Files
openlayers/examples/tile-load-events.js
2022-03-19 10:50:04 +01:00

94 lines
2.0 KiB
JavaScript

import Map from '../src/ol/Map.js';
import TileLayer from '../src/ol/layer/Tile.js';
import View from '../src/ol/View.js';
import XYZ from '../src/ol/source/XYZ.js';
/**
* Renders a progress bar.
* @param {HTMLElement} el The target element.
* @class
*/
function Progress(el) {
this.el = el;
this.loading = 0;
this.loaded = 0;
}
/**
* Increment the count of loading tiles.
*/
Progress.prototype.addLoading = function () {
++this.loading;
this.update();
};
/**
* Increment the count of loaded tiles.
*/
Progress.prototype.addLoaded = function () {
++this.loaded;
this.update();
};
/**
* Update the progress bar.
*/
Progress.prototype.update = function () {
const width = ((this.loaded / this.loading) * 100).toFixed(1) + '%';
this.el.style.width = width;
};
/**
* Show the progress bar.
*/
Progress.prototype.show = function () {
this.el.style.visibility = 'visible';
};
/**
* Hide the progress bar.
*/
Progress.prototype.hide = function () {
const style = this.el.style;
setTimeout(function () {
style.visibility = 'hidden';
style.width = 0;
}, 250);
};
const progress = new Progress(document.getElementById('progress'));
const key = 'get_your_own_D6rA4zTHduk6KOKTXzGB';
const attributions =
'<a href="https://www.maptiler.com/copyright/" target="_blank">&copy; MapTiler</a> ' +
'<a href="https://www.openstreetmap.org/copyright" target="_blank">&copy; OpenStreetMap contributors</a>';
const source = new XYZ({
attributions: attributions,
url: 'https://api.maptiler.com/maps/streets/{z}/{x}/{y}.png?key=' + key,
tileSize: 512,
});
source.on('tileloadstart', function () {
progress.addLoading();
});
source.on(['tileloadend', 'tileloaderror'], function () {
progress.addLoaded();
});
const map = new Map({
layers: [new TileLayer({source: source})],
target: 'map',
view: new View({
center: [0, 0],
zoom: 2,
}),
});
map.on('loadstart', function () {
progress.show();
});
map.on('loadend', function () {
progress.hide();
});