[OpenLayers-Users] Drag+Line=Distance in KMs

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great, it works! just if(!firsttime) must be replaced by if(firsttime) ;-)
thanks a lot
alex

On 4/21/12, Steve Nelson <snelson at webapper.com> wrote:
> Dragging is a tiny bit more complex, but the logic is essentially the same.
> This is totally untested, but maybe it'll get you going in the right
> direction. I added some inline comments. Give it a whirl.
>
>
> var firstClickMercator;
> OpenLayers.Control.Click = OpenLayers.Class(OpenLayers.Control, {
>
> defaultHandlerOptions: {
> 'single': true,
> 'double': false,
> 'pixelTolerance': 0,
> 'stopSingle': false,
> 'stopDouble': false
> },
> handleRightClicks:true,
> initialize: function(options) {
> this.handlerOptions = OpenLayers.Util.extend(
> {}, this.defaultHandlerOptions
> );
> OpenLayers.Control.prototype.initialize.apply(
> this, arguments
> );
> this.handler = new OpenLayers.Handler.Click(
> this, {
> 'click': this.singleClick
> }, this.handlerOptions
> );
> },
>  singleClick: function(e) {
>   //You want to convert the xy coordinate in the e variable to a LonLat
> var clickLonLat=map.getLonLatFromPixel(e.xy)
>  //Projections confuse the hell out of me. But what I've learned is you
> probably want to transform to a Mercator projection
> var clickLonLatMercator=clickLonLat.transform(map.getProjectionObject(),new
> OpenLayers.Projection("EPSG:4326"));
>  if (!firstClick){
>  //If this is the first store it into a global variable:
> firstClickMercator=clickLonLatMercator
> }else{
>  //if the global variable firstClick already exists, calculate the distance
> in KM
> var
> distanceInKM=OpenLayers.Util.distVincenty(firstClickMercator,clickLonLatMercator)
>  //you'll have to output it where you want, this should display the value
> in the google chrome console:
> console.log(distanceInKM)
>  //reset the global variable to null.
> firstClick=null;
> }
> },
>
> });
>
>
> //Define the global map:
> var map = new OpenLayers.Map("map")
>
> //Add the click control to the map
> var click = new OpenLayers.Control.Click();
> map.addControl(click);
> click.activate();
>
>
>
> On Fri, Apr 20, 2012 at 10:41 AM, alexe100
> <imoveisnacionais at gmail.com>wrote:
>
>> Hi all , i am new here and in GEO* purposes...
>> I am doing a web based application where i need to show some markers, that
>> it aldready working.
>> Now I need to give the oortunity to the user of drag a line on the map and
>> while dragging see the distance in kms in a label box (html external obj)
>> I saw already the openlayer example for distance but it has various
>> options
>> (and that make me confusing because i am a beginner). I did not found a
>> (very) simple example doing this.
>> Please, could you tell me how to do this. A littl example would be very
>> appreciated.
>>
>> Thanks a lot
>>
>> Alex
>>
>> --
>> View this message in context:
>> http://osgeo-org.1560.n6.nabble.com/Drag-Line-Distance-in-KMs-tp4902194p4902194.html
>> Sent from the OpenLayers Users mailing list archive at Nabble.com.
>> _______________________________________________
>> Users mailing list
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>>
>