Added SensorManager.getMinDelay()

Exposed the new "min delay" sensor property through native and
java sensor apis. This allows the caller to know what is the
maximum rate at which a sensor can return events, or, if a sensor
works in "update" mode (events returned only when the value changes).

Also augmented SensorManager.regusterSensorEvent() so that it can
accept a value in microsecond in addition to the 4 constants already
defined.

Change-Id: If425e9979892666df8c989d7de3c362230fa19e0

1 files changed, 10 insertions, 1 deletions

diff --git a/native/include/android/sensor.h b/native/include/android/sensor.h
index 00d95d8..b4ce024 100644
--- a/native/include/android/sensor.h
+++ b/native/include/android/sensor.h
@@ -121,6 +121,7 @@ typedef struct ASensorEvent {
         float           temperature;
         float           distance;
         float           light;
+        float           pressure;
     };
     int32_t reserved1[4];
 } ASensorEvent;
@@ -188,7 +189,8 @@ int ASensorEventQueue_disableSensor(ASensorEventQueue* queue, ASensor const* sen
 /*
  * Sets the delivery rate of events in microseconds for the given sensor.
  * Note that this is a hint only, generally event will arrive at a higher
- * rate.
+ * rate. It is an error to set a rate inferior to the value returned by
+ * ASensor_getMinDelay().
  * Returns a negative error code on failure.
  */
 int ASensorEventQueue_setEventRate(ASensorEventQueue* queue, ASensor const* sensor, int32_t usec);
@@ -239,6 +241,13 @@ int ASensor_getType(ASensor const* sensor);
  */
 float ASensor_getResolution(ASensor const* sensor);
 
+/*
+ * Returns the minimum delay allowed between events in microseconds.
+ * A value of zero means that this sensor doesn't report events at a
+ * constant rate, but rather only when a new data is available.
+ */
+int ASensor_getMinDelay(ASensor const* sensor);
+
 
 #ifdef __cplusplus
 };