Beginning of JavaScript-only routing UI

app/assets/javascripts/index.js

@@ -5,6 +5,7 @@
 //= require leaflet.key
 //= require leaflet.note
 //= require leaflet.share
+//= require leaflet.polyline
 //= require index/search
 //= require index/browse
 //= require index/export
@@ -13,6 +14,7 @@
 //= require index/note
 //= require index/new_note
 //= require router
+//= require routing
 
 (function() {
   var loaderTimeout;
@@ -322,12 +324,18 @@ $(document).ready(function () {
 
   $(".search_form").on("submit", function(e) {
     e.preventDefault();
-    $("header").addClass("closed");
-    var query = $(this).find("input[name=query]").val();
-    if (query) {
-      OSM.router.route("/search?query=" + encodeURIComponent(query) + OSM.formatHash(map));
+    if ($(".query_wrapper.routing").is(":visible")) {
+      // Routing
+      OSM.routing.requestRoute();
     } else {
-      OSM.router.route("/" + OSM.formatHash(map));
+      // Search
+      $("header").addClass("closed");
+      var query = $(this).find("input[name=query]").val();
+      if (query) {
+        OSM.router.route("/search?query=" + encodeURIComponent(query) + OSM.formatHash(map));
+      } else {
+        OSM.router.route("/" + OSM.formatHash(map));
+      }
     }
   });
 
@@ -338,4 +346,19 @@ $(document).ready(function () {
       map.getCenter().lat.toFixed(precision) + "," +
       map.getCenter().lng.toFixed(precision)));
   });
+
+  $(".get_directions").on("click",function(e) {
+	e.preventDefault();
+	$(".query_wrapper.search").hide();
+	$(".query_wrapper.routing").show();
+  });
+
+  $(".close_directions").on("click",function(e) {
+	e.preventDefault();
+	$(".query_wrapper.search").show();
+	$(".query_wrapper.routing").hide();
+  });
+
+  OSM.routing = OSM.Routing(map,'OSM.routing',$('.query_wrapper.routing'));
+
 });

