(NS | UI)EdgeInsets operators

[indragiek]

Related: github/Archimedes#17

Currently, RACSignal+RCLGeometryAdditions.h has -insetWidth:height: which isn't too useful for applying insets where top/bottom and left/right aren't equal. I propose a new operator, -inset: which accepts a signal that sends boxed NSEdgeInsets or UIEdgeInsets values and applies them to a CGRect.

I would be happy to implement this. Any thoughts?

[indragiek]

Also: as I tried to poorly explain the the Archimedes issue, should there be any consideration to flippedness when dealing with operators that use edge insets? ie. Should it accept a flipped BOOL signal as a parameter and then transform the insets accordingly (flipping top/bottom) before applying them to the rect?

[jspahrsummers]

👍 on an operator for this, but I would want a cross-platform answer to github/Archimedes#17 first.

should there be any consideration to flippedness when dealing with operators that use edge insets?

No, RCL globally assumes an unflipped coordinate system right now.

[indragiek]

Unflipped as in a top left or bottom left origin? Unflipped seems ambiguous when dealing with both Mac and iOS :)

EDIT: Maybe you meant unflipped with respect to the platform, so bottom left on Mac and top left on iOS?

[jspahrsummers]

Correct, unflipped per platform.

[indragiek]

The Archimedes side of things has been implemented in github/Archimedes#18. Once this has been reviewed and merged I can start on these operators.

[jspahrsummers]

@indragiek You can always feel free to open a PR that depends on another, even across repos. Just make sure the submodule is on the correct SHA for it.