WIP : Generic Sensor API implementation

device/sensors/android/java/src/org/chromium/device/sensors/SensorFactoryImpl_Internal.java

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.device.sensors;
+
+import android.content.Context;
+import android.hardware.SensorManager;
+import android.os.Handler;
+import android.os.HandlerThread;
+import android.util.SparseArray;
+
+import org.chromium.mojo.bindings.Callbacks;
+import org.chromium.mojo.bindings.InterfaceRequest;
+import org.chromium.mojo.system.Core;
+import org.chromium.mojo.system.MessagePipeHandle;
+import org.chromium.mojo.system.SharedBufferHandle;
+import org.chromium.mojom.device.sensors.Sensor;
+import org.chromium.mojom.device.sensors.SensorConstants;
+import org.chromium.mojom.device.sensors.SensorFactory.CreateSensorResponse;
+import org.chromium.mojom.device.sensors.SensorType;
+import org.chromium.mojom.device.sensors.Result;
+
+
+/**
+ * Internal implementation of SensorFactory.
+ */
+public final class SensorFactoryImpl_Internal implements SensorStateObserver {
+    private static SensorFactoryImpl_Internal mInstance = null;
+    private final SensorManager mSensorManager;
+    private final HandlerThread mSensorsThread;
+    private final Handler mHandler;
+    private final SparseArray<SensorBase> mActiveSensors = new SparseArray<>();
+    private SharedBufferHandle mSharedBufferHandle;
+    private static final long READING_SIZE_IN_BYTES = SensorConstants.SENSOR_READING_FIELD_SIZE * SensorConstants.SENSOR_READING_FIELDS_COUNT;
+    private static final long SHARED_BUFFER_SIZE_IN_BYTES = READING_SIZE_IN_BYTES * (long)SensorType.LAST;
+
+    public static SensorFactoryImpl_Internal getInstance(Context context) {
+        if (mInstance == null) mInstance = new SensorFactoryImpl_Internal(context);
+        return mInstance;
+    }
+
+    public static void reset() {
+        mInstance = null;
+    }
+
+    public void onSensorNotInUse(SensorBase sensor) {
+        if (mActiveSensors.indexOfKey(sensor.getType()) >= 0) {
+            mActiveSensors.remove(sensor.getType());
+        }
+    }
+
+    public void createSensor(int type, InterfaceRequest<Sensor> request, CreateSensorResponse callback) {
+
+        if (mSensorManager == null) {
+            callback.call(Result.ERROR, null, 0L, 0L, 0);
+            return;
+        }
+
+        try {
+            long offset = (type - (long)SensorType.FIRST) * READING_SIZE_IN_BYTES;
+
+            if (mActiveSensors.indexOfKey(type) >= 0) {
+                SensorBase sensor = mActiveSensors.get(type);
+                Sensor.MANAGER.bind(new SensorImpl(sensor), request);
+                callback.call(Result.SUCCESS,
+                        mSharedBufferHandle.duplicate(new SharedBufferHandle.DuplicateOptions()),
+                        offset, READING_SIZE_IN_BYTES, sensor.reportingMode());
+                return;
+            }
+
+            MessagePipeHandle messagePipeHandle = request.passHandle();
+            createSharedBuffer(messagePipeHandle.getCore());
+
+            SensorBase sensor = createSensor(type, offset);
+            Sensor.MANAGER.bind(new SensorImpl(sensor), messagePipeHandle.pass());
+            mActiveSensors.put(type, sensor);
+            callback.call(Result.SUCCESS,
+                    mSharedBufferHandle.duplicate(new SharedBufferHandle.DuplicateOptions()),
+                    offset, READING_SIZE_IN_BYTES, sensor.reportingMode());
+        } catch (SensorException e) {
+            callback.call(Result.ERROR, null, 0L, 0L, 0);
+        }
+    }
+
+    private SensorBase createSensor(int type, long offset)
+            throws SensorException {
+        switch (type) {
+        case SensorType.AMBIENT_LIGHT:
+            return new AmbientLightSensorImpl(mSensorManager, mHandler, mSharedBufferHandle,
+                    offset, READING_SIZE_IN_BYTES, this);
+        case SensorType.PROXIMITY:
+            return new ProximitySensorImpl(mSensorManager, mHandler, mSharedBufferHandle,
+                    offset, READING_SIZE_IN_BYTES, this);
+        case SensorType.PRESSURE:
+            return new PressureSensorImpl(mSensorManager, mHandler, mSharedBufferHandle,
+                    offset, READING_SIZE_IN_BYTES, this);
+        case SensorType.GYROSCOPE:
+            return new GyroscopeSensorImpl(mSensorManager, mHandler, mSharedBufferHandle,
+                    offset, READING_SIZE_IN_BYTES, this);
+        case SensorType.LINEAR_ACCELERATION:
+        default:
+            throw new SensorException();
+        }
+    }
+
+    private void createSharedBuffer(Core core) throws SensorException {
+        if (mSharedBufferHandle != null) return;
+
+        mSharedBufferHandle = core.createSharedBuffer(new SharedBufferHandle.CreateOptions(),
+                SHARED_BUFFER_SIZE_IN_BYTES);
+        if (mSharedBufferHandle == null) throw new SensorException();
+    }
+
+    private SensorFactoryImpl_Internal(Context context) {
+        mSensorManager = (SensorManager)context.getSystemService(Context.SENSOR_SERVICE);
+        if (mSensorManager != null) {
+            mSensorsThread = new HandlerThread("SensorsHandlerThread");
+            mSensorsThread.start();
+            mHandler = new Handler(mSensorsThread.getLooper());
+        } else {
+            mSensorsThread = null;
+            mHandler = null;
+        }
+    }
+
+}