openlayers(三)util2
//这个是指PNG图片的alpha透明处理是不是需要，一般浏览器都支持PNG的alpha透明，只有IE6不支持，所以要单独CSS Hack一下 OpenLayers.Util.alphaHackNeeded = null; //测试是否需要alpha hack，IE6则需要 OpenLayers.Util.alphaHack = function() { if (OpenLayers.Util.alphaHackNeeded == null) { var arVersion = navigator.appVersion.split("MSIE"); var version = parseFloat(arVersion); var filter = false; try { filter = !!(document.body.filters); } catch (e) {} OpenLayers.Util.alphaHackNeeded = (filter && (version >= 5.5) && (version < 7)); } return OpenLayers.Util.alphaHackNeeded; }; //修改一个有image背景的div，针对IE6的alpha 透明，使用了AlphaImageLoader。具体说明可以参考这里http://support.microsoft.com/kb/294714/zh-cn OpenLayers.Util.modifyAlphaImageDiv = function(div, id, px, sz, imgURL, position, border, sizing, opacity) { OpenLayers.Util.modifyDOMElement(div, id, px, sz, position, null, null, opacity); var img = div.childNodes; if (imgURL) { img.src = imgURL; } OpenLayers.Util.modifyDOMElement(img, div.id + "_innerImage", null, sz, "relative", border); if (OpenLayers.Util.alphaHack()) { if(div.style.display != "none") { div.style.display = "inline-block"; } if (sizing == null) { sizing = "scale"; } div.style.filter = "progid:DXImageTransform.Microsoft" + ".AlphaImageLoader(src='" + img.src + "', " + "sizingMethod='" + sizing + "')"; if (parseFloat(div.style.opacity) >= 0.0 && parseFloat(div.style.opacity) < 1.0) { div.style.filter += " alpha(opacity=" + div.style.opacity * 100 + ")"; } img.style.filter = "alpha(opacity=0)"; } }; //创建一个带背景的div OpenLayers.Util.createAlphaImageDiv = function(id, px, sz, imgURL, position, border, sizing, opacity, delayDisplay) { var div = OpenLayers.Util.createDiv(); var img = OpenLayers.Util.createImage(null, null, null, null, null, null, null, false); div.appendChild(img); if (delayDisplay) { img.style.display = "none"; OpenLayers.Event.observe(img, "load", OpenLayers.Function.bind(OpenLayers.Util.onImageLoad, div)); OpenLayers.Event.observe(img, "error", OpenLayers.Function.bind(OpenLayers.Util.onImageLoadError, div)); } OpenLayers.Util.modifyAlphaImageDiv(div, id, px, sz, imgURL, position, border, sizing, opacity); return div; }; //很简单的一个函数，把对象的属性名全改成大写 OpenLayers.Util.upperCaseObject = function (object) { var uObject = {}; for (var key in object) { uObject = object; } return uObject; }; //一个简单的浅拷贝，如果目标对象有这个属性，则不拷贝，否则拷贝 OpenLayers.Util.applyDefaults = function (to, from) { to = to || {}; var fromIsEvt = typeof window.Event == "function" && from instanceof window.Event; for (var key in from) { if (to === undefined || (!fromIsEvt && from.hasOwnProperty && from.hasOwnProperty(key) && !to.hasOwnProperty(key))) { to = from; } } if(!fromIsEvt && from && from.hasOwnProperty && from.hasOwnProperty('toString') && !to.hasOwnProperty('toString')) { to.toString = from.toString; } return to; }; //把对象属性和值，转换成url的参数格式，这个函数在ajax中，经常调用 OpenLayers.Util.getParameterString = function(params) { var paramsArray = []; for (var key in params) { var value = params; if ((value != null) && (typeof value != 'function')) { var encodedValue; if (typeof value == 'object' && value.constructor == Array) { /* value is an array; encode items and separate with "," */ var encodedItemArray = []; for (var itemIndex=0, len=value.length; itemIndex<len; itemIndex++) { encodedItemArray.push(encodeURIComponent(value)); } encodedValue = encodedItemArray.join(","); } else { /* value is a string; simply encode */ encodedValue = encodeURIComponent(value); } paramsArray.push(encodeURIComponent(key) + "=" + encodedValue); } } return paramsArray.join("&"); }; //img的路径 OpenLayers.ImgPath = ''; //获取Openlayers的img路径 OpenLayers.Util.getImagesLocation = function() { return OpenLayers.ImgPath || (OpenLayers._getScriptLocation() + "img/"); }; //这个函数的参数就是函数指针，运行这些函数，只到第一个不抛出异常的函数，返回其返回值 