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/*
*
* 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.
*
*/
var argscheck = require('cordova/argscheck'),
utils = require('cordova/utils'),
exec = require('cordova/exec'),
PositionError = require('./PositionError'),
Position = require('./Position');
var timers = {}; // list of timers in use
// Returns default params, overrides if provided with values
function parseParameters(options) {
var opt = {
maximumAge: 0,
enableHighAccuracy: false,
timeout: Infinity
};
if (options) {
if (options.maximumAge !== undefined && !isNaN(options.maximumAge) && options.maximumAge > 0) {
opt.maximumAge = options.maximumAge;
}
if (options.enableHighAccuracy !== undefined) {
opt.enableHighAccuracy = options.enableHighAccuracy;
}
if (options.timeout !== undefined && !isNaN(options.timeout)) {
if (options.timeout < 0) {
opt.timeout = 0;
} else {
opt.timeout = options.timeout;
}
}
}
return opt;
}
// Returns a timeout failure, closed over a specified timeout value and error callback.
function createTimeout(errorCallback, timeout) {
var t = setTimeout(function() {
clearTimeout(t);
t = null;
errorCallback({
code:PositionError.TIMEOUT,
message:"Position retrieval timed out."
});
}, timeout);
return t;
}
var geolocation = {
lastPosition:null, // reference to last known (cached) position returned
/**
* Asynchronously acquires the current position.
*
* @param {Function} successCallback The function to call when the position data is available
* @param {Function} errorCallback The function to call when there is an error getting the heading position. (OPTIONAL)
* @param {PositionOptions} options The options for getting the position data. (OPTIONAL)
*/
getCurrentPosition:function(successCallback, errorCallback, options) {
argscheck.checkArgs('fFO', 'geolocation.getCurrentPosition', arguments);
options = parseParameters(options);
// Timer var that will fire an error callback if no position is retrieved from native
// before the "timeout" param provided expires
var timeoutTimer = {timer:null};
var win = function(p) {
clearTimeout(timeoutTimer.timer);
if (!(timeoutTimer.timer)) {
// Timeout already happened, or native fired error callback for
// this geo request.
// Don't continue with success callback.
return;
}
var pos = new Position(
{
latitude:p.latitude,
longitude:p.longitude,
altitude:p.altitude,
accuracy:p.accuracy,
heading:p.heading,
velocity:p.velocity,
altitudeAccuracy:p.altitudeAccuracy
},
(p.timestamp === undefined ? new Date() : ((p.timestamp instanceof Date) ? p.timestamp : new Date(p.timestamp)))
);
geolocation.lastPosition = pos;
successCallback(pos);
};
var fail = function(e) {
clearTimeout(timeoutTimer.timer);
timeoutTimer.timer = null;
var err = new PositionError(e.code, e.message);
if (errorCallback) {
errorCallback(err);
}
};
// Check our cached position, if its timestamp difference with current time is less than the maximumAge, then just
// fire the success callback with the cached position.
if (geolocation.lastPosition && options.maximumAge && (((new Date()).getTime() - geolocation.lastPosition.timestamp.getTime()) <= options.maximumAge)) {
successCallback(geolocation.lastPosition);
// If the cached position check failed and the timeout was set to 0, error out with a TIMEOUT error object.
} else if (options.timeout === 0) {
fail({
code:PositionError.TIMEOUT,
message:"timeout value in PositionOptions set to 0 and no cached Position object available, or cached Position object's age exceeds provided PositionOptions' maximumAge parameter."
});
// Otherwise we have to call into native to retrieve a position.
} else {
if (options.timeout !== Infinity) {
// If the timeout value was not set to Infinity (default), then
// set up a timeout function that will fire the error callback
// if no successful position was retrieved before timeout expired.
timeoutTimer.timer = createTimeout(fail, options.timeout);
} else {
// This is here so the check in the win function doesn't mess stuff up
// may seem weird but this guarantees timeoutTimer is
// always truthy before we call into native
timeoutTimer.timer = true;
}
exec(win, fail, "Geolocation", "getLocation", [options.enableHighAccuracy, options.maximumAge]);
}
return timeoutTimer;
},
/**
* Asynchronously watches the geolocation for changes to geolocation. When a change occurs,
* the successCallback is called with the new location.
*
* @param {Function} successCallback The function to call each time the location data is available
* @param {Function} errorCallback The function to call when there is an error getting the location data. (OPTIONAL)
* @param {PositionOptions} options The options for getting the location data such as frequency. (OPTIONAL)
* @return String The watch id that must be passed to #clearWatch to stop watching.
*/
watchPosition:function(successCallback, errorCallback, options) {
argscheck.checkArgs('fFO', 'geolocation.getCurrentPosition', arguments);
options = parseParameters(options);
var id = utils.createUUID();
// Tell device to get a position ASAP, and also retrieve a reference to the timeout timer generated in getCurrentPosition
timers[id] = geolocation.getCurrentPosition(successCallback, errorCallback, options);
var fail = function(e) {
clearTimeout(timers[id].timer);
var err = new PositionError(e.code, e.message);
if (errorCallback) {
errorCallback(err);
}
};
var win = function(p) {
clearTimeout(timers[id].timer);
if (options.timeout !== Infinity) {
timers[id].timer = createTimeout(fail, options.timeout);
}
var pos = new Position(
{
latitude:p.latitude,
longitude:p.longitude,
altitude:p.altitude,
accuracy:p.accuracy,
heading:p.heading,
velocity:p.velocity,
altitudeAccuracy:p.altitudeAccuracy
},
(p.timestamp === undefined ? new Date() : ((p.timestamp instanceof Date) ? p.timestamp : new Date(p.timestamp)))
);
geolocation.lastPosition = pos;
successCallback(pos);
};
exec(win, fail, "Geolocation", "addWatch", [id, options.enableHighAccuracy]);
return id;
},
/**
* Clears the specified heading watch.
*
* @param {String} id The ID of the watch returned from #watchPosition
*/
clearWatch:function(id) {
if (id && timers[id] !== undefined) {
clearTimeout(timers[id].timer);
timers[id].timer = false;
exec(null, null, "Geolocation", "clearWatch", [id]);
}
}
};
module.exports = geolocation;
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