Add support to populate custom context menu items.

Source/core/page/CustomContextMenuProvider.cpp

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "config.h"
+#include "core/page/CustomContextMenuProvider.h"
+
+#include "core/dom/Document.h"
+#include "core/dom/ElementTraversal.h"
+#include "core/events/EventDispatcher.h"
+#include "core/events/MouseEvent.h"
+#include "core/html/HTMLMenuElement.h"
+#include "core/html/HTMLMenuItemElement.h"
+#include "core/page/ContextMenuController.h"
+#include "core/page/Page.h"
+#include "platform/ContextMenu.h"
+
+namespace blink {
+
+using namespace HTMLNames;
+
+CustomContextMenuProvider::CustomContextMenuProvider(HTMLMenuElement& menu, HTMLElement& subject)
+    : m_menu(menu)
+    , m_subjectElement(subject)
+{
+}
+
+CustomContextMenuProvider::~CustomContextMenuProvider()
+{
+}
+
+void CustomContextMenuProvider::populateContextMenu(ContextMenu* menu)
+{
+    populateContextMenuItems(*m_menu, *menu);
+}
+
+void CustomContextMenuProvider::contextMenuItemSelected(const ContextMenuItem* item)
+{
+    if (HTMLElement* element = menuItemAt(item->action())) {
+        RefPtrWillBeRawPtr<SimulatedMouseEvent> click = SimulatedMouseEvent::create(EventTypeNames::click, m_menu->document().domWindow(), Event::create());
+        click->setRelatedTarget(m_subjectElement.get());
+        element->dispatchEvent(click.release());
+    }
+}
+
+void CustomContextMenuProvider::contextMenuCleared()
+{
+    m_menuItems.clear();
+    m_subjectElement = nullptr;
+}
+
+void CustomContextMenuProvider::appendSeparator(ContextMenu& contextMenu)
+{
+    // Avoid separators at the start of any menu and submenu.
+    if (!contextMenu.items().size())
+        return;
+
+    // Collapse all sequences of two or more adjacent separators in the menu or any submenus to a single separator.

[tkent, 2014/08/25 23:07:42]

I recommend to wrap code comments in 80 columns.

[pals, 2014/08/26 07:13:23]

Done.

+    ContextMenuItem lastItem = contextMenu.items().last();
+    if (lastItem.type() == SeparatorType)
+        return;
+
+    contextMenu.appendItem(ContextMenuItem(SeparatorType, ContextMenuItemCustomTagNoAction, String()));
+}
+
+void CustomContextMenuProvider::appendMenuItem(HTMLMenuItemElement* menuItem, ContextMenu& contextMenu)
+{
+    // Avoid menuitems with no label.
+    String labelString = menuItem->fastGetAttribute(labelAttr);
+    if (labelString.isNull() || labelString.isEmpty())

[tkent, 2014/08/25 23:07:42]

isEmpty() is enough.  isEmpty() contains isNull().

[pals, 2014/08/26 07:13:23]

Done.

+        return;
+
+    m_menuItems.append(menuItem);
+    contextMenu.appendItem(ContextMenuItem(ActionType, static_cast<ContextMenuAction>(ContextMenuItemBaseCustomTag + m_menuItems.size() - 1), labelString));
+}
+
+void CustomContextMenuProvider::populateContextMenuItems(const HTMLMenuElement& menu, ContextMenu& contextMenu)
+{
+    HTMLElement* nextElement = Traversal<HTMLElement>::firstWithin(menu);
+    while (nextElement) {
+        if (isHTMLHRElement(*nextElement)) {
+            appendSeparator(contextMenu);
+            nextElement = Traversal<HTMLElement>::next(*nextElement, &menu);
+        } else if (isHTMLMenuElement(*nextElement)) {
+            ContextMenu subMenu;
+            String labelString = nextElement->fastGetAttribute(labelAttr);
+            if (labelString.isNull() || labelString.isEmpty()) {

[tkent, 2014/08/25 23:07:42]

This looks incorrect.

The following code is for the third bullet of step 2. So, the condition should
be isNull().
For isEmpty(), we need to do step 3, right?

[pals, 2014/08/26 07:13:23]

My understanding from the above two statements is that the child menu (submenu)
with no label attribute should be flattened out inside two separator in the
parent menu, and child menu (submenu) should not be created. The code below
implements the same.


I think these two statements are somewhat contradictory. I asked for
clarification on whatwg@whatwg.org.

[tkent, 2014/08/26 08:11:26]

ok, let's revisit here after the clarification.

+                appendSeparator(contextMenu);
+                populateContextMenuItems(*toHTMLMenuElement(nextElement), contextMenu);
+                appendSeparator(contextMenu);
+            } else {
+                populateContextMenuItems(*toHTMLMenuElement(nextElement), subMenu);
+                contextMenu.appendItem(ContextMenuItem(SubmenuType, ContextMenuItemCustomTagNoAction, labelString, &subMenu));
+            }
+            nextElement = Traversal<HTMLElement>::nextSibling(*nextElement);
+        } else if (isHTMLMenuItemElement(*nextElement)) {
+            appendMenuItem(toHTMLMenuItemElement(nextElement), contextMenu);
+            if (ContextMenuItemBaseCustomTag + m_menuItems.size() >= ContextMenuItemLastCustomTag)
+                break;
+            nextElement = Traversal<HTMLElement>::next(*nextElement, &menu);
+        } else {
+            nextElement = Traversal<HTMLElement>::next(*nextElement, &menu);
+        }
+    }
+
+    // Remove separators at the end of the menu and any submenus.
+    while (contextMenu.items().last().type() == SeparatorType)

[tkent, 2014/08/25 23:07:42]

Need a test in a case of <menu type=popup> without any children.

[pals, 2014/08/26 07:13:23]

Done.

+        contextMenu.removeLastItem();
+}
+
+HTMLElement* CustomContextMenuProvider::menuItemAt(unsigned menuId)
+{
+    int itemIndex = menuId - ContextMenuItemBaseCustomTag;
+    if (itemIndex < 0 || static_cast<unsigned long>(itemIndex) >= m_menuItems.size())
+        return 0;
+    return m_menuItems[itemIndex].get();
+}
+
+} // namespace blink