Separator obscures panel content #956
Description
Separators are rendered as a pseudoelement on top of a container. This makes it difficult to create pixel-perfect panel content layouts.
I've edited the basic demo to add a 1px red border to the panel content:
The border is visible on the top, right and bottom, but not on the left. The separator pseudoelement is on top of it.
If we set the pseudoelement's background color to transparent, we can see the left border:
The edge(s) that are covered by the separator depend on the layout and specific view type (dock/grid/split/pane).
This makes it difficult to have a pixel-perfect layout for my content.
Describe the solution you'd like
Ideally, the view containers are aware of separators. Their sizes do not include the separator, so when I make my panel content fill the container, none of it is obscured by the separator.
Describe alternatives you've considered
Deriving the visible container dimensions is hard (requires context of the surrounding layout), and it's not immediately clear how I can change the styling.