1// Copyright 2015 The Chromium Authors. All rights reserved.
2// Copyright (C) 2016 Apple Inc. All rights reserved.
3//
4// Redistribution and use in source and binary forms, with or without
5// modification, are permitted provided that the following conditions are
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7//
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17//
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28// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29
30#include "config.h"
31#include "CSSVariableReferenceValue.h"
32
33#include "RenderStyle.h"
34#include "StyleResolver.h"
35
36namespace WebCore {
37
38String CSSVariableReferenceValue::customCSSText() const
39{
40 if (!m_serialized) {
41 m_serialized = true;
42 m_stringValue = m_data->tokenRange().serialize();
43 }
44 return m_stringValue;
45}
46
47static bool resolveTokenRange(CSSParserTokenRange, Vector<CSSParserToken>&, ApplyCascadedPropertyState&);
48
49static bool resolveVariableFallback(CSSParserTokenRange range, Vector<CSSParserToken>& result, ApplyCascadedPropertyState& state)
50{
51 if (range.atEnd())
52 return false;
53 ASSERT(range.peek().type() == CommaToken);
54 range.consume();
55 return resolveTokenRange(range, result, state);
56}
57
58static bool resolveVariableReference(CSSParserTokenRange range, Vector<CSSParserToken>& result, ApplyCascadedPropertyState& state)
59{
60 auto& registeredProperties = state.styleResolver->document().getCSSRegisteredCustomPropertySet();
61 auto& style = *state.styleResolver->style();
62
63 range.consumeWhitespace();
64 ASSERT(range.peek().type() == IdentToken);
65 String variableName = range.consumeIncludingWhitespace().value().toString();
66 ASSERT(range.atEnd() || (range.peek().type() == CommaToken));
67
68 // Apply this variable first, in case it is still unresolved
69 state.styleResolver->applyCascadedCustomProperty(variableName, state);
70
71 // Apply fallback to detect cycles
72 Vector<CSSParserToken> fallbackResult;
73 bool fallbackReturn = resolveVariableFallback(CSSParserTokenRange(range), fallbackResult, state);
74
75 auto* property = style.getCustomProperty(variableName);
76
77 if (!property || property->isUnset()) {
78 auto* registered = registeredProperties.get(variableName);
79 if (registered && registered->initialValue())
80 property = registered->initialValue();
81 }
82
83 if (!property || property->isInvalid()) {
84 if (fallbackReturn)
85 result.appendVector(fallbackResult);
86 return fallbackReturn;
87 }
88
89 ASSERT(property->isResolved());
90 result.appendVector(property->tokens());
91
92 return true;
93}
94
95static bool resolveTokenRange(CSSParserTokenRange range, Vector<CSSParserToken>& result, ApplyCascadedPropertyState& state)
96{
97 bool success = true;
98 while (!range.atEnd()) {
99 if (range.peek().functionId() == CSSValueVar || range.peek().functionId() == CSSValueEnv)
100 success &= resolveVariableReference(range.consumeBlock(), result, state);
101 else
102 result.append(range.consume());
103 }
104 return success;
105}
106
107RefPtr<CSSVariableData> CSSVariableReferenceValue::resolveVariableReferences(ApplyCascadedPropertyState& state) const
108{
109 Vector<CSSParserToken> resolvedTokens;
110 CSSParserTokenRange range = m_data->tokenRange();
111
112 if (!resolveTokenRange(range, resolvedTokens, state))
113 return nullptr;
114
115 return CSSVariableData::create(resolvedTokens);
116}
117
118} // namespace WebCore
119