Basic Interop

Calling Objective-C Methods from Scala

You can call Objective-C class and instance methods using the normal Scala method call syntax, if there is a binding defined for that class, e.g.:

    [[NSNumber alloc] initWithInt:42]; 

    NSNumber.alloc().initWithInt(42)

SNCocoa provides bindings for the Foundation and AppKit frameworks, located in the packages cocoa.foundation and cocoa.appkit, respectively.

Objective-C Functions

Bindings to global Objective-C functions are provided as functions in an object named after the framework to which they belong. NSLog() for example is provided by cocoa.foundation.Foundation

import cocoa.foundation._

Foundation.NSLog(ns"Hello world!")

Strings and Numbers

Literals

Similar to Objective-C, SNCocoa provides short-forms to create strings and numbers from Scala literals:

    #import <Cocoa/Cocoa.h>
    
    NSString *thString = @"A string";
    NSNumber *intNumber = @42; 
    NSNumber *doubleNumber = @1e42;

    import cocoa.foundation._
    
    val theString = ns"A string"
    val intNumber = @@(42)
    val doubleNumber = @@(1e42) 

Scala Extensions

SNCocoa provides extension methods for NSString:

import cocoa.foundation._

val nsString = ns"The String"
nsString.string     // returns the NSString value as Scala string
nsString.cstring    // returns the NSString value as CString

Enums

Enums defined by cocoa frameworks are represented in Scala as type aliases for NSInteger and NSUInteger, plus a companion object that holds the enum values. For example, the values for NSStringEncoding are defined in cocoa.foundation.NSStringEncoding:

import scalanative.native._
import cocoa.foundation._

val string = NSString.stringWithCString(c"The string", NSStringEncoding.NSUTF8StringEncoding)