OpenLayers.Util.Try = function() { var returnValue = null; for (var i=0, len=arguments.length; i<len; i++) { var lambda = arguments; try { returnValue = lambda(); break; } catch (e) {} } return returnValue; }; //把对象p个子节点中的所有tagName的节点，做成数组返回 OpenLayers.Util.getNodes=function(p, tagName) { var nodes = OpenLayers.Util.Try( function () { return OpenLayers.Util._getNodes(p.documentElement.childNodes, tagName); }, function () { return OpenLayers.Util._getNodes(p.childNodes, tagName); } ); return nodes; }; //过滤出指定tagName的node，做成数组返回 OpenLayers.Util._getNodes=function(nodes, tagName) { var retArray = []; for (var i=0, len=nodes.length; i<len; i++) { if (nodes.nodeName==tagName) { retArray.push(nodes); } } return retArray; }; //取parent的节点标签名为item的第index项的nodeValue OpenLayers.Util.getTagText = function (parent, item, index) { var result = OpenLayers.Util.getNodes(parent, item); if (result && (result.length > 0)) { if (!index) { index=0; } if (result.childNodes.length > 1) { return result.childNodes.nodeValue; } else if (result.childNodes.length == 1) { return result.firstChild.nodeValue; } } else { return ""; } }; //取指定节点的nodeValue值，因为Firefox的标签中空白占一个位置，而IE不占。所以有两套函数。 OpenLayers.Util.getXmlNodeValue = function(node) { var val = null; OpenLayers.Util.Try( function() { val = node.text; if (!val) { val = node.textContent; } if (!val) { val = node.firstChild.nodeValue; } }, function() { val = node.textContent; }); return val; }; /** * Function: mouseLeft * * Parameters: * evt - {Event} * div - {HTMLDivElement} * * Returns: * {Boolean} */OpenLayers.Util.mouseLeft = function (evt, div) { // start with the element to which the mouse has moved var target = (evt.relatedTarget) ? evt.relatedTarget : evt.toElement; // walk up the DOM tree. while (target != div && target != null) { target = target.parentNode; } // if the target we stop at isn't the div, then we've left the div. return (target != div); }; /** * Property: precision * {Number} The number of significant digits to retain to avoid * floating point precision errors. * * We use 14 as a "safe" default because, although IEEE 754 double floats * (standard on most modern operating systems) support up to about 16 * significant digits, 14 significant digits are sufficient to represent * sub-millimeter accuracy in any coordinate system that anyone is likely to * use with OpenLayers. * * If DEFAULT_PRECISION is set to 0, the original non-truncating behavior * of OpenLayers <2.8 is preserved. Be aware that this will cause problems * with certain projections, e.g. spherical Mercator. * */OpenLayers.Util.DEFAULT_PRECISION = 14; /** * Function: toFloat * Convenience method to cast an object to a Number, rounded to the * desired floating point precision. * * Parameters: * number - {Number} The number to cast and round. * precision - {Number} An integer suitable for use with * Number.toPrecision(). Defaults to OpenLayers.Util.DEFAULT_PRECISION. * If set to 0, no rounding is performed. * * Returns: * {Number} The cast, rounded number. */OpenLayers.Util.toFloat = function (number, precision) { if (precision == null) { precision = OpenLayers.Util.DEFAULT_PRECISION; } var number; if (precision == 0) { number = parseFloat(number); } else { number = parseFloat(parseFloat(number).toPrecision(precision)); } return number; }; /** * Function: rad * * Parameters: * x - {Float} * * Returns: * {Float} */OpenLayers.Util.rad = function(x) {return x*Math.PI/180;}; /** * Function: distVincenty * Given two objects representing points with geographic coordinates, this * calculates the distance between those points on the surface of an * ellipsoid. * * Parameters: * p1 - {<OpenLayers.LonLat>} (or any object with both .lat, .lon properties) * p2 - {<OpenLayers.LonLat>} (or any