| 1 | <!DOCTYPE html> |
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| 2 | <html> |
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| 3 | <head> |
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| 4 | <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> |
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| 5 | <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0"> |
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| 6 | <meta name="apple-mobile-web-app-capable" content="yes"> |
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| 7 | <title>OpenLayers Vector Styles</title> |
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| 8 | <link rel="stylesheet" href="../theme/default/style.css" type="text/css"> |
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| 9 | <link rel="stylesheet" href="style.css" type="text/css"> |
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| 10 | <script src="../lib/OpenLayers.js"></script> |
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| 11 | <script type="text/javascript"> |
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| 12 | var map; |
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| 13 | |
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| 14 | function init(){ |
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| 15 | map = new OpenLayers.Map('map', {maxResolution:'auto'}); |
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| 16 | var wms = new OpenLayers.Layer.WMS( "OpenLayers WMS", |
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| 17 | "http://vmap0.tiles.osgeo.org/wms/vmap0", {layers: 'basic'} ); |
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| 18 | map.addLayer(wms); |
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| 19 | map.setCenter(new OpenLayers.LonLat(0, 0), 0); |
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| 20 | |
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| 21 | // Strategy 1: Style features based on some attribute. |
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| 22 | |
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| 23 | // create 50 random features in the northern hemisphere |
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| 24 | // give them a "type" attribute that will be used to style |
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| 25 | // them by size |
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| 26 | var features = new Array(50); |
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| 27 | for (var i=0; i<features.length; i++) { |
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| 28 | features[i] = new OpenLayers.Feature.Vector( |
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| 29 | new OpenLayers.Geometry.Point( |
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| 30 | (360 * Math.random()) - 180, 90 * Math.random() |
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| 31 | ), { |
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| 32 | type: 5 + parseInt(5 * Math.random()) |
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| 33 | } |
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| 34 | ); |
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| 35 | } |
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| 36 | |
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| 37 | // allow testing of specific renderers via "?renderer=Canvas", etc |
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| 38 | var renderer = OpenLayers.Util.getParameters(window.location.href).renderer; |
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| 39 | renderer = (renderer) ? [renderer] : OpenLayers.Layer.Vector.prototype.renderers; |
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| 40 | |
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| 41 | // create the layer styleMap with a simple symbolizer template |
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| 42 | var layer1 = new OpenLayers.Layer.Vector('Points', { |
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| 43 | styleMap: new OpenLayers.StyleMap({ |
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| 44 | pointRadius: "${type}", // based on feature.attributes.type |
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| 45 | fillColor: "#666666" |
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| 46 | }), |
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| 47 | renderers: renderer |
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| 48 | }); |
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| 49 | layer1.addFeatures(features); |
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| 50 | |
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| 51 | // Strategy 2: Style features based on something besides attributes. |
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| 52 | |
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| 53 | // create 50 random features in the southern hemisphere |
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| 54 | var features = new Array(50); |
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| 55 | for (var i=0; i<features.length; i++) { |
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| 56 | features[i] = new OpenLayers.Feature.Vector( |
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| 57 | new OpenLayers.Geometry.Point( |
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| 58 | (360 * Math.random()) - 180, -90 * Math.random() |
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| 59 | ), { |
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| 60 | type: 5 + parseInt(5 * Math.random()) |
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| 61 | } |
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| 62 | ); |
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| 63 | } |
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| 64 | // create the layer styleMap by giving the default style a context |
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| 65 | var colors = ["red", "green", "blue"]; |
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| 66 | var context = { |
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| 67 | getColor: function(feature) { |
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| 68 | var region = parseInt((feature.geometry.x + 180) / 120); |
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| 69 | return colors[region]; |
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| 70 | }, |
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| 71 | getSize: function(feature) { |
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| 72 | return feature.attributes["type"] / map.getResolution() * .703125; |
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| 73 | } |
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| 74 | }; |
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| 75 | var template = { |
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| 76 | pointRadius: "${getSize}", // using context.getSize(feature) |
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| 77 | fillColor: "${getColor}" // using context.getColor(feature) |
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| 78 | }; |
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| 79 | var style = new OpenLayers.Style(template, {context: context}); |
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| 80 | var layer2 = new OpenLayers.Layer.Vector('Points', { |
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| 81 | styleMap: new OpenLayers.StyleMap(style), |
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| 82 | renderers: renderer |
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| 83 | }); |
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| 84 | layer2.addFeatures(features); |
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| 85 | |
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| 86 | |
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| 87 | map.addLayers([layer1, layer2]); |
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| 88 | } |
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| 89 | </script> |
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| 90 | </head> |
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| 91 | <body onload="init()"> |
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| 92 | <h1 id="title">Feature Styles Example</h1> |
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| 93 | |
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| 94 | <div id="tags"> |
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| 95 | vector, feature, stylemap, light |
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| 96 | </div> |
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| 97 | |
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| 98 | <p id="shortdesc"> |
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| 99 | To style features with a custom function that evaluates each feature, use |
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| 100 | the context option of an OpenLayers.Style object. If the context object |
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| 101 | contains a function and this function is referenced in a symbolizer, the |
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| 102 | function will be called with the feature as an argument.. |
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| 103 | </p> |
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| 104 | |
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| 105 | <div id="map" class="smallmap"></div> |
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| 106 | |
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| 107 | <div id="docs"> |
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| 108 | <p>Features in the northern hemisphere are styled according to their |
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| 109 | "type" attribute. This is accomplished with a simple template that |
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| 110 | is evaluated with the feature attributes as context.</p> |
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| 111 | <p>Features in the sourthern hemisphere are styled according to a |
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| 112 | combination of their attributes and non-attribute properties. This |
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| 113 | is accomplished using an advanced template that calls functions |
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| 114 | on the context object passed to the Style constructor.</p> |
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| 115 | </div> |
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| 116 | </body> |
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| 117 | </html> |
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