2 * Called as the user scrolls/zooms around to aniplate hrefs of the
3 * view tab and various other links
5 function updatelinks(lon,lat,zoom,layers,minlon,minlat,maxlon,maxlat, obj_type, obj_id) {
6 var decimals = Math.pow(10, Math.floor(zoom/3));
9 lat = Math.round(lat * decimals) / decimals;
10 lon = Math.round(lon * decimals) / decimals;
12 node = document.getElementById("permalinkanchor");
14 var args = getArgs(node.href);
19 args["layers"] = layers;
21 if (obj_type && obj_id) {
22 args[obj_type] = obj_id;
24 node.href = setArgs(node.href, args);
27 node = document.getElementById("viewanchor");
29 var args = getArgs(node.href);
34 args["layers"] = layers;
36 node.href = setArgs(node.href, args);
39 node = document.getElementById("exportanchor");
41 var args = getArgs(node.href);
46 args["layers"] = layers;
48 node.href = setArgs(node.href, args);
51 node = document.getElementById("editanchor");
54 var args = new Object();
58 node.href = setArgs("/edit", args);
59 node.style.fontStyle = 'normal';
61 node.href = 'javascript:alert("zoom in to edit map");';
62 node.style.fontStyle = 'italic';
66 node = document.getElementById("historyanchor");
69 var args = new Object();
70 //set bbox param from 'extents' object
71 if (typeof minlon == "number" &&
72 typeof minlat == "number" &&
73 typeof maxlon == "number" &&
74 typeof maxlat == "number") {
76 minlon = Math.round(minlon * decimals) / decimals;
77 minlat = Math.round(minlat * decimals) / decimals;
78 maxlon = Math.round(maxlon * decimals) / decimals;
79 maxlat = Math.round(maxlat * decimals) / decimals;
80 args.bbox = minlon + "," + minlat + "," + maxlon + "," + maxlat;
83 node.href = setArgs("/history", args);
84 node.style.fontStyle = 'normal';
86 node.href = 'javascript:alert("zoom in to see editing history");';
87 node.style.fontStyle = 'italic';
91 node = document.getElementById("shortlinkanchor");
93 var args = getArgs(node.href);
94 var code = makeShortCode(lat, lon, zoom);
95 var prefix = shortlinkPrefix();
97 // Add ?{node,way,relation}=id to the arguments
98 if (obj_type && obj_id) {
99 args[obj_type] = obj_id;
102 // little hack. may the gods of hardcoding please forgive me, or
103 // show me the Right way to do it.
104 if (layers && (layers != "B000FTF")) {
105 args["layers"] = layers;
106 node.href = setArgs(prefix + "/go/" + code, args);
108 node.href = prefix + "/go/" + code;
115 * This is a hack to hardcode opestreetmap.org -> osm.org in the
118 function shortlinkPrefix() {
119 var hostname = window.location.hostname;
120 var normalized_hostname = hostname.replace(/^:www\./i,'');
123 if (normalized_hostname.match(/^openstreetmap\.org$/i)) {
124 prefix = "http://osm.org";
130 function getArgs(url) {
131 var args = new Object();
132 var querystart = url.indexOf("?");
134 if (querystart >= 0) {
135 var querystring = url.substring(querystart + 1);
136 var queryitems = querystring.split("&");
138 for (var i = 0; i < queryitems.length; i++) {
139 if (match = queryitems[i].match(/^(.*)=(.*)$/)) {
140 args[unescape(match[1])] = unescape(match[2]);
142 args[unescape(queryitems[i])] = null
151 * Called to set the arguments on a URL from the given hash.
153 function setArgs(url, args) {
154 var queryitems = new Array();
158 if (args[arg] == null) {
159 queryitems.push(escape(arg));
161 queryitems.push(escape(arg) + "=" + escape(args[arg]));
165 return url.replace(/\?.*$/, "") + "?" + queryitems.join("&");
169 * Called to get the arguments from a URL as a hash.
171 function getStyle(el, property) {
174 if (el.currentStyle) {
175 style = el.currentStyle[property];
176 } else if( window.getComputedStyle ) {
177 style = document.defaultView.getComputedStyle(el,null).getPropertyValue(property);
179 style = el.style[property];
186 * Called to interpolate JavaScript variables in strings using a
187 * similar syntax to rails I18n string interpolation - the only
188 * difference is that [[foo]] is the placeholder syntax instead
189 * of {{foo}} which allows the same string to be processed by both
190 * rails and then later by javascript.
192 function i18n(string, keys) {
193 for (var key in keys) {
194 var re_key = '\\[\\[' + key + '\\]\\]';
195 var re = new RegExp(re_key, "g");
197 string = string.replace(re, keys[key]);
203 function makeShortCode(lat, lon, zoom) {
204 char_array = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_@";
205 var x = Math.round((lon + 180.0) * ((1 << 30) / 90.0));
206 var y = Math.round((lat + 90.0) * ((1 << 30) / 45.0));
207 // hack around the fact that JS apparently only allows 53-bit integers?!?
208 // note that, although this reduces the accuracy of the process, it's fine for
209 // z18 so we don't need to care for now.
211 for (var i = 31; i > 16; --i) {
212 c1 = (c1 << 1) | ((x >> i) & 1);
213 c1 = (c1 << 1) | ((y >> i) & 1);
215 for (var i = 16; i > 1; --i) {
216 c2 = (c2 << 1) | ((x >> i) & 1);
217 c2 = (c2 << 1) | ((y >> i) & 1);
220 for (var i = 0; i < Math.ceil((zoom + 8) / 3.0) && i < 5; ++i) {
221 digit = (c1 >> (24 - 6 * i)) & 0x3f;
222 str += char_array.charAt(digit);
224 for (var i = 5; i < Math.ceil((zoom + 8) / 3.0); ++i) {
225 digit = (c2 >> (24 - 6 * (i - 5))) & 0x3f;
226 str += char_array.charAt(digit);
228 for (var i = 0; i < ((zoom + 8) % 3); ++i) {