app/views/browse/start.rjs

   1 page.replace_html :sidebar_title, 'Browse'
   2 page.replace_html :sidebar_content, :partial => 'start'
   3 page << <<EOJ
   4
   5     var gml, sf, objList, currentFeature, featureList;
   6     OpenLayers.Feature.Vector.style['default'].strokeWidth = 3;
   7     OpenLayers.Feature.Vector.style['default'].cursor = "pointer";
   8
   9     function start() {
  10       openSidebar({ onclose: stopBrowse });
  11       var vectors = new OpenLayers.Layer.Vector();
  12
  13       box = new OpenLayers.Control.DrawFeature(vectors, OpenLayers.Handler.RegularPolygon, {
  14         handlerOptions: {
  15           sides: 4,
  16           snapAngle: 90,
  17           irregular: true,
  18           persist: true,
  19           callbacks: { done: endDrag }
  20         }
  21       });
  22       map.addControl(box);
  23     }
  24
  25     function stopBrowse() {
  26         if (gml) {
  27             gml.destroy();
  28             gml = null;
  29         }
  30         if (sf) {
  31             sf.destroy();
  32             sf = null;
  33         }
  34         if (currentFeature) {
  35             currentFeature.destroy();
  36             currentFeature = null;
  37         }
  38     }
  39
  40     function startDrag() {
  41       $("drag_box").innerHTML='Drag a box on the map to select an area';
  42        box.activate();
  43        return false;
  44     };
  45     $("drag_box").onclick = startDrag;
  46
  47     function useMap() {
  48         var bounds = map.getExtent();
  49         setBounds(bounds);
  50         getData(bounds);
  51         return false;
  52     }
  53     $("use_map").onclick = useMap;
  54
  55     function endDrag(bbox) {
  56         var bounds = bbox.getBounds();
  57         setBounds(bounds);
  58         box.deactivate();
  59         getData(bounds);
  60         $("drag_box").innerHTML = "Manually select a different area";
  61     }
  62     function displayFeatureWarning() {
  63         var div = document.createElement("div");
  64         var p = document.createElement("p");
  65         p.appendChild(document.createTextNode("You have loaded an area which contains " + featureList.length + " features. In general, some browsers may not cope well with displaying this quantity of data. Generally, browsers work best at displaying less than 100 features at a time: doing anything else may make your browser slow/unresponsive. If you are sure you want to display this data, you may do so by clicking the button below."));
  66         div.appendChild(p);
  67         var input = document.createElement("input");
  68         input.type = "submit";
  69         input.value = "Load Data";
  70         input.onclick = loadFeatureList;
  71         div.appendChild(input);
  72         $("object").innerHTML="";
  73         $("object").appendChild(div);
  74     }
  75
  76     function loadFeatureList() {
  77         gml.addFeatures(featureList);
  78         gml.events.triggerEvent("loadend");
  79     }
  80
  81     function customDataLoader(request) {
  82         var doc = request.responseXML;
  83
  84         if (!doc || !doc.documentElement) {
  85             doc = request.responseText;
  86         }
  87
  88         var options = {};
  89
  90         OpenLayers.Util.extend(options, this.formatOptions);
  91         if (this.map && !this.projection.equals(this.map.getProjectionObject())) {
  92             options.externalProjection = this.projection;
  93             options.internalProjection = this.map.getProjectionObject();
  94         }
  95
  96         var gml = this.format ? new this.format(options) : new OpenLayers.Format.GML(options);
  97         var features = gml.read(doc);
  98         if (!this.maxFeatures || features.length <= this.maxFeatures) {
  99             this.addFeatures(features);
 100             this.events.triggerEvent("loadend");
 101             featureList = [];
 102         } else {
 103             featureList = features;
 104             displayFeatureWarning();
 105         }
 106     }
 107
 108     function getData(bounds) {
 109         $("status").innerHTML = "Loading...";
 110
 111         bounds.transform(new OpenLayers.Projection("EPSG:900913"), new OpenLayers.Projection("EPSG:4326"));
 112         var url = "/api/0.5/map?bbox="+bounds.toBBOX();
 113
 114         if (!gml) {
 115             var def = OpenLayers.Feature.Vector.style['default'];
 116             var style = new OpenLayers.Style();
 117             style.addRules([new OpenLayers.Rule(
 118               {'symbolizer':
 119                 {"Polygon": {'fillColor': '#ff0000', 'strokeColor': '#ff0000'},
 120                  "Line": {'fillColor': '#ffff00', 'strokeColor': '#000000', strokeOpacity: '0.4'},
 121                  "Point": {'fillColor': '#00ff00', 'strokeColor': '#00ff00'}}
 122               }
 123             )]);
 124             gml = new OpenLayers.Layer.GML("Data",url,
 125                     {format: OpenLayers.Format.OSM, formatOptions: {checkTags: true},
 126                      maxFeatures: 100, requestSuccess: customDataLoader,
 127                      styleMap: new OpenLayers.StyleMap({'default': style, 'select': {'strokeColor': '#0000ff'}})
 128                     }
 129             );
 130             gml.events.register("loadend", gml, dataLoaded );
