1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
|
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset=utf-8>
<meta name="viewport" content="width=620">
<title>HTML5 Demo: geolocation</title>
<script src="//code.jquery.com/jquery-1.11.3.min.js"></script>
<script src="//code.jquery.com/jquery-migrate-1.2.1.min.js"></script>
</head>
<body>
<section id="wrapper">
<header>
<h1>geolocation</h1>
</header>
<meta name="viewport" content="width=620"/>
<script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script>
<article>
<p>Finding your location: <span id="status">checking...</span></p>
<p><span id="distance"></span> meters away from target location</p>
</article>
<script>
var target_lat = 22.31064;
var target_long = 114.22656;
var current_lat = "";
var current_long = "";
function check_distance(target_lat, target_long, current_lat, current_long) {
var lat = [target_lat, current_lat];
var lng = [target_long, current_long];
var R = 6378137;
var dLat = (lat[1] - lat[0]) * Math.PI / 180;
var dLng = (lng[1] - lng[0]) * Math.PI / 180;
var a = Math.sin(dLat / 2) * Math.sin(dLat / 2) +
Math.cos(lat[0] * Math.PI / 180) * Math.cos(lat[1] * Math.PI / 180) *
Math.sin(dLng / 2) * Math.sin(dLng / 2);
var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
var d = R * c;
//console.log(Math.round(d));
//alert(Math.round(d));
$("#distance").text(Math.round(d));
}
function success(position) {
var s = document.querySelector('#status');
if (s.className == 'success') {
// not sure why we're hitting this twice in FF, I think it's to do with a cached result coming back
return;
}
s.innerHTML = "found you!";
s.className = 'success';
var mapcanvas = document.createElement('div');
mapcanvas.id = 'mapcanvas';
mapcanvas.style.height = '400px';
mapcanvas.style.width = '560px';
document.querySelector('article').appendChild(mapcanvas);
var current_lat = position.coords.latitude;
var current_long = position.coords.longitude;
var latlng = new google.maps.LatLng(position.coords.latitude, position.coords.longitude);
var myOptions = {
zoom: 18,
center: latlng,
mapTypeControl: false,
navigationControlOptions: {style: google.maps.NavigationControlStyle.SMALL},
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById("mapcanvas"), myOptions);
var marker = new google.maps.Marker({
position: latlng,
map: map,
title: "You are here! (at least within a " + position.coords.accuracy + " meter radius)"
});
var target_latlng = new google.maps.LatLng(22.31064, 114.22656);
var cityCircle = new google.maps.Circle({
strokeColor: '#FF0000',
strokeOpacity: 0.8,
strokeWeight: 2,
fillColor: '#FF0000',
fillOpacity: 0.35,
map: map,
center: target_latlng,
radius: 100
});
check_distance(target_lat, target_long, current_lat, current_long);
}
function error(msg) {
var s = document.querySelector('#status');
s.innerHTML = typeof msg == 'string' ? msg : "failed";
s.className = 'fail';
// console.log(arguments);
}
if (navigator.geolocation) {
navigator.geolocation.getCurrentPosition(success, error);
} else {
error('not supported');
}
</script>
</section>
<div id="map"></div>
</body>
</html>
|