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.apache.cordova.geolocation; import org.apache.cordova.CallbackContext; import org.apache.cordova.CordovaPlugin; import org.apache.cordova.PluginResult; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import android.content.Context; import android.location.Location; import android.location.LocationManager; /* * This class is the interface to the Geolocation. It's bound to the geo object. * * This class only starts and stops various GeoListeners, which consist of a GPS and a Network Listener */ public class GeoBroker extends CordovaPlugin { private GPSListener gpsListener; private NetworkListener networkListener; private LocationManager locationManager; /** * Executes the request and returns PluginResult. * * @param action The action to execute. * @param args JSONArry of arguments for the plugin. * @param callbackContext The callback id used when calling back into JavaScript. * @return True if the action was valid, or false if not. */ public boolean execute(String action, JSONArray args, CallbackContext callbackContext) throws JSONException { if (locationManager == null) { locationManager = (LocationManager) this.cordova.getActivity() .getSystemService(Context.LOCATION_SERVICE); } if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER) || locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER)) { if (networkListener == null) { networkListener = new NetworkListener(locationManager, this); } if (gpsListener == null) { gpsListener = new GPSListener(locationManager, this); } if (action.equals("getLocation")) { boolean enableHighAccuracy = args.getBoolean(0); int maximumAge = args.getInt(1); String provider = (enableHighAccuracy && locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) ? LocationManager.GPS_PROVIDER : LocationManager.NETWORK_PROVIDER; Location last = this.locationManager.getLastKnownLocation(provider); // Check if we can use lastKnownLocation to get a quick reading and use less battery if (last != null && (System.currentTimeMillis() - last.getTime()) <= maximumAge) { PluginResult result = new PluginResult(PluginResult.Status.OK, this.returnLocationJSON(last)); callbackContext.sendPluginResult(result); } else { this.getCurrentLocation(callbackContext, enableHighAccuracy, args.optInt(2, 60000)); } } else if (action.equals("addWatch")) { String id = args.getString(0); boolean enableHighAccuracy = args.getBoolean(1); this.addWatch(id, callbackContext, enableHighAccuracy); } else if (action.equals("clearWatch")) { String id = args.getString(0); this.clearWatch(id); } else { return false; } } else { PluginResult.Status status = PluginResult.Status.NO_RESULT; String message = "Location API is not available for this device."; PluginResult result = new PluginResult(status, message); callbackContext.sendPluginResult(result); } return true; } private void clearWatch(String id) { this.gpsListener.clearWatch(id); this.networkListener.clearWatch(id); } private void getCurrentLocation(CallbackContext callbackContext, boolean enableHighAccuracy, int timeout) { if (enableHighAccuracy && locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) { this.gpsListener.addCallback(callbackContext, timeout); } else { this.networkListener.addCallback(callbackContext, timeout); } } private void addWatch(String timerId, CallbackContext callbackContext, boolean enableHighAccuracy) { if (enableHighAccuracy && locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) { this.gpsListener.addWatch(timerId, callbackContext); } else { this.networkListener.addWatch(timerId, callbackContext); } } /** * Called when the activity is to be shut down. * Stop listener. */ public void onDestroy() { if (this.networkListener != null) { this.networkListener.destroy(); this.networkListener = null; } if (this.gpsListener != null) { this.gpsListener.destroy(); this.gpsListener = null; } } /** * Called when the view navigates. * Stop the listeners. */ public void onReset() { this.onDestroy(); } public JSONObject returnLocationJSON(Location loc) { JSONObject o = new JSONObject(); try { o.put("latitude", loc.getLatitude()); o.put("longitude", loc.getLongitude()); o.put("altitude", (loc.hasAltitude() ? loc.getAltitude() : null)); o.put("accuracy", loc.getAccuracy()); o.put("heading", (loc.hasBearing() ? (loc.hasSpeed() ? loc.getBearing() : null) : null)); o.put("velocity", loc.getSpeed()); o.put("timestamp", loc.getTime()); } catch (JSONException e) { // TODO Auto-generated catch block e.printStackTrace(); } return o; } public void win(Location loc, CallbackContext callbackContext, boolean keepCallback) { PluginResult result = new PluginResult(PluginResult.Status.OK, this.returnLocationJSON(loc)); result.setKeepCallback(keepCallback); callbackContext.sendPluginResult(result); } /** * Location failed. Send error back to JavaScript. * * @param code The error code * @param msg The error message * @throws JSONException */ public void fail(int code, String msg, CallbackContext callbackContext, boolean keepCallback) { JSONObject obj = new JSONObject(); String backup = null; try { obj.put("code", code); obj.put("message", msg); } catch (JSONException e) { obj = null; backup = "{'code':" + code + ",'message':'" + msg.replaceAll("'", "\'") + "'}"; } PluginResult result; if (obj != null) { result = new PluginResult(PluginResult.Status.ERROR, obj); } else { result = new PluginResult(PluginResult.Status.ERROR, backup); } result.setKeepCallback(keepCallback); callbackContext.sendPluginResult(result); } public boolean isGlobalListener(CordovaLocationListener listener) { if (gpsListener != null && networkListener != null) { return gpsListener.equals(listener) || networkListener.equals(listener); } else return false; } }