Add ability to rotate screen in AoD.

This patch prevents DisplayRotation from disabling the
OrientationListener when the screen turns off, if and only if the
underlying sensor is a wakeup device_orientation sensor (i.e. we don't
have to keep the AP on to keep listening). This then allows the AoD on
the device to rotate.

Since many devices doesn't have a wake orienation sensor, a config flag is
provided to force this behaviour on (although note that the AoD might
not rotate if the AP shuts down). This can be enabled by setting
config_forceOrientationListenerEnabledWhileDreaming to true.

Test: Not yet, finding tests...
Change-Id: Ie1ee8e297ebe9a8a73793d07f173bada8e0699f1

4 files changed, 30 insertions, 2 deletions

diff --git a/core/res/res/values/config.xml b/core/res/res/values/config.xml
index 1845faacc891..010d047c2c31 100644
--- a/core/res/res/values/config.xml
+++ b/core/res/res/values/config.xml
@@ -4610,4 +4610,9 @@
          If omitted, image editing will not be offered via Chooser.
          This name is in the ComponentName flattened format (package/class) [DO NOT TRANSLATE]  -->
     <string name="config_systemImageEditor" translatable="false"></string>
+
+    <!-- Whether to force WindowOrientationListener to keep listening to its sensor, even when
+         dreaming. This allows the AoD to rotate on devices without a wake device_orientation
+         sensor. Note that this flag should only be enabled for development/testing use. -->
+    <bool name="config_forceOrientationListenerEnabledWhileDreaming">false</bool>
 </resources>
diff --git a/core/res/res/values/symbols.xml b/core/res/res/values/symbols.xml
index c72a0cd63b36..20db4c6f2e3f 100644
--- a/core/res/res/values/symbols.xml
+++ b/core/res/res/values/symbols.xml
@@ -4146,4 +4146,6 @@
   <java-symbol type="bool" name="config_attachNavBarToAppDuringTransition" />
 
   <java-symbol type="bool" name="config_enableBackSound" />
+
+  <java-symbol type="bool" name="config_forceOrientationListenerEnabledWhileDreaming" />
 </resources>
diff --git a/services/core/java/com/android/server/policy/WindowOrientationListener.java b/services/core/java/com/android/server/policy/WindowOrientationListener.java
index 0157706866c7..17e81daa80cc 100644
--- a/services/core/java/com/android/server/policy/WindowOrientationListener.java
+++ b/services/core/java/com/android/server/policy/WindowOrientationListener.java
@@ -62,6 +62,7 @@ public abstract class WindowOrientationListener {
     private Sensor mSensor;
     private OrientationJudge mOrientationJudge;
     private int mCurrentRotation = -1;
+    private final Context mContext;
 
     private final Object mLock = new Object();
 
@@ -88,6 +89,7 @@ public abstract class WindowOrientationListener {
      * This constructor is private since no one uses it.
      */
     private WindowOrientationListener(Context context, Handler handler, int rate) {
+        mContext = context;
         mHandler = handler;
         mSensorManager = (SensorManager)context.getSystemService(Context.SENSOR_SERVICE);
         mRate = rate;
@@ -284,6 +286,19 @@ public abstract class WindowOrientationListener {
         }
     }
 
+    /**
+     * Returns whether this WindowOrientationListener can remain enabled while the device is dozing.
+     * If this returns true, it implies that the underlying sensor can still run while the AP is
+     * asleep, and that the underlying sensor will wake the AP on an event.
+     */
+    public boolean shouldStayEnabledWhileDreaming() {
+        if (mContext.getResources().getBoolean(
+                com.android.internal.R.bool.config_forceOrientationListenerEnabledWhileDreaming)) {
+            return true;
+        }
+        return mSensor.getType() == Sensor.TYPE_DEVICE_ORIENTATION && mSensor.isWakeUpSensor();
+    }
+
     abstract class OrientationJudge implements SensorEventListener {
         // Number of nanoseconds per millisecond.
         protected static final long NANOS_PER_MS = 1000000;
diff --git a/services/core/java/com/android/server/wm/DisplayRotation.java b/services/core/java/com/android/server/wm/DisplayRotation.java
index c4aaf7c8a935..df5d3ea3c150 100644
--- a/services/core/java/com/android/server/wm/DisplayRotation.java
+++ b/services/core/java/com/android/server/wm/DisplayRotation.java
@@ -955,10 +955,16 @@ public class DisplayRotation {
                 keyguardDrawComplete, windowManagerDrawComplete);
 
         boolean disable = true;
+
+        // If the orientation listener uses a wake sensor, keep the orientation listener on if the
+        // screen is on (regardless of wake state). This allows the AoD to rotate.
+        //
         // Note: We postpone the rotating of the screen until the keyguard as well as the
         // window manager have reported a draw complete or the keyguard is going away in dismiss
         // mode.
-        if (screenOnEarly && awake && ((keyguardDrawComplete && windowManagerDrawComplete))) {
+        if (screenOnEarly
+                && (awake || mOrientationListener.shouldStayEnabledWhileDreaming())
+                && ((keyguardDrawComplete && windowManagerDrawComplete))) {
             if (needSensorRunning()) {
                 disable = false;
                 // Enable listener if not already enabled.
@@ -974,7 +980,7 @@ public class DisplayRotation {
             }
         }
         // Check if sensors need to be disabled.
-        if (disable && mOrientationListener.mEnabled) {
+        if (disable) {
             mOrientationListener.disable();
         }
     }