76 lines
2.1 KiB
JavaScript
76 lines
2.1 KiB
JavaScript
import GeoJSON from '../src/ol/format/GeoJSON.js';
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import Map from '../src/ol/Map.js';
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import VectorLayer from '../src/ol/layer/Vector.js';
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import VectorSource from '../src/ol/source/Vector.js';
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import View from '../src/ol/View.js';
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import {Fill, Stroke, Style} from '../src/ol/style.js';
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import {getBottomLeft, getHeight, getWidth} from '../src/ol/extent.js';
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import {toContext} from '../src/ol/render.js';
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const fill = new Fill();
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const stroke = new Stroke({
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color: 'rgba(255,255,255,0.8)',
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width: 2,
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});
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const style = new Style({
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renderer: function (pixelCoordinates, state) {
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const context = state.context;
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const geometry = state.geometry.clone();
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geometry.setCoordinates(pixelCoordinates);
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const extent = geometry.getExtent();
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const width = getWidth(extent);
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const height = getHeight(extent);
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const flag = state.feature.get('flag');
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if (!flag || height < 1 || width < 1) {
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return;
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}
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// Stitch out country shape from the blue canvas
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context.save();
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const renderContext = toContext(context, {
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pixelRatio: 1,
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});
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renderContext.setFillStrokeStyle(fill, stroke);
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renderContext.drawGeometry(geometry);
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context.clip();
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// Fill transparent country with the flag image
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const bottomLeft = getBottomLeft(extent);
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const left = bottomLeft[0];
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const bottom = bottomLeft[1];
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context.drawImage(flag, 2, 12, 60, 40, left, bottom, width, height);
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context.restore();
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},
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});
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const vectorLayer = new VectorLayer({
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source: new VectorSource({
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url:
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'https://openlayersbook.github.io/openlayers_book_samples/assets/data/countries.geojson',
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format: new GeoJSON(),
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}),
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style: style,
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});
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// Load country flags and set them as `flag` attribute on the country feature
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vectorLayer.getSource().on('addfeature', function (event) {
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const feature = event.feature;
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const img = new Image();
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img.onload = function () {
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feature.set('flag', img);
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};
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img.src =
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'https://www.countryflags.io/' +
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feature.get('iso_a2').toLowerCase() +
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'/flat/64.png';
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});
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new Map({
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layers: [vectorLayer],
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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: 1,
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}),
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});
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