CSS Custom Properties (Variables)

third_party/WebKit/Source/core/css/CSSVariableData.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/CSSVariableData.h"
+
+#include "core/css/parser/CSSParserTokenRange.h"
+#include "wtf/text/StringBuilder.h"
+
+namespace blink {
+
+template<typename CharacterType> void CSSVariableData::updateTokens()
+{
+    const CharacterType* currentOffset = m_string.getCharacters<CharacterType>();
+    for (auto&& token : m_tokens) {
+        if (!token.needsStringBacking())
+            continue;
+
+        token.m_valueDataCharRaw = currentOffset;

[Timothy Loh, 2015/09/30 02:09:27]

How about building m_tokens in this function instead of the other one:

if (token.needsStringBacking()) {
    unsigned length = token.value().length();
    CSSParserString parserString(currentOffset, length);
    m_tokens.append(token.copyWithUpdatedString(parserString)));
    currentOffset += length;
} else {
    m_tokens.append(token);
}

This lets us keep CSSParserToken immutable.

+        currentOffset += token.m_valueLength;
+    }
+    ASSERT(currentOffset == m_string.getCharacters<CharacterType>() + m_string.length());
+}
+
+void CSSVariableData::consumeAndUpdateTokens(const CSSParserTokenRange& range)
+{
+    StringBuilder stringBuilder;
+    CSSParserTokenRange localRange = range;
+
+    while (!localRange.atEnd()) {
+        CSSParserToken token = localRange.consume();
+        if (token.needsStringBacking()) {
+            if (token.valueIs8Bit())

[Timothy Loh, 2015/09/30 02:09:27]

Let's just get the string data off token.value() instead of exposing more and
friending.

+                stringBuilder.append(static_cast<const LChar*>(token.m_valueDataCharRaw), token.m_valueLength);
+            else
+                stringBuilder.append(static_cast<const UChar*>(token.m_valueDataCharRaw), token.m_valueLength);
+        }
+        m_tokens.append(token);
+    }
+    m_string = stringBuilder.toString();
+    if (m_string.is8Bit())
+        updateTokens<LChar>();
+    else
+        updateTokens<UChar>();
+}
+
+CSSVariableData::CSSVariableData(const CSSParserTokenRange& range, bool needsVariableResolution)
+    : m_needsVariableResolution(needsVariableResolution)
+{
+    ASSERT(!range.atEnd());
+    consumeAndUpdateTokens(range);
+}
+
+} // namespace blink