components/omnibox/browser/omnibox_event_global_tracker.h

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef COMPONENTS_OMNIBOX_BROWSER_OMNIBOX_EVENT_GLOBAL_TRACKER_H_
   6 #define COMPONENTS_OMNIBOX_BROWSER_OMNIBOX_EVENT_GLOBAL_TRACKER_H_
   7
   8 #include "base/callback_list.h"
   9 #include "base/macros.h"
  10 #include "base/memory/scoped_ptr.h"
  11
  12 namespace base {
  13 template <typename T>
  14 struct DefaultSingletonTraits;
  15 }  // namespace base
  16
  17 struct OmniboxLog;
  18
  19 // Omnibox code tracks events on a per-user-context basis, but there are
  20 // several clients who need to observe these events for all user contexts
  21 // (e.g., all Profiles in the //chrome embedder).  This class serves as an
  22 // intermediary to bridge the gap: omnibox code calls the
  23 // OmniboxEventGlobalTracker singleton on an event of interest, and it then
  24 // forwards the event to its registered observers.
  25 class OmniboxEventGlobalTracker {
  26  public:
  27   typedef base::Callback<void(OmniboxLog*)> OnURLOpenedCallback;
  28
  29   // Returns the instance of OmniboxEventGlobalTracker.
  30   static OmniboxEventGlobalTracker* GetInstance();
  31
  32   // Registers |cb| to be invoked when user open an URL from the omnibox.
  33   scoped_ptr<base::CallbackList<void(OmniboxLog*)>::Subscription>
  34       RegisterCallback(const OnURLOpenedCallback& cb);
  35
  36   // Called to notify all registered callbacks that an URL was opened from
  37   // the omnibox.
  38   void OnURLOpened(OmniboxLog* log);
  39
  40  private:
  41   friend struct base::DefaultSingletonTraits<OmniboxEventGlobalTracker>;
  42
  43   OmniboxEventGlobalTracker();
  44   ~OmniboxEventGlobalTracker();
  45
  46   base::CallbackList<void(OmniboxLog*)> on_url_opened_callback_list_;
  47
  48   DISALLOW_COPY_AND_ASSIGN(OmniboxEventGlobalTracker);
  49 };
  50
  51 #endif  // COMPONENTS_OMNIBOX_BROWSER_OMNIBOX_EVENT_GLOBAL_TRACKER_H_