NSAnimationContext.runAnimationGroup in OS X 10.11 and older

runAnimationGroup shim.swift

// By Ben Leggiero on 2019-05-07
// License is BH-1-PS: https://github.com/BlueHuskyStudios/Licenses/blob/master/Licenses/BH-1-PS.txt



import AppKit



public extension NSAnimationContext {

    /// Allows those who must support old versions of macOS / OS X to use the better, modern block syntax
    public static func __shim__runAnimationGroup(_ changes: (NSAnimationContext) -> Void,
                                                 completionHandler: (() -> Void)? = nil) {
        if #available(macOS 10.12, *) {
            return runAnimationGroup(changes, completionHandler)
        }
        else {
            beginGrouping()
            current.completionHandler = completionHandler
            changes(current)
            endGrouping()
        }
    }
}