app/assets/javascripts/routing.js.erb

@@ -0,0 +1,159 @@
+/*
+	osm.org routing interface
+	
+	See also:
+	https://github.com/apmon/openstreetmap-website/tree/routing2
+	https://github.com/apmon/openstreetmap-website/compare/routing2
+	https://github.com/apmon/openstreetmap-website/blob/9755c3ae0a8d0684d43760f91dc864ff42d8477a/app/views/routing/start.js.erb
+
+	*** draggable start/end markers
+	
+*/
+
+var TURN_INSTRUCTIONS=["",
+	"Continue on ",				// 1
+	"Slight right onto ",		// 2
+	"Turn right onto ",			// 3
+	"Sharp right onto ",		// 4
+	"U-turn along ",			// 5
+	"Sharp left onto ",			// 6
+	"Turn left onto ",			// 7
+	"Slight left onto ",		// 8
+	"(via point) ",				// 9
+	"Follow ",					// 10
+	"At roundabout take ",		// 11
+	"Leave roundabout - ",		// 12
+	"Stay on roundabout - ",	// 13
+	"Start at end of ",			// 14
+	"Reach destination",		// 15
+	"Go against one-way on ",	// 16
+	"End of one-way on "]		// 17
+
+var ROUTING_POLYLINE={
+	color: '#03f',
+	opacity: 0.3,
+	weight: 10
+};
+
+
+OSM.Routing=function(map,name,jqSearch) {
+	var r={};
+	r.map=map;				// Leaflet map
+	r.name=name;			// global variable name of this instance (needed for JSONP)
+	r.jqSearch=jqSearch;	// JQuery object for search panel
+
+	r.route_from=null;
+	r.route_to=null;
+	r.viaPoints=[];
+	r.polyline=null;
+
+	// Geocoding
+
+	r.geocode=function(id,event) { var _this=this;
+		var field=event.target;
+		var v=event.target.value;
+		// *** do something if v==''
+		var querystring = '<%= NOMINATIM_URL %>search?q=' + encodeURIComponent(v) + '&format=json';
+		// *** &accept-language=<%#= request.user_preferred_languages.join(',') %>
+		// *** prefer current viewport
+		$.getJSON(querystring, function(json) { _this._gotGeocode(json,field); });
+	};
+	
+	r._gotGeocode=function(json,field) {
+		if (json.length==0) {
+			alert("Sorry, couldn't find that place."); 	// *** internationalise
+			r[field.id]=null;
+			return;
+		}
+		field.value=json[0].display_name;
+		var lat=Number(json[0].lat), lon=Number(json[0].lon);
+		r[field.id]=[lat,lon];
+		// ** update markers
+	};
+	
+	// Route-fetching UI
+
+	r.requestRoute=function() {
+		if (r.route_from && r.route_to) {
+			var chosen=jqSearch.find('select.routing_engines :selected').val();
+			r.engines[chosen].getRoute(true,[r.route_from,r.route_to]);
+			// then, when the route has been fetched, it'll call the engine's gotRoute function
+		}
+	};
+
+	// Take an array of Leaflet LatLngs and draw it as a polyline
+	r.setPolyline=function(line) {
+		if (r.polyline) map.removeLayer(r.polyline);
+		r.polyline=L.polyline(line, ROUTING_POLYLINE).addTo(r.map);
+		// *** zoom to fit
+	};
+
+	// Take an array of directions and write it out
+	// (we use OSRM's route_instructions format)
+	r.setItinerary=function(steps) {
+		$("#content").removeClass("overlay-sidebar");
+		$('#sidebar_content').empty();
+		var html="";
+		for (var i=0; i<steps.length; i++) {
+			var s=steps[i];
+			html+="<div class='route_step'>";
+			html+=TURN_INSTRUCTIONS[s[0]] || s[0];
+			html+=s[1];
+			html+="</div>";
+		}
+        $('#sidebar_content').html(html);
+	};
+
+
+	// Add engines
+	
+	r.engines=[];
+	r.addEngine=function(engine) {
+		// Save engine
+		var i=r.engines.length;
+		engine.subscript=i;
+		r['engine'+i]=engine;
+		r.engines.push(engine);
+
+		// Add generic JSONP function
+		engine.requestJSONP=function(url) {
+			var script = document.createElement('script');
+			script.src = url+"&jsonp="+r.name+".engine"+this.subscript+".gotRoute";
+ 			// OSRM doesn't like non-alphanumeric, otherwise we could just do OSM.routing.engines["+engine.subscript+"].gotRoute
+			document.body.appendChild(script); 
+		};
+
+		// Populate dropdown
+		var select=jqSearch.find('select.routing_engines');
+		select.append("<option value='"+i+"'>"+engine.name+"</option>");
+	};
+
+	// OSRM car engine
+	// *** this should all be shared from an OSRM library somewhere
+	// *** need to clear hints at some point
+
+	r.addEngine({
+		name: 'Car (OSRM)',
+		draggable: true,
+		_hints: {},
+		getRoute: function(final,points) {
+			var url="http://router.project-osrm.org/viaroute?z=14&output=json";
+			for (var i=0; i<points.length; i++) {
+				var pair=points[i].join(',');
+				url+="&loc="+pair;
+				if (this._hints[pair]) url+= "&hint="+this._hints[pair];
+			}
+			if (final) url+="&instructions=true";
+			this.requestJSONP(url);
+		},
+		gotRoute: function(data) {
+			// *** save hints
+			var line=L.PolylineUtil.decode(data.route_geometry);
+			for (i=0; i<line.length; i++) { line[i].lat/=10; line[i].lng/=10; }
+			r.setPolyline(line);
+			r.setItinerary(data.route_instructions);
+		}
+	});
+
+	return r;
+};

app/assets/stylesheets/common.css.scss

@@ -953,6 +953,10 @@ header .search_form {
     font-size: 10px;
     color: $blue;
   }
+
+  .query_wrapper.routing {
+    display: none;
+  }
 }
 
 /* Rules for the map key which appears in the popout sidebar */

app/views/layouts/_search.html.erb

@@ -1,7 +1,22 @@
 <%= form_tag search_path, :class => "search_form" do %>
   <%= submit_tag t('site.search.submit_text') %>
-  <div class='query_wrapper'>
+
+  <div class='query_wrapper search'>
     <%= text_field_tag "query", params[:query], :placeholder => t("site.search.search"), :autofocus => autofocus %>
-    <%= link_to t('site.search.where_am_i'), '#', { :class => "describe_location", :title => t('site.search.where_am_i_title') } %>
+    <div class='query_options'>
+      <%= link_to t('site.search.get_directions'), '#', { :class => "get_directions", :title => t('site.search.get_directions_title') } %>
+      &middot;
+      <%= link_to t('site.search.where_am_i'), '#', { :class => "describe_location", :title => t('site.search.where_am_i_title') } %>
+    </div>
   </div>
+
+  <div class='query_wrapper routing'>
+    <%= text_field_tag "route_from", params[:from], :placeholder => "From", :onchange=>"OSM.routing.geocode('route_from',event)" %>
+    <%= text_field_tag "route_to"  , params[:to]  , :placeholder => "To"  , :onchange=>"OSM.routing.geocode('route_to'  ,event)" %>
+    <div class='query_options'>
+      <select class='routing_engines'></select>
+      <%= link_to t('site.search.close_directions'), '#', { :class => "close_directions", :title => t('site.search.close_directions_title') } %>
+    </div>
+  </div>
+
 <% end %>

