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| import Feature from 'ol/Feature.js';
import LineString from 'ol/geom/LineString.js';
import Map from 'ol/Map.js';
import View from 'ol/View.js';
import {OSM, Vector as VectorSource} from 'ol/source.js';
import {Stroke, Style} from 'ol/style.js';
import {Tile as TileLayer, Vector as VectorLayer} from 'ol/layer.js';
const raster = new TileLayer({
source: new OSM(),
});
const style = new Style({
stroke: new Stroke({
color: 'black',
width: 1,
}),
});
const feature = new Feature(
new LineString([
[-4000000, 0],
[4000000, 0],
])
);
const vector = new VectorLayer({
source: new VectorSource({
features: [feature],
}),
style: style,
});
const map = new Map({
layers: [raster, vector],
target: 'map',
view: new View({
center: [0, 0],
zoom: 2,
}),
});
let hitTolerance;
const statusElement = document.getElementById('status');
map.on('singleclick', function (e) {
let hit = false;
map.forEachFeatureAtPixel(
e.pixel,
function () {
hit = true;
},
{
hitTolerance: hitTolerance,
}
);
if (hit) {
style.getStroke().setColor('green');
statusElement.innerHTML = 'A feature got hit!';
} else {
style.getStroke().setColor('black');
statusElement.innerHTML = 'No feature got hit.';
}
feature.changed();
});
const selectHitToleranceElement = document.getElementById('hitTolerance');
const circleCanvas = document.getElementById('circle');
const changeHitTolerance = function () {
hitTolerance = parseInt(selectHitToleranceElement.value, 10);
const size = 2 * hitTolerance + 2;
circleCanvas.width = size;
circleCanvas.height = size;
const ctx = circleCanvas.getContext('2d');
ctx.clearRect(0, 0, size, size);
ctx.beginPath();
ctx.arc(
hitTolerance + 1,
hitTolerance + 1,
hitTolerance + 0.5,
0,
2 * Math.PI
);
ctx.fill();
ctx.stroke();
};
selectHitToleranceElement.onchange = changeHitTolerance;
changeHitTolerance();
|
)
