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 | /** |
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8 | * @requires OpenLayers/Tile/Image.js |
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9 | */ |
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10 | |
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11 | /** |
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12 | * Class: OpenLayers.Tile.Image.IFrame |
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13 | * Instances of OpenLayers.Tile.Image.IFrame are used to manage the image tiles |
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14 | * used by Layer.WMS.Post loaded via HTTP-POST-protocol. Create a new image |
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15 | * tile with the <OpenLayers.Tile.Image.IFrame> constructor. |
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16 | * |
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17 | * Inherits from: |
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18 | * - <OpenLayers.Tile.Image> |
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19 | */ |
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20 | OpenLayers.Tile.Image.IFrame = OpenLayers.Class(OpenLayers.Tile.Image, { |
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21 | |
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22 | /** |
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23 | * Property: layerAlphaHack |
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24 | * {Boolean} Always false for an instance. |
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25 | */ |
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26 | |
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27 | /** |
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28 | * Constructor: OpenLayers.Tile.Image.IFrame |
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29 | * Constructor for a new <OpenLayers.Tile.Image.IFrame> instance. |
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30 | * |
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31 | * Parameters: |
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32 | * layer - {<OpenLayers.Layer>} layer that the tile will go in. |
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33 | * position - {<OpenLayers.Pixel>} |
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34 | * bounds - {<OpenLayers.Bounds>} |
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35 | * size - {<OpenLayers.Size>} |
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36 | */ |
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37 | initialize: function(layer, position, bounds, url, size) { |
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38 | OpenLayers.Tile.Image.prototype.initialize.apply(this, arguments); |
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39 | this.layerAlphaHack = false; |
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40 | }, |
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41 | |
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42 | /** |
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43 | * Method: destroy |
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44 | * nullify references to prevent circular references and memory leaks |
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45 | */ |
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46 | destroy: function() { |
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47 | if(this.imgDiv != null) { |
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48 | // unregister the "load" handler |
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49 | OpenLayers.Event.stopObservingElement(this.imgDiv.firstChild); |
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50 | } |
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51 | OpenLayers.Tile.Image.prototype.destroy.apply(this, arguments); |
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52 | }, |
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53 | |
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54 | /** |
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55 | * Method: clear |
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56 | * Removes the iframe from DOM (avoids back-button problems). |
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57 | */ |
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58 | clear: function() { |
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59 | if(this.imgDiv) { |
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60 | var iFrame = this.imgDiv.firstChild; |
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61 | OpenLayers.Event.stopObservingElement(iFrame); |
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62 | this.imgDiv.removeChild(iFrame); |
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63 | } |
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64 | }, |
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65 | |
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66 | /** |
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67 | * Method: clone |
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68 | * |
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69 | * Parameters: |
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70 | * obj - {<OpenLayers.Tile.Image.IFrame>} The tile to be cloned |
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71 | * |
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72 | * Returns: |
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73 | * {<OpenLayers.Tile.Image.IFrame>} An exact clone of this |
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74 | * <OpenLayers.Tile.Image.IFrame> |
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75 | */ |
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76 | clone: function (obj) { |
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77 | if (obj == null) { |
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78 | obj = new OpenLayers.Tile.Image.IFrame( |
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79 | this.layer, this.position, this.bounds, this.url, this.size); |
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80 | } |
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81 | |
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82 | //pick up properties from superclass |
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83 | obj = OpenLayers.Tile.Image.prototype.clone.apply(this, [obj]); |
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84 | |
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85 | return obj; |
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86 | }, |
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87 | |
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88 | /** |
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89 | * Method: renderTile |
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90 | */ |
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91 | renderTile: function() { |
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92 | if(OpenLayers.Tile.Image.prototype.renderTile.apply(this, arguments)) { |
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93 | // create a html form and add it temporary to the layer div |
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94 | var form = this.createRequestForm(); |
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95 | this.imgDiv.appendChild(form); |
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96 | |
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97 | // submit the form (means fetching the image) |
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98 | form.submit(); |
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99 | this.imgDiv.removeChild(form); |
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100 | } |
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101 | }, |
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102 | |
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103 | /** |
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104 | * Method: initImgDiv |
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105 | * Creates the imgDiv property on the tile. |
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106 | */ |
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107 | initImgDiv: function() { |
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108 | this.imgDiv = this.createImgDiv(); |
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109 | |
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110 | OpenLayers.Util.modifyDOMElement(this.imgDiv, this.id, null, |
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111 | this.layer.getImageSize(), "relative"); |
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112 | this.imgDiv.className = 'olTileImage'; |
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113 | |
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114 | this.frame.appendChild(this.imgDiv); |
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115 | this.layer.div.appendChild(this.frame); |
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116 | |
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117 | if(this.layer.opacity != null) { |
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118 | |
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119 | OpenLayers.Util.modifyDOMElement(this.imgDiv, null, null, null, |
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120 | null, null, null, |
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121 | this.layer.opacity); |
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122 | } |
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123 | |
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124 | // we need this reference to check back the viewRequestID |
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125 | this.imgDiv.map = this.layer.map; |
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126 | }, |
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127 | |
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128 | /** |
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129 | * Method: createImgDiv |
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130 | * Creates a div with iframe.and eventPane |
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131 | * |
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132 | * Returns: |
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133 | * {DOMElement} |
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134 | */ |
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135 | createImgDiv: function() { |
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136 | var eventPane = document.createElement("div"); |
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137 | |
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138 | if(OpenLayers.Util.getBrowserName() == "msie") { |
