Refactoring: Extract StyleSheetCandidate from DocumentStyleSheetCollection

Source/core/dom/StyleSheetCandidate.cpp

+/*
+ * Copyright (C) 2013 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:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "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 THE COPYRIGHT
+ * OWNER 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 "core/dom/StyleSheetCandidate.h"
+
+#include "HTMLNames.h"
+#include "core/dom/Element.h"
+#include "core/dom/ProcessingInstruction.h"
+#include "core/dom/StyleEngine.h"
+#include "core/html/HTMLLinkElement.h"
+#include "core/html/HTMLStyleElement.h"
+#include "core/svg/SVGStyleElement.h"
+
+namespace WebCore {
+
+using namespace HTMLNames;
+
+AtomicString StyleSheetCandidate::title() const
+{
+    return isElement() ? toElement(m_node).getAttribute(titleAttr) : nullAtom;
+}
+
+bool StyleSheetCandidate::isXSL() const
+{
+    return !m_node.document().isHTMLDocument() && m_type == Pi && toProcessingInstruction(m_node).isXSL();
+}
+
+bool StyleSheetCandidate::isAlternate() const
+{
+    if (!isElement())
+        return false;
+    return toElement(m_node).getAttribute(relAttr).contains("alternate");
+}
+
+bool StyleSheetCandidate::isEnabledViaScript() const
+{
+    return isHTMLLink() && toHTMLLinkElement(m_node).isEnabledViaScript();
+}
+
+bool StyleSheetCandidate::isEnabledAndLoading() const
+{
+    return isHTMLLink() && !toHTMLLinkElement(m_node).isDisabled() && toHTMLLinkElement(m_node).styleSheetIsLoading();
+}
+
+bool StyleSheetCandidate::hasPreferrableName(const String& currentPreferrableName) const
+{
+    ASSERT(isEnabledAndLoading() || sheet());
+    return !isEnabledViaScript() && !title().isEmpty() && !isAlternate() && currentPreferrableName.isEmpty();
+}
+
+bool StyleSheetCandidate::canBeActivated(const String& currentPreferrableName) const
+{
+    StyleSheet* sheet = this->sheet();
+    if (!sheet || sheet->disabled() || !sheet->isCSSStyleSheet())
+        return false;
+    const AtomicString& title = this->title();
+    if (!isEnabledViaScript() && !title.isEmpty() && title != currentPreferrableName)
+        return false;
+    if (isAlternate() && title.isEmpty())
+        return false;
+
+    return true;
+}
+
+StyleSheetCandidate::Type StyleSheetCandidate::typeOf(Node& node)
+{
+    if (node.nodeType() == Node::PROCESSING_INSTRUCTION_NODE)
+        return Pi;
+
+    if (node.isHTMLElement()) {
+        if (node.hasTagName(linkTag))
+            return HTMLLink;
+        if (node.hasTagName(styleTag))
+            return HTMLStyle;
+
+        ASSERT_NOT_REACHED();
+        return HTMLStyle;
+    }
+
+    if (node.isSVGElement() && node.hasTagName(SVGNames::styleTag))
+        return SVGStyle;
+
+    ASSERT_NOT_REACHED();
+    return HTMLStyle;
+}
+
+StyleSheet* StyleSheetCandidate::sheet() const
+{
+    switch (m_type) {
+    case HTMLLink:
+        return toHTMLLinkElement(m_node).sheet();
+    case HTMLStyle:
+        return toHTMLStyleElement(m_node).sheet();
+    case SVGStyle:
+        return toSVGStyleElement(m_node).sheet();
+    case Pi:
+        return toProcessingInstruction(m_node).sheet();
+    }
+
+    ASSERT_NOT_REACHED();
+    return 0;
+}
+
+}