[76] | 1 | /* Copyright (c) 2006-2010 by OpenLayers Contributors (see authors.txt for |
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| 2 | * full list of contributors). Published under the Clear BSD license. |
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| 3 | * See http://svn.openlayers.org/trunk/openlayers/license.txt for the |
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| 4 | * full text of the license. */ |
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| 5 | |
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| 6 | /** |
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| 7 | * @requires OpenLayers/Control.js |
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| 8 | */ |
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| 9 | |
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| 10 | /** |
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| 11 | * Class: OpenLayers.Control.ScaleLine |
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| 12 | * The ScaleLine displays a small line indicator representing the current |
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| 13 | * map scale on the map. By default it is drawn in the lower left corner of |
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| 14 | * the map. |
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| 15 | * |
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| 16 | * Inherits from: |
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| 17 | * - <OpenLayers.Control> |
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| 18 | * |
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| 19 | * Is a very close copy of: |
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| 20 | * - <OpenLayers.Control.Scale> |
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| 21 | */ |
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| 22 | OpenLayers.Control.ScaleLine = OpenLayers.Class(OpenLayers.Control, { |
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| 23 | |
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| 24 | /** |
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| 25 | * Property: maxWidth |
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| 26 | * {Integer} Maximum width of the scale line in pixels. Default is 100. |
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| 27 | */ |
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| 28 | maxWidth: 100, |
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| 29 | |
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| 30 | /** |
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| 31 | * Property: topOutUnits |
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| 32 | * {String} Units for zoomed out on top bar. Default is km. |
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| 33 | */ |
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| 34 | topOutUnits: "km", |
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| 35 | |
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| 36 | /** |
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| 37 | * Property: topInUnits |
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| 38 | * {String} Units for zoomed in on top bar. Default is m. |
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| 39 | */ |
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| 40 | topInUnits: "m", |
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| 41 | |
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| 42 | /** |
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| 43 | * Property: bottomOutUnits |
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| 44 | * {String} Units for zoomed out on bottom bar. Default is mi. |
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| 45 | */ |
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| 46 | bottomOutUnits: "mi", |
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| 47 | |
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| 48 | /** |
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| 49 | * Property: bottomInUnits |
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| 50 | * {String} Units for zoomed in on bottom bar. Default is ft. |
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| 51 | */ |
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| 52 | bottomInUnits: "ft", |
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| 53 | |
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| 54 | /** |
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| 55 | * Property: eTop |
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| 56 | * {DOMElement} |
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| 57 | */ |
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| 58 | eTop: null, |
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| 59 | |
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| 60 | /** |
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| 61 | * Property: eBottom |
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| 62 | * {DOMElement} |
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| 63 | */ |
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| 64 | eBottom:null, |
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| 65 | |
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| 66 | /** |
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| 67 | * APIProperty: geodesic |
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| 68 | * {Boolean} Use geodesic measurement. Default is false. The recommended |
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| 69 | * setting for maps in EPSG:4326 is false, and true EPSG:900913. If set to |
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| 70 | * true, the scale will be calculated based on the horizontal size of the |
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| 71 | * pixel in the center of the map viewport. |
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| 72 | */ |
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| 73 | geodesic: false, |
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| 74 | |
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| 75 | /** |
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| 76 | * Constructor: OpenLayers.Control.ScaleLine |
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| 77 | * Create a new scale line control. |
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| 78 | * |
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| 79 | * Parameters: |
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| 80 | * options - {Object} An optional object whose properties will be used |
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| 81 | * to extend the control. |
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| 82 | */ |
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| 83 | initialize: function(options) { |
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| 84 | OpenLayers.Control.prototype.initialize.apply(this, [options]); |
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| 85 | }, |
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| 86 | |
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| 87 | /** |
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| 88 | * Method: draw |
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| 89 | * |
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| 90 | * Returns: |
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| 91 | * {DOMElement} |
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| 92 | */ |
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| 93 | draw: function() { |
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| 94 | OpenLayers.Control.prototype.draw.apply(this, arguments); |
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| 95 | if (!this.eTop) { |
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| 96 | // stick in the top bar |
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| 97 | this.eTop = document.createElement("div"); |
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| 98 | this.eTop.className = this.displayClass + "Top"; |
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| 99 | var theLen = this.topInUnits.length; |
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| 100 | this.div.appendChild(this.eTop); |
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| 101 | if((this.topOutUnits == "") || (this.topInUnits == "")) { |
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| 102 | this.eTop.style.visibility = "hidden"; |
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| 103 | } else { |
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| 104 | this.eTop.style.visibility = "visible"; |
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| 105 | } |
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| 106 | |
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| 107 | // and the bottom bar |
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| 108 | this.eBottom = document.createElement("div"); |
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| 109 | this.eBottom.className = this.displayClass + "Bottom"; |
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| 110 | this.div.appendChild(this.eBottom); |
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| 111 | if((this.bottomOutUnits == "") || (this.bottomInUnits == "")) { |
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| 112 | this.eBottom.style.visibility = "hidden"; |
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| 113 | } else { |
