Add a box feature selection example

2014-07-08 16:26:06 +02:00
parent 227f3bae18
commit 79445e993b
2 changed files with 140 additions and 0 deletions
--- a/examples/box-selection.html
+++ b/examples/box-selection.html
@@ -0,0 +1,59 @@
+<!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>Box selection example</title>
+  </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="span4">
+          <h4 id="title">Box selection example</h4>
+          <p id="shortdesc">Using a DragBox interaction to select features.</p>
+          <div id="docs">
+            <p>This example shows how to use a <code>DragBox</code> interaction to select features. Selected features are added
+            to the feature overlay of a select interaction (<code>ol.interaction.Select</code>) for highlighting.</p>
+            <p>Use <code>SHIFT+drag</code> to draw boxes.</p>
+            <p>See the <a href="box-selection.js" target="_blank">box-selection.js source</a> to see how this is done.</p>
+          </div>
+          <div id="tags">DragBox, feature, selection, box</div>
+        </div>
+        <div class="span4 offset4">
+          <div id="info" class="alert alert-success">
+            &nbsp;
+          </div>
+        </div>
+
+      </div>
+
+    </div>
+
+    <script src="jquery.min.js" type="text/javascript"></script>
+    <script src="../resources/example-behaviour.js" type="text/javascript"></script>
+    <script src="loader.js?id=box-selection" type="text/javascript"></script>
+
+  </body>
+</html>
--- a/examples/box-selection.js
+++ b/examples/box-selection.js
@@ -0,0 +1,81 @@
+goog.require('ol.Map');
+goog.require('ol.View');
+goog.require('ol.events.condition');
+goog.require('ol.interaction');
+goog.require('ol.interaction.DragBox');
+goog.require('ol.interaction.Select');
+goog.require('ol.layer.Tile');
+goog.require('ol.layer.Vector');
+goog.require('ol.source.GeoJSON');
+goog.require('ol.source.OSM');
+goog.require('ol.style.Stroke');
+goog.require('ol.style.Style');
+
+
+var vectorSource = new ol.source.GeoJSON({
+  projection: 'EPSG:3857',
+  url: 'data/geojson/countries.geojson'
+});
+
+
+var map = new ol.Map({
+  layers: [
+    new ol.layer.Tile({
+      source: new ol.source.OSM()
+    }),
+    new ol.layer.Vector({
+      source: vectorSource
+    })
+  ],
+  renderer: 'canvas',
+  target: 'map',
+  view: new ol.View({
+    center: [0, 0],
+    zoom: 2
+  })
+});
+
+// a normal select interaction to handle click
+var select = new ol.interaction.Select();
+map.addInteraction(select);
+
+var selectedFeatures = select.getFeatures();
+
+// a DragBox interaction used to select features by drawing boxes
+var dragBox = new ol.interaction.DragBox({
+  condition: ol.events.condition.shiftKeyOnly,
+  style: new ol.style.Style({
+    stroke: new ol.style.Stroke({
+      color: [0, 0, 255, 1]
+    })
+  })
+});
+
+map.addInteraction(dragBox);
+
+var infoBox = document.getElementById('info');
+
+dragBox.on('boxend', function(e) {
+  // features that intersect the box are added to the collection of
+  // selected features, and their names are displayed in the "info"
+  // div
+  var info = [];
+  var extent = dragBox.getGeometry().getExtent();
+  vectorSource.forEachFeatureIntersectingExtent(extent, function(feature) {
+    selectedFeatures.push(feature);
+    info.push(feature.get('name'));
+  });
+  if (info.length > 0) {
+    infoBox.innerHTML = info.join(', ');
+  }
+});
+
+// clear selection when drawing a new box and when clicking on the map
+dragBox.on('boxstart', function(e) {
+  selectedFeatures.clear();
+  infoBox.innerHTML = '&nbsp;';
+});
+map.on('click', function() {
+  selectedFeatures.clear();
+  infoBox.innerHTML = '&nbsp;';
+});