Smooth scroll experience when scrolling upwards.

adilhussain · mportuga · commit 660f518c2ed0 · 2019-10-07T10:59:19.000-04:00
Hi there, I've been struggling with infinite-scroll upwards since last two days. Whenever I am trying to scroll upwards, the scroll is very flickery(jumpy) and jumps to previous pages even when I am not scrolling. I found out a plunkr today which I tried, and the scrolling seems to work. http://plnkr.co/edit/DfXkANDYkBOmjauF1HmF?p=preview <= jumpy scroll. Inconsistent behaviour http://plnkr.co/edit/33b8FAHHfNO0ryQ9oSD4?p=preview <= smooth scroll experience. what the guy has does is that, he has removed the line scrollEvent.y = {percentage: 1/scrollHeight} with scrollEvent.y = {pixels: 1}; And that fixes the issue. Can anyone from the team check this and let me know if it is a bug which gets fixed by making this change.
diff --git a/packages/infinite-scroll/src/js/infinite-scroll.js b/packages/infinite-scroll/src/js/infinite-scroll.js
@@ -426,7 +426,7 @@
         // for infinite scroll, if there are pages upwards then never allow it to be at the zero position so the up button can be active
         if (scrollTop === 0 && grid.infiniteScroll.scrollUp) {
           // using pixels results in a relative scroll, hence we have to use percentage
-          scrollEvent.y = {percentage: 1/scrollHeight};
+          scrollEvent.y = {pixels: 1};
         }
         else {
           scrollEvent.y = {percentage: scrollTop/scrollHeight};

Original file line number	Diff line number	Diff line change
`@@ -426,7 +426,7 @@`
`426`	`426`	`// for infinite scroll, if there are pages upwards then never allow it to be at the zero position so the up button can be active`
`427`	`427`	`if (scrollTop === 0 && grid.infiniteScroll.scrollUp) {`
`428`	`428`	`// using pixels results in a relative scroll, hence we have to use percentage`
`429`		`- scrollEvent.y = {percentage: 1/scrollHeight};`
	`429`	`+ scrollEvent.y = {pixels: 1};`
`430`	`430`	`}`
`431`	`431`	`else {`
`432`	`432`	`scrollEvent.y = {percentage: scrollTop/scrollHeight};`