a171ae13b6
git-svn-id: http://svn.openlayers.org/trunk/openlayers@1011 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf
86 lines
2.3 KiB
JavaScript
86 lines
2.3 KiB
JavaScript
/* Copyright (c) 2006 MetaCarta, Inc., published under the BSD license.
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* See http://svn.openlayers.org/trunk/openlayers/license.txt for the full
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* text of the license. */
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// @require: OpenLayers/Control.js
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/**
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* @class
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*/
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OpenLayers.Control.Scale = Class.create();
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OpenLayers.Control.Scale.prototype =
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Object.extend( new OpenLayers.Control(), {
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INCHES_PER_UNIT: { // borrowed from MapServer mapscale.c
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inches: 1.0,
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ft: 12.0,
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mi: 63360.0,
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m: 39.3701,
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km: 39370.1,
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dd: 4374754
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},
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/** @type DOMElement */
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element: null,
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/** @type String */
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units: 'dd',
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/** @type Integer */
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dpi: 72,
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/**
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* @constructor
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*
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* @param {DOMElement} element
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* @param {String} base
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*/
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initialize: function(element, units) {
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OpenLayers.Control.prototype.initialize.apply(this, arguments);
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this.element = element;
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if (units) this.units = units;
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},
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/**
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* @type DOMElement
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*/
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draw: function() {
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OpenLayers.Control.prototype.draw.apply(this, arguments);
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if (!this.element) {
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this.element = document.createElement("div");
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this.div.style.right = "3px";
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this.div.style.bottom = "2em";
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this.div.style.left = "";
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this.div.style.top = "";
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this.div.style.display = "block";
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this.div.style.position = "absolute";
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this.element.style.fontSize="smaller";
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this.div.appendChild(this.element);
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}
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this.map.events.register( 'moveend', this, this.updateScale);
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this.updateScale();
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return this.div;
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},
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/**
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*
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*/
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updateScale: function() {
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var res = this.map.getResolution();
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if (!res) return;
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var scale = res * this.INCHES_PER_UNIT[this.units] * this.dpi;
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if (scale >= 9500 && scale <= 950000) {
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scale = Math.round(scale / 1000) + "K";
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} else if (scale >= 950000) {
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scale = Math.round(scale / 1000000) + "M";
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} else {
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scale = Math.round(scale / 100) * 100;
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}
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this.element.innerHTML = "Scale = 1 : " + scale;
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},
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/** @final @type String */
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CLASS_NAME: "OpenLayers.Control.Scale"
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});
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