Add contextmenu attribute for HTMLElement.

Source/core/html/HTMLElement.cpp

Index: Source/core/html/HTMLElement.cpp
diff --git a/Source/core/html/HTMLElement.cpp b/Source/core/html/HTMLElement.cpp
index 041571390d1c06175442ff1acafa8f5410bc8275..acde71cadf5ebee8dba54e196ca8089d2aef67d7 100644
--- a/Source/core/html/HTMLElement.cpp
+++ b/Source/core/html/HTMLElement.cpp
@@ -48,6 +48,7 @@
 #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"
@@ -901,6 +902,31 @@ bool HTMLElement::isInteractiveContent() const
     return false;
 }
 
+
+HTMLMenuElement* HTMLElement::contextMenu() const
+{
+    const AtomicString& contextMenuId(fastGetAttribute(contextmenuAttr));
+    if (contextMenuId.isNull())
+        return nullptr;
+
+    Element* element = treeScope().getElementById(contextMenuId);
+    return isHTMLMenuElement(element) ? toHTMLMenuElement(element) : nullptr;

[pals, 2014/08/17 17:18:13]

Specification
http://www.whatwg.org/specs/web-apps/current-work/#reflect
under section
"If a reflecting IDL attribute has the type HTMLElement ..."

[tkent, 2014/08/18 02:24:52]

Off topic: Please refer to multipage version URL.  The single page version is
too slow.

We should have a comment that ignoring type attribute is intentional according
to the standard.

[pals, 2014/08/18 14:23:24]

Done.

+}
+
+void HTMLElement::setContextMenu(HTMLMenuElement* contextMenu)
+{
+    if (!contextMenu)
+        return;
+
+    const AtomicString& contextMenuId(contextMenu->fastGetAttribute(idAttr));
+    const AtomicString& contextMenuType(contextMenu->fastGetAttribute(typeAttr));
+
+    if (!contextMenuId.isNull() && equalIgnoringCase(contextMenuType, "popup") &&  contextMenu->inDocument())

[pals, 2014/08/17 17:18:13]

http://www.whatwg.org/specs/web-apps/current-work/#attr-contextmenu
"The value must be the ID of a menu element in the same home subtree whose type
attribute is in the popup menu state."

[tkent, 2014/08/18 02:24:52]

You misread the specification.  This paragraph is for web authors.  This
paragraph doesn't say UA should reject IDs of <menu type=popup> elements.
According to the reflect behavior specification, we should accept any <menu>
elements.

[tkent, 2014/08/18 02:27:27]

reject IDs of <menu type=popup> -> reject IDs of *no* <menu type=popup>

[pals, 2014/08/18 14:23:24]

Done.

+        setAttribute(contextmenuAttr, contextMenuId);
+    else
+        setAttribute(contextmenuAttr, "");

[pals, 2014/08/17 17:18:13]

Specification
http://www.whatwg.org/specs/web-apps/current-work/#reflect
under section
"On setting, if the given element has an id attribute, and has the same home
subtree as the element of the attribute being set, and the given element is the
first element in that home subtree whose ID is the value of that id attribute,
then the content attribute must be set to the value of that id attribute.
Otherwise, the content attribute must be set to the empty string."

[tkent, 2014/08/18 02:24:52]

"same home subtree" means we need to check treeScope identity in Blink because
the HTML specification doesn't care about Shadow DOM.

There is no code to check "the first element"

[pals, 2014/08/18 14:23:24]

Done. I was doing inDocument() check. Also added a test with shadow dom.

+}
+
 void HTMLElement::defaultEventHandler(Event* event)
 {
     if (event->type() == EventTypeNames::keypress && event->isKeyboardEvent()) {