Example Codea Addon

AppDelegate.mm

//
//  AppDelegate.mm
//  <#MyProjectName#>
//
//  Created by <#AuthorName#> on <#CurrentDate#>
//  Copyright (c) <#AuthorName#>. All rights reserved.
//

#import "AppDelegate.h"
#import "CodeaViewController.h"

//Import our custom Addon
#import "GameCenterAddon.h"

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    self.viewController = [[CodeaViewController alloc] init];
    
    //Create and add our GameCenterAddon to Codea
    [self.viewController registerAddon:[GameCenterAddon sharedInstance]];
    
    //Replace with your project!
    NSString* projectPath = [[[NSBundle mainBundle] bundlePath] stringByAppendingPathComponent:@"MyProject.codea"];
    
    [self.viewController loadProjectAtPath:projectPath];
    
    self.window.rootViewController = self.viewController;
    [self.window makeKeyAndVisible];
    
    return YES;
}

- (void)applicationWillResignActive:(UIApplication *)application
{
}

- (void)applicationDidEnterBackground:(UIApplication *)application
{
}

- (void)applicationWillEnterForeground:(UIApplication *)application
{
}

- (void)applicationDidBecomeActive:(UIApplication *)application
{
}

- (void)applicationWillTerminate:(UIApplication *)application
{
}

@end

GameCenterAddon.h

//
//  GameCenterAddon.h
//  MyProject
//
//  Created by Simeon on 8/04/13.
//  Copyright (c) 2013 MyCompany. All rights reserved.
//

#import <Foundation/Foundation.h>

#import "GCDSingleton.h"
#import "CodeaAddon.h"

@interface GameCenterAddon : NSObject<CodeaAddon>

DEFINE_SHARED_INSTANCE

@end

GameCenterAddon.m

//
//  GameCenterAddon.m
//  MyProject
//
//  Created by Simeon on 8/04/13.
//  Copyright (c) 2013 MyCompany. All rights reserved.
//

#import <GameKit/GameKit.h>

#import "GameCenterAddon.h"

#import "lua.h"

//Forward declare our Lua functions
static int GameCenterStart(struct lua_State *state);

//=================================================================================================
// Private GameCenterAddon Protocols
//=================================================================================================

@interface GameCenterAddon ()<GKGameCenterControllerDelegate>

@property (nonatomic, weak) CodeaViewController *codeaViewController;

@end

//=================================================================================================
// Game Center Addon
//=================================================================================================

@implementation GameCenterAddon

DEFINE_SHARED_INSTANCE_IMPL

- (void) codea:(CodeaViewController*)controller didCreateLuaState:(struct lua_State*)L
{
    NSLog(@"GameCenterAddon Registering Functions");
    
    //Store the Codea view controller, so we can present UI from Game Center functions
    self.codeaViewController = controller;
    
    //Register the Game Center Start function, defined below
    lua_register(L, "GameCenterStart", GameCenterStart);
}

- (void) gameCenterViewControllerDidFinish:(GKGameCenterViewController *)gameCenterViewController
{
    //Dismiss the Game Center view
    [self.codeaViewController dismissViewControllerAnimated:YES completion:^
    {
        //Unpause Codea
        self.codeaViewController.paused = NO;
    }];
}

@end

//=================================================================================================
// Game Center Functions
//=================================================================================================

static int GameCenterStart(struct lua_State *state)
{
    GKLocalPlayer *localPlayer = [GKLocalPlayer localPlayer];
    
    /* iOS 6.x */
    
    localPlayer.authenticateHandler = ^(UIViewController *viewController, NSError *error)
    {
        CodeaViewController *codea = [GameCenterAddon sharedInstance].codeaViewController;
        
        if( viewController != nil )
        {
            //Pause Codea and present the Game Center view
            codea.paused = YES;
            [codea presentViewController:viewController animated:YES completion:NULL];
        }
        else if( [GKLocalPlayer localPlayer].isAuthenticated )
        {
            //The player has been authenticated
            
            //Normally you would now make your game aware that Game Center is available
            // and show things like buttons to access leaderboards
            
            //But we are just going to pop up the main Game Center view controller
            GKGameCenterViewController *gc = [[GKGameCenterViewController alloc] init];
            gc.gameCenterDelegate = [GameCenterAddon sharedInstance];

            [codea presentViewController:gc animated:YES completion:NULL];            
        }
        else
        {
            //Disable Game Center
            
            //Unpause Codea
            codea.paused = NO;
        }
    };
    
    /* iOS 5.x */
    
//    [localPlayer authenticateWithCompletionHandler:^(NSError *error)
//    {
//        CodeaViewController *codea = [GameCenterAddon sharedInstance].codeaViewController;
//        codea.paused = YES;
//
//        if( [GKLocalPlayer localPlayer].isAuthenticated )
//        {
//            //The player has been authenticated
//
//            //Normally you would now make your game aware that Game Center is available
//            // and show things like buttons to access leaderboards
//
//            //But we are just going to pop up the main Game Center view controller
//            GKGameCenterViewController *gc = [[GKGameCenterViewController alloc] init];
//            gc.gameCenterDelegate = [GameCenterAddon sharedInstance];
//
//            [codea presentViewController:gc animated:YES completion:NULL];
//        }
//        else
//        {
//            //Disable Game Center
//
//            //Unpause Codea
//            codea.paused = NO;
//        }
//        
//    }];
    
    return 0;
}

GCDSingleton.h

/*
 From https://gist.github.com/1057420
 A singleton macro using Grand Central Dispatch's dispatch_once function to create the singleton the first time it is accessed.
 
 * Modified so that the name of the function is always sharedInstance.
 
*/

/*
    USAGE:
 
    @interface MySharedThing
    
    DEFINE_SHARED_INSTANCE
 
    @end
 
 
    @implementation MySharedThing

    DEFINE_SHARED_INSTANCE_IMPL
 
    @end
 
    OR, you can define the initialiser with a block (this is equivalent to using DEFINE_SHARED_INSTANCE_IMPL):
 
    @implementation MySharedThing

    DEFINE_SHARED_INSTANCE_USING_BLOCK(^{
        return [[self alloc] init];
    })

    @end
*/

#define DEFINE_SHARED_INSTANCE_USING_BLOCK(block) \
+ (instancetype)sharedInstance\
{\
  static dispatch_once_t pred = 0; \
  __strong static id _sharedObject = nil; \
  dispatch_once(&pred, ^{ \
    _sharedObject = block(); \
  }); \
  return _sharedObject; \
}\


#define DEFINE_SHARED_INSTANCE \
+ (instancetype)sharedInstance;\


#define DEFINE_SHARED_INSTANCE_IMPL \
DEFINE_SHARED_INSTANCE_USING_BLOCK(^{\
return [[self alloc] init];\
})\