStyleFixup) {
         aTreeMatchContext.mSkippingFlexItemStyleFixup = true;
       }
     }
   private:
     mozilla::AutoRestore<bool> mAutoRestorer;
     MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
   };
   // Is this matching operation for the creation of a style context?
   // (If it is, we need to set slow selector bits on nodes indicating
   // that certain restyling needs to happen.)
   const bool mForStyling;
  private:
   // When mVisitedHandling is eRelevantLinkUnvisited, this is set to true if a
   // relevant link (see explanation in definition of VisitedHandling enum) was
   // encountered during the matching process, which means that matching needs
   // to be rerun with eRelevantLinkVisited.  Otherwise, its behavior is
   // undefined (it might get set appropriately, or might not).
   bool mHaveRelevantLink;
   // If true, then our contextual reference element set is specified,
   // and is given by mScopes.
   bool mHaveSpecifiedScope;
   // How matching should be performed.  See the documentation for
   // nsRuleWalker::VisitedHandlingType.
   nsRuleWalker::VisitedHandlingType mVisitedHandling;
   // For matching :scope
   nsAutoTArray<mozilla::dom::Element*, 1> mScopes;
  public:
   // The document we're working with.
   nsIDocument* const mDocument;
   // Root of scoped stylesheet (set and unset by the supplier of the
   // scoped stylesheet).
   nsIContent* mScopedRoot;
   // Whether our document is HTML (as opposed to XML of some sort,
   // including XHTML).
   // XXX XBL2 issue: Should we be caching this?  What should it be for XBL2?
   const bool mIsHTMLDocument;
   // Possibly remove use of mCompatMode in SelectorMatches?
   // XXX XBL2 issue: Should we be caching this?  What should it be for XBL2?
   const nsCompatibility mCompatMode;
   // The nth-index cache we should use
   nsNthIndexCache mNthIndexCache;
   // An ancestor filter
   AncestorFilter mAncestorFilter;
   // Whether this document is using PB mode
   bool mUsingPrivateBrowsing;
   // Whether we're currently skipping the flex item chunk of ApplyStyleFixups
   // when resolving style (e.g. for children of elements that have a mandatory
   // frame-type and can't be flex containers despite having "display:flex").
   bool mSkippingFlexItemStyleFixup;
   // Whether this TreeMatchContext is being used with an nsCSSRuleProcessor
   // for an HTML5 scoped style sheet.
   bool mForScopedStyle;
   enum MatchVisited {
     eNeverMatchVisited,
     eMatchVisitedDefault
   };
   // List of ancestor elements that define a style scope (due to having a
   // <style scoped> child).
   nsAutoTArray<mozilla::dom::Element*, 1> mStyleScopes;
   // The current style scope element for selector matching.
   mozilla::dom::Element* mCurrentStyleScope;
   // Constructor to use when creating a tree match context for styling
   TreeMatchContext(bool aForStyling,
                    nsRuleWalker::VisitedHandlingType aVisitedHandling,
                    nsIDocument* aDocument,
                    MatchVisited aMatchVisited = eMatchVisitedDefault)
     : mForStyling(aForStyling)
     , mHaveRelevantLink(false)
     , mHaveSpecifiedScope(false)
     , mVisitedHandling(aVisitedHandling)
     , mDocument(aDocument)
     , mScopedRoot(nullptr)
     , mIsHTMLDocument(aDocument->IsHTML())
     , mCompatMode(aDocument->GetCompatibilityMode())
     , mUsingPrivateBrowsing(false)
     , mSkippingFlexItemStyleFixup(false)
     , mForScopedStyle(false)
     , mCurrentStyleScope(nullptr)
   {
     if (aMatchVisited != eNeverMatchVisited) {
       nsCOMPtr<nsISupports> container = mDocument->GetContainer();
       if (container) {
         nsCOMPtr<nsILoadContext> loadContext = do_QueryInterface(container);
         NS_ASSERTION(loadContext, "Couldn't get loadContext from container; assuming no private browsing.");
         if (loadContext) {
           mUsingPrivateBrowsing = loadContext->UsePrivateBrowsing();
         }
       }
     }
   }
 };
 struct MOZ_STACK_CLASS RuleProcessorData {
   RuleProcessorData(nsPresContext* aPresContext,
                     nsRuleWalker* aRuleWalker)
     : mPresContext(aPresContext),
       mRuleWalker(aRuleWalker),
       mScope(nullptr)
   {
     NS_PRECONDITION(mPresContext, "Must have prescontext");
   }
   nsPresContext* const mPresContext;
   nsRuleWalker* const mRuleWalker; // Used to add rules to our results.
