From e0c02b16e19f7279e49ba63140484513d87b807a Mon Sep 17 00:00:00 2001
From: Oliver Wang <mengmeng@codeaurora.org>
Date: Wed, 2 Oct 2013 20:01:50 +0800
Subject: [PATCH] Sensor: Enable the motion accelerometer for screen
 orientation change

The screen orientation can be detected by the motion accelerometer
instead of generic accelerometer to save power.

Change-Id: Iaeb3e5958d2ef7cc33080d7091ed8a5462695c67
---
 core/java/android/hardware/Sensor.java             | 14 ++++++++++++++
 core/res/res/values/config.xml                     |  4 ++++
 core/res/res/values/symbols.xml                    |  1 +
 .../policy/impl/WindowOrientationListener.java     | 13 +++++++++++--
 4 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/core/java/android/hardware/Sensor.java b/core/java/android/hardware/Sensor.java
index f514e428e5253..afd2d0b908bae 100644
--- a/core/java/android/hardware/Sensor.java
+++ b/core/java/android/hardware/Sensor.java
@@ -502,6 +502,20 @@ public final class Sensor {
      */
     public static final String STRING_TYPE_PICK_UP_GESTURE = "android.sensor.pick_up_gesture";
 
+    /**
+     * A constant describing the motion accelerometer sensor.
+     * <p>
+     * This sensor is similar to the accelerometer sensor, however it only
+     * streams data when the device is in motion, and stops streaming data
+     * when the device is stationary.
+     * Generally this kind of sensor would consume less power than the generic
+     * accelerometer sensor, and hence can be used in applications that do not
+     * require accelerometer streaming when device is stationary, such as the
+     * screen auto-rotation.
+     * {@hide}
+     */
+    public static final int TYPE_MOTION_ACCEL = 33171011;
+
     /**
      * A constant describing all sensor types.
      */
diff --git a/core/res/res/values/config.xml b/core/res/res/values/config.xml
index b1c00549ab6f7..443161a1e3ba9 100644
--- a/core/res/res/values/config.xml
+++ b/core/res/res/values/config.xml
@@ -1895,4 +1895,8 @@
     <!-- Configuration to restart radio upon PDP_DEACTIVATE with
          error cause as Regular deactivation(36). -->
     <bool name="config_radio_reset_on_regular_deactivation">true</bool>
+
+    <!-- bool value to for enabling motion accelerometer -->
+    <bool name="use_motion_accel">false</bool>
+
 </resources>
diff --git a/core/res/res/values/symbols.xml b/core/res/res/values/symbols.xml
index 6f7823caeec0f..c839fbb04c0f4 100644
--- a/core/res/res/values/symbols.xml
+++ b/core/res/res/values/symbols.xml
@@ -2101,6 +2101,7 @@
   <java-symbol type="bool" name="config_sms_force_7bit_encoding" />
   <java-symbol type="string" name="config_partial_segment_expire_age" />
   <java-symbol type="bool" name="config_global_phone_enabled" />
+  <java-symbol type="bool" name="use_motion_accel" />
 
   <!-- sim refresh for dual mode card -->
   <java-symbol type="bool" name="config_sim_refresh_for_dual_mode_card" />
diff --git a/policy/src/com/android/internal/policy/impl/WindowOrientationListener.java b/policy/src/com/android/internal/policy/impl/WindowOrientationListener.java
index 704da33a650ab..32772fdf4e5df 100644
--- a/policy/src/com/android/internal/policy/impl/WindowOrientationListener.java
+++ b/policy/src/com/android/internal/policy/impl/WindowOrientationListener.java
@@ -87,8 +87,17 @@ private WindowOrientationListener(Context context, Handler handler, int rate) {
         mHandler = handler;
         mSensorManager = (SensorManager)context.getSystemService(Context.SENSOR_SERVICE);
         mRate = rate;
-        mSensor = mSensorManager.getDefaultSensor(USE_GRAVITY_SENSOR
-                ? Sensor.TYPE_GRAVITY : Sensor.TYPE_ACCELEROMETER);
+        mSensor = null;
+
+        if (context.getResources().getBoolean(
+                                com.android.internal.R.bool.use_motion_accel) == true) {
+                mSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_MOTION_ACCEL);
+        }
+        if (mSensor == null) {
+                mSensor = mSensorManager.getDefaultSensor(USE_GRAVITY_SENSOR
+                                ? Sensor.TYPE_GRAVITY : Sensor.TYPE_ACCELEROMETER);
+        }
+
         if (mSensor != null) {
             // Create listener only if sensors do exist
             mSensorEventListener = new SensorEventListenerImpl();