Add an example showing the use of ol.style.Style#geometry

This commit is contained in:
Andreas Hocevar
2014-12-09 20:07:53 +01:00
parent 2d12531105
commit 8d9acb8f48
2 changed files with 230 additions and 0 deletions

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<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="chrome=1">
<meta name="viewport" content="initial-scale=1.0, user-scalable=no, width=device-width">
<link rel="stylesheet" href="../css/ol.css" type="text/css">
<link rel="stylesheet" href="../resources/bootstrap/css/bootstrap.min.css" type="text/css">
<link rel="stylesheet" href="../resources/layout.css" type="text/css">
<link rel="stylesheet" href="../resources/bootstrap/css/bootstrap-responsive.min.css" type="text/css">
<title>Earthquake Clusters</title>
<style>
#map {
position: relative;
}
#info {
position: absolute;
height: 1px;
width: 1px;
z-index: 100;
}
.tooltip.in {
opacity: 1;
filter: alpha(opacity=100);
}
.tooltip.top .tooltip-arrow {
border-top-color: white;
}
.tooltip-inner {
border: 2px solid white;
}
</style>
</head>
<body>
<div class="navbar navbar-inverse navbar-fixed-top">
<div class="navbar-inner">
<div class="container">
<a class="brand" href="./"><img src="../resources/logo.png"> OpenLayers 3 Examples</a>
</div>
</div>
</div>
<div class="container-fluid">
<div class="row-fluid">
<div class="span12">
<div id="map" class="map"></div>
</div>
</div>
<div class="row-fluid">
<div class="span12">
<h4 id="title">Earthquake Clusters</h4>
<p id="shortdesc">Demonstrates the use of style geometries to render source features of a cluster.</p>
<div id="docs">
<p>
This example parses a KML file and renders the features as clusters on a vector layer. The styling in this example is quite involved. Single earthquake locations (rendered as stars) have a size relative to their magnitude. Clusters have an opacity relative to the number of features in the cluster, and a size that represents the extent of the features that make up the cluster. When clicking or hovering on a cluster, the individual features that make up the cluster will be shown.
</p>
<p>To achieve this, we make heavy use of style functions and <code>ol.style.Style#geometry</code>. See the <a href="earthquake-clusters.js" target="_blank">earthquake-clusters.js source</a> to see how this is done.</p>
</div>
<div id="tags">KML, vector, style, geometry, cluster</div>
</div>
</div>
</div>
<script src="../resources/jquery.min.js" type="text/javascript"></script>
<script src="../resources/bootstrap/js/bootstrap.min.js" type="text/javascript"></script>
<script src="../resources/example-behaviour.js" type="text/javascript"></script>
<script src="loader.js?id=earthquake-clusters" type="text/javascript"></script>
</body>
</html>

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goog.require('ol.Map');
goog.require('ol.View');
goog.require('ol.extent');
goog.require('ol.interaction');
goog.require('ol.interaction.Select');
goog.require('ol.layer.Tile');
goog.require('ol.layer.Vector');
goog.require('ol.source.Cluster');
goog.require('ol.source.KML');
goog.require('ol.source.Stamen');
goog.require('ol.style.Circle');
goog.require('ol.style.Fill');
goog.require('ol.style.RegularShape');
goog.require('ol.style.Stroke');
goog.require('ol.style.Style');
goog.require('ol.style.Text');
var earthquakeFill = new ol.style.Fill({
color: 'rgba(255, 153, 0, 0.8)'
});
var earthquakeStroke = new ol.style.Stroke({
color: 'rgba(255, 204, 0, 0.2)',
width: 1
});
var textFill = new ol.style.Fill({
color: '#fff'
});
var textStroke = new ol.style.Stroke({
color: 'rgba(0, 0, 0, 0.6)',
width: 3
});
var invisibleFill = new ol.style.Fill({
color: 'rgba(255, 255, 255, 0.01)'
});
function createEarthquakeStyle(feature) {
// 2012_Earthquakes_Mag5.kml stores the magnitude of each earthquake in a
// standards-violating <magnitude> tag in each Placemark. We extract it
// from the Placemark's name instead.
var name = feature.get('name');
var magnitude = parseFloat(name.substr(2));
var radius = 5 + 20 * (magnitude - 5);
return new ol.style.Style({
geometry: feature.getGeometry(),
image: new ol.style.RegularShape({
radius1: radius,
radius2: 3,
points: 5,
angle: Math.PI,
fill: earthquakeFill,
stroke: earthquakeStroke
})
});
}
var maxFeatureCount;
function calculateClusterInfo(resolution) {
maxFeatureCount = 0;
var features = vector.getSource().getFeatures();
var feature, radius;
for (var i = features.length - 1; i >= 0; --i) {
feature = features[i];
var originalFeatures = feature.get('features');
var extent = ol.extent.createEmpty();
for (var j = 0, jj = originalFeatures.length; j < jj; ++j) {
ol.extent.extendCoordinate(extent,
originalFeatures[j].getGeometry().getCoordinates());
}
maxFeatureCount = Math.max(maxFeatureCount, jj);
radius = 0.25 * (ol.extent.getWidth(extent) + ol.extent.getHeight(extent)) /
resolution;
feature.set('radius', radius);
}
}
var currentResolution;
function styleFunction(feature, resolution) {
if (resolution != currentResolution) {
calculateClusterInfo(resolution);
currentResolution = resolution;
}
var style;
var size = feature.get('features').length;
if (size > 1) {
style = [new ol.style.Style({
image: new ol.style.Circle({
radius: feature.get('radius'),
fill: new ol.style.Fill({
color: [255, 153, 0, Math.min(0.8, 0.4 + (size / maxFeatureCount))]
})
}),
text: new ol.style.Text({
text: size.toString(),
fill: textFill,
stroke: textStroke
})
})];
} else {
var originalFeature = feature.get('features')[0];
style = [createEarthquakeStyle(originalFeature)];
}
return style;
}
function selectStyleFunction(feature, resolution) {
var styles = [new ol.style.Style({
image: new ol.style.Circle({
radius: feature.get('radius'),
fill: invisibleFill
})
})];
var originalFeatures = feature.get('features');
var originalFeature;
for (var i = originalFeatures.length - 1; i >= 0; --i) {
originalFeature = originalFeatures[i];
styles.push(createEarthquakeStyle(originalFeature));
}
return styles;
}
var vector = new ol.layer.Vector({
source: new ol.source.Cluster({
distance: 40,
source: new ol.source.KML({
extractStyles: false,
projection: 'EPSG:3857',
url: 'data/kml/2012_Earthquakes_Mag5.kml'
})
}),
style: styleFunction
});
var raster = new ol.layer.Tile({
source: new ol.source.Stamen({
layer: 'toner'
})
});
var map = new ol.Map({
layers: [raster, vector],
interactions: ol.interaction.defaults().extend([new ol.interaction.Select({
condition: function(evt) {
return evt.originalEvent.type == 'mousemove' ||
evt.type == 'singleclick';
},
style: selectStyleFunction
})]),
target: 'map',
view: new ol.View({
center: [0, 0],
zoom: 2
})
});