From 5a5e4e294a8bbd666339d58ac3fdb68df5ca019c Mon Sep 17 00:00:00 2001
From: Ed Opare-Aryee <ed@thisissoon.com>
Date: Sun, 18 Feb 2018 12:16:51 +0000
Subject: [PATCH] fix(ScrollCollapse): remove debounce operator when set to 0
 for rubber band scrolling

---
 src/app/scroll-collapse/scroll-collapse.directive.ts | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/app/scroll-collapse/scroll-collapse.directive.ts b/src/app/scroll-collapse/scroll-collapse.directive.ts
index d017239..b4ed5a0 100644
--- a/src/app/scroll-collapse/scroll-collapse.directive.ts
+++ b/src/app/scroll-collapse/scroll-collapse.directive.ts
@@ -13,7 +13,9 @@ import {
   takeUntil,
   bufferCount,
   map,
-  startWith
+  startWith,
+  distinctUntilChanged,
+  tap
 } from 'rxjs/operators';
 import { fromEvent } from 'rxjs/observable/fromEvent';
 import { merge } from 'rxjs/observable/merge';
@@ -137,9 +139,12 @@ export class ScrollCollapseDirective implements AfterViewInit, OnDestroy {
         fromEvent(this.windowRef as any, eventData.eventResize)
       )
         .pipe(
-          debounceTime(this.debounce),
+          startWith(null),
           map(() => this.getViewport()),
           bufferCount(2, 1),
+          distinctUntilChanged(),
+          // Do not apply debounce operator if debounce is set to 0
+          this.debounce ? debounceTime(this.debounce) : tap(null),
           takeUntil(this.ngUnsubscribe$)
         )
         .subscribe((events: Viewport[]) =>