Revert "CSS Custom Properties (Variables)"

third_party/WebKit/Source/core/css/resolver/CSSVariableResolver.cpp

-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "config.h"
-#include "core/css/resolver/CSSVariableResolver.h"
-
-#include "core/CSSPropertyNames.h"
-#include "core/CSSValueKeywords.h"
-#include "core/StyleBuilderFunctions.h"
-#include "core/css/CSSVariableData.h"
-#include "core/css/CSSVariableReferenceValue.h"
-#include "core/css/parser/CSSParserToken.h"
-#include "core/css/parser/CSSParserTokenRange.h"
-#include "core/css/parser/CSSParserValues.h"
-#include "core/css/parser/CSSPropertyParser.h"
-#include "core/css/resolver/StyleBuilder.h"
-#include "core/css/resolver/StyleResolverState.h"
-#include "core/style/StyleVariableData.h"
-#include "wtf/Vector.h"
-
-namespace blink {
-
-// TODO(leviw): This should take a CSSParserTokenRange
-static void findEndIndexOfVariableReference(const Vector<CSSParserToken>& resolvedTokens, unsigned startIndex, unsigned& endIndex, unsigned& commaIndex, bool& hasClosingBracket)
-{
-    endIndex = 0;
-    commaIndex = 0;
-    unsigned bracketCount = 1;
-    for (unsigned i = startIndex; i < resolvedTokens.size(); ++i) {
-        CSSParserTokenType type = resolvedTokens[i].type();
-
-        if (type == CommaToken && !commaIndex) {
-            commaIndex = i;
-        } else if (type == LeftParenthesisToken || type == FunctionToken) {
-            bracketCount++;
-        } else if (type == RightParenthesisToken) {
-            if (bracketCount == 1) {
-                hasClosingBracket = true;
-                endIndex = i;
-                return;
-            }
-            bracketCount--;
-        }
-    }
-    hasClosingBracket = false;
-    endIndex = resolvedTokens.size() - 1;
-}
-
-unsigned CSSVariableResolver::resolveVariableTokensRecursive(Vector<CSSParserToken>& resolvedTokens, unsigned startIndex)
-{
-    unsigned variableLocation = startIndex;
-    while (resolvedTokens[variableLocation].type() != IdentToken)
-        variableLocation++;
-
-    unsigned commaIndex;
-    unsigned endIndex;
-    bool hasClosingBracket;
-    // Find default value and match braces
-    findEndIndexOfVariableReference(resolvedTokens, variableLocation + 1, endIndex, commaIndex, hasClosingBracket);
-
-    unsigned length = endIndex - startIndex + 1;
-    unsigned varFunctionPosition = startIndex;
-
-    AtomicString variableName = resolvedTokens[variableLocation].value();
-
-    if (m_variablesSeen.contains(variableName)) {
-        m_cycleDetected = true;
-        resolvedTokens.clear();
-        return 0;
-    }
-
-    CSSVariableData* variableData = m_styleVariableData ? m_styleVariableData->getVariable(variableName) : nullptr;
-    if (variableData) {
-        Vector<CSSParserToken> tokens(variableData->tokens());
-        if (variableData->needsVariableResolution()) {
-            m_variablesSeen.add(variableName);
-            resolveVariableReferencesFromTokens(tokens);
-            m_variablesSeen.remove(variableName);
-
-            // The old variable data holds onto the backing string the new resolved CSSVariableData
-            // relies on. Ensure it will live beyond us overwriting the RefPtr in StyleVariableData.
-            ASSERT(variableData->refCount() > 1);
-
-            m_styleVariableData->setVariable(variableName, CSSVariableData::createResolved(tokens));
-        }
-        if (tokens.size()) {
-            resolvedTokens.remove(startIndex, length);
-            resolvedTokens.insert(startIndex, tokens);
-            return tokens.size();
-        }
-    }
-
-    // Fallback on default value if present
-    if (!commaIndex || m_cycleDetected) {
-        resolvedTokens.clear();
-        return 0;
-    }
-
-    // Move the tokens to the beginning of the variable reference
-    unsigned defaultValueStart = commaIndex + 1;
-    unsigned defaultValueLength = endIndex - commaIndex - (hasClosingBracket ? 1 : 0);
-    for (unsigned i = 0; i < defaultValueLength; ++i)
-        resolvedTokens[varFunctionPosition + i] = resolvedTokens[defaultValueStart + i];
-    resolvedTokens.remove(varFunctionPosition + defaultValueLength, length - defaultValueLength);
-
-    resolveVariableReferencesFromTokens(resolvedTokens);
-
-    return resolvedTokens.size();
-}
-
-void CSSVariableResolver::resolveVariableReferencesFromTokens(Vector<CSSParserToken>& tokens)
-{
-    for (unsigned i = 0; i < tokens.size(); ++i) {
-        if (tokens[i].functionId() == CSSValueVar) {
-            unsigned validTokens = resolveVariableTokensRecursive(tokens, i);
-            if (validTokens < 1 || m_cycleDetected) {
-                tokens.clear();
-                break;
-            }
-            i += validTokens - 1;
-        }
-    }
-}
-
-void CSSVariableResolver::resolveAndApplyVariableReferences(StyleResolverState& state, CSSPropertyID id, const CSSVariableReferenceValue& value)
-{
-    // TODO(leviw): This should be a stack
-    Vector<CSSParserToken> tokens = value.variableDataValue()->tokens();
-
-    CSSVariableResolver resolver(state.style()->variables());
-
-    resolver.resolveVariableReferencesFromTokens(tokens);
-
-    if (!tokens.size())
-        return;
-
-    CSSParserContext context(HTMLStandardMode, 0);
-
-    WillBeHeapVector<CSSProperty, 256> parsedProperties;
-
-    CSSPropertyParser::parseValue(id, false, CSSParserTokenRange(tokens), context, parsedProperties, StyleRule::Type::Style);
-
-    unsigned parsedPropertiesCount = parsedProperties.size();
-    for (unsigned i = 0; i < parsedPropertiesCount; ++i)
-        StyleBuilder::applyProperty(parsedProperties[i].id(), state, parsedProperties[i].value());
-}
-
-void CSSVariableResolver::resolveVariableDefinitions(StyleVariableData* variables)
-{
-    if (!variables)
-        return;
-
-    for (auto& variable : variables->m_data) {
-        if (!variable.value->needsVariableResolution())
-            continue;
-        Vector<CSSParserToken> resolvedTokens(variable.value->tokens());
-
-        CSSVariableResolver resolver(variables, variable.key);
-        resolver.resolveVariableReferencesFromTokens(resolvedTokens);
-
-        variable.value = CSSVariableData::createResolved(resolvedTokens);
-    }
-}
-
-CSSVariableResolver::CSSVariableResolver(StyleVariableData* styleVariableData)
-    : m_styleVariableData(styleVariableData)
-    , m_cycleDetected(false)
-{
-}
-
-CSSVariableResolver::CSSVariableResolver(StyleVariableData* styleVariableData, AtomicString& variable)
-    : m_styleVariableData(styleVariableData)
-    , m_cycleDetected(false)
-{
-    m_variablesSeen.add(variable);
-}
-
-} // namespace blink