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 template <typename T>
  13 struct DefaultSingletonTraits;
  14
  15 struct OmniboxLog;
  16
  17 // Omnibox code tracks events on a per-user-context basis, but there are
  18 // several clients who need to observe these events for all user contexts
  19 // (e.g., all Profiles in the //chrome embedder).  This class serves as an
  20 // intermediary to bridge the gap: omnibox code calls the
  21 // OmniboxEventGlobalTracker singleton on an event of interest, and it then
  22 // forwards the event to its registered observers.
  23 class OmniboxEventGlobalTracker {
  24  public:
  25   typedef base::Callback<void(OmniboxLog*)> OnURLOpenedCallback;
  26
  27   // Returns the instance of OmniboxEventGlobalTracker.
  28   static OmniboxEventGlobalTracker* GetInstance();
  29
  30   // Registers |cb| to be invoked when user open an URL from the omnibox.
  31   scoped_ptr<base::CallbackList<void(OmniboxLog*)>::Subscription>
  32       RegisterCallback(const OnURLOpenedCallback& cb);
  33
  34   // Called to notify all registered callbacks that an URL was opened from
  35   // the omnibox.
  36   void OnURLOpened(OmniboxLog* log);
  37
  38  private:
  39   friend struct DefaultSingletonTraits<OmniboxEventGlobalTracker>;
  40
  41   OmniboxEventGlobalTracker();
  42   ~OmniboxEventGlobalTracker();
  43
  44   base::CallbackList<void(OmniboxLog*)> on_url_opened_callback_list_;
  45
  46   DISALLOW_COPY_AND_ASSIGN(OmniboxEventGlobalTracker);
  47 };
  48
  49 #endif  // COMPONENTS_OMNIBOX_BROWSER_OMNIBOX_EVENT_GLOBAL_TRACKER_H_