allow the icon of GPX overlay markers to be chosen (#41)

README.md

@@ -295,6 +295,12 @@ As per the geojson overlay you can also inject a KML layer or TOPOJSON layer. Th
         kml:"<kml>...your kml placemarks...</kml>"
     };
 
+
+ For GPX layers, it is possible to define which icon to use for point markers by adding the
+ following properties to `msg.payload.command.map`:
+ - **icon** : <a href="http://fortawesome.github.io/Font-Awesome/icons/" target="mapinfo">font awesome</a> icon name.
+ - **iconColor** : Standard CSS colour name or #rrggbb hex value.
+
 Again the `fit` property can be added to make the map zoom to the relevant area.
 
 #### To add a Velocity Grid Overlay

worldmap/index.html

@@ -1322,7 +1322,23 @@ function doCommand(cmd) {
             map.removeLayer(overlays[cmd.map.overlay]);
             existsalready = true;
         }
-        overlays[cmd.map.overlay] = omnivore.gpx.parse(cmd.map.gpx);
+
+        var customLayer = L.geoJson();
+        if (cmd.map.hasOwnProperty("icon")) {
+            var col = cmd.map.iconColor || "#910000";
+            var myMarker = L.divIcon({
+                className:"faicon",
+                html: '<center><i class="fa fa-fw '+cmd.map.icon+'" style="color:'+col+'"></i></center>',
+                iconSize: [15, 15],
+            });
+            customLayer = L.geoJson(null, {
+                pointToLayer: function(geoJsonPoint, latlng) {
+                    return L.marker(latlng, {icon: myMarker, title: geoJsonPoint.properties.name});
+                }
+            });
+        }
+        overlays[cmd.map.overlay] = omnivore.gpx.parse(cmd.map.gpx, null, customLayer);
+
         if (!existsalready) {
             layercontrol.addOverlay(overlays[cmd.map.overlay],cmd.map.overlay);
         }