object with both .lat, .lon properties) * * Returns: * {Float} The distance (in km) between the two input points as measured on an * ellipsoid.Note that the input point objects must be in geographic * coordinates (decimal degrees) and the return distance is in kilometers. */OpenLayers.Util.distVincenty=function(p1, p2) { var a = 6378137, b = 6356752.3142,f = 1/298.257223563; var L = OpenLayers.Util.rad(p2.lon - p1.lon); var U1 = Math.atan((1-f) * Math.tan(OpenLayers.Util.rad(p1.lat))); var U2 = Math.atan((1-f) * Math.tan(OpenLayers.Util.rad(p2.lat))); var sinU1 = Math.sin(U1), cosU1 = Math.cos(U1); var sinU2 = Math.sin(U2), cosU2 = Math.cos(U2); var lambda = L, lambdaP = 2*Math.PI; var iterLimit = 20; while (Math.abs(lambda-lambdaP) > 1e-12 && --iterLimit>0) { var sinLambda = Math.sin(lambda), cosLambda = Math.cos(lambda); var sinSigma = Math.sqrt((cosU2*sinLambda) * (cosU2*sinLambda) + (cosU1*sinU2-sinU1*cosU2*cosLambda) * (cosU1*sinU2-sinU1*cosU2*cosLambda)); if (sinSigma==0) { return 0;// co-incident points } var cosSigma = sinU1*sinU2 + cosU1*cosU2*cosLambda; var sigma = Math.atan2(sinSigma, cosSigma); var alpha = Math.asin(cosU1 * cosU2 * sinLambda / sinSigma); var cosSqAlpha = Math.cos(alpha) * Math.cos(alpha); var cos2SigmaM = cosSigma - 2*sinU1*sinU2/cosSqAlpha; var C = f/16*cosSqAlpha*(4+f*(4-3*cosSqAlpha)); lambdaP = lambda; lambda = L + (1-C) * f * Math.sin(alpha) * (sigma + C*sinSigma*(cos2SigmaM+C*cosSigma*(-1+2*cos2SigmaM*cos2SigmaM))); } if (iterLimit==0) { return NaN;// formula failed to converge } var uSq = cosSqAlpha * (a*a - b*b) / (b*b); var A = 1 + uSq/16384*(4096+uSq*(-768+uSq*(320-175*uSq))); var B = uSq/1024 * (256+uSq*(-128+uSq*(74-47*uSq))); var deltaSigma = B*sinSigma*(cos2SigmaM+B/4*(cosSigma*(-1+2*cos2SigmaM*cos2SigmaM)- B/6*cos2SigmaM*(-3+4*sinSigma*sinSigma)*(-3+4*cos2SigmaM*cos2SigmaM))); var s = b*A*(sigma-deltaSigma); var d = s.toFixed(3)/1000; // round to 1mm precision return d; }; /** * Function: getParameters * Parse the parameters from a URL or from the current page itself into a * JavaScript Object. Note that parameter values with commas are separated * out into an Array. * * Parameters: * url - {String} Optional url used to extract the query string. * If null, query string is taken from page location. * * Returns: * {Object} An object of key/value pairs from the query string. */OpenLayers.Util.getParameters = function(url) { // if no url specified, take it from the location bar url = url || window.location.href; //parse out parameters portion of url string var paramsString = ""; if (OpenLayers.String.contains(url, '?')) { var start = url.indexOf('?') + 1; var end = OpenLayers.String.contains(url, "#") ? url.indexOf('#') : url.length; paramsString = url.substring(start, end); } var parameters = {}; var pairs = paramsString.split(/[&;]/); for(var i=0, len=pairs.length; i<len; ++i) { var keyValue = pairs.split('='); if (keyValue) { var key = decodeURIComponent(keyValue); var value = keyValue || ''; //empty string if no value //decode individual values value = value.split(","); for(var j=0, jlen=value.length; j<jlen; j++) { value = decodeURIComponent(value); } //if there's only one value, do not return as array if (value.length == 1) { value = value; } parameters = value; } } return parameters; }; /** * Function: getArgs * *Deprecated*.Will be removed in 3.0.Please use instead * <OpenLayers.Util.getParameters> * * Parameters: * url - {String} Optional url used to extract the query string. * If null, query string is taken from page location. * * Returns: * {Object} An object of key/value pairs from the query string. */OpenLayers.Util.getArgs = function(url) { OpenLayers.Console.warn( OpenLayers.i18n( "methodDeprecated", {'newMethod': 