Hook up device sensors for DeviceOrientation

Change-Id: Ic7165a07a02e3c38165b2f92e3ec7368d2b60e19

1 files changed, 142 insertions, 9 deletions

diff --git a/core/java/android/webkit/DeviceOrientationService.java b/core/java/android/webkit/DeviceOrientationService.java
index 07d3d2fedf82..4ff849ea0162 100755
--- a/core/java/android/webkit/DeviceOrientationService.java
+++ b/core/java/android/webkit/DeviceOrientationService.java
@@ -16,19 +16,39 @@
 
 package android.webkit;
 
+import android.content.Context;
+import android.hardware.Sensor;
+import android.hardware.SensorEvent;
+import android.hardware.SensorEventListener;
+import android.hardware.SensorManager;
 import android.os.Handler;
 import android.webkit.DeviceOrientationManager;
 import java.lang.Runnable;
+import java.util.List;
 
 
-final class DeviceOrientationService {
+final class DeviceOrientationService implements SensorEventListener {
+    // The gravity vector expressed in the body frame.
+    private float[] mGravityVector;
+    // The geomagnetic vector expressed in the body frame.
+    private float[] mMagneticFieldVector;
+
     private DeviceOrientationManager mManager;
     private boolean mIsRunning;
     private Handler mHandler;
+    private SensorManager mSensorManager;
+    private Context mContext;
+    private Double mAlpha;
+    private Double mBeta;
+    private Double mGamma;
+
+    private static final double DELTA_DEGRESS = 1.0;
 
-    public DeviceOrientationService(DeviceOrientationManager manager) {
+    public DeviceOrientationService(DeviceOrientationManager manager, Context context) {
         mManager = manager;
         assert(mManager != null);
+        mContext = context;
+        assert(mContext != null);
      }
 
     public void start() {
@@ -55,9 +75,6 @@ final class DeviceOrientationService {
 
     private void sendErrorEvent() {
         assert WebViewCore.THREAD_NAME.equals(Thread.currentThread().getName());
-        if (mHandler == null) {
-            mHandler = new Handler();
-        }
         mHandler.post(new Runnable() {
             @Override
             public void run() {
@@ -70,12 +87,128 @@ final class DeviceOrientationService {
     }
 
     private void registerForSensors() {
-        // Send the error event for now.
-        // FIXME: Implement.
-        sendErrorEvent();
+        if (mHandler == null) {
+            mHandler = new Handler();
+        }
+        if (!registerForAccelerometerSensor() || !registerForMagneticFieldSensor()) {
+            unregisterFromSensors();
+            sendErrorEvent();
+        }
+    }
+
+    private void getOrientationUsingGetRotationMatrix() {
+        if (mGravityVector == null || mMagneticFieldVector == null) {
+            return;
+        }
+
+        // Get the rotation matrix.
+        // The rotation matrix that transforms from the body frame to the earth frame.
+        float[] deviceRotationMatrix = new float[9];
+        if (!SensorManager.getRotationMatrix(
+                deviceRotationMatrix, null, mGravityVector, mMagneticFieldVector)) {
+            return;
+        }
+
+        // Convert rotation matrix to rotation angles.
+        // Assuming that the rotations are appied in the order listed at
+        // http://developer.android.com/reference/android/hardware/SensorEvent.html#values
+        // the rotations are applied about the same axes and in the same order as required by the
+        // API. The only conversions are sign changes as follows.
+        // The angles are in radians
+        float[] rotationAngles = new float[3];
+        SensorManager.getOrientation(deviceRotationMatrix, rotationAngles);
+        double alpha = Math.toDegrees(-rotationAngles[0]) - 90.0;
+        while (alpha < 0.0) { alpha += 360.0; } // [0, 360)
+        double beta = Math.toDegrees(-rotationAngles[1]);
+        while (beta < -180.0) { beta += 360.0; } // [-180, 180)
+        double gamma = Math.toDegrees(rotationAngles[2]);
+        while (gamma < -90.0) { gamma += 360.0; } // [-90, 90)
+
+        maybeSendChange(alpha, beta, gamma);
+    }
+
+    private SensorManager getSensorManager() {
+        assert WebViewCore.THREAD_NAME.equals(Thread.currentThread().getName());
+        if (mSensorManager == null) {
+            mSensorManager = (SensorManager) mContext.getSystemService(Context.SENSOR_SERVICE);
+        }
+        return mSensorManager;
+    }
+
+    private boolean registerForAccelerometerSensor() {
+        List<Sensor> sensors = getSensorManager().getSensorList(Sensor.TYPE_ACCELEROMETER);
+        if (sensors.isEmpty()) {
+            return false;
+        }
+        // TODO: Consider handling multiple sensors.
+        return getSensorManager().registerListener(
+                this, sensors.get(0), SensorManager.SENSOR_DELAY_FASTEST, mHandler);
+    }
+
+    private boolean registerForMagneticFieldSensor() {
+        List<Sensor> sensors = getSensorManager().getSensorList(Sensor.TYPE_MAGNETIC_FIELD);
+        if (sensors.isEmpty()) {
+            return false;
+        }
+        // TODO: Consider handling multiple sensors.
+        return getSensorManager().registerListener(
+                this, sensors.get(0), SensorManager.SENSOR_DELAY_FASTEST, mHandler);
     }
 
     private void unregisterFromSensors() {
-        // FIXME: Implement.
+        getSensorManager().unregisterListener(this);
+    }
+
+    private void maybeSendChange(double alpha, double beta, double gamma) {
+        assert WebViewCore.THREAD_NAME.equals(Thread.currentThread().getName());
+        if (mAlpha == null || mBeta == null || mGamma == null
+                || Math.abs(alpha - mAlpha) > DELTA_DEGRESS
+                || Math.abs(beta - mBeta) > DELTA_DEGRESS
+                || Math.abs(gamma - mGamma) > DELTA_DEGRESS) {
+            mAlpha = alpha;
+            mBeta = beta;
+            mGamma = gamma;
+            mManager.onOrientationChange(mAlpha, mBeta, mGamma);
+        }
+    }
+
+    /**
+     * SensorEventListener implementation.
+     * Callbacks happen on the thread on which we registered - the WebCore thread.
+     */
+    public void onSensorChanged(SensorEvent event) {
+        assert(event.values.length == 3);
+        assert WebViewCore.THREAD_NAME.equals(Thread.currentThread().getName());
+
+        if (!mIsRunning) {
+            return;
+        }
+
+        switch (event.sensor.getType()) {
+          case Sensor.TYPE_ACCELEROMETER:
+            if (mGravityVector == null) {
+                mGravityVector = new float[3];
+            }
+            mGravityVector[0] = event.values[0];
+            mGravityVector[1] = event.values[1];
+            mGravityVector[2] = event.values[2];
+            getOrientationUsingGetRotationMatrix();
+            break;
+          case Sensor.TYPE_MAGNETIC_FIELD:
+            if (mMagneticFieldVector == null) {
+                mMagneticFieldVector = new float[3];
+            }
+            mMagneticFieldVector[0] = event.values[0];
+            mMagneticFieldVector[1] = event.values[1];
+            mMagneticFieldVector[2] = event.values[2];
+            getOrientationUsingGetRotationMatrix();
+            break;
+          default:
+            assert(false);
+        }
+    }
+
+    public void onAccuracyChanged(Sensor sensor, int accuracy) {
+        assert WebViewCore.THREAD_NAME.equals(Thread.currentThread().getName());
     }
 }