Menu for the OSX app launcher.

ui/base/cocoa/controls/hover_image_menu_button.h

Index: ui/base/cocoa/controls/hover_image_menu_button.h
diff --git a/ui/base/cocoa/controls/hover_image_menu_button.h b/ui/base/cocoa/controls/hover_image_menu_button.h
new file mode 100644
index 0000000000000000000000000000000000000000..f6af7bf894ceab39f9dbb18fba641f982afe7814
--- /dev/null
+++ b/ui/base/cocoa/controls/hover_image_menu_button.h
@@ -0,0 +1,29 @@
+// Copyright 2013 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.
+
+#ifndef UI_BASE_COCOA_CONTROLS_HOVER_IMAGE_MENU_BUTTON_H_
+#define UI_BASE_COCOA_CONTROLS_HOVER_IMAGE_MENU_BUTTON_H_
+
+#import <Cocoa/Cocoa.h>
+
+#import "ui/base/cocoa/tracking_area.h"
+#include "ui/base/ui_export.h"
+
+@class HoverImageMenuButtonCell;
+
+// An NSPopUpButton that additionally tracks mouseover state and calls
+// [[self cell] setHovered:flag] when the hover state changes. Uses
+// HoverImageMenuButtonCell as the default cellClass. Note that the menu item at
+// index 0 is ignored and client code should populate it with a dummy item.

[Nico, 2013/06/11 18:09:33]

Does it make sense to combine this with chrome/browser/ui/cocoa/menu_button.mm
somehow?

[tapted, 2013/06/11 23:43:34]

I gave this a go in some earlier attempts. menu_button.mm has a sticky web of
dependencies: clickhold_button_cell -> image_button_cell -> {themed_window,
c/b/themes/theme_service.h} -> {extensions, profiles, everything}. I can have a
crack at taking it out and pairing it up with some kind of ThemeDelegate, but it
would be a pretty disruptive change..

Also, there's not much beyond NSPopUpButton that's actually needed (e.g.
patchset 1). chrome/brower's MenuButton doesn't use NSPopUpButton, but NSButton
(via ToolbarButton) instead, so I think it's also a bit more complex than it
needs to be. Perhaps a follow-up could be to look at where menu_button.h is
being used in c/b now, and see if there are cases better suited to the trim
version here?

+UI_EXPORT
+@interface HoverImageMenuButton : NSPopUpButton {
+ @private
+  ui::ScopedCrTrackingArea trackingArea_;
+}
+
+- (HoverImageMenuButtonCell*)hoverImageMenuButtonCell;
+
+@end
+
+#endif  // UI_BASE_COCOA_CONTROLS_HOVER_IMAGE_MENU_BUTTON_H_