'OpenLayers.Util.getParameters'} ) ); return OpenLayers.Util.getParameters(url); }; /** * Property: lastSeqID * {Integer} The ever-incrementing count variable. * Used for generating unique ids. */OpenLayers.Util.lastSeqID = 0; /** * Function: createUniqueID * Create a unique identifier for this session.Each time this function * is called, a counter is incremented.The return will be the optional * prefix (defaults to "id_") appended with the counter value. * * Parameters: * prefix {String} Optionsal string to prefix unique id. Default is "id_". * * Returns: * {String} A unique id string, built on the passed in prefix. */OpenLayers.Util.createUniqueID = function(prefix) { if (prefix == null) { prefix = "id_"; } OpenLayers.Util.lastSeqID += 1; return prefix + OpenLayers.Util.lastSeqID; }; /** * Constant: INCHES_PER_UNIT * {Object} Constant inches per unit -- borrowed from MapServer mapscale.c * derivation of nautical miles from http://en.wikipedia.org/wiki/Nautical_mile * Includes the full set of units supported by CS-MAP (http://trac.osgeo.org/csmap/) * and PROJ.4 (http://trac.osgeo.org/proj/) * The hardcoded table is maintain in a CS-MAP source code module named CSdataU.c * The hardcoded table of PROJ.4 units are in pj_units.c. */OpenLayers.INCHES_PER_UNIT = { 'inches': 1.0, 'ft': 12.0, 'mi': 63360.0, 'm': 39.3701, 'km': 39370.1, 'dd': 4374754, 'yd': 36 }; OpenLayers.INCHES_PER_UNIT["in"]= OpenLayers.INCHES_PER_UNIT.inches; OpenLayers.INCHES_PER_UNIT["degrees"] = OpenLayers.INCHES_PER_UNIT.dd; OpenLayers.INCHES_PER_UNIT["nmi"] = 1852 * OpenLayers.INCHES_PER_UNIT.m; // Units from CS-Map OpenLayers.METERS_PER_INCH = 0.02540005080010160020; OpenLayers.Util.extend(OpenLayers.INCHES_PER_UNIT, { "Inch": OpenLayers.INCHES_PER_UNIT.inches, "Meter": 1.0 / OpenLayers.METERS_PER_INCH, //EPSG:9001 "Foot": 0.30480060960121920243 / OpenLayers.METERS_PER_INCH, //EPSG:9003 "IFoot": 0.30480000000000000000 / OpenLayers.METERS_PER_INCH, //EPSG:9002 "ClarkeFoot": 0.3047972651151 / OpenLayers.METERS_PER_INCH, //EPSG:9005 "SearsFoot": 0.30479947153867624624 / OpenLayers.METERS_PER_INCH, //EPSG:9041 "GoldCoastFoot": 0.30479971018150881758 / OpenLayers.METERS_PER_INCH, //EPSG:9094 "IInch": 0.02540000000000000000 / OpenLayers.METERS_PER_INCH, "MicroInch": 0.00002540000000000000 / OpenLayers.METERS_PER_INCH, "Mil": 0.00000002540000000000 / OpenLayers.METERS_PER_INCH, "Centimeter": 0.01000000000000000000 / OpenLayers.METERS_PER_INCH, "Kilometer": 1000.00000000000000000000 / OpenLayers.METERS_PER_INCH, //EPSG:9036 "Yard": 0.91440182880365760731 / OpenLayers.METERS_PER_INCH, "SearsYard": 0.914398414616029 / OpenLayers.METERS_PER_INCH, //EPSG:9040 "IndianYard": 0.91439853074444079983 / OpenLayers.METERS_PER_INCH, //EPSG:9084 "IndianYd37": 0.91439523 / OpenLayers.METERS_PER_INCH, //EPSG:9085 "IndianYd62": 0.9143988 / OpenLayers.METERS_PER_INCH, //EPSG:9086 "IndianYd75": 0.9143985 / OpenLayers.METERS_PER_INCH, //EPSG:9087 "IndianFoot": 0.30479951 / OpenLayers.METERS_PER_INCH, //EPSG:9080 "IndianFt37": 0.30479841 / OpenLayers.METERS_PER_INCH, //EPSG:9081 "IndianFt62": 0.3047996 / OpenLayers.METERS_PER_INCH, //EPSG:9082 "IndianFt75": 0.3047995 / OpenLayers.METERS_PER_INCH, //EPSG:9083 "Mile": 1609.34721869443738887477 / OpenLayers.METERS_PER_INCH, "IYard": 0.91440000000000000000 / OpenLayers.METERS_PER_INCH, //EPSG:9096 "IMile": 1609.34400000000000000000 / OpenLayers.METERS_PER_INCH, //EPSG:9093 "NautM": 1852.00000000000000000000 / OpenLayers.METERS_PER_INCH, //EPSG:9030 "Lat-66": 110943.316488932731 / OpenLayers.METERS_PER_INCH, "Lat-83": 110946.25736872234125 / OpenLayers.METERS_PER_INCH, "Decimeter": 0.10000000000000000000 / OpenLayers.METERS_PER_INCH, "Millimeter": 0.00100000000000000000 / OpenLayers.METERS_PER_INCH, "Dekameter": 