feat(Snackbar): Add an option to control whether opening a new snackbar prematurely closes existing ones

[ManelBH]

Feature Description

I propose having an option to control whether new snackbars automatically dismiss the existing one. When this autodismissal is disabled snackbars would be queued and shown for the specified duration one after another.

The current implementation is not fully compliant with the material specification which says:

Snackbars appear without warning, and don't require user interaction. They automatically disappear from the screen after a minimum of four seconds, and a maximum of ten seconds.
When multiple snackbar updates are necessary, they should appear one at a time.

Use case

Being able to have a material compliant option while keeping the original behaviour.

[KinokoF]

The sentences you quoted are from the Material Design specification (M2).

The Material Design specification (M3) instead says that:

Behavior

Appearing and disappearing

Snackbars appear without warning, but they don’t block users from interacting with page content.

Snackbars without actions can auto-dismiss after 4–10 seconds, depending on platform. Avoid using auto-dismissing snackbars on web unless there's also inline feedback.

Snackbars with actions should remain on the screen until the user takes an action on the snackbar, or dismisses it.

Consecutive snackbars

Consecutive snackbars must appear one at a time.

Snackbars without actions appear and disappear automatically, while those with actions remain on screen until dismissed. However, a snackbar with updated information can immediately replace an outdated snackbar.

Ref: https://m3.material.io/components/snackbar/guidelines#12145fa5-ada2-4c3b-b2ae-9cdf8ee54ca1

[KinokoF]

The problem is that the Material Design specifications were and remain a bit ambiguous and open to interpretation. A clarification from the authors is needed in my opinion

[ManelBH]

I would argue that if you think there's ambiguity it's just another reason to make it an option.

In particular when it comes to this extra remark:

• However, a snackbar with updated information can immediately replace an outdated snackbar.

I think it's up to us to decide what constitutes an outdated snackbar.