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 | * @requires OpenLayers/Feature/Vector.js |
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9 | */ |
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10 | |
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11 | /** |
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12 | * Class: OpenLayers.Control.Measure |
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13 | * Allows for drawing of features for measurements. |
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14 | * |
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15 | * Inherits from: |
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16 | * - <OpenLayers.Control> |
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17 | */ |
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18 | OpenLayers.Control.Measure = OpenLayers.Class(OpenLayers.Control, { |
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19 | |
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20 | /** |
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21 | * Constant: EVENT_TYPES |
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22 | * {Array(String)} Supported application event types. Register a listener |
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23 | * for a particular event with the following syntax: |
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24 | * (code) |
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25 | * control.events.register(type, obj, listener); |
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26 | * (end) |
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27 | * |
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28 | * Listeners will be called with a reference to an event object. The |
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29 | * properties of this event depends on exactly what happened. |
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30 | * |
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31 | * Supported control event types (in addition to those from <OpenLayers.Control>): |
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32 | * measure - Triggered when a measurement sketch is complete. Listeners |
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33 | * will receive an event with measure, units, order, and geometry |
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34 | * properties. |
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35 | * measurepartial - Triggered when a new point is added to the |
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36 | * measurement sketch. Listeners receive an event with measure, |
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37 | * units, order, and geometry. |
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38 | */ |
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39 | EVENT_TYPES: ['measure', 'measurepartial'], |
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40 | |
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41 | /** |
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42 | * APIProperty: handlerOptions |
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43 | * {Object} Used to set non-default properties on the control's handler |
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44 | */ |
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45 | handlerOptions: null, |
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46 | |
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47 | /** |
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48 | * Property: callbacks |
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49 | * {Object} The functions that are sent to the handler for callback |
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50 | */ |
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51 | callbacks: null, |
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52 | |
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53 | /** |
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54 | * Property: displaySystem |
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55 | * {String} Display system for output measurements. Supported values |
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56 | * are 'english', 'metric', and 'geographic'. Default is 'metric'. |
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57 | */ |
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58 | displaySystem: 'metric', |
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59 | |
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60 | /** |
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61 | * Property: geodesic |
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62 | * {Boolean} Calculate geodesic metrics instead of planar metrics. This |
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63 | * requires that geometries can be transformed into Geographic/WGS84 |
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64 | * (if that is not already the map projection). Default is false. |
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65 | */ |
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66 | geodesic: false, |
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67 | |
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68 | /** |
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69 | * Property: displaySystemUnits |
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70 | * {Object} Units for various measurement systems. Values are arrays |
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71 | * of unit abbreviations (from OpenLayers.INCHES_PER_UNIT) in decreasing |
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72 | * order of length. |
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73 | */ |
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74 | displaySystemUnits: { |
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75 | geographic: ['dd'], |
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76 | english: ['mi', 'ft', 'in'], |
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77 | metric: ['km', 'm'] |
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78 | }, |
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79 | |
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80 | /** |
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81 | * Property: delay |
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82 | * {Number} Number of milliseconds between clicks before the event is |
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83 | * considered a double-click. The "measurepartial" event will not |
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84 | * be triggered if the sketch is completed within this time. This |
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85 | * is required for IE where creating a browser reflow (if a listener |
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86 | * is modifying the DOM by displaying the measurement values) messes |
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87 | * with the dblclick listener in the sketch handler. |
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88 | */ |
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89 | partialDelay: 300, |
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90 | |
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91 | /** |
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92 | * Property: delayedTrigger |
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93 | * {Number} Timeout id of trigger for measurepartial. |
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94 | */ |
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95 | delayedTrigger: null, |
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96 | |
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97 | /** |
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98 | * APIProperty: persist |
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99 | * {Boolean} Keep the temporary measurement sketch drawn after the |
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100 | * measurement is complete. The geometry will persist until a new |
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101 | * measurement is started, the control is deactivated, or <cancel> is |
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102 | * called. |
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103 | */ |
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104 | persist: false, |
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105 | |
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106 | /** |
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107 | * Constructor: OpenLayers.Control.Measure |
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108 | * |
