NativeScript - Angular Service to watch iOS keyboard event listeners

Question

I'm writing an app with NativeScript 6.4.1 and Angular version 8.

There are a series of UI events in iOS that you can watch to see what the keyboard is doing: https://developer.apple.com/documentation/uikit/uikeyboarddidhidenotification?language=objc

I wrote a service to watch and subscribe to these changes.

Do you see any issues in the code with having too many Observables and listeners?

Here is my service:

import { Injectable } from '@angular/core';
import { Observable } from 'rxjs';
import * as application from 'tns-core-modules/application';

@Injectable({
    providedIn: 'root'
})
export class iOSKeyboardObserverService {

    public didShow$(): Observable<any> {

        return new Observable((observer) => {

            const iosObserver = application.ios.addNotificationObserver(UIKeyboardDidShowNotification, (notification) => {
                observer.next(true);
            });

            return () => {
                application.ios.removeNotificationObserver(iosObserver, UIKeyboardDidShowNotification);
            }
        });

    }

    public didHide$(): Observable<any> {

        return new Observable((observer) => {

            const iosObserver = application.ios.addNotificationObserver(UIKeyboardDidHideNotification, (notification) => {
                observer.next(false);
            });

            return () => {
                application.ios.removeNotificationObserver(iosObserver, UIKeyboardDidHideNotification);
            }
        });

    }
}

Example usage:

public isKeyboardShowing: boolean;

constructor(private page: Page, private ngZone: NgZone, private keyboardObserver: iOSKeyboardObserverService) {

    this.page.on(Page.layoutChangedEvent, (args: EventData) => this.onLayoutChanged(args));
    this.isKeyboardShowing = false;

    if (utils.ios) {

        this.keyboardObserver.didHide$().subscribe((result) => {
            this.setIsKeyboardShowing(result);
        });

        this.keyboardObserver.didShow$().subscribe((result) => {
            this.setIsKeyboardShowing(result);
        });
    }

}