curve.js

用来在地图上做操作GIS,在地图上做标记

/* Copyright (c) 2006-2007 MetaCarta, Inc., published under the BSD license.
 * See http://svn.openlayers.org/trunk/openlayers/release-license.txt 
 * for the full text of the license. */

/**
 * @requires OpenLayers/Geometry/MultiPoint.js
 * 
 * Class: OpenLayers.Geometry.Curve
 * A Curve is a MultiPoint, whose points are assumed to be connected. To 
 * this end, we provide a "getLength()" function, which iterates through 
 * the points, summing the distances between them. 
 * 
 * Inherits: 
 *  - <OpenLayers.Geometry.MultiPoint>
 */
OpenLayers.Geometry.Curve = OpenLayers.Class(OpenLayers.Geometry.MultiPoint, {

    /**
     * Property: componentTypes
     * {Array(String)} 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.
     */
    componentTypes: ["OpenLayers.Geometry.Point"],

    /**
     * Constructor: OpenLayers.Geometry.Curve
     * 
     * Parameters:
     * point - {Array(<OpenLayers.Geometry.Point>)}
     */
    initialize: function(points) {
        OpenLayers.Geometry.MultiPoint.prototype.initialize.apply(this, 
                                                                  arguments);
    },
    
    /**
     * APIMethod: getLength
     * 
     * Returns:
     * {Float} The length of the curve
     */
    getLength: function() {
        var length = 0.0;
        if ( this.components && (this.components.length > 1)) {
            for(var i=1; i < this.components.length; i++) {
                length += this.components[i-1].distanceTo(this.components[i]);
            }
        }
        return length;
    },

    CLASS_NAME: "OpenLayers.Geometry.Curve"
});