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_READER_H_ 6 #define CHROMEOS_ACCELEROMETER_ACCELEROMETER_READER_H_ 7 8 #include <vector> 9 10 #include "base/memory/ref_counted.h" 11 #include "base/memory/weak_ptr.h" 12 #include "base/observer_list.h" 13 #include "chromeos/chromeos_export.h" 14 #include "ui/gfx/geometry/vector3d_f.h" 15 16 namespace base { 17 class TaskRunner; 18 } 19 20 namespace chromeos { 21 22 // Reads an accelerometer device and reports data back to an 23 // AccelerometerDelegate. 24 class CHROMEOS_EXPORT AccelerometerReader { 25 public: 26 // Configuration structure for accelerometer device. 27 struct ConfigurationData { 28 ConfigurationData(); 29 ~ConfigurationData(); 30 31 // Scale of accelerometers (i.e. raw value * 1.0f / scale = G's). 32 unsigned int base_scale; 33 unsigned int lid_scale; 34 35 // Index of each accelerometer axis in data stream. 36 std::vector<unsigned int> index; 37 }; 38 typedef base::RefCountedData<ConfigurationData> Configuration; 39 typedef base::RefCountedData<char[12]> Reading; 40 41 // An interface to receive data from the AccelerometerReader. 42 class Delegate { 43 public: 44 virtual void HandleAccelerometerReading(const gfx::Vector3dF& base, 45 const gfx::Vector3dF& lid) = 0; 46 }; 47 48 AccelerometerReader(base::TaskRunner* blocking_task_runner, 49 Delegate* delegate); 50 ~AccelerometerReader(); 51 52 private: 53 // Dispatched when initialization is complete. If |success|, |configuration| 54 // provides the details of the detected accelerometer. 55 void OnInitialized(scoped_refptr<Configuration> configuration, bool success); 56 57 // Triggers an asynchronous read from the accelerometer, signalling 58 // OnDataRead with the result. 59 void TriggerRead(); 60 61 // If |success|, converts the raw reading to a pair of Vector3dF 62 // values and notifies the |delegate_| with the new readings. 63 // Triggers another read from the accelerometer at the current sampling rate. 64 void OnDataRead(scoped_refptr<Reading> reading, bool success); 65 66 // The task runner to use for blocking tasks. 67 scoped_refptr<base::TaskRunner> task_runner_; 68 69 // A weak pointer to the delegate to send accelerometer readings to. 70 Delegate* delegate_; 71 72 // The accelerometer configuration. 73 scoped_refptr<Configuration> configuration_; 74 75 base::WeakPtrFactory<AccelerometerReader> weak_factory_; 76 77 DISALLOW_COPY_AND_ASSIGN(AccelerometerReader); 78 }; 79 80 } // namespace chromeos 81 82 #endif // CHROMEOS_ACCELEROMETER_ACCELEROMETER_READER_H_ 83