Notify <picture> elements when a media query (potentially) changes

Source/core/html/HTMLSourceElement.h

 /*
  * Copyright (C) 2007, 2008, 2010 Apple 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 COMPUTER, 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 COMPUTER, 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
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  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef HTMLSourceElement_h
 #define HTMLSourceElement_h
 
+#include "core/css/MediaQueryListListener.h"
 #include "core/html/HTMLElement.h"
 #include "platform/Timer.h"
 
 namespace WebCore {
 
 template<typename T> class EventSender;
 typedef EventSender<HTMLSourceElement> SourceEventSender;
 
 class HTMLSourceElement FINAL : public HTMLElement {
 public:
+    class Listener : public MediaQueryListListener {
+    public:
+        explicit Listener(HTMLSourceElement* element) : m_element(element) { }
+        virtual void call() OVERRIDE
+        {
+            if (m_element)
+                m_element->notifyMediaQueryChanged();
+        }
+
+        void clearElement() { m_element = nullptr; }
+    private:
+        HTMLSourceElement* m_element;
+    };
+
     DECLARE_NODE_FACTORY(HTMLSourceElement);
     virtual ~HTMLSourceElement();
 
     const AtomicString& type() const;
     void setSrc(const String&);
     void setType(const AtomicString&);
 
     void scheduleErrorEvent();
     void cancelPendingErrorEvent();
 
     void dispatchPendingEvent(SourceEventSender*);
 
+    bool mediaQueryMatches() const;
+
 private:
     explicit HTMLSourceElement(Document&);
 
     virtual InsertionNotificationRequest insertedInto(ContainerNode*) OVERRIDE;
     virtual void removedFrom(ContainerNode*) OVERRIDE;
     virtual bool isURLAttribute(const Attribute&) const OVERRIDE;
     virtual void parseAttribute(const QualifiedName&, const AtomicString&) OVERRIDE;
+
+    void notifyMediaQueryChanged();
+
+    RefPtrWillBeRawPtr<MediaQueryList> m_mediaQueryList;
+    RefPtrWillBeRawPtr<Listener> m_listener;
 };
 
 } // namespace WebCore
 
 #endif