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109 | * Parameters: |
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110 | * handler - {<OpenLayers.Handler>} |
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111 | * options - {Object} |
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112 | */ |
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113 | initialize: function(handler, options) { |
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114 | // concatenate events specific to measure with those from the base |
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115 | this.EVENT_TYPES = |
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116 | OpenLayers.Control.Measure.prototype.EVENT_TYPES.concat( |
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117 | OpenLayers.Control.prototype.EVENT_TYPES |
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118 | ); |
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119 | OpenLayers.Control.prototype.initialize.apply(this, [options]); |
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120 | this.callbacks = OpenLayers.Util.extend( |
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121 | {done: this.measureComplete, point: this.measurePartial}, |
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122 | this.callbacks |
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123 | ); |
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124 | |
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125 | // let the handler options override, so old code that passes 'persist' |
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126 | // directly to the handler does not need an update |
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127 | this.handlerOptions = OpenLayers.Util.extend( |
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128 | {persist: this.persist}, this.handlerOptions |
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129 | ); |
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130 | this.handler = new handler(this, this.callbacks, this.handlerOptions); |
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131 | }, |
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132 | |
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133 | /** |
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134 | * APIMethod: cancel |
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135 | * Stop the control from measuring. If <persist> is true, the temporary |
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136 | * sketch will be erased. |
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137 | */ |
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138 | cancel: function() { |
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139 | this.handler.cancel(); |
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140 | }, |
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141 | |
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142 | /** |
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143 | * Method: updateHandler |
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144 | * |
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145 | * Parameters: |
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146 | * handler - {Function} One of the sketch handler constructors. |
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147 | * options - {Object} Options for the handler. |
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148 | */ |
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149 | updateHandler: function(handler, options) { |
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150 | var active = this.active; |
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151 | if(active) { |
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152 | this.deactivate(); |
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153 | } |
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154 | this.handler = new handler(this, this.callbacks, options); |
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155 | if(active) { |
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156 | this.activate(); |
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157 | } |
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158 | }, |
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159 | |
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160 | /** |
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161 | * Method: measureComplete |
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162 | * Called when the measurement sketch is done. |
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163 | * |
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164 | * Parameters: |
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165 | * geometry - {<OpenLayers.Geometry>} |
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166 | */ |
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167 | measureComplete: function(geometry) { |
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168 | if(this.delayedTrigger) { |
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169 | window.clearTimeout(this.delayedTrigger); |
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170 | } |
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171 | this.measure(geometry, "measure"); |
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172 | }, |
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173 | |
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174 | /** |
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175 | * Method: measurePartial |
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176 | * Called each time a new point is added to the measurement sketch. |
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177 | * |
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178 | * Parameters: |
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179 | * point - {<OpenLayers.Geometry.Point>} The last point added. |
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180 | * geometry - {<OpenLayers.Geometry>} The sketch geometry. |
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181 | */ |
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182 | measurePartial: function(point, geometry) { |
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183 | if (geometry.getLength() > 0) { |
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184 | geometry = geometry.clone(); |
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185 | this.delayedTrigger = window.setTimeout( |
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186 | OpenLayers.Function.bind(function() { |
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187 | this.measure(geometry, "measurepartial"); |
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188 | }, this), |
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189 | this.partialDelay |
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190 | ); |
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191 | } |
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192 | }, |
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193 | |
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194 | /** |
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195 | * Method: measure |
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196 | * |
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197 | * Parameters: |
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198 | * geometry - {<OpenLayers.Geometry>} |
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199 | * eventType - {String} |
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200 | */ |
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201 | measure: function(geometry, eventType) { |
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202 | var stat, order; |
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203 | if(geometry.CLASS_NAME.indexOf('LineString') > -1) { |
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204 | stat = this.getBestLength(geometry); |
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205 | order = 1; |
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206 | } else { |
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207 | stat = this.getBestArea(geometry); |
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208 | order = 2; |
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209 | } |
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210 | this.events.triggerEvent(eventType, { |
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211 | measure: stat[0], |
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212 | units: stat[1], |
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213 | order: order, |
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214 | geometry: geometry |
