user_metrics.h revision a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7 
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#include "content/public/common/user_metrics_action.h"
13
14namespace content {
15
16// This module provides some helper functions for logging actions tracked by
17// the user metrics system.
18
19// Record that the user performed an action.
20// "Action" here means a user-generated event:
21//   good: "Reload", "CloseTab", and "IMEInvoked"
22//   not good: "SSLDialogShown", "PageLoaded", "DiskFull"
23// We use this to gather anonymized information about how users are
24// interacting with the browser.
25// WARNING: In calls to this function, UserMetricsAction and a
26// string literal parameter must be on the same line, e.g.
27//   content::RecordAction(
28//       content::UserMetricsAction("my extremely long action name"));
29// This ensures that our processing scripts can associate this action's hash
30// with its metric name. Therefore, it will be possible to retrieve the metric
31// name from the hash later on.
32//
33// Once a new recorded action is added, run
34// tools/metrics/actions/extract_actions.py --hash
35// to generate a new mapping of [action hashes -> metric names] and send it
36// out for review to be updated.
37//
38// For more complicated situations (like when there are many different
39// possible actions), see RecordComputedAction.
40CONTENT_EXPORT void RecordAction(const UserMetricsAction& action);
41
42// This function has identical input and behavior to RecordAction, but is
43// not automatically found by the action-processing scripts.  It can be used
44// when it's a pain to enumerate all possible actions, but if you use this
45// you need to also update the rules for extracting known actions in
46// tools/metrics/actions/extract_actions.py.
47CONTENT_EXPORT void RecordComputedAction(const std::string& action);
48
49// Called with the action string.
50typedef base::Callback<void(const std::string&)> ActionCallback;
51
52// Add/remove action callbacks (see above).
53CONTENT_EXPORT void AddActionCallback(const ActionCallback& callback);
54CONTENT_EXPORT void RemoveActionCallback(const ActionCallback& callback);
55
56}  // namespace content
57
58#endif  // CONTENT_PUBLIC_BROWSER_USER_METRICS_H_
59