Polygon.js
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/* Copyright (c) 2006 MetaCarta, Inc., published under the BSD license.
* See http://svn.openlayers.org/trunk/openlayers/release-license.txt
* for the full text of the license. */
/**
* @class
*
* Polygon is a collection of Geometry.LinearRings.
*
* The first ring (this.component[0])is the outer bounds of the polygon and
* all subsequent rings (this.component[1-n]) are internal holes.
*
* @requires OpenLayers/Geometry/Collection.js
*/
OpenLayers.Geometry.Polygon = OpenLayers.Class.create();
OpenLayers.Geometry.Polygon.prototype =
OpenLayers.Class.inherit(OpenLayers.Geometry.Collection, {
/**
* An array of class names representing the types of components that
* the collection can include. A null value means the component types
* are not restricted.
* @type Array(String)
*/
componentTypes: ["OpenLayers.Geometry.LinearRing"],
/**
* @constructor
*
* @param {Array(OpenLayers.Geometry.LinearRing)}
*/
initialize: function(components) {
OpenLayers.Geometry.Collection.prototype.initialize.apply(this,
arguments);
},
/** Calculated by subtracting the areas of the internal holes from the
* area of the outer hole.
*
* @returns The area of the geometry
* @type float
*/
getArea: function() {
var area = 0.0;
if ( this.components && (this.components.length > 0)) {
area += Math.abs(this.components[0].getArea());
for (var i = 1; i < this.components.length; i++) {
area -= Math.abs(this.components[i].getArea());
}
}
return area;
},
/** @final @type String */
CLASS_NAME: "OpenLayers.Geometry.Polygon"
});