Add a WebDocument::watchCssSelectors(selectors)

Source/core/dom/CSSSelectorWatch.cpp

Index: Source/core/dom/CSSSelectorWatch.cpp
diff --git a/Source/core/dom/CSSSelectorWatch.cpp b/Source/core/dom/CSSSelectorWatch.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..94eb34e9c8c50f7d4a563e9e8e2280a8fe0cea41
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+++ b/Source/core/dom/CSSSelectorWatch.cpp
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+/*
+ * 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.
+ *     * 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.
+ *     * 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/CSSSelectorWatch.h"
+
+#include "core/css/CSSParser.h"
+#include "core/css/CSSSelectorList.h"
+#include "core/css/StylePropertySet.h"
+#include "core/css/StyleRule.h"
+#include "core/dom/Document.h"
+#include "core/dom/ScriptExecutionContext.h"
+#include "core/loader/FrameLoaderClient.h"
+#include "core/page/Frame.h"
+#include "core/rendering/style/StyleRareNonInheritedData.h"
+
+namespace WebCore {
+
+// The address of this string is important; its value is just documentation.
+static const char kSupplementName[] = "CSSSelectorWatch";
+
+CSSSelectorWatch::CSSSelectorWatch(Document* document)
+    : m_document(document)
+    , m_callbackSelectorChangeTimer(this, &CSSSelectorWatch::callbackSelectorChangeTimerFired)
+    , m_weakThisFactory(this)
+{
+}
+
+CSSSelectorWatch::~CSSSelectorWatch()
+{
+}

[esprehn, 2013/07/17 07:14:32]

We often just leave this in the header like  { }

[Jeffrey Yasskin, 2013/08/02 01:34:07]

'k.

+
+CSSSelectorWatch* CSSSelectorWatch::from(Document* document)
+{
+    CSSSelectorWatch* watch = static_cast<CSSSelectorWatch*>(Supplement<ScriptExecutionContext>::from(document, kSupplementName));
+    if (!watch) {
+        watch = new CSSSelectorWatch(document);
+        Supplement<ScriptExecutionContext>::provideTo(document, kSupplementName, adoptPtr(watch));
+    }
+    return watch;
+}
+
+void CSSSelectorWatch::callbackSelectorChangeTimerFired(Timer<CSSSelectorWatch>*)
+{
+    if (m_addedSelectors.isEmpty() && m_removedSelectors.isEmpty())
+        return;
+    if (m_document->frame()) {
+        Vector<String> addedSelectors, removedSelectors;
+        copyToVector(m_addedSelectors, addedSelectors);
+        copyToVector(m_removedSelectors, removedSelectors);

[esprehn, 2013/07/17 07:14:32]

Use swap() instead.

[Jeffrey Yasskin, 2013/08/02 01:34:07]

m_removedSelectors is a HashSet, while removedSelectors is a Vector, making swap
not work.

+        m_document->frame()->loader()->client()->selectorMatchChanged(addedSelectors, removedSelectors);
+    }
+    m_addedSelectors.clear();
+    m_removedSelectors.clear();

[esprehn, 2013/07/17 07:14:32]

remove once you swap()

+}
+
+void CSSSelectorWatch::addSelectorMatch(const String& selector, StyleRareNonInheritedData* data)
+{
+    // Set m_selectorWatch here to avoid exposing the weakFactory outside of CSSSelectorWatch.
+    data->m_selectorWatch = m_weakThisFactory.createWeakPtr();
+
+    HashMap<String, int>::iterator count = m_matchingCallbackSelectors.find(selector);
+    if (count != m_matchingCallbackSelectors.end()) {
+        ++count->value;
+        return;
+    }
+    if (!m_callbackSelectorChangeTimer.isActive())
+        m_callbackSelectorChangeTimer.startOneShot(0);
+
+    m_matchingCallbackSelectors.set(selector, 1);
+    if (m_removedSelectors.contains(selector))
+        m_removedSelectors.remove(selector);
+    else
+        m_addedSelectors.add(selector);
+}
+
+void CSSSelectorWatch::removeSelectorMatch(const String& selector)
+{
+    HashMap<String, int>::iterator count = m_matchingCallbackSelectors.find(selector);
+    if (count == m_matchingCallbackSelectors.end())
+        return;
+    --count->value;
+    if (!count->value) {
+        if (!m_callbackSelectorChangeTimer.isActive())
+            m_callbackSelectorChangeTimer.startOneShot(0);
+
+        m_matchingCallbackSelectors.remove(count);
+        if (m_addedSelectors.contains(selector))
+            m_addedSelectors.remove(selector);
+        else
+            m_removedSelectors.add(selector);
+    }
+}
+
+void CSSSelectorWatch::watchCSSSelectors(const Vector<String>& selectors)
+{
+    m_watchedCallbackSelectors.clear();
+    CSSParserContext context(UASheetMode);
+    CSSParser parser(context);
+
+    const CSSProperty callbackProperty(CSSPropertyInternalCallback, CSSPrimitiveValue::createIdentifier(CSSValueInternalPresence));
+    const RefPtr<StylePropertySet> callbackPropertySet = ImmutableStylePropertySet::create(&callbackProperty, 1, UASheetMode);
+
+    CSSSelectorList selectorList;
+    for (unsigned i = 0; i < selectors.size(); ++i) {
+        RefPtr<StyleRule> rule = StyleRule::create(i);
+
+        parser.parseSelector(selectors[i], selectorList);

[esprehn, 2013/07/17 07:14:32]

What about invalid selectors?

[Jeffrey Yasskin, 2013/08/02 01:34:07]

Fixed this by omitting invalid selectors, and testing that. Is
!selectorList.isValid() the right way to detect this?

+        rule->wrapperAdoptSelectorList(selectorList);
+
+        rule->setProperties(callbackPropertySet);
+
+        m_watchedCallbackSelectors.append(rule.release());
+    }
+    m_document->styleResolverChanged(DeferRecalcStyle);
+}
+
+} // namespace WebCore