Files
openlayers/examples/kml-earthquakes.js
2022-08-22 19:26:23 +02:00

106 lines
2.5 KiB
JavaScript

import KML from '../src/ol/format/KML.js';
import Map from '../src/ol/Map.js';
import Stamen from '../src/ol/source/Stamen.js';
import VectorSource from '../src/ol/source/Vector.js';
import View from '../src/ol/View.js';
import {Circle as CircleStyle, Fill, Stroke, Style} from '../src/ol/style.js';
import {Tile as TileLayer, Vector as VectorLayer} from '../src/ol/layer.js';
const styleCache = {};
const styleFunction = function (feature) {
// 2012_Earthquakes_Mag5.kml stores the magnitude of each earthquake in a
// standards-violating <magnitude> tag in each Placemark. We extract it from
// the Placemark's name instead.
const name = feature.get('name');
const magnitude = parseFloat(name.substr(2));
const radius = 5 + 20 * (magnitude - 5);
let style = styleCache[radius];
if (!style) {
style = new Style({
image: new CircleStyle({
radius: radius,
fill: new Fill({
color: 'rgba(255, 153, 0, 0.4)',
}),
stroke: new Stroke({
color: 'rgba(255, 204, 0, 0.2)',
width: 1,
}),
}),
});
styleCache[radius] = style;
}
return style;
};
const vector = new VectorLayer({
source: new VectorSource({
url: 'data/kml/2012_Earthquakes_Mag5.kml',
format: new KML({
extractStyles: false,
}),
}),
style: styleFunction,
});
const raster = new TileLayer({
source: new Stamen({
layer: 'toner',
}),
});
const map = new Map({
layers: [raster, vector],
target: 'map',
view: new View({
center: [0, 0],
zoom: 2,
}),
});
const info = document.getElementById('info');
info.style.pointerEvents = 'none';
const tooltip = new bootstrap.Tooltip(info, {
animation: false,
customClass: 'pe-none',
offset: [0, 5],
title: '-',
trigger: 'manual',
});
let currentFeature;
const displayFeatureInfo = function (pixel) {
const feature = map.forEachFeatureAtPixel(pixel, function (feature) {
return feature;
});
if (feature) {
info.style.left = pixel[0] + 'px';
info.style.top = pixel[1] + 'px';
if (feature !== currentFeature) {
tooltip.setContent({'.tooltip-inner': feature.get('name')});
}
if (currentFeature) {
tooltip.update();
} else {
tooltip.show();
}
} else {
tooltip.hide();
}
currentFeature = feature;
};
map.on('pointermove', function (evt) {
if (evt.dragging) {
tooltip.hide();
currentFeature = undefined;
return;
}
const pixel = map.getEventPixel(evt.originalEvent);
displayFeatureInfo(pixel);
});
map.on('click', function (evt) {
displayFeatureInfo(evt.pixel);
});