//
//  PdDispatcher.h
//  libpd
//
//  Copyright (c) 2011 Peter Brinkmann (peter.brinkmann@gmail.com)
//
//  For information on usage and redistribution, and for a DISCLAIMER OF ALL
//  WARRANTIES, see the file, "LICENSE.txt," in this distribution.
//
//  Updated 2013, 2018 Dan Wilcox <danomatika@gmail.com>
//

#import <Foundation/Foundation.h>
#import "PdBase.h"

/// Implementation of the PdReceiverDelegate protocol from PdBase.h. Client code
/// registers one instance of this class with PdBase, and then listeners for
/// individual sources will be registered with the dispatcher object.
///
/// Printing from Pd is done via NSLog by default; subclass and override the
/// receivePrint method if you want different printing behavior.
@interface PdDispatcher : NSObject<PdReceiverDelegate> {
	NSMutableDictionary *listenerMap;
	NSMutableDictionary *subscriptions;
}

/// Adds a listener for the given source (i.e., send symbol) in Pd.  If this is
/// the first listener for this source, a subscription for this symbol will
/// automatically be registered with PdBase.
- (int)addListener:(NSObject<PdListener> *)listener
         forSource:(NSString *)source;

/// Removes a listener for a source symbol and unsubscribes from messages to
/// this symbol if the listener was the last listener for this symbol.
- (int)removeListener:(NSObject<PdListener> *)listener
            forSource:(NSString *)source;

/// Removes all listeners.
- (void)removeAllListeners;

@end

/// Subclass of PdDispatcher that logs all callbacks,
/// mostly for development and debugging.
@interface LoggingDispatcher : PdDispatcher {}
@end