Files
openlayers/examples/webgl-points-layer.js
2019-10-03 17:06:39 +02:00

117 lines
2.9 KiB
JavaScript

import Map from '../src/ol/Map.js';
import View from '../src/ol/View.js';
import TileLayer from '../src/ol/layer/Tile.js';
import WebGLPointsLayer from '../src/ol/layer/WebGLPoints.js';
import GeoJSON from '../src/ol/format/GeoJSON.js';
import Vector from '../src/ol/source/Vector.js';
import OSM from '../src/ol/source/OSM.js';
const vectorSource = new Vector({
url: 'data/geojson/world-cities.geojson',
format: new GeoJSON()
});
const predefinedStyles = {
'icons': {
symbol: {
symbolType: 'image',
src: 'data/icon.png',
size: [18, 28],
color: 'lightyellow',
rotateWithView: false,
offset: [0, 9]
}
},
'triangles': {
symbol: {
symbolType: 'triangle',
size: 18,
color: [
['stretch', ['get', 'population'], 20000, 300000, 0.1, 1.0],
['stretch', ['get', 'population'], 20000, 300000, 0.6, 0.3],
0.6,
1.0
],
rotateWithView: true
}
},
'circles': {
symbol: {
symbolType: 'circle',
size: ['stretch', ['get', 'population'], 40000, 2000000, 8, 28],
color: '#006688',
rotateWithView: false,
offset: [0, 0],
opacity: ['stretch', ['get', 'population'], 40000, 2000000, 0.6, 0.92]
}
}
};
const map = new Map({
layers: [
new TileLayer({
source: new OSM()
})
],
target: document.getElementById('map'),
view: new View({
center: [0, 0],
zoom: 2
})
});
let literalStyle;
let pointsLayer;
function refreshLayer(newStyle) {
const previousLayer = pointsLayer;
pointsLayer = new WebGLPointsLayer({
source: vectorSource,
style: newStyle
});
map.addLayer(pointsLayer);
if (previousLayer) {
map.removeLayer(previousLayer);
}
literalStyle = newStyle;
}
const spanValid = document.getElementById('style-valid');
const spanInvalid = document.getElementById('style-invalid');
function setStyleStatus(errorMsg) {
const isError = typeof errorMsg === 'string';
spanValid.style.display = errorMsg === null ? 'initial' : 'none';
spanInvalid.firstElementChild.innerText = isError ? errorMsg : '';
spanInvalid.style.display = isError ? 'initial' : 'none';
}
const editor = document.getElementById('style-editor');
editor.addEventListener('input', function() {
const textStyle = editor.value;
try {
const newLiteralStyle = JSON.parse(textStyle);
if (JSON.stringify(newLiteralStyle) !== JSON.stringify(literalStyle)) {
refreshLayer(newLiteralStyle);
}
setStyleStatus(null);
} catch (e) {
setStyleStatus(e.message);
}
});
const select = document.getElementById('style-select');
select.value = 'circles';
function onSelectChange() {
const style = select.value;
const newLiteralStyle = predefinedStyles[style];
editor.value = JSON.stringify(newLiteralStyle, null, 2);
try {
refreshLayer(newLiteralStyle);
setStyleStatus();
} catch (e) {
setStyleStatus(e.message);
}
}
onSelectChange();
select.addEventListener('change', onSelectChange);