Example of using the Select interaction.
Choose between Single-click
, Click
, Hover
and Alt+Click
as the event type for selection in the combobox below. When using Single-click
or Click
you can hold the Shift
key to toggle the feature in the selection.
Note: when Single-click
is used double-clicks won't select features. This in contrast to Click
, where a double-click will both select the feature and zoom the map (because of the DoubleClickZoom
interaction). Note that Single-click
is less responsive than Click
because of the delay it uses to detect double-clicks.
In this example, a listener is registered for the Select interaction's select
event in order to update the selection status above.
import GeoJSON from 'ol/format/GeoJSON.js';
import Map from 'ol/Map.js';
import Select from 'ol/interaction/Select.js';
import VectorLayer from 'ol/layer/Vector.js';
import VectorSource from 'ol/source/Vector.js';
import View from 'ol/View.js';
import {Fill, Stroke, Style} from 'ol/style.js';
import {altKeyOnly, click, pointerMove} from 'ol/events/condition.js';
const style = new Style({
fill: new Fill({
color: '#eeeeee',
}),
});
const vector = new VectorLayer({
source: new VectorSource({
url: 'https://openlayers.org/data/vector/ecoregions.json',
format: new GeoJSON(),
}),
background: 'white',
style: function (feature) {
const color = feature.get('COLOR') || '#eeeeee';
style.getFill().setColor(color);
return style;
},
});
const map = new Map({
layers: [vector],
target: 'map',
view: new View({
center: [0, 0],
zoom: 2,
}),
});
let select = null; // ref to currently selected interaction
const selected = new Style({
fill: new Fill({
color: '#eeeeee',
}),
stroke: new Stroke({
color: 'rgba(255, 255, 255, 0.7)',
width: 2,
}),
});
function selectStyle(feature) {
const color = feature.get('COLOR') || '#eeeeee';
selected.getFill().setColor(color);
return selected;
}
// select interaction working on "singleclick"
const selectSingleClick = new Select({style: selectStyle});
// select interaction working on "click"
const selectClick = new Select({
condition: click,
style: selectStyle,
});
// select interaction working on "pointermove"
const selectPointerMove = new Select({
condition: pointerMove,
style: selectStyle,
});
const selectAltClick = new Select({
style: selectStyle,
condition: function (mapBrowserEvent) {
return click(mapBrowserEvent) && altKeyOnly(mapBrowserEvent);
},
});
const selectElement = document.getElementById('type');
const changeInteraction = function () {
if (select !== null) {
map.removeInteraction(select);
}
const value = selectElement.value;
if (value == 'singleclick') {
select = selectSingleClick;
} else if (value == 'click') {
select = selectClick;
} else if (value == 'pointermove') {
select = selectPointerMove;
} else if (value == 'altclick') {
select = selectAltClick;
} else {
select = null;
}
if (select !== null) {
map.addInteraction(select);
select.on('select', function (e) {
document.getElementById('status').innerHTML =
' ' +
e.target.getFeatures().getLength() +
' selected features (last operation selected ' +
e.selected.length +
' and deselected ' +
e.deselected.length +
' features)';
});
}
};
/**
* onchange callback on the select element.
*/
selectElement.onchange = changeInteraction;
changeInteraction();
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Select Features</title>
<link rel="stylesheet" href="node_modules/ol/ol.css">
<style>
.map {
width: 100%;
height: 400px;
}
</style>
</head>
<body>
<div id="map" class="map"></div>
<form>
<label for="type">Action type </label>
<select id="type">
<option value="click" selected>Click</option>
<option value="singleclick">Single-click</option>
<option value="pointermove">Hover</option>
<option value="altclick">Alt+Click</option>
<option value="none">None</option>
</select>
<span id="status"> 0 selected features</span>
</form>
<script type="module" src="main.js"></script>
</body>
</html>
{
"name": "select-features",
"dependencies": {
"ol": "10.3.1"
},
"devDependencies": {
"vite": "^3.2.3"
},
"scripts": {
"start": "vite",
"build": "vite build"
}
}