Leaflet/debug/vector/geojson.html
2025-05-06 21:11:43 +02:00

162 lines
3.5 KiB
HTML

<!doctype html>
<html>
<head>
<meta charset="utf-8" />
<title>Leaflet debug page - GeoJSON</title>
<meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=0" />
<link rel="stylesheet" href="../../dist/leaflet.css" />
<link rel="stylesheet" href="../css/screen.css" />
<style>
.info {
padding: 6px 8px;
font: 14px/16px Arial, Helvetica, sans-serif;
background: white;
background: rgba(255,255,255,0.8);
box-shadow: 0 0 15px rgba(0,0,0,0.2);
border-radius: 5px;
}
.info h4 {
margin: 0 0 5px;
color: #777;
}
.legend {
text-align: left;
line-height: 18px;
color: #555;
}
.legend i {
width: 18px;
height: 18px;
float: left;
margin-right: 8px;
opacity: 0.7;
}
</style>
<script type="importmap">
{
"imports": {
"leaflet": "../../dist/leaflet-src.js"
}
}
</script>
</head>
<body>
<div id="map"></div>
<script type="module">
import {Map, TileLayer, Control, DomUtil, GeoJSON} from 'leaflet';
import statesData from './us-states.js';
const map = new Map('map').setView([37.8, -96], 4);
const tiles = new TileLayer('https://tile.openstreetmap.org/{z}/{x}/{y}.png');
map.addLayer(tiles);
// control that shows state info on hover
const info = new Control();
info.onAdd = function () {
this._div = DomUtil.create('div', 'info');
this.update();
return this._div;
};
info.update = function (props) {
this._div.innerHTML = `
<h4>US Population Density</h4>
${(props ? `<b>${props.name}</b><br />${props.density} people / mi<sup>2</sup>` : 'Hover over a state')}
`;
};
map.addControl(info);
// get color depending on population density value
function getColor(d) {
return (
d > 1000 ? '#800026' :
d > 500 ? '#BD0026' :
d > 200 ? '#E31A1C' :
d > 100 ? '#FC4E2A' :
d > 50 ? '#FD8D3C' :
d > 20 ? '#FEB24C' :
d > 10 ? '#FED976' :
'#FFEDA0'
);
}
function style(feature) {
return {
weight: 2,
opacity: 1,
color: 'white',
dashArray: '3',
fillOpacity: 0.7,
fillColor: getColor(feature.properties.density)
};
}
function highlightFeature(e) {
const layer = e.target;
layer.setStyle({
weight: 5,
color: '#666',
dashArray: '',
fillOpacity: 0.7
});
layer.bringToFront();
info.update(layer.feature.properties);
}
const geojson = new GeoJSON(statesData, {
style,
onEachFeature,
attribution: 'Population data &copy; <a href="http://census.gov/">US Census Bureau</a>'
});
map.addLayer(geojson);
function resetHighlight(e) {
geojson.resetStyle(e.target);
info.update();
}
function zoomToFeature(e) {
map.fitBounds(e.target.getBounds());
}
function onEachFeature(feature, layer) {
layer.on({
pointerover: highlightFeature,
pointerout: resetHighlight,
click: zoomToFeature
});
}
const legend = new Control({position: 'bottomright'});
legend.onAdd = function () {
const div = DomUtil.create('div', 'info legend');
const grades = [0, 10, 20, 50, 100, 200, 500, 1000];
const labels = [];
for (let i = 0; i < grades.length; i++) {
const from = grades[i];
const to = grades[i + 1];
labels.push(
`<i style="background: ${getColor(from + 1)};"></i> ${from + (to ? ` &ndash; ${to}` : '+')}`
);
}
div.innerHTML = labels.join('<br>');
return div;
};
legend.addTo(map);
</script>
</body>
</html>