Windows: Ambient Light API

content/browser/device_sensors/data_fetcher_shared_memory_win.cc

 // 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.
 
 #include "data_fetcher_shared_memory.h"
 
 #include <GuidDef.h>
 #include <InitGuid.h>
 #include <PortableDeviceTypes.h>
 #include <Sensors.h>
 
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/win/iunknown_impl.h"
 #include "base/win/windows_version.h"
 
 namespace {
 
 const double kMeanGravity = 9.80665;
 
+static bool SetLightBuffer(content::DeviceLightHardwareBuffer* buffer,

[timvolodine, 2015/03/02 17:39:58]

no need for static

[riju_, 2015/03/03 09:53:55]

Done.

+                           double lux) {
+  if (!buffer)
+    return false;
+  buffer->seqlock.WriteBegin();
+  buffer->data.value = lux;
+  buffer->seqlock.WriteEnd();
+  return true;

[timvolodine, 2015/03/02 17:39:58]

do you need to return anything at all? the result doesn't seem to be used
anywhere in the code..

[riju_, 2015/03/03 09:53:55]

Done.

+}
+
 }  // namespace
 
 
 namespace content {
 
 class DataFetcherSharedMemory::SensorEventSink
     : public ISensorEvents, public base::win::IUnknownImpl {
  public:
   SensorEventSink() {}
   virtual ~SensorEventSink() {}
@@ skipping 184 matching lines @@
 
     return true;
   }
 
  private:
   DeviceMotionHardwareBuffer* const buffer_;
 
   DISALLOW_COPY_AND_ASSIGN(SensorEventSinkMotion);
 };
 
+class DataFetcherSharedMemory::SensorEventSinkLight
+    : public DataFetcherSharedMemory::SensorEventSink {
+ public:
+  explicit SensorEventSinkLight(DeviceLightHardwareBuffer* const buffer)
+      : buffer_(buffer) {}
+  virtual ~SensorEventSinkLight() {}
+
+ protected:
+  virtual bool UpdateSharedMemoryBuffer(ISensor* sensor,
+                                        ISensorDataReport* new_data) override {
+    double lux;
+    bool has_lux;
+
+    GetSensorValue(SENSOR_DATA_TYPE_LIGHT_LEVEL_LUX, new_data, &lux, &has_lux);

[timvolodine, 2015/03/02 17:39:58]

has_lux does not seem be used after the call. should anything special happen in
case has_lux == false?

[riju_, 2015/03/03 09:53:55]

Done. returning early if valid no lux value is found.

+
+    SetLightBuffer(buffer_, lux);
+
+    return true;
+  }
+
+ private:
+  DeviceLightHardwareBuffer* const buffer_;
+
+  DISALLOW_COPY_AND_ASSIGN(SensorEventSinkLight);
+};
+
 DataFetcherSharedMemory::DataFetcherSharedMemory()
-    : motion_buffer_(nullptr), orientation_buffer_(nullptr) {
+    : motion_buffer_(nullptr),
+      orientation_buffer_(nullptr),
+      light_buffer_(nullptr) {
 }
 
 DataFetcherSharedMemory::~DataFetcherSharedMemory() {
 }
 
 DataFetcherSharedMemory::FetcherType DataFetcherSharedMemory::GetType() const {
   return FETCHER_TYPE_SEPARATE_THREAD;
 }
 
 bool DataFetcherSharedMemory::Start(ConsumerType consumer_type, void* buffer) {
@@ skipping 33 matching lines @@
         if (accelerometer_available || gyrometer_available) {
           motion_buffer_->seqlock.WriteBegin();
           motion_buffer_->data.interval = GetInterval().InMilliseconds();
           motion_buffer_->seqlock.WriteEnd();
           return true;
         }
         // if no sensors are available set buffer to ready, to fire null-events.
         SetBufferAvailableState(consumer_type, true);
       }
       break;
+      case CONSUMER_TYPE_LIGHT:

[timvolodine, 2015/03/02 17:39:58]

alignment as with above cases

[riju_, 2015/03/03 09:53:55]

Done.

+      {
+        light_buffer_ = static_cast<DeviceLightHardwareBuffer*>(buffer);
+        scoped_refptr<SensorEventSink> sink(
+            new SensorEventSinkLight(light_buffer_));
+        bool sensor_light_available = RegisterForSensor(
+            SENSOR_TYPE_AMBIENT_LIGHT, sensor_light_.Receive(), sink);
+        if (sensor_light_available)

[timvolodine, 2015/03/02 17:39:58]

what's the value of the buffer? should it be initialized to -1?

[riju_, 2015/03/03 09:53:55]

Done.

+          return true;
+
+        // if no sensors are available, fire an Infinity event.
+        SetLightBuffer(light_buffer_, std::numeric_limits<double>::infinity());
+      }
+      break;
     default:
       NOTREACHED();
   }
   return false;
 }
 
 bool DataFetcherSharedMemory::Stop(ConsumerType consumer_type) {
   DisableSensors(consumer_type);
   SetBufferAvailableState(consumer_type, false);
   switch (consumer_type) {
     case CONSUMER_TYPE_ORIENTATION:
       orientation_buffer_ = nullptr;
       return true;
     case CONSUMER_TYPE_MOTION:
       motion_buffer_ = nullptr;
       return true;
+    case CONSUMER_TYPE_LIGHT:
+      SetLightBuffer(light_buffer_, -1);

[timvolodine, 2015/03/02 17:39:58]

also light_buffer = nullptr?

[riju_, 2015/03/03 09:53:55]

Done.

+      return true;
     default:
       NOTREACHED();
   }
   return false;
 }
 
 bool DataFetcherSharedMemory::RegisterForSensor(
     REFSENSOR_TYPE_ID sensor_type,
     ISensor** sensor,
     scoped_refptr<SensorEventSink> event_sink) {
@@ skipping 55 matching lines @@
     case CONSUMER_TYPE_MOTION:
       if (sensor_accelerometer_.get()) {
         sensor_accelerometer_->SetEventSink(nullptr);
         sensor_accelerometer_.Release();
       }
       if (sensor_gyrometer_.get()) {
         sensor_gyrometer_->SetEventSink(nullptr);
         sensor_gyrometer_.Release();
       }
       break;
+    case CONSUMER_TYPE_LIGHT:
+      if (sensor_light_.get()) {
+        sensor_light_->SetEventSink(nullptr);
+        sensor_light_.Release();
+      }
+      break;
     default:
       NOTREACHED();
   }
 }
 
 void DataFetcherSharedMemory::SetBufferAvailableState(
     ConsumerType consumer_type, bool enabled) {
   switch(consumer_type) {
     case CONSUMER_TYPE_ORIENTATION:
       if (orientation_buffer_) {
         orientation_buffer_->seqlock.WriteBegin();
         orientation_buffer_->data.allAvailableSensorsAreActive = enabled;
         orientation_buffer_->seqlock.WriteEnd();
       }
       break;
     case CONSUMER_TYPE_MOTION:
       if (motion_buffer_) {
         motion_buffer_->seqlock.WriteBegin();
         motion_buffer_->data.allAvailableSensorsAreActive = enabled;
         motion_buffer_->seqlock.WriteEnd();
       }
       break;
     default:
       NOTREACHED();
   }
 }
 
 }  // namespace content