bigbuffet-rw/app/soapbox/utils/favicon_service.ts
2022-04-24 14:28:07 -05:00

81 lines
2.8 KiB
TypeScript

// Adapted from Pleroma FE
// https://git.pleroma.social/pleroma/pleroma-fe/-/blob/ef5bbc4e5f84bb9e8da76a0440eea5d656d36977/src/services/favicon_service/favicon_service.js
type Favicon = {
favcanvas: HTMLCanvasElement,
favimg: HTMLImageElement,
favcontext: CanvasRenderingContext2D | null,
favicon: HTMLLinkElement,
};
/** Service to draw and update a notifications dot on the favicon */
const createFaviconService = () => {
const favicons: Favicon[] = [];
const faviconWidth = 128;
const faviconHeight = 128;
const badgeRadius = 24;
/** Start the favicon service */
const initFaviconService = (): void => {
const nodes: NodeListOf<HTMLLinkElement> = document.querySelectorAll('link[rel="icon"]');
nodes.forEach(favicon => {
if (favicon) {
const favcanvas = document.createElement('canvas');
favcanvas.width = faviconWidth;
favcanvas.height = faviconHeight;
const favimg = new Image();
favimg.crossOrigin = 'anonymous';
favimg.src = favicon.href;
const favcontext = favcanvas.getContext('2d');
favicons.push({ favcanvas, favimg, favcontext, favicon });
}
});
};
/** Check if the image is loaded */
const isImageLoaded = (img: HTMLImageElement): boolean => img.complete && img.naturalHeight !== 0;
/** Reset the favicon image to its initial state */
const clearFaviconBadge = (): void => {
if (favicons.length === 0) return;
favicons.forEach(({ favimg, favcanvas, favcontext, favicon }) => {
if (!favimg || !favcontext || !favicon) return;
favcontext.clearRect(0, 0, faviconWidth, faviconHeight);
if (isImageLoaded(favimg)) {
favcontext.drawImage(favimg, 0, 0, favimg.width, favimg.height, 0, 0, faviconWidth, faviconHeight);
}
favicon.href = favcanvas.toDataURL('image/png');
});
};
/** Replace the favicon image with one that has a notification dot */
const drawFaviconBadge = (): void => {
if (favicons.length === 0) return;
clearFaviconBadge();
favicons.forEach(({ favimg, favcanvas, favcontext, favicon }) => {
if (!favimg || !favcontext || !favcontext) return;
const style = getComputedStyle(document.body);
const badgeColor = `${style.getPropertyValue('--badge-notification') || 'rgb(255, 0, 0)'}`;
if (isImageLoaded(favimg)) {
favcontext.drawImage(favimg, 0, 0, favimg.width, favimg.height, 0, 0, faviconWidth, faviconHeight);
}
favcontext.fillStyle = badgeColor;
favcontext.beginPath();
favcontext.arc(faviconWidth - badgeRadius, badgeRadius, badgeRadius, 0, 2 * Math.PI, false);
favcontext.fill();
favicon.href = favcanvas.toDataURL('image/png');
});
};
return {
initFaviconService,
clearFaviconBadge,
drawFaviconBadge,
};
};
const FaviconService = createFaviconService();
export default FaviconService;