1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef CHRE_CORE_SENSOR_H_
18 #define CHRE_CORE_SENSOR_H_
19 
20 #include "chre/platform/platform_sensor.h"
21 #include "chre/util/non_copyable.h"
22 #include "chre/util/optional.h"
23 
24 namespace chre {
25 
26 /**
27  * Represents a sensor in the system that is exposed to nanoapps in CHRE.
28  *
29  * Note that like chre::Nanoapp, this class uses inheritance to separate the
30  * common code (Sensor) from common interface with platform-specific
31  * implementation (PlatformSensor) from the fully platform-specific part
32  * (PlatformSensorBase). However, this inheritance relationship does *not* imply
33  * polymorphism, and this object must only be referred to via the most-derived
34  * type, i.e. chre::Sensor.
35  */
36 class Sensor : public PlatformSensor {
37  public:
38   /**
39    * Constructs a sensor in an unspecified state. Should not be called directly
40    * by common code, as platform-specific initialization of the Sensor object is
41    * required for it to be usable.
42    *
43    * @see PlatformSensor::getSensors
44    */
45   Sensor() = default;
46 
47   Sensor(Sensor&& other) = default;
48   Sensor& operator=(Sensor&& other) = default;
49 
50   /**
51    * Obtains a reference to the latest request that has been accepted by the
52    * platform.
53    *
54    * @return A const reference to the SensorRequest.
55    */
getRequest()56   const SensorRequest& getRequest() const {
57     return mSensorRequest;
58   }
59 
60   /**
61    * Sets the current request of this sensor. If this request is a change from
62    * the previous request, it is sent to the underlying platform. If isValid()
63    * returns false this function will also return false and do nothing.
64    *
65    * @param request The new request for this sensor.
66    * @return true if there was no change required or the platform has set the
67    *         request successfully.
68    */
69   bool setRequest(const SensorRequest& request);
70 
71  private:
72   //! The most recent sensor request accepted by the platform.
73   SensorRequest mSensorRequest;
74 };
75 
76 }  // namespace chre
77 
78 #endif  // CHRE_CORE_SENSOR_H_
79