From 51a0c35b5a14705bdf4bda8ffe2def2cb445a71e Mon Sep 17 00:00:00 2001
From: Anthony Stange <stange@google.com>
Date: Thu, 16 Jan 2020 14:56:27 -0500
Subject: [PATCH] Add hinge angle sensor type to sensors framework

Adds new hinge angle sensor type that will expose the angle, in degrees,
between two displays on a device.

Bug: 144139857
Test: Make SDK docs and verify updated wording is present
Change-Id: I20e93bc788f06c4dd48d481c368da01b30cc8d4d
---
 api/current.txt                             |  2 ++
 core/java/android/hardware/Sensor.java      | 19 +++++++++++++++++++
 core/java/android/hardware/SensorEvent.java | 10 ++++++++++
 3 files changed, 31 insertions(+)

diff --git a/api/current.txt b/api/current.txt
index 16786ffe701a6..2de94a7e96ba1 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -16614,6 +16614,7 @@ package android.hardware {
     field public static final String STRING_TYPE_GYROSCOPE_UNCALIBRATED = "android.sensor.gyroscope_uncalibrated";
     field public static final String STRING_TYPE_HEART_BEAT = "android.sensor.heart_beat";
     field public static final String STRING_TYPE_HEART_RATE = "android.sensor.heart_rate";
+    field public static final String STRING_TYPE_HINGE_ANGLE = "android.sensor.hinge_angle";
     field public static final String STRING_TYPE_LIGHT = "android.sensor.light";
     field public static final String STRING_TYPE_LINEAR_ACCELERATION = "android.sensor.linear_acceleration";
     field public static final String STRING_TYPE_LOW_LATENCY_OFFBODY_DETECT = "android.sensor.low_latency_offbody_detect";
@@ -16643,6 +16644,7 @@ package android.hardware {
     field public static final int TYPE_GYROSCOPE_UNCALIBRATED = 16; // 0x10
     field public static final int TYPE_HEART_BEAT = 31; // 0x1f
     field public static final int TYPE_HEART_RATE = 21; // 0x15
+    field public static final int TYPE_HINGE_ANGLE = 36; // 0x24
     field public static final int TYPE_LIGHT = 5; // 0x5
     field public static final int TYPE_LINEAR_ACCELERATION = 10; // 0xa
     field public static final int TYPE_LOW_LATENCY_OFFBODY_DETECT = 34; // 0x22
diff --git a/core/java/android/hardware/Sensor.java b/core/java/android/hardware/Sensor.java
index a71a7b63f30e6..cc4c45699bd4e 100644
--- a/core/java/android/hardware/Sensor.java
+++ b/core/java/android/hardware/Sensor.java
@@ -692,6 +692,22 @@ public final class Sensor {
     public static final String STRING_TYPE_ACCELEROMETER_UNCALIBRATED =
             "android.sensor.accelerometer_uncalibrated";
 
+    /**
+     * A constant describing a hinge angle sensor.
+     *
+     * See {@link android.hardware.SensorEvent#values SensorEvent.values} for more details.
+     *
+     */
+    public static final int TYPE_HINGE_ANGLE = 36;
+
+    /**
+     * A constant string describing a hinge angle sensor.
+     *
+     * @see #TYPE_HINGE_ANGLE
+     *
+     */
+    public static final String STRING_TYPE_HINGE_ANGLE = "android.sensor.hinge_angle";
+
     /**
      * A constant describing all sensor types.
      */
@@ -811,6 +827,7 @@ public final class Sensor {
             16, // skip over additional sensor info type
             1, // SENSOR_TYPE_LOW_LATENCY_OFFBODY_DETECT
             6, // SENSOR_TYPE_ACCELEROMETER_UNCALIBRATED
+            1, // SENSOR_TYPE_HINGE_ANGLE
     };
 
     /**
@@ -1226,6 +1243,8 @@ public final class Sensor {
             case TYPE_ACCELEROMETER_UNCALIBRATED:
                 mStringType = STRING_TYPE_ACCELEROMETER_UNCALIBRATED;
                 return true;
+            case TYPE_HINGE_ANGLE:
+                mStringType = STRING_TYPE_HINGE_ANGLE;
             default:
                 return false;
         }
diff --git a/core/java/android/hardware/SensorEvent.java b/core/java/android/hardware/SensorEvent.java
index 64c45bf290ec0..5fbf0da8b5a5c 100644
--- a/core/java/android/hardware/SensorEvent.java
+++ b/core/java/android/hardware/SensorEvent.java
@@ -630,6 +630,16 @@ public class SensorEvent {
      * x_bias, y_bias, z_bias are the estimated biases.
      * </p>
      *
+     * <h4>{@link android.hardware.Sensor#TYPE_HINGE_ANGLE Sensor.TYPE_HINGE_ANGLE}:</h4>
+     *
+     * A sensor of this type measures the angle, in degrees, between two integral parts of the
+     * device. Movement of a hinge measured by this sensor type is expected to alter the ways in
+     * which the user may interact with the device, for example by unfolding or revealing a display.
+     *
+     * <ul>
+     *  <li> values[0]: Measured hinge angle between 0 and 360 degrees inclusive</li>
+     * </ul>
+     *
      * @see GeomagneticField
      */
     public final float[] values;