Thursday, 5 March 2015

javascript - Openlayers get coordinates of a circle vector after draw


I have made a openlayers map. I have made two features on the map.


Navigate

DRAW POLYGON


I have made 40 sides to my polygon which turns out to be a circle.


After I have drawn my circle I want to show the coordinates of the bounding box of the circle.


So after I draw a circle i want to be able show the top, left, bottom and right coordinates for that circle in a ALERT BOX?


         

    

    

    
    

    
       
       
    

        


            

                    

  •                                             value="none" id="noneToggle"
                            onclick="polygonControl.deactivate()"
                            checked="checked" />
                        
                    

    •                 

  •                     
                            value="polygon" id="polygonToggle"
                            onclick="polygonControl.activate()" />
                        
                    

    •




Answer




register the featuresadded event on the layer.


var polygonLayer = new OpenLayers.Layer.Vector("Polygon Layer");

polygonLayer.events.on({
    featuresadded: onFeaturesAdded
});

And do this on the function:


function onFeaturesAdded(event){
    var bounds = event.features[0].geometry.getBounds();

    var answer = "bottom: " + bounds.bottom  + "\n";
    answer += "left: " + bounds.left  + "\n";
    answer += "right: " + bounds.right  + "\n";
    answer += "top: " + bounds.top  + "\n";
    alert(answer);
}

or to get all vertices:


function onFeaturesAdded(event) {
    var vertices = event.features[0].geometry.getVertices();

    var strVertices = "";
    for (var x in vertices) {
        strVertices += "(" + vertices[x].x + "," + vertices[x].y + ")";
    }

    alert(strVertices);
}
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