74 lines
1.9 KiB
JavaScript
74 lines
1.9 KiB
JavaScript
import Map from '../src/ol/Map.js';
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import View from '../src/ol/View.js';
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import {platformModifierKeyOnly} from '../src/ol/events/condition.js';
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import GeoJSON from '../src/ol/format/GeoJSON.js';
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import DragBox from '../src/ol/interaction/DragBox.js';
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import Select from '../src/ol/interaction/Select.js';
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import TileLayer from '../src/ol/layer/Tile.js';
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import VectorLayer from '../src/ol/layer/Vector.js';
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import OSM from '../src/ol/source/OSM.js';
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import VectorSource from '../src/ol/source/Vector.js';
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const vectorSource = new VectorSource({
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url: 'data/geojson/countries.geojson',
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format: new GeoJSON()
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});
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const map = new Map({
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layers: [
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new TileLayer({
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source: new OSM()
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}),
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new VectorLayer({
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source: vectorSource
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})
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],
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target: 'map',
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view: new View({
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center: [0, 0],
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zoom: 2
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})
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});
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// a normal select interaction to handle click
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const select = new Select();
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map.addInteraction(select);
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const selectedFeatures = select.getFeatures();
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// a DragBox interaction used to select features by drawing boxes
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const dragBox = new DragBox({
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condition: platformModifierKeyOnly
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});
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map.addInteraction(dragBox);
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dragBox.on('boxend', function() {
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// features that intersect the box are added to the collection of
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// selected features
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const extent = dragBox.getGeometry().getExtent();
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vectorSource.forEachFeatureIntersectingExtent(extent, function(feature) {
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selectedFeatures.push(feature);
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});
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});
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// clear selection when drawing a new box and when clicking on the map
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dragBox.on('boxstart', function() {
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selectedFeatures.clear();
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});
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const infoBox = document.getElementById('info');
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selectedFeatures.on(['add', 'remove'], function() {
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const names = selectedFeatures.getArray().map(function(feature) {
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return feature.get('name');
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});
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if (names.length > 0) {
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infoBox.innerHTML = names.join(', ');
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} else {
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infoBox.innerHTML = 'No countries selected';
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}
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});
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