Refactoring select popup on Mac....

chrome/browser/tab_contents/popup_menu_helper_mac.mm

+// Copyright (c) 2010 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.
+
+#import <Carbon/Carbon.h>
+
+#include "chrome/browser/tab_contents/popup_menu_helper_mac.h"
+
+#import "base/chrome_application_mac.h"
+#include "base/message_loop.h"
+#include "base/scoped_nsobject.h"
+#import "chrome/browser/cocoa/base_view.h"
+#include "chrome/browser/renderer_host/render_view_host.h"
+#include "chrome/browser/renderer_host/render_widget_host_view_mac.h"
+#include "chrome/common/notification_source.h"
+#include "webkit/glue/webmenurunner_mac.h"
+
+PopupMenuHelper::PopupMenuHelper(RenderViewHost* render_view_host)
+    : render_view_host_(render_view_host) {
+  notification_registrar_.Add(
+      this, NotificationType::RENDER_WIDGET_HOST_DESTROYED,
+      Source<RenderWidgetHost>(render_view_host));
+}
+
+void PopupMenuHelper::ShowPopupMenu(
+    const gfx::Rect& bounds,
+    int item_height,
+    double item_font_size,
+    int selected_item,
+    const std::vector<WebMenuItem>& items,
+    bool right_aligned) {
+  // Retain the Cocoa view for the duration of the pop-up so that it can't be
+  // dealloced if my Destroy() method is called while the pop-up's up (which
+  // would in turn delete me, causing a crash once the -runMenuInView
+  // call returns. That's what was happening in <http://crbug.com/33250>).
+  RenderWidgetHostViewMac* rwhvm =
+      static_cast<RenderWidgetHostViewMac*>(render_view_host_->view());
+  scoped_nsobject<RenderWidgetHostViewCocoa> cocoa_view
+      ([rwhvm->native_view() retain]);
+
+  // Display the menu.
+  scoped_nsobject<WebMenuRunner> menu_runner;
+  menu_runner.reset([[WebMenuRunner alloc] initWithItems:items
+                                                fontSize:item_font_size
+                                            rightAligned:right_aligned]);
+
+  {
+    // Make sure events can be pumped while the menu is up.
+    MessageLoop::ScopedNestableTaskAllower allow(MessageLoop::current());
+
+    // One of the events that could be pumped is |window.close()|.
+    // User-initiated event-tracking loops protect against this by
+    // setting flags in -[CrApplication sendEvent:], but since
+    // web-content menus are initiated by IPC message the setup has to
+    // be done manually.
+    chrome_application_mac::ScopedSendingEvent sendingEventScoper;
+
+    // Now run a SYNCHRONOUS NESTED EVENT LOOP until the pop-up is finished.
+    [menu_runner runMenuInView:cocoa_view
+                    withBounds:[cocoa_view flipRectToNSRect:bounds]
+                  initialIndex:selected_item];
+  }
+
+  if (!render_view_host_) {
+    // Bad news, the RenderViewHost got deleted while we were off running the
+    // menu. Nothing to do.
+    return;
+  }
+
+  if ([menu_runner menuItemWasChosen]) {
+    render_view_host_->DidSelectPopupMenuItem(
+        [menu_runner indexOfSelectedItem]);
+  } else {
+    render_view_host_->DidCancelPopupMenu();
+  }
+}
+
+void PopupMenuHelper::Observe(
+    NotificationType type,
+    const NotificationSource& source,
+    const NotificationDetails& details) {
+  DCHECK(type == NotificationType::RENDER_WIDGET_HOST_DESTROYED);
+  RenderViewHost* rvh = Source<RenderViewHost>(source).ptr();
+  DCHECK_EQ(render_view_host_, rvh);
+  render_view_host_ = NULL;
+}
+