// Copyright 2014 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 BASE_METRICS_USER_METRICS_H_
#define BASE_METRICS_USER_METRICS_H_
#include <string>
#include "base/base_export.h"
#include "base/callback.h"
#include "base/metrics/user_metrics_action.h"
namespace base {
// This module provides some helper functions for logging actions tracked by
// the user metrics system.
// Record that the user performed an action.
// "Action" here means a user-generated event:
// good: "Reload", "CloseTab", and "IMEInvoked"
// not good: "SSLDialogShown", "PageLoaded", "DiskFull"
// We use this to gather anonymized information about how users are
// interacting with the browser.
// WARNING: In calls to this function, UserMetricsAction and a
// string literal parameter must be on the same line, e.g.
// RecordAction(UserMetricsAction("my extremely long action name"));
// This ensures that our processing scripts can associate this action's hash
// with its metric name. Therefore, it will be possible to retrieve the metric
// name from the hash later on.
//
// Once a new recorded action is added, run
// tools/metrics/actions/extract_actions.py
// to add the metric to actions.xml, then update the <owner>s and <description>
// sections. Make sure to include the actions.xml file when you upload your code
// for review!
//
// For more complicated situations (like when there are many different
// possible actions), see RecordComputedAction.
BASE_EXPORT void RecordAction(const UserMetricsAction& action);
// This function has identical input and behavior to RecordAction, but is
// not automatically found by the action-processing scripts. It can be used
// when it's a pain to enumerate all possible actions, but if you use this
// you need to also update the rules for extracting known actions in
// tools/metrics/actions/extract_actions.py.
BASE_EXPORT void RecordComputedAction(const std::string& action);
// Called with the action string.
typedef base::Callback<void(const std::string&)> ActionCallback;
// Add/remove action callbacks (see above).
BASE_EXPORT void AddActionCallback(const ActionCallback& callback);
BASE_EXPORT void RemoveActionCallback(const ActionCallback& callback);
} // namespace base
#endif // BASE_METRICS_USER_METRICS_H_