Implement contextmenu attribute with basic support of <menu>

Source/core/page/ContextMenuController.cpp

Index: Source/core/page/ContextMenuController.cpp
diff --git a/Source/core/page/ContextMenuController.cpp b/Source/core/page/ContextMenuController.cpp
index 9e97e69bafd3d7dd0439fc22ff6960a5bce5e70a..deff996cb9f7276036e0caa6463ee895f8add4eb 100644
--- a/Source/core/page/ContextMenuController.cpp
+++ b/Source/core/page/ContextMenuController.cpp
@@ -28,18 +28,26 @@
 #include "core/page/ContextMenuController.h"
 
 #include "core/dom/Document.h"
+#include "core/dom/ElementTraversal.h"
+#include "core/dom/Node.h"
 #include "core/events/Event.h"
+#include "core/events/EventDispatchMediator.h"
+#include "core/events/EventDispatcher.h"
 #include "core/events/MouseEvent.h"
-#include "core/dom/Node.h"
+#include "core/events/RelatedEvent.h"
 #include "core/frame/LocalFrame.h"
+#include "core/html/HTMLMenuElement.h"
 #include "core/page/ContextMenuClient.h"
 #include "core/page/ContextMenuProvider.h"
+#include "core/page/CustomContextMenuProvider.h"
 #include "core/page/EventHandler.h"
 #include "platform/ContextMenu.h"
 #include "platform/ContextMenuItem.h"
 
 namespace blink {
 
+using namespace HTMLNames;
+
 ContextMenuController::ContextMenuController(Page*, ContextMenuClient* client)
     : m_client(client)
 {
@@ -74,12 +82,57 @@ void ContextMenuController::documentDetached(Document* document)
     }
 }
 
+void ContextMenuController::populateContextMenuItems(const HTMLMenuElement& menu, ContextMenu& contextMenu)
+{
+    HTMLElement* nextElement = Traversal<HTMLElement>::firstWithin(menu);
+    while (nextElement) {
+        if (isHTMLMenuElement(*nextElement)) {
+            ContextMenu subMenu;
+            populateContextMenuItems(*toHTMLMenuElement(nextElement), subMenu);
+            contextMenu.appendItem(ContextMenuItem(SubmenuType, ContextMenuItemCustomTagNoAction, nextElement->fastGetAttribute(labelAttr), &subMenu));
+            nextElement = Traversal<HTMLElement>::nextSibling(*nextElement);
+        } else if (isHTMLMenuItemElement(*nextElement)) {
+            m_menuItems.append(nextElement);
+            contextMenu.appendItem(ContextMenuItem(ActionType, static_cast<ContextMenuAction>(ContextMenuItemBaseCustomTag + m_menuItems.size() - 1), nextElement->fastGetAttribute(labelAttr)));
+            if (ContextMenuItemBaseCustomTag + m_menuItems.size() >= ContextMenuItemLastCustomTag)
+                break;
+            nextElement = Traversal<HTMLElement>::next(*nextElement, &menu);
+        } else {
+            nextElement = Traversal<HTMLElement>::next(*nextElement, &menu);
+        }
+    }
+}
+
+HTMLElement* ContextMenuController::menuItemAt(unsigned menuId)
+{
+    int itemIndex = menuId - ContextMenuItemBaseCustomTag;
+    if (itemIndex < 0 || static_cast<unsigned long>(itemIndex) >= m_menuItems.size())
+        return 0;
+    return m_menuItems[itemIndex];
+}
+
 void ContextMenuController::handleContextMenuEvent(Event* event)
 {
     m_contextMenu = createContextMenu(event);
     if (!m_contextMenu)
         return;
 
+    Node* node = event->target()->toNode();

[tkent, 2014/07/31 06:07:56]

I recommend to make new function for this block of new code.

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

Done.

+    if (node && node->isHTMLElement() && RuntimeEnabledFeatures::contextMenuEnabled()) {
+        const HTMLElement& element = toHTMLElement(*node);
+        if (RefPtrWillBeRawPtr<HTMLMenuElement> menuElement = element.contextMenu()) {
+            RefPtr<RelatedEvent> relatedEvent = RelatedEvent::create(EventTypeNames::show);
+            relatedEvent->setRelatedTarget(node);
+            m_subject = toHTMLElement(node);

[tkent, 2014/07/31 06:07:56]

toHTMLElement is unnecessary we already have |element|.

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

Done.

+            bool notCanceled = menuElement->dispatchEvent(relatedEvent.release());

[tkent, 2014/07/31 06:07:56]

|notCanceled| is unnecessary.
  if (menuElement->dispatchEvet...) {

If you'd like to add a variable for code readability, the name should not
contain 'not'.  It should be |shouldProceed| or something.

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

Done.

+            if (notCanceled) {
+                ContextMenu menu;

[tkent, 2014/07/31 06:07:56]

Because dispatchEvent runs arbitrary JavaScript code, |menuElement| might be
disassociated with the subject element. We need to check
HTMLElement::contextMenu() again.

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

Done.

+                populateContextMenuItems(*menuElement, menu);

[tkent, 2014/07/31 06:07:56]

I'm sorry I changed my mind.  populateContextMenuItems() should be a member
function of CustomContextMenuProvider.

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

Done. Moved to CustomContextMenuProvider. After this move the code looks more
logically organised. Thanks. 

+                m_menuProvider = CustomContextMenuProvider::create(&menuElement->document(), menu.items());
+                m_menuProvider->populateContextMenu(m_contextMenu.get());
+            }
+        }
+    }
     showContextMenu(event);
 }