feat(screen-orientation): Viewport add new service

libs/screen-orientation/src/viewport.service.ts

@@ -0,0 +1,26 @@
+import {inject, Injectable} from '@angular/core';
+import {WINDOW} from '@ng-web-apis/common';
+import {EMPTY, filter, fromEvent, map, merge, Observable, shareReplay} from 'rxjs';
+
+@Injectable({
+    providedIn: 'root',
+})
+export class ViewportService extends Observable<VisualViewport> {
+    private readonly visualViewport = inject(WINDOW).visualViewport;
+
+    private readonly stream$ = this.visualViewport
+        ? merge(
+              fromEvent(this.visualViewport, 'resize'),
+              fromEvent(this.visualViewport, 'scroll'),
+              fromEvent(this.visualViewport, 'scrollend'),
+          ).pipe(
+              map(() => this.visualViewport),
+              filter(Boolean),
+              shareReplay({bufferSize: 1, refCount: true}),
+          )
+        : EMPTY;
+
+    constructor() {
+        super((subscriber) => this.stream$.subscribe(subscriber));
+    }
+}