athena/system/orientation_controller.cc

   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 #include "athena/screen/public/screen_manager.h"
   6 #include "athena/system/orientation_controller.h"
   7 #include "base/bind.h"
   8 #include "base/files/file_path_watcher.h"
   9 #include "base/files/file_util.h"
  10 #include "base/message_loop/message_loop.h"
  11 #include "base/task_runner.h"
  12 #include "chromeos/accelerometer/accelerometer_reader.h"
  13
  14 namespace athena {
  15
  16 namespace {
  17
  18 // Threshold after which to rotate in a given direction.
  19 const int kGravityThreshold = 6.0f;
  20
  21 }  // namespace
  22
  23 OrientationController::OrientationController() {
  24 }
  25
  26 void OrientationController::InitWith(
  27     scoped_refptr<base::TaskRunner> blocking_task_runner) {
  28   chromeos::AccelerometerReader::GetInstance()->Initialize(
  29       blocking_task_runner);
  30   chromeos::AccelerometerReader::GetInstance()->AddObserver(this);
  31 }
  32
  33 OrientationController::~OrientationController() {
  34 }
  35
  36 void OrientationController::Shutdown() {
  37   chromeos::AccelerometerReader::GetInstance()->RemoveObserver(this);
  38 }
  39
  40 void OrientationController::OnAccelerometerUpdated(
  41     const ui::AccelerometerUpdate& update) {
  42   if (!update.has(ui::ACCELEROMETER_SOURCE_SCREEN))
  43     return;
  44
  45   float gravity_x = update.get(ui::ACCELEROMETER_SOURCE_SCREEN).x();
  46   float gravity_y = update.get(ui::ACCELEROMETER_SOURCE_SCREEN).y();
  47   gfx::Display::Rotation rotation;
  48   if (gravity_x < -kGravityThreshold) {
  49     rotation = gfx::Display::ROTATE_270;
  50   } else if (gravity_x > kGravityThreshold) {
  51     rotation = gfx::Display::ROTATE_90;
  52   } else if (gravity_y < -kGravityThreshold) {
  53     rotation = gfx::Display::ROTATE_180;
  54   } else if (gravity_y > kGravityThreshold) {
  55     rotation = gfx::Display::ROTATE_0;
  56   } else {
  57     // No rotation as gravity threshold was not hit.
  58     return;
  59   }
  60
  61   if (rotation == current_rotation_)
  62     return;
  63
  64   current_rotation_ = rotation;
  65   ScreenManager::Get()->SetRotation(rotation);
  66 }
  67
  68 }  // namespace athena