Align scroll behind definition when using buttonFixedLayout or equivalent

[aweell]

Goal

Align the definition of how is shown when a content scrolls under the actions in a button layout.

Context

Currently there are three different definitions in the system:

• Button fixed layout (Example) : The top part of the footer show a shadow when the content goes underneath.
• Sheet [Only mobile] (Example): When the content goes underneath, a divider appears.
• Dialog (Example): No divider and no shadow

Impact

Consistency in similar behaviours

Discussion Questions

• Should we use the divider for all cases?

Additional considerations

There were two reasons why the sheet was defined like that:

• We stated the shadow was little bit outdated and was cleaner to use the divider
• The shadow wasn't working very good in the header of the sheet when the content was going underneath.

[aweell]

I would say that at least i would fix the current dialog to show the divider, now seems like a bug.

For the consistency of the other cases i suggest to always use a divider.

In dark mode for example is clearer the division than using a shadow that wouldn't be seen at all.