1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 | <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>OpenLayers Layer Opacity Example</title> <link rel="stylesheet" href="../theme/default/style.css" type="text/css" /> <link rel="stylesheet" href="style.css" type="text/css" /> <style type="text/css"> body { font-family: sans-serif; } p { width: 512px; } a { text-decoration: none; color: black; font-weight: bold; font-size: 1.1em; } #opacity { padding: 0; text-align: center; width: 2em; font-family: sans-serif; background: transparent; color: black; border: 0; } p.note { font-style: italic; font-size: 0.8em; } </style> <script src="../lib/OpenLayers.js"></script> <script type="text/javascript"> var map = null; var shade = null; var maxOpacity = 0.9; var minOpacity = 0.1; function changeOpacity(byOpacity) { var newOpacity = (parseFloat(OpenLayers.Util.getElement('opacity').value) + byOpacity).toFixed(1); newOpacity = Math.min(maxOpacity, Math.max(minOpacity, newOpacity)); OpenLayers.Util.getElement('opacity').value = newOpacity; shade.setOpacity(newOpacity); } function init(){ var options = { maxExtent: new OpenLayers.Bounds(-110.994, 45.885, -110.950, 45.929), maxResolution: "auto" }; map = new OpenLayers.Map('map', options); var drg = new OpenLayers.Layer.WMS("Topo Maps", "http://terraservice.net/ogcmap.ashx", {layers: "DRG"}); shade = new OpenLayers.Layer.WMS("Shaded Relief", "http://gisdata.usgs.gov/wmsconnector/com.esri.wms.Esrimap?ServiceName=USGS_EDC_Elev_NED_3", {layers: "HR-NED.IMAGE", reaspect: "false", transparent: 'true'}, {isBaseLayer: false, opacity: 0.3}); map.addLayers([drg, shade]); map.addControl(new OpenLayers.Control.LayerSwitcher()); map.zoomToMaxExtent(); } </script> </head> <body onload="init()"> <h1 id="title">Layer Opacity Example</h1> <div id="tags"></div> <p id="shortdesc"> Demonstrate a change in the opacity for an overlay layer. </p> <div id="map" class="smallmap"></div> <div id="docs"> <p> Note that if you also have the setOpacity method defined on the Layer class, you can tweak the layer opacity after it has been added to the map. </p> <p>Opacity: <a title="decrease opacity" href="javascript: changeOpacity(-0.1);"><<</a> <input id="opacity" type="text" value="0.3" size="3" disabled="true" /> <a title="increase opacity" href="javascript: changeOpacity(0.1);">>></a> </p> <p class="note">IE users: Wait until the shade layer has finished loading to try this.</p> </div> </body> </html> |