Add basic watchOS support

[lammertw]

This basically disabled all functions for watchOS that are not supported by the watchOS sdk by wrapping them in preprocessor statements.

For example:

#if os(iOS) || os(tvOS)
/// `UIImage(named: "Utilitarian", bundle: ..., traitCollection: ...)`
static func utilitarian(compatibleWith traitCollection: UIKit.UITraitCollection? = nil) -> UIKit.UIImage? {
  return UIKit.UIImage(resource: R.image.utilitarian, compatibleWith: traitCollection)
}
#endif

[tomlokhorst]

Thanks for this PR!

It's been a while, but I'm finally working om merging this.

I'm getting a build error about watchOS not knowing UITraitCollection, when I try to build the Rswift-watchOS target in this library. I'm guessing those files shouldn't be part of the Watch target at all?

[lammertw]

That's correct. I guess there is some new code added using UITraitCollection. If you look in for example UIColor+ColorResource.swift you can see how to deal with that:

  #if os(iOS) || os(tvOS)
  /**
   Returns the color from this resource (R.color.*) that is compatible with the trait collection.

   - parameter resource: The resource you want the image of (R.color.*)
   - parameter traitCollection: Traits that describe the desired color to retrieve, pass nil to use traits that describe the main screen.

   - returns: A color that exactly or best matches the desired traits with the given resource (R.color.*), or nil if no suitable color was found.
   */
  public convenience init?(resource: ColorResourceType, compatibleWith traitCollection: UITraitCollection? = nil) {
    self.init(named: resource.name, in: resource.bundle, compatibleWith: traitCollection)
  }
  #endif

[fnuky]

Hi! How it looks? I started adding watch support because it would be good for me and I'm looking and here is this PR already :).

[tomlokhorst]

@lammertw I'm not seeing that #if os(iOS) || os(tvOS) in this PR

[lammertw]

Right, I just noticed it as well. It seems I added this code once locally at a later time after merging in a new version but never put that into this pull request. I've pushed it now.

[teameh]

Any updates on this? Would be great if this could be merged in :)

[tomlokhorst]

Merging with mac-cain13/R.swift#441