Adding ArcBridge interface for synchronizing brightness settings

components/arc/power/arc_power_bridge.cc

 // Copyright 2015 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 "components/arc/power/arc_power_bridge.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "ash/shell.h"
@@ skipping 16 matching lines @@
 }
 
 void ArcPowerBridge::OnInstanceReady() {
   mojom::PowerInstance* power_instance =
       ARC_GET_INSTANCE_FOR_METHOD(arc_bridge_service()->power(), Init);
   DCHECK(power_instance);
   power_instance->Init(binding_.CreateInterfacePtrAndBind());
   ash::Shell::GetInstance()->display_configurator()->AddObserver(this);
   chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->
       AddObserver(this);
+  chromeos::DBusThreadManager::Get()
+      ->GetPowerManagerClient()
+      ->SyncScreenBrightness();

[Luis Héctor Chávez, 2017/04/05 21:28:02]

You don't need SyncScreenBrightness() either :) Instead you can do

chromeos::DBusThreadManager::Get()
  ->GetPowerManagerClient()
  ->GetGetScreenBrightnessPercent(
     base::Bind(&ArcPowerBridge::UpdateBrightness,
                weak_ptr_factory_.GetWeakPtr()));

then declare a private method

void ArcPowerBridge::UpdateBrightness(double percent) {
   mojom::PowerInstance* power_instance = ARC_GET_INSTANCE_FOR_METHOD(
       arc_bridge_service()->power(), UpdateBrightness);
   if (!power_instance)
     return;
   power_instance->UpdateBrightness(percent);
}

And call it from the callback:

void ArcPowerBridge::BrightnessChanged(int level, double percent) {
  UpdateBrightness(percent);
}

See other places where a base::WeakPtrFactory is used to see how you need to
declare it.

[yueli, 2017/04/05 23:27:17]

Thanks Luis!
Done.

 }
 
 void ArcPowerBridge::OnInstanceClosed() {
   ash::Shell::GetInstance()->display_configurator()->RemoveObserver(this);
   chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->
       RemoveObserver(this);
   ReleaseAllDisplayWakeLocks();
 }
 
 void ArcPowerBridge::SuspendImminent() {
@@ skipping 20 matching lines @@
     chromeos::DisplayPowerState power_state) {
   mojom::PowerInstance* power_instance = ARC_GET_INSTANCE_FOR_METHOD(
       arc_bridge_service()->power(), SetInteractive);
   if (!power_instance)
     return;
 
   bool enabled = (power_state != chromeos::DISPLAY_POWER_ALL_OFF);
   power_instance->SetInteractive(enabled);
 }
 
+void ArcPowerBridge::BrightnessChanged(int level, bool user_initiated) {
+  mojom::PowerInstance* power_instance = ARC_GET_INSTANCE_FOR_METHOD(
+      arc_bridge_service()->power(), UpdateBrightness);
+  if (!power_instance)
+    return;
+  // Android side brightness is of the range [0, 255]
+  int brightness = round(level * 2.55);
+  power_instance->UpdateBrightness(brightness);
+}
+
 void ArcPowerBridge::OnAcquireDisplayWakeLock(mojom::DisplayWakeLockType type) {
   if (!chromeos::PowerPolicyController::IsInitialized()) {
     LOG(WARNING) << "PowerPolicyController is not available";
     return;
   }
   chromeos::PowerPolicyController* controller =
       chromeos::PowerPolicyController::Get();
 
   int wake_lock_id = -1;
   switch (type) {
@@ skipping 32 matching lines @@
   }
   controller->RemoveWakeLock(it->second);
   wake_locks_.erase(it);
 }
 
 void ArcPowerBridge::IsDisplayOn(const IsDisplayOnCallback& callback) {
   callback.Run(
       ash::Shell::GetInstance()->display_configurator()->IsDisplayOn());
 }
 
+void ArcPowerBridge::SetBrightness(int32_t brightness) {
+  // Android side brightness is of the range [0, 255]
+  chromeos::DBusThreadManager::Get()
+      ->GetPowerManagerClient()
+      ->SetScreenBrightnessPercent(brightness / 2.55, true);
+  return;
+}
+
 void ArcPowerBridge::ReleaseAllDisplayWakeLocks() {
   if (!chromeos::PowerPolicyController::IsInitialized()) {
     LOG(WARNING) << "PowerPolicyController is not available";
     return;
   }
   chromeos::PowerPolicyController* controller =
       chromeos::PowerPolicyController::Get();
 
   for (const auto& it : wake_locks_) {
     controller->RemoveWakeLock(it.second);
   }
   wake_locks_.clear();
 }
 
 }  // namespace arc