/* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */ /* 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/. */ /* object that resolves CSS variables using specified and inherited variable * values */ #ifndef mozilla_CSSVariableResolver_h #define mozilla_CSSVariableResolver_h #include "mozilla/DebugOnly.h" #include "nsCSSParser.h" #include "nsCSSScanner.h" #include "nsDataHashtable.h" #include "nsTArray.h" namespace mozilla { class CSSVariableDeclarations; class CSSVariableValues; class EnumerateVariableReferencesData; class CSSVariableResolver { friend class CSSVariableDeclarations; friend class CSSVariableValues; friend class EnumerateVariableReferencesData; public: /** * Creates a new CSSVariableResolver that will output a set of resolved, * computed variables into aOutput. */ explicit CSSVariableResolver(CSSVariableValues* aOutput) : mOutput(aOutput) #ifdef DEBUG , mResolved(false) #endif { MOZ_ASSERT(aOutput); } /** * Resolves the set of inherited variables from aInherited and the * set of specified variables from aSpecified. The resolved variables * are written into mOutput. */ void Resolve(const CSSVariableValues* aInherited, const CSSVariableDeclarations* aSpecified); private: struct Variable { Variable(const nsAString& aVariableName, nsString aValue, nsCSSTokenSerializationType aFirstToken, nsCSSTokenSerializationType aLastToken, bool aWasInherited) : mVariableName(aVariableName) , mValue(aValue) , mFirstToken(aFirstToken) , mLastToken(aLastToken) , mWasInherited(aWasInherited) , mResolved(false) , mReferencesNonExistentVariable(false) , mInStack(false) , mIndex(0) , mLowLink(0) { } nsString mVariableName; nsString mValue; nsCSSTokenSerializationType mFirstToken; nsCSSTokenSerializationType mLastToken; // Whether this variable came from the set of inherited variables. bool mWasInherited; // Whether this variable has been resolved yet. bool mResolved; // Whether this variables includes any references to non-existent variables. bool mReferencesNonExistentVariable; // Bookkeeping for the cycle remover algorithm. bool mInStack; size_t mIndex; size_t mLowLink; }; /** * Adds or modifies an existing entry in the set of variables to be resolved. * This is intended to be called by the AddVariablesToResolver functions on * the CSSVariableDeclarations and CSSVariableValues objects passed in to * Resolve. * * @param aName The variable name (not including any "--" prefix that would * be part of the custom property name) whose value is to be set. * @param aValue The variable value. * @param aFirstToken The type of token at the start of the variable value. * @param aLastToken The type of token at the en of the variable value. * @param aWasInherited Whether this variable came from the set of inherited * variables. */ void Put(const nsAString& aVariableName, nsString aValue, nsCSSTokenSerializationType aFirstToken, nsCSSTokenSerializationType aLastToken, bool aWasInherited); // Helper functions for Resolve. void RemoveCycles(size_t aID); void ResolveVariable(size_t aID); // A mapping of variable names to an ID that indexes into mVariables // and mReferences. nsDataHashtable<nsStringHashKey, size_t> mVariableIDs; // The set of variables. nsTArray<Variable> mVariables; // The list of variables that each variable references. nsTArray<nsTArray<size_t> > mReferences; // The next index to assign to a variable found during the cycle removing // algorithm's traversal of the variable reference graph. size_t mNextIndex; // Stack of variable IDs that we push to as we traverse the variable reference // graph while looking for cycles. Variable::mInStack reflects whether a // given variable has its ID in mStack. nsTArray<size_t> mStack; // CSS parser to use for parsing property values with variable references. nsCSSParser mParser; // The object to output the resolved variables into. CSSVariableValues* mOutput; #ifdef DEBUG // Whether Resolve has been called. bool mResolved; #endif }; } // namespace mozilla #endif