[OpenLayers-Users] mousePositionControl and google Elevation service - better way to do this?

[Phil Scadden]

I have successfully got google elevation service to add elevation to end 
of a mouse position string.
Some crude code for this below...

While this works, it effectively queues up a lot of requests while the 
mousemoves. More effective would be elevation only when mouse stops 
moving but can you detect this in js? I am reluctant to do increase 
granularity much.

       elevator = new google.maps.ElevationService();
     mousePositionControl = new OpenLayers.Control.MousePosition({
         formatOutput: function (lonLat) {
             var digits = parseInt(this.numDigits);
             newHtml = this.prefix + 'Lat/Long:<BR>' + 
lonLat.lat.toFixed(digits) + this.separator + lonLat.lon.toFixed(digits) 
+ this.suffix;
             if (map.displayProjection.proj.units == "m") {
                 digits = 1;
                 newHtml = this.prefix + 'East/North:<BR>' + 
lonLat.lon.toFixed(digits) + this.separator + lonLat.lat.toFixed(digits) 
+ this.suffix;
             }
             newHtml = scaleOut + '<BR>' + newHtml ;
             if (elevator) {
                 var locations = [];
                 locations.push( new google.maps.LatLng(lonLat.lat, 
lonLat.lon));
                 var positionalRequest = {'locations': locations };

                 // Initiate the location request
                 elevator.getElevationForLocations(positionalRequest, 
function(results, status) {
                   if (status == google.maps.ElevationStatus.OK){
                        // Retrieve the first result
                     if (results[0]){
                         var el = 
document.getElementById(mousePositionControl.element.id);
                         el.innerHTML = newHtml + '&nbsp;,' + 
results[0].elevation.toFixed(1)+'m' + '<BR>' + measurementOut;
                     }
                   }
                 });
             }
             return newHtml + '<BR>' + measurementOut;
         }
     });



-- 
Phil Scadden, Senior Scientist GNS Science Ltd 764 Cumberland St, 
Private Bag 1930, Dunedin, New Zealand Ph +64 3 4799663, fax +64 3 477 5232


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