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| 114 | this.eBottom.style.visibility = "visible"; |
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| 115 | } |
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| 116 | } |
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| 117 | this.map.events.register('moveend', this, this.update); |
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| 118 | this.update(); |
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| 119 | return this.div; |
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| 120 | }, |
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| 121 | |
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| 122 | /** |
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| 123 | * Method: getBarLen |
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| 124 | * Given a number, round it down to the nearest 1,2,5 times a power of 10. |
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| 125 | * That seems a fairly useful set of number groups to use. |
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| 126 | * |
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| 127 | * Parameters: |
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| 128 | * maxLen - {float} the number we're rounding down from |
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| 129 | * |
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| 130 | * Returns: |
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| 131 | * {Float} the rounded number (less than or equal to maxLen) |
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| 132 | */ |
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| 133 | getBarLen: function(maxLen) { |
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| 134 | // nearest power of 10 lower than maxLen |
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| 135 | var digits = parseInt(Math.log(maxLen) / Math.log(10)); |
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| 136 | var pow10 = Math.pow(10, digits); |
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| 137 | |
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| 138 | // ok, find first character |
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| 139 | var firstChar = parseInt(maxLen / pow10); |
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| 140 | |
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| 141 | // right, put it into the correct bracket |
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| 142 | var barLen; |
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| 143 | if(firstChar > 5) { |
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| 144 | barLen = 5; |
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| 145 | } else if(firstChar > 2) { |
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| 146 | barLen = 2; |
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| 147 | } else { |
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| 148 | barLen = 1; |
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| 149 | } |
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| 150 | |
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| 151 | // scale it up the correct power of 10 |
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| 152 | return barLen * pow10; |
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| 153 | }, |
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| 154 | |
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| 155 | /** |
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| 156 | * Method: update |
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| 157 | * Update the size of the bars, and the labels they contain. |
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| 158 | */ |
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| 159 | update: function() { |
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| 160 | var res = this.map.getResolution(); |
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| 161 | if (!res) { |
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| 162 | return; |
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| 163 | } |
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| 164 | |
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| 165 | var curMapUnits = this.map.getUnits(); |
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| 166 | var inches = OpenLayers.INCHES_PER_UNIT; |
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| 167 | |
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| 168 | // convert maxWidth to map units |
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| 169 | var maxSizeData = this.maxWidth * res * inches[curMapUnits]; |
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| 170 | var geodesicRatio = 1; |
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| 171 | if(this.geodesic === true) { |
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| 172 | var maxSizeGeodesic = (this.map.getGeodesicPixelSize().w || |
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| 173 | 0.000001) * this.maxWidth; |
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| 174 | var maxSizeKilometers = maxSizeData / inches["km"]; |
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| 175 | geodesicRatio = maxSizeGeodesic / maxSizeKilometers; |
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| 176 | maxSizeData *= geodesicRatio; |
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| 177 | } |
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| 178 | |
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| 179 | // decide whether to use large or small scale units |
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| 180 | var topUnits; |
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| 181 | var bottomUnits; |
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| 182 | if(maxSizeData > 100000) { |
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| 183 | topUnits = this.topOutUnits; |
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| 184 | bottomUnits = this.bottomOutUnits; |
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| 185 | } else { |
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| 186 | topUnits = this.topInUnits; |
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| 187 | bottomUnits = this.bottomInUnits; |
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| 188 | } |
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| 189 | |
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| 190 | // and to map units units |
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| 191 | var topMax = maxSizeData / inches[topUnits]; |
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| 192 | var bottomMax = maxSizeData / inches[bottomUnits]; |
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| 193 | |
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| 194 | // now trim this down to useful block length |
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| 195 | var topRounded = this.getBarLen(topMax); |
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| 196 | var bottomRounded = this.getBarLen(bottomMax); |
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| 197 | |
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| 198 | // and back to display units |
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| 199 | topMax = topRounded / inches[curMapUnits] * inches[topUnits]; |
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| 200 | bottomMax = bottomRounded / inches[curMapUnits] * inches[bottomUnits]; |
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| 201 | |
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| 202 | // and to pixel units |
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| 203 | var topPx = topMax / res / geodesicRatio; |
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| 204 | var bottomPx = bottomMax / res / geodesicRatio; |
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| 205 | |
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| 206 | // now set the pixel widths |
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| 207 | // and the values inside them |
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| 208 | |
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| 209 | if (this.eBottom.style.visibility == "visible"){ |
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| 210 | this.eBottom.style.width = Math.round(bottomPx) + "px"; |
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| 211 | this.eBottom.innerHTML = bottomRounded + " " + bottomUnits ; |
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| 212 | } |
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| 213 | |
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| 214 | if (this.eTop.style.visibility == "visible"){ |
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| 215 | this.eTop.style.width = Math.round(topPx) + "px"; |
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| 216 | this.eTop.innerHTML = topRounded + " " + topUnits; |
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| 217 | } |
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| 218 | |
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| 219 | }, |
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| 220 | |
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| 221 | CLASS_NAME: "OpenLayers.Control.ScaleLine" |
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| 222 | }); |
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| 223 | |
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