   mozilla::dom::Element* mScope;
 };
 struct MOZ_STACK_CLASS ElementDependentRuleProcessorData :
                           public RuleProcessorData {
   ElementDependentRuleProcessorData(nsPresContext* aPresContext,
                                     mozilla::dom::Element* aElement,
                                     nsRuleWalker* aRuleWalker,
                                     TreeMatchContext& aTreeMatchContext)
     : RuleProcessorData(aPresContext, aRuleWalker)
     , mElement(aElement)
     , mTreeMatchContext(aTreeMatchContext)
   {
     NS_ASSERTION(aElement, "null element leaked into SelectorMatches");
     NS_ASSERTION(aElement->OwnerDoc(), "Document-less node here?");
     NS_PRECONDITION(aTreeMatchContext.mForStyling == !!aRuleWalker,
                     "Should be styling if and only if we have a rule walker");
   }
   mozilla::dom::Element* const mElement; // weak ref, must not be null
   TreeMatchContext& mTreeMatchContext;
 };
 struct MOZ_STACK_CLASS ElementRuleProcessorData :
                           public ElementDependentRuleProcessorData {
   ElementRuleProcessorData(nsPresContext* aPresContext,
                            mozilla::dom::Element* aElement,
                            nsRuleWalker* aRuleWalker,
                            TreeMatchContext& aTreeMatchContext)
     : ElementDependentRuleProcessorData(aPresContext, aElement, aRuleWalker,
                                         aTreeMatchContext)
   {
     NS_PRECONDITION(aTreeMatchContext.mForStyling, "Styling here!");
     NS_PRECONDITION(aRuleWalker, "Must have rule walker");
   }
 };
 struct MOZ_STACK_CLASS PseudoElementRuleProcessorData :
                           public ElementDependentRuleProcessorData {
   PseudoElementRuleProcessorData(nsPresContext* aPresContext,
                                  mozilla::dom::Element* aParentElement,
                                  nsRuleWalker* aRuleWalker,
                                  nsCSSPseudoElements::Type aPseudoType,
                                  TreeMatchContext& aTreeMatchContext,
                                  mozilla::dom::Element* aPseudoElement)
     : ElementDependentRuleProcessorData(aPresContext, aParentElement, aRuleWalker,
                                         aTreeMatchContext),
       mPseudoType(aPseudoType),
       mPseudoElement(aPseudoElement)
   {
     NS_PRECONDITION(aPseudoType <
                       nsCSSPseudoElements::ePseudo_PseudoElementCount,
                     "invalid aPseudoType value");
     NS_PRECONDITION(aTreeMatchContext.mForStyling, "Styling here!");
     NS_PRECONDITION(aRuleWalker, "Must have rule walker");
   }
   nsCSSPseudoElements::Type mPseudoType;
   mozilla::dom::Element* const mPseudoElement; // weak ref
 };
 struct MOZ_STACK_CLASS AnonBoxRuleProcessorData : public RuleProcessorData {
   AnonBoxRuleProcessorData(nsPresContext* aPresContext,
                            nsIAtom* aPseudoTag,
                            nsRuleWalker* aRuleWalker)
     : RuleProcessorData(aPresContext, aRuleWalker),
       mPseudoTag(aPseudoTag)
   {
     NS_PRECONDITION(aPseudoTag, "Must have pseudo tag");
     NS_PRECONDITION(aRuleWalker, "Must have rule walker");
   }
   nsIAtom* mPseudoTag;
 };
 #ifdef MOZ_XUL
 struct MOZ_STACK_CLASS XULTreeRuleProcessorData :
                           public ElementDependentRuleProcessorData {
   XULTreeRuleProcessorData(nsPresContext* aPresContext,
                            mozilla::dom::Element* aParentElement,
                            nsRuleWalker* aRuleWalker,
                            nsIAtom* aPseudoTag,
                            nsICSSPseudoComparator* aComparator,