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215 | }); |
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216 | }, |
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217 | |
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218 | /** |
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219 | * Method: getBestArea |
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220 | * Based on the <displaySystem> returns the area of a geometry. |
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221 | * |
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222 | * Parameters: |
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223 | * geometry - {<OpenLayers.Geometry>} |
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224 | * |
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225 | * Returns: |
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226 | * {Array([Float, String])} Returns a two item array containing the |
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227 | * area and the units abbreviation. |
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228 | */ |
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229 | getBestArea: function(geometry) { |
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230 | var units = this.displaySystemUnits[this.displaySystem]; |
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231 | var unit, area; |
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232 | for(var i=0, len=units.length; i<len; ++i) { |
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233 | unit = units[i]; |
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234 | area = this.getArea(geometry, unit); |
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235 | if(area > 1) { |
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236 | break; |
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237 | } |
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238 | } |
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239 | return [area, unit]; |
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240 | }, |
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241 | |
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242 | /** |
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243 | * Method: getArea |
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244 | * |
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245 | * Parameters: |
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246 | * geometry - {<OpenLayers.Geometry>} |
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247 | * units - {String} Unit abbreviation |
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248 | * |
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249 | * Returns: |
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250 | * {Float} The geometry area in the given units. |
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251 | */ |
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252 | getArea: function(geometry, units) { |
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253 | var area, geomUnits; |
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254 | if(this.geodesic) { |
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255 | area = geometry.getGeodesicArea(this.map.getProjectionObject()); |
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256 | geomUnits = "m"; |
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257 | } else { |
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258 | area = geometry.getArea(); |
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259 | geomUnits = this.map.getUnits(); |
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260 | } |
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261 | var inPerDisplayUnit = OpenLayers.INCHES_PER_UNIT[units]; |
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262 | if(inPerDisplayUnit) { |
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263 | var inPerMapUnit = OpenLayers.INCHES_PER_UNIT[geomUnits]; |
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264 | area *= Math.pow((inPerMapUnit / inPerDisplayUnit), 2); |
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265 | } |
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266 | return area; |
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267 | }, |
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268 | |
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269 | /** |
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270 | * Method: getBestLength |
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271 | * Based on the <displaySystem> returns the length of a geometry. |
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272 | * |
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273 | * Parameters: |
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274 | * geometry - {<OpenLayers.Geometry>} |
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275 | * |
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276 | * Returns: |
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277 | * {Array([Float, String])} Returns a two item array containing the |
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278 | * length and the units abbreviation. |
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279 | */ |
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280 | getBestLength: function(geometry) { |
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281 | var units = this.displaySystemUnits[this.displaySystem]; |
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282 | var unit, length; |
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283 | for(var i=0, len=units.length; i<len; ++i) { |
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284 | unit = units[i]; |
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285 | length = this.getLength(geometry, unit); |
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286 | if(length > 1) { |
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287 | break; |
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288 | } |
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289 | } |
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290 | return [length, unit]; |
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291 | }, |
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292 | |
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293 | /** |
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294 | * Method: getLength |
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295 | * |
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296 | * Parameters: |
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297 | * geometry - {<OpenLayers.Geometry>} |
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298 | * units - {String} Unit abbreviation |
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299 | * |
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300 | * Returns: |
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301 | * {Float} The geometry length in the given units. |
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302 | */ |
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303 | getLength: function(geometry, units) { |
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304 | var length, geomUnits; |
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305 | if(this.geodesic) { |
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306 | length = geometry.getGeodesicLength(this.map.getProjectionObject()); |
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307 | geomUnits = "m"; |
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308 | } else { |
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309 | length = geometry.getLength(); |
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310 | geomUnits = this.map.getUnits(); |
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311 | } |
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312 | var inPerDisplayUnit = OpenLayers.INCHES_PER_UNIT[units]; |
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313 | if(inPerDisplayUnit) { |
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314 | var inPerMapUnit = OpenLayers.INCHES_PER_UNIT[geomUnits]; |
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315 | length *= (inPerMapUnit / inPerDisplayUnit); |
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316 | } |
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317 | return length; |
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318 | }, |
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319 | |
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320 | CLASS_NAME: "OpenLayers.Control.Measure" |
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321 | }); |
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