10.00000000000000000000 / OpenLayers.METERS_PER_INCH, "Decameter": 10.00000000000000000000 / OpenLayers.METERS_PER_INCH, "Hectometer": 100.00000000000000000000 / OpenLayers.METERS_PER_INCH, "GermanMeter": 1.0000135965 / OpenLayers.METERS_PER_INCH, //EPSG:9031 "CaGrid": 0.999738 / OpenLayers.METERS_PER_INCH, "ClarkeChain": 20.1166194976 / OpenLayers.METERS_PER_INCH, //EPSG:9038 "GunterChain": 20.11684023368047 / OpenLayers.METERS_PER_INCH, //EPSG:9033 "BenoitChain": 20.116782494375872 / OpenLayers.METERS_PER_INCH, //EPSG:9062 "SearsChain": 20.11676512155 / OpenLayers.METERS_PER_INCH, //EPSG:9042 "ClarkeLink": 0.201166194976 / OpenLayers.METERS_PER_INCH, //EPSG:9039 "GunterLink": 0.2011684023368047 / OpenLayers.METERS_PER_INCH, //EPSG:9034 "BenoitLink": 0.20116782494375872 / OpenLayers.METERS_PER_INCH, //EPSG:9063 "SearsLink": 0.2011676512155 / OpenLayers.METERS_PER_INCH, //EPSG:9043 "Rod": 5.02921005842012 / OpenLayers.METERS_PER_INCH, "IntnlChain": 20.1168 / OpenLayers.METERS_PER_INCH, //EPSG:9097 "IntnlLink": 0.201168 / OpenLayers.METERS_PER_INCH, //EPSG:9098 "Perch": 5.02921005842012 / OpenLayers.METERS_PER_INCH, "Pole": 5.02921005842012 / OpenLayers.METERS_PER_INCH, "Furlong": 201.1684023368046 / OpenLayers.METERS_PER_INCH, "Rood": 3.778266898 / OpenLayers.METERS_PER_INCH, "CapeFoot": 0.3047972615 / OpenLayers.METERS_PER_INCH, "Brealey": 375.00000000000000000000 / OpenLayers.METERS_PER_INCH, "ModAmFt": 0.304812252984505969011938 / OpenLayers.METERS_PER_INCH, "Fathom": 1.8288 / OpenLayers.METERS_PER_INCH, "NautM-UK": 1853.184 / OpenLayers.METERS_PER_INCH, "50kilometers": 50000.0 / OpenLayers.METERS_PER_INCH, "150kilometers": 150000.0 / OpenLayers.METERS_PER_INCH }); //unit abbreviations supported by PROJ.4 OpenLayers.Util.extend(OpenLayers.INCHES_PER_UNIT, { "mm": OpenLayers.INCHES_PER_UNIT["Meter"] / 1000.0, "cm": OpenLayers.INCHES_PER_UNIT["Meter"] / 100.0, "dm": OpenLayers.INCHES_PER_UNIT["Meter"] * 100.0, "km": OpenLayers.INCHES_PER_UNIT["Meter"] * 1000.0, "kmi": OpenLayers.INCHES_PER_UNIT["nmi"], //International Nautical Mile "fath": OpenLayers.INCHES_PER_UNIT["Fathom"], //International Fathom "ch": OpenLayers.INCHES_PER_UNIT["IntnlChain"],//International Chain "link": OpenLayers.INCHES_PER_UNIT["IntnlLink"], //International Link "us-in": OpenLayers.INCHES_PER_UNIT["inches"], //U.S. Surveyor's Inch "us-ft": OpenLayers.INCHES_PER_UNIT["Foot"], //U.S. Surveyor's Foot "us-yd": OpenLayers.INCHES_PER_UNIT["Yard"], //U.S. Surveyor's Yard "us-ch": OpenLayers.INCHES_PER_UNIT["GunterChain"], //U.S. Surveyor's Chain "us-mi": OpenLayers.INCHES_PER_UNIT["Mile"], //U.S. Surveyor's Statute Mile "ind-yd": OpenLayers.INCHES_PER_UNIT["IndianYd37"],//Indian Yard "ind-ft": OpenLayers.INCHES_PER_UNIT["IndianFt37"],//Indian Foot "ind-ch": 20.11669506 / OpenLayers.METERS_PER_INCH//Indian Chain }); /** * Constant: DOTS_PER_INCH * {Integer} 72 (A sensible default) */OpenLayers.DOTS_PER_INCH = 72; /** * Function: normalizeScale * * Parameters: * scale - {float} * * Returns: * {Float} A normalized scale value, in 1 / X format. * This means that if a value less than one ( already 1/x) is passed * in, it just returns scale directly. Otherwise, it returns * 1 / scale */OpenLayers.Util.normalizeScale = function (scale) { var normScale = (scale > 1.0) ? (1.0 / scale) : scale; return normScale; }; /** * Function: getResolutionFromScale * * Parameters: * scale - {Float} * units - {String} Index into OpenLayers.INCHES_PER_UNIT hashtable. * Default is degrees * * Returns: * {Float} The corresponding resolution given passed-in scale and unit * parameters. */OpenLayers.Util.getResolutionFromScale = function (scale, units) { if (units == null) { units = "degrees"; } var normScale = OpenLayers.Util.normalizeScale(scale); var