header

//
//  JLNetworkActivityIndicatorManager.h
//  EcoCr
//
//  Created by Jack Lawrence on 6/27/12.
//
//

#import <Foundation/Foundation.h>

/** Manages the animation state of the network activity indicator in the top left of the screen. Threadsafe. */
@interface JLNetworkActivityIndicatorManager : NSObject

/** Designated Initializer */

/** 
 Returns a shared instance of `JLNetworkActivityIndicatorManager`.
 
 @return A shared instance of `JLNetworkActivityIndicatorManager`
 */
+ (id)sharedManager;

/** Increments the number of network connections that are currently active. */
- (void)increment;
/** Decrements the number of network connections that are currently active. */
- (void)decrement;

@end

implementation

//
//  JLNetworkActivityIndicatorManager.m
//  EcoCr
//
//  Created by Jack Lawrence on 6/27/12.
//
//

#import "JLNetworkActivityIndicatorManager.h"

@implementation JLNetworkActivityIndicatorManager {
    NSInteger _activeNetworkRequests;
    dispatch_queue_t _serialQueue;
}

+ (id)sharedManager
{
    __strong static id _sharedObject = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        _sharedObject = [[self alloc] init];
    });
    
    return _sharedObject;
}

- (id)init
{
    self = [super init];
    
    if (self)
    {
        _serialQueue = dispatch_queue_create("com.McGeehan.EcoCr.netIndicatorManager", DISPATCH_QUEUE_SERIAL);
    }
    
    return self;
}

- (void)dealloc
{
    dispatch_release(_serialQueue);
}

- (void)increment
{
    dispatch_async(_serialQueue, ^{
        if (_activeNetworkRequests == 0) {
            [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES];
        }
        _activeNetworkRequests += 1;
    });
}

- (void)decrement
{
    dispatch_async(_serialQueue, ^{
        if (_activeNetworkRequests > 0) {
            _activeNetworkRequests -= 1;
            if (_activeNetworkRequests <= 0) {
                [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
            }
        }
    });
}

@end