iPhone SDK 3 : Making Connections with GameKit and Bonjour - iPhone to iPhone Gaming Via BonjourHelper

#define DO_DATA_CALLBACK(X, Y) if (sharedInstance.dataDelegate && \
    [sharedInstance.dataDelegate respondsToSelector:@selector(X)]) \
    [sharedInstance.dataDelegate performSelector:@selector(X) \
    withObject:Y];
#define BARBUTTON(TITLE, SELECTOR)     [[[UIBarButtonItem alloc] \
    initWithTitle:TITLE style:UIBarButtonItemStylePlain \
    target:[BonjourHelper class] action:SELECTOR] autorelease]
@implementation BonjourHelper
@synthesize server;
@synthesize browser;
@synthesize inConnection;
@synthesize outConnection;

@synthesize dataDelegate;
@synthesize viewController;
@synthesize sessionID;
@synthesize isConnected;
@synthesize hud;

static BonjourHelper *sharedInstance = nil;
BOOL inConnected;
BOOL outConnected;

+ (BonjourHelper *) sharedInstance
{
    if(!sharedInstance) sharedInstance = [[self alloc] init];
    return sharedInstance;
}

#pragma mark Class utilities
+ (void) assignViewController: (UIViewController *) aViewController
{
    // By assigning the optional view controller, this class
    // takes charge of the connect/disconnect button
    sharedInstance.viewController = aViewController;
    if (sharedInstance.viewController)
        sharedInstance.viewController.navigationItem.rightBarButtonItem
        = BARBUTTON(@"Connect", @selector(connect));
}

#pragma mark Handshaking

- (void) updateStatus
{
    // Must be connected to continue
    if (!(self.inConnection && self.outConnection) ||
        !(inConnected && outConnected))
    {
        self.isConnected = NO;
        return;
    }

    // Send callback, dismiss HUD, update bar button
    self.isConnected = YES;
    DO_DATA_CALLBACK(connectionEstablished, nil);
    [self.hud dismissWithClickedButtonIndex:1 animated:YES];
    if (self.viewController)
        self.viewController.navigationItem.rightBarButtonItem =
            BARBUTTON(@"Disconnect", @selector(disconnect));
}

// Upon resolving address, create a connection to that address
// and request data
- (void)netServiceDidResolveAddress:(NSNetService *)netService
{
    NSArray* addresses = [netService addresses];
    if (addresses && addresses.count)
    {
        for (int i = 0; i < addresses.count; i++)
        {
            // The IP utility implementations can be found in
           // They are omitted here for space considerations.
            struct sockaddr* address =
                (struct sockaddr*)[[addresses objectAtIndex:i] bytes];
            NSString *addressString =
                [BonjourHelper stringFromAddress:address];
            if (!addressString) continue;

            if ([addressString hasPrefix:
                    [BonjourHelper localIPAddress]])
            {
                printf("Will not resolve with self. \
                    Continuing to browse.\n");
                continue;
            }

            printf("Found a matching external service\n");
            printf("My address: %s\n",
                [[BonjourHelper localIPAddress] UTF8String]);
            printf("Remote address: %s\n", [addressString UTF8String]);

            // Stop browsing for services
            [self.browser stop];
            [netService release];

            // Create an outbound connection to this new service
            self.outConnection = [[[TCPConnection alloc]
                initWithRemoteAddress:address] autorelease];
            [self.outConnection setDelegate:self];
            [self performSelector:@selector(checkForData)];
            [self updateStatus];
            return;
        }
    }

    [netService stop];
}

- (void)netServiceBrowser:(NSNetServiceBrowser *)netServiceBrowser
    didFindService:(NSNetService *)netService
    moreComing:(BOOL)moreServicesComing
{
    // start to resolve the service that was found
    [[netService retain] setDelegate:self];
    [netService resolveWithTimeout:0.0f];
}

+ (void) startBrowsingForServices
{
    // look for matching Bonjour services. The double-retain was
    // added for security. You can almost certainly discard it.
    sharedInstance.browser =
        [[[NSNetServiceBrowser alloc] init] retain];
    [sharedInstance.browser setDelegate:sharedInstance];
    NSString *type = [TCPConnection
        bonjourTypeFromIdentifier:sharedInstance.sessionID];
    [sharedInstance.browser searchForServicesOfType:type
        inDomain:@"local"];
}

+ (void) publish
{
    // Publish service to peers
    sharedInstance.server =
        [[[TCPServer alloc] initWithPort:0] autorelease];
    [sharedInstance.server setDelegate:sharedInstance];
    [sharedInstance.server startUsingRunLoop:
        [NSRunLoop currentRunLoop]];
    [sharedInstance.server enableBonjourWithDomain:@"local"
        applicationProtocol:sharedInstance.sessionID
        name:[self localHostname]];
}

+ (void) initConnections
{
    // Return to base unconnected state
    [sharedInstance.browser stop];
    [sharedInstance.server stop];

    sharedInstance.inConnection = nil;
    sharedInstance.outConnection = nil;
    sharedInstance.isConnected = NO;
    inConnected = NO;
    outConnected = NO;
}