                            TreeMatchContext& aTreeMatchContext)
     : ElementDependentRuleProcessorData(aPresContext, aParentElement,
                                         aRuleWalker, aTreeMatchContext),
       mPseudoTag(aPseudoTag),
       mComparator(aComparator)
   {
     NS_PRECONDITION(aPseudoTag, "null pointer");
     NS_PRECONDITION(aRuleWalker, "Must have rule walker");
     NS_PRECONDITION(aComparator, "must have a comparator");
     NS_PRECONDITION(aTreeMatchContext.mForStyling, "Styling here!");
   }
   nsIAtom*                 mPseudoTag;
   nsICSSPseudoComparator*  mComparator;
 };
 #endif
 struct MOZ_STACK_CLASS StateRuleProcessorData :
                           public ElementDependentRuleProcessorData {
   StateRuleProcessorData(nsPresContext* aPresContext,
                          mozilla::dom::Element* aElement,
                          mozilla::EventStates aStateMask,
                          TreeMatchContext& aTreeMatchContext)
     : ElementDependentRuleProcessorData(aPresContext, aElement, nullptr,
                                         aTreeMatchContext),
       mStateMask(aStateMask)
   {
     NS_PRECONDITION(!aTreeMatchContext.mForStyling, "Not styling here!");
   }
   // |HasStateDependentStyle| for which state(s)?
   // Constants defined in mozilla/EventStates.h .
   const mozilla::EventStates mStateMask;
 };
 struct MOZ_STACK_CLASS PseudoElementStateRuleProcessorData :
                           public StateRuleProcessorData {
   PseudoElementStateRuleProcessorData(nsPresContext* aPresContext,
                                       mozilla::dom::Element* aElement,
                                       mozilla::EventStates aStateMask,
                                       nsCSSPseudoElements::Type aPseudoType,
                                       TreeMatchContext& aTreeMatchContext,
                                       mozilla::dom::Element* aPseudoElement)
     : StateRuleProcessorData(aPresContext, aElement, aStateMask,
                              aTreeMatchContext),
       mPseudoType(aPseudoType),
       mPseudoElement(aPseudoElement)
   {
     NS_PRECONDITION(!aTreeMatchContext.mForStyling, "Not styling here!");
   }
   // We kind of want to inherit from both StateRuleProcessorData and
   // PseudoElementRuleProcessorData.  Instead we've just copied those
   // members from PseudoElementRuleProcessorData to this struct.
   nsCSSPseudoElements::Type mPseudoType;
   mozilla::dom::Element* const mPseudoElement; // weak ref
 };
 struct MOZ_STACK_CLASS AttributeRuleProcessorData :
                           public ElementDependentRuleProcessorData {
   AttributeRuleProcessorData(nsPresContext* aPresContext,
                              mozilla::dom::Element* aElement,
                              nsIAtom* aAttribute,
                              int32_t aModType,
                              bool aAttrHasChanged,
                              TreeMatchContext& aTreeMatchContext)
     : ElementDependentRuleProcessorData(aPresContext, aElement, nullptr,
                                         aTreeMatchContext),
       mAttribute(aAttribute),
       mModType(aModType),
       mAttrHasChanged(aAttrHasChanged)
   {
     NS_PRECONDITION(!aTreeMatchContext.mForStyling, "Not styling here!");
   }
   nsIAtom* mAttribute; // |HasAttributeDependentStyle| for which attribute?
   int32_t mModType;    // The type of modification (see nsIDOMMutationEvent).
   bool mAttrHasChanged; // Whether the attribute has already changed.
 };
 #endif /* !defined(nsRuleProcessorData_h_) */

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layout/style/nsRuleProcessorData.h@8bccb770b82d (annotated)

layout/style/nsRuleProcessorData.h