openaire-library/utils/smooth-scroll.ts

70 lines
2.0 KiB
TypeScript

import {NavigationEnd, Router} from "@angular/router";
import {Injectable} from "@angular/core";
import {Subscription} from "rxjs";
@Injectable({
providedIn: "root"
})
export class SmoothScroll {
private interval;
private readonly sub;
private lastRoute;
constructor(private router: Router) {
this.sub = router.events.subscribe(event => {
if (event instanceof NavigationEnd) {
if(this.interval) {
clearInterval(this.interval);
}
const fragment = router.parseUrl(router.url).fragment;
if (fragment) {
let i = 0;
this.interval = setInterval(() => {
i++;
const element = document.getElementById(fragment);
if (element) {
if(this.interval) {
clearInterval(this.interval);
}
const yOffset = -100;
let position = 0;
let interval = setInterval(() => {
if(position !== element.getBoundingClientRect().top) {
position = element.getBoundingClientRect().top;
} else {
clearInterval(interval);
const y = element.getBoundingClientRect().top + window.pageYOffset + yOffset;
window.scrollTo({top: y, behavior: 'smooth'});
}
}, 50);
}
if(i > 4 && this.interval) {
clearInterval(this.interval);
}
}, 100);
} else {
if(this.lastRoute !== this.getUrl(event.url)) {
window.scrollTo({top: 0});
} else {
window.scrollTo({top: 0, behavior: "smooth"});
}
}
this.lastRoute = this.getUrl(event.url);
}
});
}
private getUrl(url: string) {
return url.split('?')[0].split('#')[0];
}
public clearSubscriptions() {
if(this.sub && this.sub instanceof Subscription) {
this.sub.unsubscribe();
}
if(this.interval) {
clearInterval(this.interval);
}
}
}