-//Called as the user scrolls/zooms around.
-//Maniplate hrefs of the view tab and various other links
-function updatelinks(lon,lat,zoom,layers,minlon,minlat,maxlon,maxlat) {
+/*
+ * Called as the user scrolls/zooms around to aniplate hrefs of the
+ * view tab and various other links
+ */
+function updatelinks(lon,lat,zoom,layers,minlon,minlat,maxlon,maxlat,objtype,objid) {
var decimals = Math.pow(10, Math.floor(zoom/3));
var node;
if (layers) {
args["layers"] = layers;
}
+ if (objtype && objid) {
+ args[objtype] = objid;
+ }
node.href = setArgs(node.href, args);
}
node.style.fontStyle = 'italic';
}
}
+
+ node = document.getElementById("shortlinkanchor");
+ if (node) {
+ var args = getArgs(node.href);
+ var code = makeShortCode(lat, lon, zoom);
+ var prefix = shortlinkPrefix();
+
+ // Add ?{node,way,relation}=id to the arguments
+ if (objtype && objid) {
+ args[objtype] = objid;
+ }
+
+ // little hack. may the gods of hardcoding please forgive me, or
+ // show me the Right way to do it.
+ if (layers && (layers != "B000FTF")) {
+ args["layers"] = layers;
+ node.href = setArgs(prefix + "/go/" + code, args);
+ } else {
+ node.href = prefix + "/go/" + code;
+ }
+ }
}
+/*
+ * Get the URL prefix to use for a short link
+ */
+function shortlinkPrefix() {
+ if (window.location.hostname.match(/^www\.openstreetmap\.org/i)) {
+ return "http://osm.org";
+ } else {
+ return "";
+ }
+}
+
+/*
+ * Called to get the arguments from a URL as a hash.
+ */
function getArgs(url) {
var args = new Object();
var querystart = url.indexOf("?");
return args;
}
+/*
+ * Called to set the arguments on a URL from the given hash.
+ */
function setArgs(url, args) {
var queryitems = new Array();
return url.replace(/\?.*$/, "") + "?" + queryitems.join("&");
}
+/*
+ * Called to get a CSS property for an element.
+ */
function getStyle(el, property) {
var style;
return style;
}
+
+/*
+ * Called to interpolate JavaScript variables in strings using a
+ * similar syntax to rails I18n string interpolation - the only
+ * difference is that [[foo]] is the placeholder syntax instead
+ * of {{foo}} which allows the same string to be processed by both
+ * rails and then later by javascript.
+ */
+function i18n(string, keys) {
+ for (var key in keys) {
+ var re_key = '\\[\\[' + key + '\\]\\]';
+ var re = new RegExp(re_key, "g");
+
+ string = string.replace(re, keys[key]);
+ }
+
+ return string;
+}
+
+function makeShortCode(lat, lon, zoom) {
+ char_array = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_@";
+ var x = Math.round((lon + 180.0) * ((1 << 30) / 90.0));
+ var y = Math.round((lat + 90.0) * ((1 << 30) / 45.0));
+ // hack around the fact that JS apparently only allows 53-bit integers?!?
+ // note that, although this reduces the accuracy of the process, it's fine for
+ // z18 so we don't need to care for now.
+ var c1 = 0, c2 = 0;
+ for (var i = 31; i > 16; --i) {
+ c1 = (c1 << 1) | ((x >> i) & 1);
+ c1 = (c1 << 1) | ((y >> i) & 1);
+ }
+ for (var i = 16; i > 1; --i) {
+ c2 = (c2 << 1) | ((x >> i) & 1);
+ c2 = (c2 << 1) | ((y >> i) & 1);
+ }
+ var str = "";
+ for (var i = 0; i < Math.ceil((zoom + 8) / 3.0) && i < 5; ++i) {
+ digit = (c1 >> (24 - 6 * i)) & 0x3f;
+ str += char_array.charAt(digit);
+ }
+ for (var i = 5; i < Math.ceil((zoom + 8) / 3.0); ++i) {
+ digit = (c2 >> (24 - 6 * (i - 5))) & 0x3f;
+ str += char_array.charAt(digit);
+ }
+ for (var i = 0; i < ((zoom + 8) % 3); ++i) {
+ str += "=";
+ }
+ return str;
+}