content/public/browser/user_metrics.h

   1 // Copyright (c) 2012 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 CONTENT_PUBLIC_BROWSER_USER_METRICS_H_
   6 #define CONTENT_PUBLIC_BROWSER_USER_METRICS_H_
   7
   8 #include <string>
   9
  10 #include "base/callback.h"
  11 #include "content/common/content_export.h"
  12
  13 namespace content {
  14
  15 // This module provides some helper functions for logging actions tracked by
  16 // the user metrics system.
  17
  18
  19 // UserMetricsAction exist purely to standardize on the paramters passed to
  20 // UserMetrics. That way, our toolset can scan the sourcecode reliable for
  21 // constructors and extract the associated string constants
  22 struct UserMetricsAction {
  23   const char* str_;
  24   explicit UserMetricsAction(const char* str) : str_(str) {}
  25 };
  26
  27 // Record that the user performed an action.
  28 // "Action" here means a user-generated event:
  29 //   good: "Reload", "CloseTab", and "IMEInvoked"
  30 //   not good: "SSLDialogShown", "PageLoaded", "DiskFull"
  31 // We use this to gather anonymized information about how users are
  32 // interacting with the browser.
  33 // WARNING: In calls to this function, UserMetricsAction and a
  34 // string literal parameter must be on the same line, e.g.
  35 //   content::RecordAction(
  36 //       content::UserMetricsAction("my extremely long action name"));
  37 // because otherwise our processing scripts won't pick up on new actions.
  38 //
  39 // Once a new recorded action is added, run
  40 // tools/metrics/actions/extract_actions.py --hash
  41 // to generate a new mapping of [action hashes -> metric names] and send it
  42 // out for review to be updated.
  43 //
  44 // For more complicated situations (like when there are many different
  45 // possible actions), see RecordComputedAction.
  46 CONTENT_EXPORT void RecordAction(const UserMetricsAction& action);
  47
  48 // This function has identical input and behavior to RecordAction, but is
  49 // not automatically found by the action-processing scripts.  It can be used
  50 // when it's a pain to enumerate all possible actions, but if you use this
  51 // you need to also update the rules for extracting known actions in
  52 // chrome/tools/extract_actions.py.
  53 CONTENT_EXPORT void RecordComputedAction(const std::string& action);
  54
  55 // Called with the action string.
  56 typedef base::Callback<void(const std::string&)> ActionCallback;
  57
  58 // Add/remove action callbacks (see above).
  59 CONTENT_EXPORT void AddActionCallback(const ActionCallback& callback);
  60 CONTENT_EXPORT void RemoveActionCallback(const ActionCallback& callback);
  61
  62 }  // namespace content
  63
  64 #endif  // CONTENT_PUBLIC_BROWSER_USER_METRICS_H_