jiti-meet/react/features/base/participants/preloadImage.web.js

49 lines
1.3 KiB
JavaScript

// @flow
import { isIconUrl } from './functions';
/**
* Tries to preload an image.
*
* @param {string | Object} src - Source of the avatar.
* @param {boolean} useCORS - Whether to use CORS or not.
* @param {boolean} tryOnce - If true we try to load the image only using the specified CORS mode. Otherwise both modes
* (CORS and no CORS) will be used to load the image if the first atempt fails.
* @returns {Promise}
*/
export function preloadImage(
src: string | Object,
useCORS: ?boolean = false,
tryOnce: ?boolean = false
): Promise<Object> {
if (isIconUrl(src)) {
return Promise.resolve({ src });
}
return new Promise((resolve, reject) => {
const image = document.createElement('img');
if (useCORS) {
image.setAttribute('crossOrigin', '');
}
image.onload = () => resolve({
src,
isUsingCORS: useCORS
});
image.onerror = error => {
if (tryOnce) {
reject(error);
} else {
preloadImage(src, !useCORS, true)
.then(resolve)
.catch(reject);
}
};
// $FlowExpectedError
image.referrerPolicy = 'no-referrer';
image.src = src;
});
}