Observable for drag-scroll-end.

dragScrollEnd.ts

import * as Rx from 'rxjs'

const pointerDown$ = Rx.Observable.race(
  Rx.Observable.fromEvent(window, 'mousedown'),
  Rx.Observable.fromEvent(window, 'touchstart'),
)

const drag$ = pointerDown$.flatMap(() => {
  const pointerUp$ = Rx.Observable.race(
    Rx.Observable.fromEvent(window, 'mouseup'),
    Rx.Observable.fromEvent(window, 'mouseleave'),
    Rx.Observable.fromEvent(window, 'touchend'),
    Rx.Observable.fromEvent(window, 'touchcancel'),
  )
  return pointerUp$
    .take(1)
    .flatMap(() => {
      const scroll$ = Rx.Observable.fromEvent(window, 'scroll')
      const activity$ = new Rx.BehaviorSubject<number>(1)
      return Rx.Observable
        .race(
          activity$
            .debounceTime(100),
          scroll$
            .do(() => activity$.next(1))
            .debounceTime(100)
            .take(1),
        )
    })
})

drag$.subscribe(() => {
  console.log('done')
})