Maplibre
Hover over GeoJSON Line Data
Maplibre
Hover over GeoJSON Line Data
Show line data from GeoJSON on the map
GeoJSON hover
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8"/>
<title>Display a Solvice Map on a webpage: hover</title>
<meta content="initial-scale=1,maximum-scale=1,user-scalable=no" name="viewport"/>
<link href="https://unpkg.com/maplibre-gl@4.1.0/dist/maplibre-gl.css" rel="stylesheet"/>
<script src="https://unpkg.com/maplibre-gl@4.1.0/dist/maplibre-gl.js"></script>
<style>
body { margin: 0; padding: 0; }
html, body, #map { height: 100%; }
</style>
</head>
<body>
<div id="map"></div>
<script>
const map = new maplibregl.Map({
container: "map",
hash: true,
center: [-122.4194, 37.7749],
zoom: 4,
style: 'https://cdn.solvice.io/styles/light.json',
});
let hoveredStateId = null;
map.on('load', () => {
map.addSource('states', {
'type': 'geojson',
'data':
'https://maplibre.org/maplibre-gl-js/docs/assets/us_states.geojson'
});
// The feature-state dependent fill-opacity expression will render the hover effect
// when a feature's hover state is set to true.
map.addLayer({
'id': 'state-fills',
'type': 'fill',
'source': 'states',
'layout': {},
'paint': {
'fill-color': '#29ade7',
'fill-opacity': [
'case',
['boolean', ['feature-state', 'hover'], false],
1,
0.5
]
}
});
map.addLayer({
'id': 'state-borders',
'type': 'line',
'source': 'states',
'layout': {},
'paint': {
'line-color': '#29ade7',
'line-width': 1
}
});
// When the user moves their mouse over the state-fill layer, we'll update the
// feature state for the feature under the mouse.
map.on('mousemove', 'state-fills', (e) => {
if (e.features.length > 0) {
if (hoveredStateId) {
map.setFeatureState(
{source: 'states', id: hoveredStateId},
{hover: false}
);
}
hoveredStateId = e.features[0].id;
map.setFeatureState(
{source: 'states', id: hoveredStateId},
{hover: true}
);
}
});
// When the mouse leaves the state-fill layer, update the feature state of the
// previously hovered feature.
map.on('mouseleave', 'state-fills', () => {
if (hoveredStateId) {
map.setFeatureState(
{source: 'states', id: hoveredStateId},
{hover: false}
);
}
hoveredStateId = null;
});
});
</script>
</body>
</html>