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139 | // IE cannot handle events on elements without backgroundcolor. So we |
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140 | // use this little hack to make elements transparent |
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141 | eventPane.style.backgroundColor = '#FFFFFF'; |
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142 | eventPane.style.filter = 'chroma(color=#FFFFFF)'; |
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143 | } |
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144 | |
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145 | OpenLayers.Util.modifyDOMElement(eventPane, null, |
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146 | new OpenLayers.Pixel(0,0), this.layer.getImageSize(), "absolute"); |
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147 | |
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148 | var imgDiv = document.createElement("div"); |
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149 | imgDiv.appendChild(eventPane); |
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150 | return imgDiv; |
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151 | }, |
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152 | |
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153 | /** |
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154 | * Method: createIFrame |
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155 | * Create the IFrame which shows the image. |
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156 | * |
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157 | * Returns: |
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158 | * {DOMElement} Iframe |
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159 | */ |
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160 | createIFrame: function() { |
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161 | var id = this.id+'_iFrame'; |
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162 | var iframe; |
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163 | if(OpenLayers.Util.getBrowserName() == "msie") { |
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164 | // InternetExplorer does not set the name attribute of an iFrame |
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165 | // properly via DOM manipulation, so we need to do it on our own with |
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166 | // this hack. |
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167 | iframe = document.createElement('<iframe name="'+id+'">'); |
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168 | |
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169 | // IFrames in InternetExplorer are not transparent, if you set the |
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170 | // backgroundColor transparent. This is a workarround to get |
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171 | // transparent iframes. |
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172 | iframe.style.backgroundColor = '#FFFFFF'; |
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173 | iframe.style.filter = 'chroma(color=#FFFFFF)'; |
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174 | } |
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175 | else { |
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176 | iframe = document.createElement('iframe'); |
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177 | iframe.style.backgroundColor = 'transparent'; |
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178 | |
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179 | // iframe.name needs to be an unique id, otherwise it |
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180 | // could happen that other iframes are overwritten. |
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181 | iframe.name = id; |
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182 | } |
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183 | iframe.id = id; |
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184 | |
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185 | // some special properties to avoid scaling the images and scrollbars |
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186 | // in the iframe |
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187 | iframe.scrolling = 'no'; |
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188 | iframe.marginWidth = '0px'; |
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189 | iframe.marginHeight = '0px'; |
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190 | iframe.frameBorder = '0'; |
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191 | |
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192 | OpenLayers.Util.modifyDOMElement(iframe, id, |
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193 | new OpenLayers.Pixel(0,0), this.layer.getImageSize(), "absolute"); |
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194 | |
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195 | //bind a listener to the onload of the iframe so that we |
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196 | // can register when a tile has finished loading. |
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197 | var onload = function() { |
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198 | this.show(); |
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199 | //normally isLoading should always be true here but there are some |
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200 | // right funky conditions where loading and then reloading a tile |
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201 | // with the same url *really*fast*. this check prevents sending |
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202 | // a 'loadend' if the msg has already been sent |
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203 | // |
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204 | if (this.isLoading) { |
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205 | this.isLoading = false; |
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206 | this.events.triggerEvent("loadend"); |
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207 | } |
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208 | }; |
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209 | OpenLayers.Event.observe(iframe, 'load', |
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210 | OpenLayers.Function.bind(onload, this)); |
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211 | |
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212 | return iframe; |
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213 | }, |
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214 | |
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215 | /** |
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216 | * Method: createRequestForm |
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217 | * Create the html <form> element with width, height, bbox and all |
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218 | * parameters specified in the layer params. |
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219 | * |
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220 | * Returns: |
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221 | * {DOMElement} The form element which sends the HTTP-POST request to the |
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222 | * WMS. |
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223 | */ |
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224 | createRequestForm: function() { |
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225 | // creation of the form element |
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226 | var form = document.createElement('form'); |
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227 | form.method = 'POST'; |
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228 | var cacheId = this.layer.params["_OLSALT"]; |
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229 | cacheId = (cacheId ? cacheId + "_" : "") + this.bounds.toBBOX(); |
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230 | form.action = OpenLayers.Util.urlAppend(this.layer.url, cacheId); |
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231 | |
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232 | // insert the iframe, which has been removed to avoid back-button |
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233 | // problems |
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234 | this.imgDiv.insertBefore(this.createIFrame(), this.imgDiv.firstChild); |
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235 | |
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236 | form.target = this.id+'_iFrame'; |
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237 | |
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238 | // adding all parameters in layer params as hidden fields to the html |
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239 | // form element |
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240 | var imageSize = this.layer.getImageSize(); |
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241 | var params = OpenLayers.Util.extend( |
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242 | { |
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243 | "BBOX": this.encodeBBOX ? this.bounds.toBBOX() : |
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244 | this.bounds.toArray(), |
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245 | "WIDTH": imageSize.w, |
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246 | "HEIGHT": imageSize.h |
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247 | }, this.layer.params); |
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248 | |
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249 | for(var par in params) { |
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250 | var field = document.createElement('input'); |
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251 | field.type = 'hidden'; |
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252 | field.name = par; |
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253 | field.value = params[par]; |
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254 | form.appendChild(field); |
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255 | } |
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256 | |
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257 | return form; |
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258 | }, |
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259 | |
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260 | CLASS_NAME: "OpenLayers.Tile.Image.IFrame" |
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261 | } |
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262 | ); |
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