Snapevents

[hvanops]

Specification

Spec review for Snap Events · Issue #943 · w3ctag/design-reviews · GitHub

Description

Snap Events allow developers to reliably listen for when the "snap target" of a scroller changes and perform style adjustments as desired.

CSS scroll snap points are often used as a mechanism to create scroll interactive "selection" components, where selection is determined with javascript intersection observers and a scroll end guesstimate. By creating built-in events, the invisible state will become actionable, at the right time, and always correct. This feature adds two JavaScript events:

• Snapchanging: This event gives developers a hint during a scroll operation that the user agent intends to snap the scroll container to a new snap target based on the scrolling input so far.

• Snapchanged: This event lets developers know that the element to which a scroller is snapped has changed, and fires at the completion of a scroll operation (including snapping)

Browser support

No response

[jamesnw]

This was added in #2103. Thanks!