为什么< android/sensor.h>中缺少某些传感器的枚举值?使用它们安全吗? [英] Why enum values for some sensors are missing from <android/sensor.h>? Is it safe to use them?

问题描述

<android/sensor.h>中似乎缺少某些传感器的枚举值.

It seems that enum values for some sensors are missing from <android/sensor.h>.

文件定义了以下枚举:

/*
 * Sensor types
 * (keep in sync with hardware/sensor.h)
 */

enum {
    ASENSOR_TYPE_ACCELEROMETER      = 1,
    ASENSOR_TYPE_MAGNETIC_FIELD     = 2,
    ASENSOR_TYPE_GYROSCOPE          = 4,
    ASENSOR_TYPE_LIGHT              = 5,
    ASENSOR_TYPE_PROXIMITY          = 8
};

评论说此枚举与<hardware/sensor.h>同步(未公开，它是android源代码的一部分).

The comment says that this enum is synced with <hardware/sensor.h> (which is not exposed, it's a part of android source).

但是在<hardware/sensor.h>中，我发现了值(例如压力，温度和湿度传感器)

But in the <hardware/sensor.h> I've found values for many more useful sensors like pressure, temperature and humidity ones:

#define SENSOR_TYPE_ACCELEROMETER         (1) 
#define SENSOR_TYPE_GEOMAGNETIC_FIELD     (2) 
#define SENSOR_TYPE_ORIENTATION           (3)
#define SENSOR_TYPE_GYROSCOPE             (4)
#define SENSOR_TYPE_LIGHT                 (5)
#define SENSOR_TYPE_PRESSURE              (6)
#define SENSOR_TYPE_TEMPERATURE           (7)
#define SENSOR_TYPE_PROXIMITY             (8)
#define SENSOR_TYPE_GRAVITY               (9)
#define SENSOR_TYPE_LINEAR_ACCELERATION   (10)
#define SENSOR_TYPE_ROTATION_VECTOR       (11)
#define SENSOR_TYPE_RELATIVE_HUMIDITY     (12)
// ...
#define SENSOR_TYPE_HEART_BEAT            (31)

为什么某些传感器未在<android/sensor.h>中列出?使用它们安全又便携吗?

Why some sensors are not listed in the <android/sensor.h>? It it safe and portable to use them?

推荐答案

由于

At the moment it is absolutely safe to use constants from <hardware/sensor.h> since SensorManager populates its internal sensor list with data from system-wide ISensorServer without any remapping of type values. And ISensorServer uses <hardware/sensor.h> constants.

我猜NDK API公开了受约束的类型集，只是因为它有一段时间没有更新.

I guess NDK API exposes constrained type set just because it was not updated for a while.

P.S.当然，如果将来出现某种映射，事情将会被打破，但是IMO AOSP会保持不变.

P.S. Of course things will be broken if some kind of mapping arise in future, but IMO AOSP will keep it unchanged.

这篇关于为什么< android/sensor.h>中缺少某些传感器的枚举值?使用它们安全吗?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！