resolution = 1 / (normScale * OpenLayers.INCHES_PER_UNIT * OpenLayers.DOTS_PER_INCH); return resolution; }; /** * Function: getScaleFromResolution * * Parameters: * resolution - {Float} * units - {String} Index into OpenLayers.INCHES_PER_UNIT hashtable. * Default is degrees * * Returns: * {Float} The corresponding scale given passed-in resolution and unit * parameters. */OpenLayers.Util.getScaleFromResolution = function (resolution, units) { if (units == null) { units = "degrees"; } var scale = resolution * OpenLayers.INCHES_PER_UNIT * OpenLayers.DOTS_PER_INCH; return scale; }; /** * Function: safeStopPropagation * *Deprecated*. This function has been deprecated. Please use directly * <OpenLayers.Event.stop> passing 'true' as the 2nd * argument (preventDefault) * * Safely stop the propagation of an event *without* preventing * the default browser action from occurring. * * Parameter: * evt - {Event} */OpenLayers.Util.safeStopPropagation = function(evt) { OpenLayers.Event.stop(evt, true); }; /** * Function: pagePositon * Calculates the position of an element on the page. * * Parameters: * forElement - {DOMElement} * * Returns: * {Array} two item array, L value then T value. */OpenLayers.Util.pagePosition = function(forElement) { var valueT = 0, valueL = 0; var element = forElement; var child = forElement; while(element) { if(element == document.body) { if(OpenLayers.Element.getStyle(child, 'position') == 'absolute') { break; } } valueT += element.offsetTop|| 0; valueL += element.offsetLeft || 0; child = element; try { // wrapping this in a try/catch because IE chokes on the offsetParent element = element.offsetParent; } catch(e) { OpenLayers.Console.error(OpenLayers.i18n( "pagePositionFailed",{'elemId':element.id})); break; } } element = forElement; while(element) { valueT -= element.scrollTop|| 0; valueL -= element.scrollLeft || 0; element = element.parentNode; } return ; }; /** * Function: isEquivalentUrl * Test two URLs for equivalence. * * Setting 'ignoreCase' allows for case-independent comparison. * * Comparison is based on: *- Protocol *- Host (evaluated without the port) *- Port (set 'ignorePort80' to ignore "80" values) *- Hash ( set 'ignoreHash' to disable) *- Pathname (for relative <-> absolute comparison) *- Arguments (so they can be out of order) * * Parameters: * url1 - {String} * url2 - {String} * options - {Object} Allows for customization of comparison: * 'ignoreCase' - Default is True * 'ignorePort80' - Default is True * 'ignoreHash' - Default is True * * Returns: * {Boolean} Whether or not the two URLs are equivalent */OpenLayers.Util.isEquivalentUrl = function(url1, url2, options) { options = options || {}; OpenLayers.Util.applyDefaults(options, { ignoreCase: true, ignorePort80: true, ignoreHash: true }); var urlObj1 = OpenLayers.Util.createUrlObject(url1, options); var urlObj2 = OpenLayers.Util.createUrlObject(url2, options); //compare all keys except for "args" (treated below) for(var key in urlObj1) { if(key !== "args") { if(urlObj1 != urlObj2) { return false; } } } // compare search args - irrespective of order for(var key in urlObj1.args) { if(urlObj1.args != urlObj2.args) { return false; } delete urlObj2.args; } // urlObj2 shouldn't have any args left for(var key in urlObj2.args) { return false; } return true; }; /** * Function: createUrlObject * * Parameters: * url - {String} * options - {Object} A hash of options.Can be one of: * ignoreCase: lowercase url, * ignorePort80: don't include explicit port if port is 80, * ignoreHash: Don't include part of url after the hash (#). * * Returns: * {Object} An object with separate url, a, port, host, and args parsed out * and ready for comparison */OpenLayers.Util.createUrlObject = function(url, options) { options = options || {}; // deal with relative urls first if(!