Java tutorial
/* Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to you 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 org.skt.runtime.html5apis; import java.util.ArrayList; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import org.skt.runtime.api.RuntimeInterface; import org.skt.runtime.api.Plugin; import org.skt.runtime.api.PluginResult; import android.hardware.Sensor; import android.hardware.SensorEvent; import android.hardware.SensorEventListener; import android.hardware.SensorManager; import android.location.Location; import android.util.Log; import android.content.Context; /** * This class listens to the accelerometer sensor and stores the latest * acceleration values x,y,z. */ public class Accelerometer extends Plugin implements SensorEventListener { public static int STOPPED = 0; public static int STARTING = 1; public static int RUNNING = 2; public static int ERROR_FAILED_TO_START = 3; private float x, y, z; // most recent acceleration values private long timestamp; // time of most recent value private int status; // status of listener private int accuracy = SensorManager.SENSOR_STATUS_UNRELIABLE; private SensorManager sensorManager; // Sensor manager private Sensor mSensor; // Acceleration sensor returned by sensor manager private String callbackId; // Keeps track of the single "start" callback ID passed in from JS /** * Create an accelerometer listener. */ public Accelerometer() { this.x = 0; this.y = 0; this.z = 0; this.timestamp = 0; this.setStatus(Accelerometer.STOPPED); } /** * Sets the context of the Command. This can then be used to do things like * get file paths associated with the Activity. * * @param ctx The context of the main Activity. */ public void setContext(RuntimeInterface ctx) { super.setContext(ctx); this.sensorManager = (SensorManager) ctx.getSystemService(Context.SENSOR_SERVICE); } /** * Executes the request and returns PluginResult. * * @param action The action to execute. * @param args JSONArry of arguments for the plugin. * @param callbackId The callback id used when calling back into JavaScript. * @return A PluginResult object with a status and message. */ public PluginResult execute(String action, JSONArray args, String callbackId) { PluginResult.Status status = PluginResult.Status.NO_RESULT; String message = ""; PluginResult result = new PluginResult(status, message); result.setKeepCallback(true); if (action.equals("start")) { this.callbackId = callbackId; if (this.status != Accelerometer.RUNNING) { // If not running, then this is an async call, so don't worry about waiting // We drop the callback onto our stack, call start, and let start and the sensor callback fire off the callback down the road this.start(); } } else if (action.equals("stop")) { if (this.status == Accelerometer.RUNNING) { this.stop(); } } else { // Unsupported action return new PluginResult(PluginResult.Status.INVALID_ACTION); } return result; } /** * Called by AccelBroker when listener is to be shut down. * Stop listener. */ public void onDestroy() { this.stop(); } //-------------------------------------------------------------------------- // LOCAL METHODS //-------------------------------------------------------------------------- // /** * Start listening for acceleration sensor. * * @return status of listener */ private int start() { // If already starting or running, then just return if ((this.status == Accelerometer.RUNNING) || (this.status == Accelerometer.STARTING)) { return this.status; } this.setStatus(Accelerometer.STARTING); // Get accelerometer from sensor manager List<Sensor> list = this.sensorManager.getSensorList(Sensor.TYPE_ACCELEROMETER); // If found, then register as listener if ((list != null) && (list.size() > 0)) { this.mSensor = list.get(0); this.sensorManager.registerListener(this, this.mSensor, SensorManager.SENSOR_DELAY_UI); this.setStatus(Accelerometer.STARTING); } else { this.setStatus(Accelerometer.ERROR_FAILED_TO_START); this.fail(Accelerometer.ERROR_FAILED_TO_START, "No sensors found to register accelerometer listening to."); return this.status; } // Wait until running long timeout = 2000; while ((this.status == STARTING) && (timeout > 0)) { timeout = timeout - 100; try { Thread.sleep(100); } catch (InterruptedException e) { e.printStackTrace(); } } if (timeout == 0) { this.setStatus(Accelerometer.ERROR_FAILED_TO_START); this.fail(Accelerometer.ERROR_FAILED_TO_START, "Accelerometer could not be started."); } return this.status; } /** * Stop listening to acceleration sensor. */ private void stop() { if (this.status != Accelerometer.STOPPED) { this.sensorManager.unregisterListener(this); } this.setStatus(Accelerometer.STOPPED); this.accuracy = SensorManager.SENSOR_STATUS_UNRELIABLE; } /** * Called when the accuracy of the sensor has changed. * * @param sensor * @param accuracy */ public void onAccuracyChanged(Sensor sensor, int accuracy) { // Only look at accelerometer events if (sensor.getType() != Sensor.TYPE_ACCELEROMETER) { return; } // If not running, then just return if (this.status == Accelerometer.STOPPED) { return; } this.accuracy = accuracy; } /** * Sensor listener event. * * @param SensorEvent event */ public void onSensorChanged(SensorEvent event) { // Only look at accelerometer events if (event.sensor.getType() != Sensor.TYPE_ACCELEROMETER) { return; } // If not running, then just return if (this.status == Accelerometer.STOPPED) { return; } this.setStatus(Accelerometer.RUNNING); if (this.accuracy >= SensorManager.SENSOR_STATUS_ACCURACY_MEDIUM) { // Save time that event was received this.timestamp = System.nanoTime(); this.x = event.values[0]; this.y = event.values[1]; this.z = event.values[2]; this.win(); } } // Sends an error back to JS private void fail(int code, String message) { // Error object JSONObject errorObj = new JSONObject(); try { errorObj.put("code", code); errorObj.put("message", message); } catch (JSONException e) { e.printStackTrace(); } PluginResult err = new PluginResult(PluginResult.Status.ERROR, errorObj); err.setKeepCallback(true); this.error(err, this.callbackId); } private void win() { // Success return object PluginResult result = new PluginResult(PluginResult.Status.OK, this.getAccelerationJSON()); result.setKeepCallback(true); this.success(result, this.callbackId); } private void setStatus(int status) { this.status = status; } private JSONObject getAccelerationJSON() { JSONObject r = new JSONObject(); try { r.put("x", this.x); r.put("y", this.y); r.put("z", this.z); r.put("timestamp", this.timestamp); } catch (JSONException e) { e.printStackTrace(); } return r; } }