Tablet-like power button behavior on Convertible/Tablet ChromeOS devices

chromeos/dbus/fake_power_manager_client.cc

 // Copyright (c) 2013 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.
 
 #include "chromeos/dbus/fake_power_manager_client.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/location.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 
 namespace chromeos {
 
 namespace {
 // Minimum power for a USB power source to be classified as AC.
-const double kUsbMinAcWatts = 24;
+constexpr double kUsbMinAcWatts = 24;
+
+// A non-zero brightness used for test.
+constexpr int kNonZeroBrightnessForTest = 10;
 }
 
 FakePowerManagerClient::FakePowerManagerClient()
     : num_request_restart_calls_(0),
       num_request_shutdown_calls_(0),
       num_set_policy_calls_(0),
       num_set_is_projecting_calls_(0),
       num_pending_suspend_readiness_callbacks_(0),
       is_projecting_(false),
       backlights_forced_off_(false),
@@ skipping 102 matching lines @@
               : power_manager::PowerSupplyProperties_ExternalPower_AC);
       break;
     }
   }
 
   NotifyObservers();
 }
 
 void FakePowerManagerClient::SetBacklightsForcedOff(bool forced_off) {
   backlights_forced_off_ = forced_off;
+  forced_off ? SendBrightnessChanged(0, true)

[Daniel Erat, 2016/11/10 22:48:55]

please don't call SendBrightnessChanged from here; it makes it impossible to
test other things happening between sending the request and receiving the
notification. tests should be able to call SendBrightnessChanged themselves when
they're ready for the notification to be sent.

[Qiang(Joe) Xu, 2016/11/11 04:39:23]

done by moving to tests.

+             : SendBrightnessChanged(kNonZeroBrightnessForTest, true);
 }
 
 void FakePowerManagerClient::GetBacklightsForcedOff(
     const GetBacklightsForcedOffCallback& callback) {
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE, base::Bind(callback, backlights_forced_off_));
 }
 
 base::Closure FakePowerManagerClient::GetSuspendReadinessCallback() {
   ++num_pending_suspend_readiness_callbacks_;
@@ skipping 26 matching lines @@
 
   for (auto& observer : observers_)
     observer.SuspendDone(base::TimeDelta());
 }
 
 void FakePowerManagerClient::SendDarkSuspendImminent() {
   for (auto& observer : observers_)
     observer.DarkSuspendImminent();
 }
 
+void FakePowerManagerClient::SendBrightnessChanged(int level,
+                                                   bool user_initiated) {
+  for (auto& observer : observers_)
+    observer.BrightnessChanged(level, user_initiated);
+}
+
 void FakePowerManagerClient::SendPowerButtonEvent(
     bool down,
     const base::TimeTicks& timestamp) {
   for (auto& observer : observers_)
     observer.PowerButtonEventReceived(down, timestamp);
 }
 
 void FakePowerManagerClient::UpdatePowerProperties(
     const power_manager::PowerSupplyProperties& power_props) {
   props_ = power_props;
   NotifyObservers();
 }
 
 void FakePowerManagerClient::NotifyObservers() {
   for (auto& observer : observers_)
     observer.PowerChanged(props_);
 }
 
 void FakePowerManagerClient::HandleSuspendReadiness() {
   CHECK(num_pending_suspend_readiness_callbacks_ > 0);
 
   --num_pending_suspend_readiness_callbacks_;
 }
 
 }  // namespace chromeos