| /* |
| * Copyright (C) 2010 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| 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.DeviceMotionAndOrientationManager; |
| import java.lang.Runnable; |
| import java.util.List; |
| |
| |
| 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 DeviceMotionAndOrientationManager mManager; |
| private boolean mIsRunning; |
| private Handler mHandler; |
| private SensorManager mSensorManager; |
| private Context mContext; |
| private Double mAlpha; |
| private Double mBeta; |
| private Double mGamma; |
| private boolean mHaveSentErrorEvent; |
| |
| private static final double DELTA_DEGRESS = 1.0; |
| |
| public DeviceOrientationService(DeviceMotionAndOrientationManager manager, Context context) { |
| mManager = manager; |
| assert(mManager != null); |
| mContext = context; |
| assert(mContext != null); |
| } |
| |
| public void start() { |
| mIsRunning = true; |
| registerForSensors(); |
| } |
| |
| public void stop() { |
| mIsRunning = false; |
| unregisterFromSensors(); |
| } |
| |
| public void suspend() { |
| if (mIsRunning) { |
| unregisterFromSensors(); |
| } |
| } |
| |
| public void resume() { |
| if (mIsRunning) { |
| registerForSensors(); |
| } |
| } |
| |
| private void sendErrorEvent() { |
| assert WebViewCore.THREAD_NAME.equals(Thread.currentThread().getName()); |
| // The spec requires that each listener receives the error event only once. |
| if (mHaveSentErrorEvent) |
| return; |
| mHaveSentErrorEvent = true; |
| mHandler.post(new Runnable() { |
| @Override |
| public void run() { |
| assert WebViewCore.THREAD_NAME.equals(Thread.currentThread().getName()); |
| if (mIsRunning) { |
| // The special case of all nulls is used to signify a failure to get data. |
| mManager.onOrientationChange(null, null, null); |
| } |
| } |
| }); |
| } |
| |
| private void registerForSensors() { |
| 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() { |
| 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); |
| // Now that we have successfully sent some data, reset whether we've sent an error. |
| mHaveSentErrorEvent = false; |
| } |
| } |
| |
| /** |
| * 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()); |
| } |
| } |