1 // Copyright 2013 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 #include "chrome/browser/chromeos/policy/recommendation_restorer.h"
6
7 #include "ash/shell.h"
8 #include "ash/wm/user_activity_detector.h"
9 #include "base/bind.h"
10 #include "base/bind_helpers.h"
11 #include "base/location.h"
12 #include "base/logging.h"
13 #include "base/prefs/pref_service.h"
14 #include "base/time/time.h"
15 #include "base/values.h"
16 #include "chrome/browser/chrome_notification_types.h"
17 #include "chrome/browser/chromeos/profiles/profile_helper.h"
18 #include "chrome/browser/profiles/profile.h"
19 #include "chrome/common/pref_names.h"
20 #include "content/public/browser/notification_details.h"
21 #include "content/public/browser/notification_service.h"
22 #include "content/public/browser/notification_source.h"
23
24 namespace policy {
25
26 namespace {
27 // The amount of idle time after which recommended values are restored.
28 const int kRestoreDelayInMs = 60 * 1000; // 1 minute.
29 } // namespace
30
RecommendationRestorer(Profile * profile)31 RecommendationRestorer::RecommendationRestorer(Profile* profile)
32 : logged_in_(false) {
33 if (!chromeos::ProfileHelper::IsSigninProfile(profile))
34 return;
35
36 pref_change_registrar_.Init(profile->GetPrefs());
37 pref_change_registrar_.Add(prefs::kLargeCursorEnabled,
38 base::Bind(&RecommendationRestorer::Restore,
39 base::Unretained(this), true));
40 pref_change_registrar_.Add(prefs::kSpokenFeedbackEnabled,
41 base::Bind(&RecommendationRestorer::Restore,
42 base::Unretained(this), true));
43 pref_change_registrar_.Add(prefs::kHighContrastEnabled,
44 base::Bind(&RecommendationRestorer::Restore,
45 base::Unretained(this), true));
46 pref_change_registrar_.Add(prefs::kScreenMagnifierEnabled,
47 base::Bind(&RecommendationRestorer::Restore,
48 base::Unretained(this), true));
49 pref_change_registrar_.Add(prefs::kScreenMagnifierType,
50 base::Bind(&RecommendationRestorer::Restore,
51 base::Unretained(this), true));
52
53 notification_registrar_.Add(this, chrome::NOTIFICATION_LOGIN_USER_CHANGED,
54 content::NotificationService::AllSources());
55
56 RestoreAll();
57 }
58
~RecommendationRestorer()59 RecommendationRestorer::~RecommendationRestorer() {
60 }
61
Shutdown()62 void RecommendationRestorer::Shutdown() {
63 StopTimer();
64 pref_change_registrar_.RemoveAll();
65 notification_registrar_.RemoveAll();
66 }
67
Observe(int type,const content::NotificationSource & source,const content::NotificationDetails & details)68 void RecommendationRestorer::Observe(
69 int type,
70 const content::NotificationSource& source,
71 const content::NotificationDetails& details) {
72 if (type == chrome::NOTIFICATION_LOGIN_USER_CHANGED) {
73 logged_in_ = true;
74 notification_registrar_.RemoveAll();
75 StopTimer();
76 RestoreAll();
77 } else {
78 NOTREACHED();
79 }
80 }
81
OnUserActivity(const ui::Event * event)82 void RecommendationRestorer::OnUserActivity(const ui::Event* event) {
83 if (restore_timer_.IsRunning())
84 restore_timer_.Reset();
85 }
86
Restore(bool allow_delay,const std::string & pref_name)87 void RecommendationRestorer::Restore(bool allow_delay,
88 const std::string& pref_name) {
89 const PrefService::Preference* pref =
90 pref_change_registrar_.prefs()->FindPreference(pref_name.c_str());
91 if (!pref) {
92 NOTREACHED();
93 return;
94 }
95
96 if (!pref->GetRecommendedValue() || !pref->HasUserSetting())
97 return;
98
99 if (logged_in_) {
100 allow_delay = false;
101 } else if (allow_delay && ash::Shell::HasInstance()) {
102 // Skip the delay if there has been no user input since the browser started.
103 const ash::UserActivityDetector* user_activity_detector =
104 ash::Shell::GetInstance()->user_activity_detector();
105 allow_delay = !user_activity_detector->last_activity_time().is_null();
106 }
107
108 if (allow_delay)
109 StartTimer();
110 else
111 pref_change_registrar_.prefs()->ClearPref(pref->name().c_str());
112 }
113
RestoreAll()114 void RecommendationRestorer::RestoreAll() {
115 Restore(false, prefs::kLargeCursorEnabled);
116 Restore(false, prefs::kSpokenFeedbackEnabled);
117 Restore(false, prefs::kHighContrastEnabled);
118 Restore(false, prefs::kScreenMagnifierEnabled);
119 Restore(false, prefs::kScreenMagnifierType);
120 }
121
StartTimer()122 void RecommendationRestorer::StartTimer() {
123 // Listen for user activity so that the timer can be reset while the user is
124 // active, causing it to fire only when the user remains idle for
125 // |kRestoreDelayInMs|.
126 if (ash::Shell::HasInstance()) {
127 ash::UserActivityDetector* user_activity_detector =
128 ash::Shell::GetInstance()->user_activity_detector();
129 if (!user_activity_detector->HasObserver(this))
130 user_activity_detector->AddObserver(this);
131 }
132
133 // There should be a separate timer for each pref. However, in the common
134 // case of the user changing settings, a single timer is sufficient. This is
135 // because a change initiated by the user implies user activity, so that even
136 // if there was a separate timer per pref, they would all be reset at that
137 // point, causing them to fire at exactly the same time. In the much rarer
138 // case of a recommended value changing, a single timer is a close
139 // approximation of the behavior that would be obtained by resetting the timer
140 // for the affected pref only.
141 restore_timer_.Start(FROM_HERE,
142 base::TimeDelta::FromMilliseconds(kRestoreDelayInMs),
143 base::Bind(&RecommendationRestorer::RestoreAll,
144 base::Unretained(this)));
145 }
146
StopTimer()147 void RecommendationRestorer::StopTimer() {
148 restore_timer_.Stop();
149 if (ash::Shell::HasInstance())
150 ash::Shell::GetInstance()->user_activity_detector()->RemoveObserver(this);
151 }
152
153 } // namespace policy
154