Create a draggable point
Drag the point to a new location on a map and populate its coordinates in a display.
NPM module setup
npm install --save @maptiler/sdk
import { Map, MapStyle, config } from '@maptiler/sdk';
import '@maptiler/sdk/dist/maptiler-sdk.css';
config.apiKey = 'YOUR_MAPTILER_API_KEY_HERE';
const coordinates = document.getElementById('coordinates');
const map = new Map({
container: 'map',
style: MapStyle.STREETS,
center: [0, 0],
zoom: 2
});
const canvas = map.getCanvasContainer();
const geojson = {
'type': 'FeatureCollection',
'features': [
{
'type': 'Feature',
'geometry': {
'type': 'Point',
'coordinates': [0, 0]
}
}
]
};
function onMove(e) {
const coords = e.lngLat;
// Set a UI indicator for dragging.
canvas.style.cursor = 'grabbing';
// Update the Point feature in `geojson` coordinates
// and call setData to the source layer `point` on it.
geojson.features[0].geometry.coordinates = [coords.lng, coords.lat];
map.getSource('point').setData(geojson);
}
function onUp(e) {
const coords = e.lngLat;
// Print the coordinates of where the point had
// finished being dragged to on the map.
coordinates.style.display = 'block';
coordinates.innerHTML =
'Longitude: ' + coords.lng + '<br />Latitude: ' + coords.lat;
canvas.style.cursor = '';
// Unbind mouse/touch events
map.off('mousemove', onMove);
map.off('touchmove', onMove);
}
map.on('load', function () {
// Add a single point to the map
map.addSource('point', {
'type': 'geojson',
'data': geojson
});
map.addLayer({
'id': 'point',
'type': 'circle',
'source': 'point',
'paint': {
'circle-radius': 10,
'circle-color': '#3887be'
}
});
// When the cursor enters a feature in the point layer, prepare for dragging.
map.on('mouseenter', 'point', function () {
map.setPaintProperty('point', 'circle-color', '#3bb2d0');
canvas.style.cursor = 'move';
});
map.on('mouseleave', 'point', function () {
map.setPaintProperty('point', 'circle-color', '#3887be');
canvas.style.cursor = '';
});
map.on('mousedown', 'point', function (e) {
// Prevent the default map drag behavior.
e.preventDefault();
canvas.style.cursor = 'grab';
map.on('mousemove', onMove);
map.once('mouseup', onUp);
});
map.on('touchstart', 'point', function (e) {
if (e.points.length !== 1) return;
// Prevent the default map drag behavior.
e.preventDefault();
map.on('touchmove', onMove);
map.once('touchend', onUp);
});
});
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="robots" content="noindex">
<title>Create a draggable point | NPM example</title>
<link rel="stylesheet" href="./style.css">
</head>
<body>
<style>
.coordinates {
background: rgba(0, 0, 0, 0.5);
color: #fff;
position: absolute;
bottom: 40px;
left: 10px;
padding: 5px 10px;
margin: 0;
font-size: 11px;
line-height: 18px;
border-radius: 3px;
display: none;
}
</style>
<div id="map"></div>
<pre id="coordinates" class="coordinates"></pre>
<script type="module" src="./main.js"></script>
</body>
</html>
body {margin: 0; padding: 0;}
#map {position: absolute; top: 0; bottom: 0; width: 100%;}
