Add-AppvClientConnectionGroup /**
- @license
- Copyright Google Inc. All Rights Reserved.
- Use of this source code is governed by an MIT-style license that can be
- found in the LICENSE file at https://angular.io/license */
import {defineInjectable, inject} from '@angular/core';
import {DOCUMENT} from './dom_tokens';
/**
- Defines a scroll position manager. Implemented by
BrowserViewportScroller. - @publicApi / export abstract class ViewportScroller { // De-sugared tree-shakable injection // See #23917 /* @nocollapse */ static ngInjectableDef = defineInjectable( {providedIn: 'root', factory: () => new BrowserViewportScroller(inject(DOCUMENT), window)});
/**
- Configures the top offset used when scrolling to an anchor.
- @param offset A position in screen coordinates (a tuple with x and y values)
- or a function that returns the top offset position.
*/ abstract setOffset(offset: [number, number]|(() => [number, number])): void;
/**
- Retrieves the current scroll position.
- @returns A position in screen coordinates (a tuple with x and y values). */ abstract getScrollPosition(): [number, number];
/**
- Scrolls to a specified position.
- @param position A position in screen coordinates (a tuple with x and y values). */ abstract scrollToPosition(position: [number, number]): void;
/**
- Scrolls to an anchor element.
- @param anchor The ID of the anchor element. */ abstract scrollToAnchor(anchor: string): void;
/**
- Disables automatic scroll restoration provided by the browser.
- See also [window.history.scrollRestoration
- info](https://developers.google.com/web/updates/2015/09/history-api-scroll-restoration). */ abstract setHistoryScrollRestoration(scrollRestoration: 'auto'|'manual'): void; }
/**
- Manages the scroll position for a browser window. */ export class BrowserViewportScroller implements ViewportScroller { private offset: () => [number, number] = () => [0, 0];
constructor(private document: any, private window: any) {}
/**
- Configures the top offset used when scrolling to an anchor.
- @param offset A position in screen coordinates (a tuple with x and y values)
- or a function that returns the top offset position.
*/ setOffset(offset: [number, number]|(() => [number, number])): void { if (Array.isArray(offset)) { this.offset = () => offset; } else { this.offset = offset; } }
/**
- Retrieves the current scroll position.
- @returns The position in screen coordinates. */ getScrollPosition(): [number, number] { if (this.supportScrollRestoration()) { return [this.window.scrollX, this.window.scrollY]; } else { return [0, 0]; } }
/**
- Sets the scroll position.
- @param position The new position in screen coordinates. */ scrollToPosition(position: [number, number]): void { if (this.supportScrollRestoration()) { this.window.scrollTo(position[0], position[1]); } }
/**
- Scrolls to an anchor element.
- @param anchor The ID of the anchor element.
*/
scrollToAnchor(anchor: string): void {
if (this.supportScrollRestoration()) {
const elSelectedById = this.document.querySelector(
#${anchor}); if (elSelectedById) { this.scrollToElement(elSelectedById); return; } const elSelectedByName = this.document.querySelector([name='${anchor}']); if (elSelectedByName) { this.scrollToElement(elSelectedByName); return; } } }
/**
- Disables automatic scroll restoration provided by the browser. */ setHistoryScrollRestoration(scrollRestoration: 'auto'|'manual'): void { if (this.supportScrollRestoration()) { const history = this.window.history; if (history && history.scrollRestoration) { history.scrollRestoration = scrollRestoration; } } }
private scrollToElement(el: any): void { const rect = el.getBoundingClientRect(); const left = rect.left + this.window.pageXOffset; const top = rect.top + this.window.pageYOffset; const offset = this.offset(); this.window.scrollTo(left - offset[0], top - offset[1]); }
/**
- We only support scroll restoration when we can get a hold of window.
- This means that we do not support this behavior when running in a web worker.
- Lifting this restriction right now would require more changes in the dom adapter.
- Since webworkers aren't widely used, we will lift it once RouterScroller is
- battle-tested. */ private supportScrollRestoration(): boolean { try { return !!this.window && !!this.window.scrollTo; } catch (e) { return false; } } }
/**
- Provides an empty implementation of the viewport scroller. This will
- live in @angular/common as it will be used by both platform-server and platform-webworker.
/
export class NullViewportScroller implements ViewportScroller {
/*
- Empty implementation */ setOffset(offset: [number, number]|(() => [number, number])): void {}
/**
- Empty implementation */ getScrollPosition(): [number, number] { return [0, 0]; }
/**
- Empty implementation */ scrollToPosition(position: [number, number]): void {}
/**
- Empty implementation */ scrollToAnchor(anchor: string): void {}
/**
- Empty implementation */ setHistoryScrollRestoration(scrollRestoration: 'auto'|'manual'): void {} }