vendor/assets/leaflet/leaflet.polyline.js

@@ -0,0 +1,127 @@
+/*
+ * L.PolylineUtil contains utilify functions for polylines, two methods
+ * are added to the L.Polyline object to support creation of polylines
+ * from an encoded string and converting existing polylines to an
+ * encoded string.
+ *
+ *  - L.Polyline.fromEncoded(encoded [, options]) returns a L.Polyline
+ *  - L.Polyline.encodePath() returns a string
+ *
+ * Actual code from:
+ * http://facstaff.unca.edu/mcmcclur/GoogleMaps/EncodePolyline/\
+ */
+
+/*jshint browser:true, debug: true, strict:false, globalstrict:false, indent:4, white:true, smarttabs:true*/
+/*global L:true, console:true*/
+
+
+// Inject functionality into Leaflet
+(function (L) {
+	if (!(L.Polyline.prototype.fromEncoded)) {
+		L.Polyline.fromEncoded = function (encoded, options) {
+			return new L.Polyline(L.PolylineUtil.decode(encoded), options);
+		};
+	}
+	if (!(L.Polygon.prototype.fromEncoded)) {
+		L.Polygon.fromEncoded = function (encoded, options) {
+			return new L.Polygon(L.PolylineUtil.decode(encoded), options);
+		};
+	}
+
+	var encodeMixin = {
+		encodePath: function () {
+			return L.PolylineUtil.encode(this.getLatLngs());
+		}
+	};
+
+	if (!L.Polyline.prototype.encodePath) {
+		L.Polyline.include(encodeMixin);
+	}
+	if (!L.Polygon.prototype.encodePath) {
+		L.Polygon.include(encodeMixin);
+	}
+})(L);
+
+// Utility functions.
+L.PolylineUtil = {};
+
+L.PolylineUtil.encode = function (latlngs) {
+	var i, dlat, dlng;
+	var plat = 0;
+	var plng = 0;
+	var encoded_points = "";
+
+	for (i = 0; i < latlngs.length; i++) {
+		var lat = latlngs[i].lat;
+		var lng = latlngs[i].lng;
+		var late5 = Math.floor(lat * 1e5);
+		var lnge5 = Math.floor(lng * 1e5);
+		dlat = late5 - plat;
+		dlng = lnge5 - plng;
+		plat = late5;
+		plng = lnge5;
+		encoded_points +=
+			L.PolylineUtil.encodeSignedNumber(dlat) +
+			L.PolylineUtil.encodeSignedNumber(dlng);
+	}
+	return encoded_points;
+};
+
+// This function is very similar to Google's, but I added
+// some stuff to deal with the double slash issue.
+L.PolylineUtil.encodeNumber = function (num) {
+	var encodeString = "";
+	var nextValue, finalValue;
+	while (num >= 0x20) {
+		nextValue = (0x20 | (num & 0x1f)) + 63;
+		encodeString += (String.fromCharCode(nextValue));
+		num >>= 5;
+	}
+	finalValue = num + 63;
+	encodeString += (String.fromCharCode(finalValue));
+	return encodeString;
+};
+
+// This one is Google's verbatim.
+L.PolylineUtil.encodeSignedNumber = function (num) {
+	var sgn_num = num << 1;
+	if (num < 0) {
+		sgn_num = ~(sgn_num);
+	}
+	return (L.PolylineUtil.encodeNumber(sgn_num));
+};
+
+L.PolylineUtil.decode = function (encoded) {
+	var len = encoded.length;
+	var index = 0;
+	var latlngs = [];
+	var lat = 0;
+	var lng = 0;
+
+	while (index < len) {
+		var b;
+		var shift = 0;
+		var result = 0;
+		do {
+			b = encoded.charCodeAt(index++) - 63;
+			result |= (b & 0x1f) << shift;
+			shift += 5;
+		} while (b >= 0x20);
+		var dlat = ((result & 1) ? ~(result >> 1) : (result >> 1));
+		lat += dlat;
+
+		shift = 0;
+		result = 0;
+		do {
+			b = encoded.charCodeAt(index++) - 63;
+			result |= (b & 0x1f) << shift;
+			shift += 5;
+		} while (b >= 0x20);
+		var dlng = ((result & 1) ? ~(result >> 1) : (result >> 1));
+		lng += dlng;
+
+		latlngs.push(new L.LatLng(lat * 1e-5, lng * 1e-5));
+	}
+
+	return latlngs;
+};