device/sensors/data_fetcher_shared_memory_chromeos.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 "device/sensors/data_fetcher_shared_memory.h"

#include "device/sensors/sensor_manager_chromeos.h"

namespace device {

DataFetcherSharedMemory::DataFetcherSharedMemory() {}

DataFetcherSharedMemory::~DataFetcherSharedMemory() {}

bool DataFetcherSharedMemory::Start(ConsumerType consumer_type, void* buffer) {
  DCHECK(buffer);
  if (!sensor_manager_)
    sensor_manager_.reset(new SensorManagerChromeOS);

  switch (consumer_type) {
    case CONSUMER_TYPE_MOTION:
      sensor_manager_->StartFetchingDeviceMotionData(
          static_cast<DeviceMotionHardwareBuffer*>(buffer));
      return true;
    case CONSUMER_TYPE_ORIENTATION:
      sensor_manager_->StartFetchingDeviceOrientationData(
          static_cast<DeviceOrientationHardwareBuffer*>(buffer));
      return true;
    case CONSUMER_TYPE_ORIENTATION_ABSOLUTE: {
      orientation_absolute_buffer_ =
          static_cast<DeviceOrientationHardwareBuffer*>(buffer);
      // Absolute device orientation not available on Chrome OS, let the
      // implementation fire an all-null event to signal this to blink.
      orientation_absolute_buffer_->seqlock.WriteBegin();
      orientation_absolute_buffer_->data.absolute = true;
      orientation_absolute_buffer_->data.all_available_sensors_are_active =
          true;
      orientation_absolute_buffer_->seqlock.WriteEnd();
      return false;
    }
  }
  NOTREACHED();
  return false;
}

bool DataFetcherSharedMemory::Stop(ConsumerType consumer_type) {
  switch (consumer_type) {
    case CONSUMER_TYPE_MOTION:
      return sensor_manager_->StopFetchingDeviceMotionData();
    case CONSUMER_TYPE_ORIENTATION:
      return sensor_manager_->StopFetchingDeviceOrientationData();
    case CONSUMER_TYPE_ORIENTATION_ABSOLUTE:
      if (orientation_absolute_buffer_) {
        orientation_absolute_buffer_->seqlock.WriteBegin();
        orientation_absolute_buffer_->data.all_available_sensors_are_active =
            false;
        orientation_absolute_buffer_->seqlock.WriteEnd();
        orientation_absolute_buffer_ = nullptr;
      }
      return true;
  }
  NOTREACHED();
  return false;
}

}  // namespace device