WebCore/html/CSSPreloadScanner.cpp
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/html/CSSPreloadScanner.cpp	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,160 @@
+/*
+ * Copyright (C) 2008 Apple Inc. All Rights Reserved.
+ * Copyright (C) 2009 Torch Mobile, Inc. http://www.torchmobile.com/
+ * Copyright (C) 2010 Google Inc. All Rights Reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "CSSPreloadScanner.h"
+
+#include "CSSHelper.h"
+#include "CachedCSSStyleSheet.h"
+#include "DocLoader.h"
+#include "Document.h"
+#include "HTMLToken.h"
+
+namespace WebCore {
+
+static inline bool isWhitespace(UChar c)
+{
+    return c == ' ' || c == '\n' || c == '\r' || c == '\t';
+}
+
+CSSPreloadScanner::CSSPreloadScanner(Document* document)
+    : m_document(document)
+{
+    reset();
+}
+
+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(); ++iter) {
+        tokenize(*iter);
+    }
+}
+
+inline void CSSPreloadScanner::tokenize(UChar c)
+{
+    // We are just interested in @import rules, no need for real tokenization here
+    // Searching for other types of resources is probably low payoff.
+    switch (m_state) {
+    case Initial:
+        if (c == '@')
+            m_state = RuleStart;
+        else if (c == '/')
+            m_state = MaybeComment;
+        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 == '/')
+            m_state = Initial;
+        else if (c == '*')
+            ;
+        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 (isWhitespace(c))
+            m_state = AfterRule;
+        else if (c == ';')
+            m_state = Initial;
+        else
+            m_rule.append(c);
+        break;
+    case AfterRule:
+        if (isWhitespace(c))
+            ;
+        else if (c == ';')
+            m_state = Initial;
+        else {
+            m_state = RuleValue;
+            m_ruleValue.append(c);
+        }
+        break;
+    case RuleValue:
+        if (isWhitespace(c))
+            m_state = AfterRuleValue;
+        else if (c == ';') {
+            emitRule();
+            m_state = Initial;
+        } else 
+            m_ruleValue.append(c);
+        break;
+    case AfterRuleValue:
+        if (isWhitespace(c))
+            ;
+        else if (c == ';') {
+            emitRule();
+            m_state = Initial;
+        } else {
+            // FIXME: media rules
+            m_state = Initial;
+        }
+        break;
+    }
+}
+
+void CSSPreloadScanner::emitRule()
+{
+    String rule(m_rule.data(), m_rule.size());
+    if (equalIgnoringCase(rule, "import") && !m_ruleValue.isEmpty()) {
+        String value(m_ruleValue.data(), m_ruleValue.size());
+        String url = deprecatedParseURL(value);
+        if (!url.isEmpty())
+            m_document->docLoader()->preload(CachedResource::CSSStyleSheet, url, String(), m_scanningBody);
+    }
+    m_rule.clear();
+    m_ruleValue.clear();
+}
+
+}