Add TYPE_HEADING sensor type to sensor framework.

Bug: 189983308
Test: Compiled
Change-Id: I183f176352fd6e08025647638cee35fd1600f3f0

2 files changed, 37 insertions, 0 deletions

diff --git a/core/java/android/hardware/Sensor.java b/core/java/android/hardware/Sensor.java
index 166ae451fb6d..0d3aaf575729 100644
--- a/core/java/android/hardware/Sensor.java
+++ b/core/java/android/hardware/Sensor.java
@@ -794,6 +794,21 @@ public final class Sensor {
             "android.sensor.gyroscope_limited_axes_uncalibrated";
 
     /**
+     * A constant string describing a heading sensor.
+     *
+     * See {@link android.hardware.SensorEvent#values SensorEvent.values} for more details.
+     */
+    public static final int TYPE_HEADING = 42;
+
+    /**
+     * A constant string describing a heading sensor.
+     *
+     * @see #TYPE_HEADING
+     *
+     */
+    public static final String STRING_TYPE_HEADING = "android.sensor.heading";
+
+    /**
      * A constant describing all sensor types.
      */
 
@@ -918,6 +933,7 @@ public final class Sensor {
             6, // SENSOR_TYPE_GYROSCOPE_LIMITED_AXES
             9, // SENSOR_TYPE_ACCELEROMETER_LIMITED_AXES_UNCALIBRATED
             9, // SENSOR_TYPE_GYROSCOPE_LIMITED_AXES_UNCALIBRATED
+            2, // SENSOR_TYPE_HEADING
     };
 
     /**
@@ -1385,6 +1401,9 @@ public final class Sensor {
             case TYPE_GYROSCOPE_LIMITED_AXES_UNCALIBRATED:
                 mStringType = STRING_TYPE_GYROSCOPE_LIMITED_AXES_UNCALIBRATED;
                 return true;
+            case TYPE_HEADING:
+                mStringType = STRING_TYPE_HEADING;
+                return true;
             default:
                 return false;
         }
diff --git a/core/java/android/hardware/SensorEvent.java b/core/java/android/hardware/SensorEvent.java
index 7da136f73c53..45d4c09921a6 100644
--- a/core/java/android/hardware/SensorEvent.java
+++ b/core/java/android/hardware/SensorEvent.java
@@ -779,6 +779,24 @@ public class SensorEvent {
      * </ul>
      * </p>
      *
+     * <h4>{@link android.hardware.Sensor#TYPE_HEADING Sensor.TYPE_HEADING}:</h4>
+     *
+     * A sensor of this type measures the direction in which the device is
+     * pointing relative to true north in degrees. The value must be between
+     * 0.0 (inclusive) and 360.0 (exclusive), with 0 indicating north, 90 east,
+     * 180 south, and 270 west.
+     *
+     * Accuracy is defined at 68% confidence. In the case where the underlying
+     * distribution is assumed Gaussian normal, this would be considered one
+     * standard deviation. For example, if heading returns 60 degrees, and
+     * accuracy returns 10 degrees, then there is a 68 percent probability of
+     * the true heading being between 50 degrees and 70 degrees.
+     *
+     * <ul>
+     *  <li> values[0]: Measured heading in degrees.</li>
+     *  <li> values[1]: Heading accuracy in degrees.</li>
+     * </ul>
+     *
      * @see GeomagneticField
      */
     public final float[] values;