I am using a Muuri grid with draggable items. On desktop, users can use the mousewheel to scroll; however, I had to add an event handler to check if the user holds the item for x time, then they can drag the item. If they immediately move a certain distance, it prevents dragging and programmatically scrolls the view with window.scrollTo.

This works fine on Android and Windows touch screens but the screen jumps around on iPhones. Worse on Safari but still occurs on Chrome. I tried using webkit style atrributes that some articles mention for smoother scrolling, used different scroll behaviors, made sure calculations lead to a top, whole number value (only setting top) of 0 or higher, and the only thing that made a difference was setting a delay. A higher delay (100ms) between scrollTo calls seems to resolve it but isn't smooth to the user.

Content for the move event is simply the method call:

window.scrollTo({top: initialTop + yStart - yEnd})