[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 | /** |
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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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