(/^\w+:\/\//).test(url)) { var loc = window.location; var port = loc.port ? ":" + loc.port : ""; var fullUrl = loc.protocol + "//" + loc.host.split(":").shift() + port; if(url.indexOf("/") === 0) { // full pathname url = fullUrl + url; } else { // relative to current path var parts = loc.pathname.split("/"); parts.pop(); url = fullUrl + parts.join("/") + "/" + url; } } if (options.ignoreCase) { url = url.toLowerCase(); } var a = document.createElement('a'); a.href = url; var urlObject = {}; //host (without port) urlObject.host = a.host.split(":").shift(); //protocol urlObject.protocol = a.protocol; //port (get uniform browser behavior with port 80 here) if(options.ignorePort80) { urlObject.port = (a.port == "80" || a.port == "0") ? "" : a.port; } else { urlObject.port = (a.port == "" || a.port == "0") ? "80" : a.port; } //hash urlObject.hash = (options.ignoreHash || a.hash === "#") ? "" : a.hash; //args var queryString = a.search; if (!queryString) { var qMark = url.indexOf("?"); queryString = (qMark != -1) ? url.substr(qMark) : ""; } urlObject.args = OpenLayers.Util.getParameters(queryString); //pathname (uniform browser behavior with leading "/") urlObject.pathname = (a.pathname.charAt(0) == "/") ? a.pathname : "/" + a.pathname; return urlObject; }; /** * Function: removeTail * Takes a url and removes everything after the ? and # * * Parameters: * url - {String} The url to process * * Returns: * {String} The string with all queryString and Hash removed */OpenLayers.Util.removeTail = function(url) { var head = null; var qMark = url.indexOf("?"); var hashMark = url.indexOf("#"); if (qMark == -1) { head = (hashMark != -1) ? url.substr(0,hashMark) : url; } else { head = (hashMark != -1) ? url.substr(0,Math.min(qMark, hashMark)) : url.substr(0, qMark); } return head; }; /** * Function: getBrowserName * * Returns: * {String} A string which specifies which is the current * browser in which we are running. * * Currently-supported browser detection and codes: * * 'opera' -- Opera * * 'msie'-- Internet Explorer * * 'safari' -- Safari * * 'firefox' -- FireFox * * 'mozilla' -- Mozilla * * If we are unable to property identify the browser, we * return an empty string. */OpenLayers.Util.getBrowserName = function() { var browserName = ""; var ua = navigator.userAgent.toLowerCase(); if ( ua.indexOf( "opera" ) != -1 ) { browserName = "opera"; } else if ( ua.indexOf( "msie" ) != -1 ) { browserName = "msie"; } else if ( ua.indexOf( "safari" ) != -1 ) { browserName = "safari"; } else if ( ua.indexOf( "mozilla" ) != -1 ) { if ( ua.indexOf( "firefox" ) != -1 ) { browserName = "firefox"; } else { browserName = "mozilla"; } } return browserName; }; /** * Method: getRenderedDimensions * Renders the contentHTML offscreen to determine actual dimensions for * popup sizing. As we need layout to determine dimensions the content * is rendered -9999px to the left and absolute to ensure the * scrollbars do not flicker * * Parameters: * contentHTML * size - {<OpenLayers.Size>} If either the 'w' or 'h' properties is * specified, we fix that dimension of the div to be measured. This is * useful in the case where we have a limit in one dimension and must * therefore meaure the flow in the other dimension. * options - {Object} * displayClass - {String} Optional parameter.A CSS class name(s) string * to provide the CSS context of the rendered content. * containerElement - {DOMElement} Optional parameter. Insert the HTML to * this node instead of the body root when calculating dimensions. * * Returns: * {OpenLayers.Size} */OpenLayers.Util.getRenderedDimensions = function(contentHTML, size, options) { var w, h; // create temp container div with restricted size var