 131             map.addLayer(gml);
 132
 133             sf = new OpenLayers.Control.SelectFeature(gml, {'onSelect': onFeatureSelect});
 134             map.addControl(sf);
 135             sf.activate();
 136         } else {
 137             gml.setUrl(url);
 138         }
 139
 140         currentFeature = null;
 141     }
 142
 143     function dataLoaded() {
 144         $("status").innerHTML = "Loaded " + this.features.length + " features. (<a href='"+ this.url+"'>API</a>)";
 145
 146         objList = document.createElement("ul");
 147         for (var i = 0; i < this.features.length; i++) {
 148             var feature = this.features[i];
 149
 150             // Type, for linking
 151             var type ="way";
 152             if (feature.geometry.CLASS_NAME == "OpenLayers.Geometry.Point") {
 153                 type = "node";
 154             }
 155             var nice_name = type.substr(0,1).toUpperCase() + type.substr(1,type.length);
 156             var li = document.createElement("li");
 157             li.appendChild(document.createTextNode(nice_name + " "));
 158
 159             // Link, for viewing in the tab
 160             var link = document.createElement("a");
 161             link.href =  "/browse/" + type + "/" + feature.osm_id;
 162             var name = feature.attributes.name || feature.osm_id;
 163             link.appendChild(document.createTextNode(name));
 164             link.feature = feature;
 165             link.onclick = OpenLayers.Function.bind(viewFeatureLink, link);
 166             li.appendChild(link);
 167
 168             objList.appendChild(li);
 169         }
 170         $("object").innerHTML = "";
 171         $("object").appendChild(objList);
 172     }
 173
 174     function viewFeatureLink() {
 175         var layer = this.feature.layer;
 176         for (var i = 0; i < layer.selectedFeatures.length; i++) {
 177             var f = layer.selectedFeatures[i];
 178             layer.drawFeature(f, layer.styleMap.createSymbolizer(f, "default"));
 179         }
 180         onFeatureSelect(this.feature);
 181         map.setCenter(this.feature.geometry.getBounds().getCenterLonLat());
 182         return false;
 183     }
 184
 185     function loadObjList() {
 186         $("object").innerHTML="";
 187         $("object").appendChild(objList);
 188         return false;
 189     }
 190
 191     function onFeatureSelect(feature) {
 192         // Unselect previously selected feature
 193         if (currentFeature) {
 194           currentFeature.layer.drawFeature(
 195             currentFeature, currentFeature.layer.styleMap.createSymbolizer(currentFeature, "default")
 196           );
 197         }
 198
 199         // Redraw in selected style
 200         feature.layer.drawFeature(
 201           feature, feature.layer.styleMap.createSymbolizer(feature, "select")
 202         );
 203
 204         // If the current object is the list, don't innerHTML="", since that could clar it.
 205         if ($("object").firstChild == objList) {
 206             $("object").removeChild(objList);
 207         } else {
 208             $("object").innerHTML = "";
 209         }
 210
 211         // Create a link back to the object list
 212         var div = document.createElement("div");
 213         var link = document.createElement("a");
 214         link.href="#";
 215         link.onclick = loadObjList;
 216         link.appendChild(document.createTextNode("Back to Object List"));
 217         div.appendChild(link)
 218         $("object").appendChild(div);
 219
 220         // Now the list of attributes
 221         var ul = document.createElement("ul");
 222         var type = "way";
 223         if (feature.geometry.CLASS_NAME == "OpenLayers.Geometry.Point") {
 224             type = "node";
 225         }
 226         var li = document.createElement("li");
 227         var link = document.createElement("a");
 228         link.href =  "/browse/"+type+"/"+feature.osm_id;
 229         link.appendChild(document.createTextNode(feature.osm_id));
 230         li.appendChild(link);
 231         ul.appendChild(li);
 232         for (var key in feature.attributes) {
 233             var li = document.createElement("li");
 234             var b = document.createElement("b");
 235             b.appendChild(document.createTextNode(key));
 236             li.appendChild(b);
 237             li.appendChild(document.createTextNode(": " + feature.attributes[key]));
 238             ul.appendChild(li);
 239         }
 240         $("object").appendChild(ul);
 241
 242         // Stash the currently drawn feature
 243         currentFeature = feature;
 244     }
 245
 246     function setBounds(bounds) {
 247       var epsg4326 = new OpenLayers.Projection("EPSG:4326");
 248       var decimals = Math.pow(10, Math.floor(map.getZoom() / 3));
 249
 250       bounds = bounds.clone().transform(map.getProjectionObject(), epsg4326);
 251
 252       $("minlon").innerHTML = Math.round(bounds.left * decimals) / decimals;
 253       $("minlat").innerHTML = Math.round(bounds.bottom * decimals) / decimals;
 254       $("maxlon").innerHTML = Math.round(bounds.right * decimals) / decimals;
 255       $("maxlat").innerHTML = Math.round(bounds.top * decimals) / decimals;
 256     }
 257
 258     start();
 259 EOJ