CSSPreloadScanner.cpp [plain text]
#include "config.h"
#include "CSSPreloadScanner.h"
#include "CachedCSSStyleSheet.h"
#include "CachedResourceLoader.h"
#include "Document.h"
#include "HTMLParserIdioms.h"
#include "HTMLToken.h"
namespace WebCore {
CSSPreloadScanner::CSSPreloadScanner(Document* document)
: m_state(Initial)
, m_scanningBody(false)
, m_document(document)
{
}
void CSSPreloadScanner::reset()
{
m_state = Initial;
m_rule.clear();
m_ruleValue.clear();
}
void CSSPreloadScanner::scan(const HTMLToken& token, bool scanningBody)
{
m_scanningBody = scanningBody;
const HTMLToken::DataVector& characters = token.characters();
for (HTMLToken::DataVector::const_iterator iter = characters.begin(); iter != characters.end() && m_state != DoneParsingImportRules; ++iter)
tokenize(*iter);
}
inline void CSSPreloadScanner::tokenize(UChar c)
{
switch (m_state) {
case Initial:
if (isHTMLSpace(c))
break;
if (c == '@')
m_state = RuleStart;
else if (c == '/')
m_state = MaybeComment;
else
m_state = DoneParsingImportRules;
break;
case MaybeComment:
if (c == '*')
m_state = Comment;
else
m_state = Initial;
break;
case Comment:
if (c == '*')
m_state = MaybeCommentEnd;
break;
case MaybeCommentEnd:
if (c == '*')
break;
if (c == '/')
m_state = Initial;
else
m_state = Comment;
break;
case RuleStart:
if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z')) {
m_rule.clear();
m_ruleValue.clear();
m_rule.append(c);
m_state = Rule;
} else
m_state = Initial;
break;
case Rule:
if (isHTMLSpace(c))
m_state = AfterRule;
else if (c == ';')
m_state = Initial;
else
m_rule.append(c);
break;
case AfterRule:
if (isHTMLSpace(c))
break;
if (c == ';')
m_state = Initial;
else if (c == '{')
m_state = DoneParsingImportRules;
else {
m_state = RuleValue;
m_ruleValue.append(c);
}
break;
case RuleValue:
if (isHTMLSpace(c))
m_state = AfterRuleValue;
else if (c == ';')
emitRule();
else
m_ruleValue.append(c);
break;
case AfterRuleValue:
if (isHTMLSpace(c))
break;
if (c == ';')
emitRule();
else if (c == '{')
m_state = DoneParsingImportRules;
else {
m_state = Initial;
}
break;
case DoneParsingImportRules:
ASSERT_NOT_REACHED();
break;
}
}
static String parseCSSStringOrURL(const UChar* characters, size_t length)
{
size_t offset = 0;
size_t reducedLength = length;
while (reducedLength && isHTMLSpace(characters[offset])) {
++offset;
--reducedLength;
}
while (reducedLength && isHTMLSpace(characters[offset + reducedLength - 1]))
--reducedLength;
if (reducedLength >= 5
&& (characters[offset] == 'u' || characters[offset] == 'U')
&& (characters[offset + 1] == 'r' || characters[offset + 1] == 'R')
&& (characters[offset + 2] == 'l' || characters[offset + 2] == 'L')
&& characters[offset + 3] == '('
&& characters[offset + reducedLength - 1] == ')') {
offset += 4;
reducedLength -= 5;
}
while (reducedLength && isHTMLSpace(characters[offset])) {
++offset;
--reducedLength;
}
while (reducedLength && isHTMLSpace(characters[offset + reducedLength - 1]))
--reducedLength;
if (reducedLength < 2 || characters[offset] != characters[offset + reducedLength - 1] || !(characters[offset] == '\'' || characters[offset] == '"'))
return String();
offset++;
reducedLength -= 2;
while (reducedLength && isHTMLSpace(characters[offset])) {
++offset;
--reducedLength;
}
while (reducedLength && isHTMLSpace(characters[offset + reducedLength - 1]))
--reducedLength;
return String(characters + offset, reducedLength);
}
void CSSPreloadScanner::emitRule()
{
if (equalIgnoringCase("import", m_rule.characters(), m_rule.length())) {
String value = parseCSSStringOrURL(m_ruleValue.characters(), m_ruleValue.length());
if (!value.isEmpty()) {
ResourceRequest request(m_document->completeURL(value));
m_document->cachedResourceLoader()->preload(CachedResource::CSSStyleSheet, request, String(), m_scanningBody);
}
m_state = Initial;
} else if (equalIgnoringCase("charset", m_rule.characters(), m_rule.length()))
m_state = Initial;
else
m_state = DoneParsingImportRules;
m_rule.clear();
m_ruleValue.clear();
}
}