Implement contextmenu attribute with basic support of <menu>

Source/core/html/HTMLElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004-2008, 2013, 2014 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2011 Motorola Mobility. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 30 matching lines @@
 #include "core/dom/Text.h"
 #include "core/dom/shadow/ElementShadow.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/editing/markup.h"
 #include "core/events/EventListener.h"
 #include "core/events/KeyboardEvent.h"
 #include "core/frame/Settings.h"
 #include "core/html/HTMLBRElement.h"
 #include "core/html/HTMLFormElement.h"
 #include "core/html/HTMLInputElement.h"
+#include "core/html/HTMLMenuElement.h"
 #include "core/html/HTMLTemplateElement.h"
 #include "core/html/HTMLTextFormControlElement.h"
 #include "core/html/parser/HTMLParserIdioms.h"
 #include "core/rendering/RenderObject.h"
 #include "platform/text/BidiResolver.h"
 #include "platform/text/BidiTextRun.h"
 #include "platform/text/TextRunIterator.h"
 #include "wtf/StdLibExtras.h"
 #include "wtf/text/CString.h"
 
@@ skipping 832 matching lines @@
         parsedColor.setRGB(parseColorStringWithCrazyLegacyRules(colorString));
 
     style->setProperty(propertyID, cssValuePool().createColorValue(parsedColor.rgb()));
 }
 
 bool HTMLElement::isInteractiveContent() const
 {
     return false;
 }
 
+PassRefPtrWillBeRawPtr<HTMLMenuElement> HTMLElement::contextMenu() const
+{
+    Element* element = treeScope().getElementById(fastGetAttribute(contextmenuAttr));
+    return isHTMLMenuElement(element) ? toHTMLMenuElement(element) : 0;
+}
+
+void HTMLElement::setContextMenu(PassRefPtrWillBeRawPtr<HTMLMenuElement> contextMenu)
+{
+    setAttribute(contextmenuAttr, contextMenu->elementData()->idForStyleResolution());

[tkent, 2014/07/31 06:07:55]

Does this behavior conform to the standard?

[pals, 2014/08/01 10:03:07]

Specification says that the contextmenu attribute value must be the ID of a menu
element in the same home subtree. So, added the treescope check.
Do you mean the same? 

[tkent, 2014/08/04 02:26:12]

The HTML specification must have a detailed algorithm to reflect HTMLElement
object to ID content attribute.  Does your code conform to the algorithm?

I don't think your code is correct.  e.g. HTMLElement without ID, multiple
HTMLElement with simple ID.

[pals, 2014/08/04 08:58:27]

Now I am checking if id is null and  I have added tests with HTMLMenuElement
without ID, multiple HTMLMenuElement with same ID.
I am not sure if it still conforms to spec. Can you please point me to the
specification link which you are referring to? or some existing blink code which
implements similar spec? or some test code which should fails with the current
code?

+}
+
 void HTMLElement::defaultEventHandler(Event* event)
 {
     if (event->type() == EventTypeNames::keypress && event->isKeyboardEvent()) {
         handleKeypressEvent(toKeyboardEvent(event));
         if (event->defaultHandled())
             return;
     }
 
     Element::defaultEventHandler(event);
 }
@@ skipping 45 matching lines @@
 #ifndef NDEBUG
 
 // For use in the debugger
 void dumpInnerHTML(blink::HTMLElement*);
 
 void dumpInnerHTML(blink::HTMLElement* element)
 {
     printf("%s\n", element->innerHTML().ascii().data());
 }
 #endif