container = document.createElement("div"); container.style.visibility = "hidden"; var containerElement = (options && options.containerElement) ? options.containerElement : document.body; //fix a dimension, if specified. if (size) { if (size.w) { w = size.w; container.style.width = w + "px"; } else if (size.h) { h = size.h; container.style.height = h + "px"; } } //add css classes, if specified if (options && options.displayClass) { container.className = options.displayClass; } // create temp content div and assign content var content = document.createElement("div"); content.innerHTML = contentHTML; // we need overflow visible when calculating the size content.style.overflow = "visible"; if (content.childNodes) { for (var i=0, l=content.childNodes.length; i<l; i++) { if (!content.childNodes.style) continue; content.childNodes.style.overflow = "visible"; } } // add content to restricted container container.appendChild(content); // append container to body for rendering containerElement.appendChild(container); // Opera and IE7 can't handle a node with position:aboslute if it inherits // position:absolute from a parent. var parentHasPositionAbsolute = false; var parent = container.parentNode; while (parent && parent.tagName.toLowerCase()!="body") { var parentPosition = OpenLayers.Element.getStyle(parent, "position"); if(parentPosition == "absolute") { parentHasPositionAbsolute = true; break; } else if (parentPosition && parentPosition != "static") { break; } parent = parent.parentNode; } if(!parentHasPositionAbsolute) { container.style.position = "absolute"; } // calculate scroll width of content and add corners and shadow width if (!w) { w = parseInt(content.scrollWidth); // update container width to allow height to adjust container.style.width = w + "px"; } // capture height and add shadow and corner image widths if (!h) { h = parseInt(content.scrollHeight); } // remove elements container.removeChild(content); containerElement.removeChild(container); return new OpenLayers.Size(w, h); }; /** * APIFunction: getScrollbarWidth * This function has been modified by the OpenLayers from the original version, * written by Matthew Eernisse and released under the Apache 2 * license here: * * http://www.fleegix.org/articles/2006/05/30/getting-the-scrollbar-width-in-pixels * * It has been modified simply to cache its value, since it is physically * impossible that this code could ever run in more than one browser at * once. * * Returns: * {Integer} */OpenLayers.Util.getScrollbarWidth = function() { var scrollbarWidth = OpenLayers.Util._scrollbarWidth; if (scrollbarWidth == null) { var scr = null; var inn = null; var wNoScroll = 0; var wScroll = 0; // Outer scrolling div scr = document.createElement('div'); scr.style.position = 'absolute'; scr.style.top = '-1000px'; scr.style.left = '-1000px'; scr.style.width = '100px'; scr.style.height = '50px'; // Start with no scrollbar scr.style.overflow = 'hidden'; // Inner content div inn = document.createElement('div'); inn.style.width = '100%'; inn.style.height = '200px'; // Put the inner div in the scrolling div scr.appendChild(inn); // Append the scrolling div to the doc document.body.appendChild(scr); // Width of the inner div sans scrollbar wNoScroll = inn.offsetWidth; // Add the scrollbar scr.style.overflow = 'scroll'; // Width of the inner div width scrollbar wScroll = inn.offsetWidth; // Remove the scrolling div from the doc document.body.removeChild(document.body.lastChild); // Pixel width of the scroller OpenLayers.Util._scrollbarWidth = (wNoScroll - wScroll); scrollbarWidth = OpenLayers.Util._scrollbarWidth; } return scrollbarWidth; };出处：http://blog.csdn.net/baozhifei/archive/2009/08/15/4450449.aspx
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