- (void)alertView:(UIAlertView *)alertView
    clickedButtonAtIndex:(NSInteger)buttonIndex
{
    // Handle user request to cancel connecting
    if (buttonIndex) return;
    [BonjourHelper disconnect];
}

+ (void) connect
{
    if (sharedInstance.viewController)
        sharedInstance.viewController.navigationItem.rightBarButtonItem
            = nil;
    if (!sharedInstance.sessionID)
        sharedInstance.sessionID = @"Sample Session";

    // Create activity view with cancel button
    sharedInstance.hud = [[[UIAlertView alloc]
        initWithTitle:
        @"Searching for connection peer on your local network"
        message:@"\n\n" delegate:sharedInstance
        cancelButtonTitle:@"Cancel" otherButtonTitles:nil]
        autorelease];
    [sharedInstance.hud show];

    // Add the progress wheel
    UIActivityIndicatorView *aiv = [[[UIActivityIndicatorView alloc]
        initWithActivityIndicatorStyle:
        UIActivityIndicatorViewStyleWhiteLarge] autorelease];
    [aiv startAnimating];
    aiv.center = CGPointMake(
        sharedInstance.hud.bounds.size.width / 2.0f,
        sharedInstance.hud.bounds.size.height/2.0f);
    [sharedInstance.hud addSubview:aiv];

    // Prepare for duplex connection
    [self initConnections];
    [self startBrowsingForServices];
    [self publish];
}

+ (void) disconnect
{
    // disable current connections
    [sharedInstance.inConnection invalidate];
    [sharedInstance.outConnection invalidate];
    [self initConnections];

    // stop server
    [sharedInstance.server stop];
    [sharedInstance updateStatus];

    // reset
    [sharedInstance.hud dismissWithClickedButtonIndex:1 animated:YES];
    if (sharedInstance.viewController)
        sharedInstance.viewController.navigationItem.rightBarButtonItem
            = BARBUTTON(@"Connect", @selector(connect));
}

#pragma mark  Data Handling
- (void) checkForData
{
    // Perform a blocking receive only when data is available
    if (!self.outConnection) return;
    if ([self.outConnection hasDataAvailable])
        [self.outConnection receiveData];
    [self performSelector:@selector(checkForData)
        withObject:self afterDelay:0.1f];
}

+ (void) sendData: (NSData *) data
{
    if (!sharedInstance.outConnection) return;
    BOOL success = [sharedInstance.outConnection sendData:data];
    if (success) {
        DO_DATA_CALLBACK(sentData:, nil); }
    else {
        DO_DATA_CALLBACK(sentData:, @"Data could not be sent.");}
}

- (void) connection:(TCPConnection*)connection
    didReceiveData:(NSData*)data;
{
    // Redirect data callback
    DO_DATA_CALLBACK(receivedData:, data);
}

#pragma mark Connection Handlers

- (BOOL) server:(TCPServer*)server
    shouldAcceptConnectionFromAddress:(const struct sockaddr*)address
{
    // Accept connections only while not connected
    return !self.isConnected;
}

- (void) connectionDidFailOpening:(TCPConnection*)connection
{
    // Handled a fail open
    if (!connection) return;
    NSString *addressString = [BonjourHelper
        stringFromAddress:connection.remoteSocketAddress];
    [BonjourHelper disconnect];

    if (addressString)
        [ModalAlert say:@"Error while opening %@ connection (from %@).\
            Wait a few seconds or relaunch before trying to connect\n
            again.", (connection == self.inConnection) ? @"incoming" :
            @"outgoing", addressString];
    else
        printf("Failed to open connection from unknown address\n");
}

- (void) server:(TCPServer*)server
    didCloseConnection:(TCPServerConnection*)connection
{
    // Handle a newly closed connection
    if (!connection) return;
    NSString *addressString = [BonjourHelper
        stringFromAddress:connection.remoteSocketAddress];
    if (!addressString) return;

    BOOL wasConnected = self.isConnected;

    [BonjourHelper disconnect];
    printf("Lost connection from %s\n", [addressString UTF8String]);

    if (wasConnected)
        [ModalAlert say:@"Disconnected from peer (%@). You are no \
            longer connected to another device.", addressString];
    else
        [ModalAlert say:@"Peer was lost before full connection could \
            be established."];
}

- (void) server:(TCPServer*)server
    didOpenConnection:(TCPServerConnection*)connection
{
    // Set the connection but wait for it to fully open
    self.inConnection = connection;
    [self updateStatus];
    [connection setDelegate:self];
}

- (void) connectionDidOpen: (TCPConnection *) connection
{
    // Fully opened connection
    printf("Connection did open: %s\n", (connection ==
        self.inConnection) ? "incoming" : "outgoing");
    if (connection == self.inConnection) inConnected = YES;
    if (connection == self.outConnection) outConnected = YES;
    [self updateStatus];
}

- (void) connectionDidClose: (TCPConnection *)connection
{
    // Closed connection
    printf("Connection did close: %s\n", (connection ==
        self.inConnection) ? "incoming" : "outgoing");
    if (connection == self.inConnection) inConnected = NO;
    if (connection == self.outConnection) outConnected = NO;
    [self updateStatus];
}
@end