chromeos/accelerometer/accelerometer_types.h

   1 // Copyright 2014 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 #ifndef CHROMEOS_ACCELEROMETER_ACCELEROMETER_TYPES_H_
   6 #define CHROMEOS_ACCELEROMETER_ACCELEROMETER_TYPES_H_
   7
   8 #include "base/macros.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "chromeos/chromeos_export.h"
  11
  12 namespace chromeos {
  13
  14 enum AccelerometerSource {
  15   // Accelerometer is located in the device's screen. In the screen's natural
  16   // orientation, positive X points to the right, consistent with the pixel
  17   // position. Positive Y points up the screen. Positive Z is perpendicular to
  18   // the screen, pointing outwards towards the user. The orientation is
  19   // described at:
  20   // http://www.html5rocks.com/en/tutorials/device/orientation/.
  21   ACCELEROMETER_SOURCE_SCREEN = 0,
  22
  23   // Accelerometer is located in a keyboard attached to the device's screen.
  24   // If the device is open 180 degrees the orientation is consistent with the
  25   // screen. I.e. Positive X points to the right, positive Y points up on the
  26   // keyboard and positive Z is perpendicular to the keyboard pointing out
  27   // towards the user.
  28   ACCELEROMETER_SOURCE_ATTACHED_KEYBOARD,
  29
  30   ACCELEROMETER_SOURCE_COUNT
  31 };
  32
  33 struct CHROMEOS_EXPORT AccelerometerReading {
  34   AccelerometerReading();
  35   ~AccelerometerReading();
  36
  37   // If true, this accelerometer is being updated.
  38   bool present;
  39
  40   // The readings from this accelerometer measured in m/s^2.
  41   float x;
  42   float y;
  43   float z;
  44 };
  45
  46 // An accelerometer update contains the last known value for each of the
  47 // accelerometers present on the device.
  48 class CHROMEOS_EXPORT AccelerometerUpdate
  49     : public base::RefCountedThreadSafe<AccelerometerUpdate> {
  50  public:
  51   AccelerometerUpdate();
  52
  53   // Returns true if |source| has a valid value in this update.
  54   bool has(AccelerometerSource source) const { return data_[source].present; }
  55
  56   // Returns the last known value for |source|.
  57   const AccelerometerReading& get(AccelerometerSource source) const {
  58     return data_[source];
  59   }
  60
  61   void Set(AccelerometerSource source, float x, float y, float z) {
  62     data_[source].present = true;
  63     data_[source].x = x;
  64     data_[source].y = y;
  65     data_[source].z = z;
  66   }
  67
  68  protected:
  69   AccelerometerReading data_[ACCELEROMETER_SOURCE_COUNT];
  70
  71  private:
  72   friend class base::RefCountedThreadSafe<AccelerometerUpdate>;
  73
  74   virtual ~AccelerometerUpdate();
  75
  76   DISALLOW_COPY_AND_ASSIGN(AccelerometerUpdate);
  77 };
  78
  79 }  // namespace chromeos
  80
  81 #endif  // CHROMEOS_ACCELEROMETER_ACCELEROMETER_TYPES_H_