22bbf98398
projections.2.patch). (Closes #1035) git-svn-id: http://svn.openlayers.org/trunk/openlayers@5405 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf
114 lines
2.9 KiB
JavaScript
114 lines
2.9 KiB
JavaScript
/* Copyright (c) 2006-2007 MetaCarta, Inc., published under a modified BSD license.
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* See http://svn.openlayers.org/trunk/openlayers/repository-license.txt
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* for the full text of the license. */
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/**
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* @requires OpenLayers/Util.js
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*
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* Class: OpenLayers.Projection
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* Class for coordinate transformations between coordinate systems.
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* Depends on the proj4js library. If proj4js is not available,
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* then this is just an empty stub.
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*/
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OpenLayers.Projection = OpenLayers.Class({
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/**
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* Constructor: OpenLayers.Projection
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* This class offers several methods for interacting with a wrapped
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* pro4js projection object.
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*
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* Parameters:
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* options - {Object} An optional object with properties to set on the
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* format
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*
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* Returns:
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* {<OpenLayers.Projection>} A projection object.
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*/
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initialize: function(projCode, options) {
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OpenLayers.Util.extend(this, options);
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this.projCode = projCode;
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if (window.Proj4js) {
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this.proj = new Proj4js.Proj(projCode);
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}
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},
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/**
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* APIMethod: getCode
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* Get the string SRS code.
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*
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* Returns:
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* {String} The SRS code.
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*/
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getCode: function() {
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return this.proj ? this.proj.srsCode : this.projCode;
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},
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/**
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* APIMethod: getUnits
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* Get the units string for the projection -- returns null if
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* proj4js is not available.
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*
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* Returns:
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* {String} The units abbreviation.
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*/
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getUnits: function() {
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return this.proj ? this.proj.units : null;
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},
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/**
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* Method: toString
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* Convert projection to string (getCode wrapper).
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*
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* Returns:
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* {String} The projection code.
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*/
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toString: function() {
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return this.getCode();
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},
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/**
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* Method: equals
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* Test equality of two projection instances. Determines equality based
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* soley on the projection code.
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*
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* Returns:
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* {Boolean} The two projections are equivalent.
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*/
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equals: function(projection) {
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if (this.getCode() == projection.getCode()) {
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return true;
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}
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return false;
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},
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/* Method: destroy
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* Destroy projection object.
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*/
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destroy: function() {
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delete this.proj;
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delete this.projCode;
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},
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CLASS_NAME: "OpenLayers.Projection"
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});
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/**
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* APIMethod: transform
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* Read data from a string, and return an object whose type depends on the
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* subclass.
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*
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* Parameters:
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* point - {object} input horizontal coodinate
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* sourceProj - {OpenLayers.Projection} source map coordinate system
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* destProj - {OpenLayers.Projection} destination map coordinate system
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*
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* Returns:
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* point - {object} trasnformed coordinate
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*/
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OpenLayers.Projection.transform = function(point, source, dest) {
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if (source.proj && dest.proj) {
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point = Proj4js.transform(source.proj, dest.proj, point);
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}
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return point;
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};
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