--- a/labs/openlayers/lib/OpenLayers/Control/Scale.js +++ b/labs/openlayers/lib/OpenLayers/Control/Scale.js @@ -1,1 +1,100 @@ +/* Copyright (c) 2006-2010 by OpenLayers Contributors (see authors.txt for + * full list of contributors). Published under the Clear BSD license. + * See http://svn.openlayers.org/trunk/openlayers/license.txt for the + * full text of the license. */ + +/** + * @requires OpenLayers/Control.js + */ + +/** + * Class: OpenLayers.Control.Scale + * The Scale control displays the current map scale as a ratio (e.g. Scale = + * 1:1M). By default it is displayed in the lower right corner of the map. + * + * Inherits from: + * - + */ +OpenLayers.Control.Scale = OpenLayers.Class(OpenLayers.Control, { + + /** + * Parameter: element + * {DOMElement} + */ + element: null, + + /** + * APIProperty: geodesic + * {Boolean} Use geodesic measurement. Default is false. The recommended + * setting for maps in EPSG:4326 is false, and true EPSG:900913. If set to + * true, the scale will be calculated based on the horizontal size of the + * pixel in the center of the map viewport. + */ + geodesic: false, + + /** + * Constructor: OpenLayers.Control.Scale + * + * Parameters: + * element - {DOMElement} + * options - {Object} + */ + initialize: function(element, options) { + OpenLayers.Control.prototype.initialize.apply(this, [options]); + this.element = OpenLayers.Util.getElement(element); + }, + + /** + * Method: draw + * + * Returns: + * {DOMElement} + */ + draw: function() { + OpenLayers.Control.prototype.draw.apply(this, arguments); + if (!this.element) { + this.element = document.createElement("div"); + this.div.appendChild(this.element); + } + this.map.events.register( 'moveend', this, this.updateScale); + this.updateScale(); + return this.div; + }, + + /** + * Method: updateScale + */ + updateScale: function() { + var scale; + if(this.geodesic === true) { + var units = this.map.getUnits(); + if(!units) { + return; + } + var inches = OpenLayers.INCHES_PER_UNIT; + scale = (this.map.getGeodesicPixelSize().w || 0.000001) * + inches["km"] * OpenLayers.DOTS_PER_INCH; + } else { + scale = this.map.getScale(); + } + + if (!scale) { + return; + } + + if (scale >= 9500 && scale <= 950000) { + scale = Math.round(scale / 1000) + "K"; + } else if (scale >= 950000) { + scale = Math.round(scale / 1000000) + "M"; + } else { + scale = Math.round(scale); + } + + this.element.innerHTML = OpenLayers.i18n("scale", {'scaleDenom':scale}); + }, + + CLASS_NAME: "OpenLayers.Control.Scale" +}); + +