[GIS] How to set polygon opacity on OpenLayers

openlayers-2openstreetmappolygon

I have some problems showing polygons in OpenLayers. I want to divide one city in areas. For the moment I have zona1 and zona2. I took lat and long from Google Maps so I think they are correct.

My problem, is that polygons are draw in black. I want them to have a inner colour but not black and not 100% opacity, I don't know how you change that.

I will explain a little my code because I think it is so strange my idea of showing more than one markers. I have all variables in arrays, so I can get any position in the array to do operations related. So I create variables for both areas and after that I put them on an array.
I have 2 arrays for points. One array keep lat and the other one keep long. So I have to take data from each one each iteration.

Sorry if there are any comment in Spanish, it is my language. I tried to change all I saw.

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<title></title>
<script type="text/javascript"  src="http://openlayers.org/api/OpenLayers.js"></script>
<script src="http://www.openstreetmap.org/openlayers/OpenStreetMap.js"></script>
<script type="text/javascript">    

var map;
var lineLayer;
var points;
var style;
var polygonFeature;

function pintarZonas(){ 

//lng and lat for both areas
var zonaALng = [-3.841867446899414, -3.838176727294922, -3.838348388671875,    -3.843669891357422];
var zonaALat = [43.466002139041116, 43.466002139041116, 43.46432016607394, 43.46276274196949];
var zonaBLng = [-3.832254409790039, -3.8265037536621094, -3.8254737854003906, -3.829936981201172,-3.832683563232422];
var zonaBLat = [43.462513550389424, 43.46375949801845, 43.461641371770504, 43.46002157809642,43.461142978339005];

//I keep all areas here
var vectorZonas = [zonaALng, zonaALat, zonaBLng, zonaBLat];

  lineLayerZona1 = new OpenLayers.Layer.Vector("zona1");
  style1 = { strokeColor: '#0000ff',
     strokeOpacity: 1,
     strokeWidth: 5
  };

  lineLayerZona2 = new OpenLayers.Layer.Vector("zona2");
  style2 = { strokeColor: '#00ff00',
     strokeOpacity: 1,
     strokeWidth: 5
  };

var vectorStyle = [style1, style2];  
var vectorLineLayer = [lineLayerZona1, lineLayerZona2];

pointZona1 = new Array(); 
pointZona2 = new Array();
vectorPoint = [pointZona1, pointZona2];
//Here I keep all points to both areas
var vectorCapas = [lineLayerZona1, lineLayerZona2];  
var i = 0;
var x = 0;
var zonaLat, zonaLng;
    var ww = 0;
for(i = 0; i < vectorZonas.length/2; i ++){
    zonaLng = vectorZonas[ww];
    zonaLat = vectorZonas[ww+1];
    point = vectorPoint[i];
    ww = i;
    ww +=2;
    for(x = 0; x < zonaLng.length; x ++){
        point[x] =new OpenLayers.LonLat(zonaLng[x],zonaLat[x] ).transform(new OpenLayers.Projection("EPSG:4326"), map.getProjectionObject());

        point[x] = new OpenLayers.Geometry.Point(point[x].lon, point[x].lat);   
    }
    //No hace falta añadir un punto de final porque se cierra solo el poligono
}

 //Añadimos las capas al mapa
 for(z = 0; z < vectorPoint.length; z++){
    linear_ring = new OpenLayers.Geometry.LinearRing(vectorPoint[z]);
    polygonFeature = new OpenLayers.Feature.Vector(
new OpenLayers.Geometry.Polygon([linear_ring]), null, vectorStyle[z]);

    vectorLineLayer[z].addFeatures([polygonFeature]);
    map.addLayer(vectorLineLayer[z]);
}


}

function initialize() 
{    
  map = new OpenLayers.Map ("map_canvas", {
        controls:[
            new OpenLayers.Control.Navigation(),
            new OpenLayers.Control.PanZoomBar(),
            new OpenLayers.Control.LayerSwitcher(),
            new OpenLayers.Control.Attribution()],
        maxExtent: new     OpenLayers.Bounds(-20037508.34,-20037508.34,20037508.34,20037508.34),
        maxResolution: 156543.0399,
        numZoomLevels: 19,
        units: 'm',
        projection: new OpenLayers.Projection("EPSG:900913"),
        displayProjection: new OpenLayers.Projection("EPSG:4326")
      });

    // Define the map layer
    // Here we use a predefined layer that will be kept up to date with URL changes
    layerMapnik = new OpenLayers.Layer.OSM.Mapnik("MapaCiudad");
    map.addLayer(layerMapnik);
  var lonLat = new     OpenLayers.LonLat(-3.8343143463134766,43.451610413300685).transform(new     OpenLayers.Projection("EPSG:4326"), map.getProjectionObject());
  //map.setCenter(new OpenLayers.LonLat(-3.862788677215576, 43.4669443349282) //     Center of the map
    map.zoomTo(13);
    map.setCenter(lonLat, 19);  

 pintarZonas();
}

</script>
</head>
<body onload="initialize()" >
<div id="map_canvas" style="width: 828px; height: 698px"></div>  
</body>
</html>

I made some changes to the code. I correct one of my question so I delete it from post.

SO my only question about it is how to set opacity?

Best Answer

To set opacity us fillOpacity property like so:

  style1 = { strokeColor: '#0000ff',
     strokeOpacity: 1,
     strokeWidth: 5,
     fillOpacity: 0.5
  };
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