Simple NetworkActivityIndicator manager

RDVNetworkActivityIndicatorManager.h

// RDVNetworkActivityIndicatorManager.h
//
// Copyright (c) 2013 Robert Dimitrov
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

#import <Foundation/Foundation.h>

@interface RDVNetworkActivityIndicatorManager : NSObject

+ (RDVNetworkActivityIndicatorManager *)sharedManager;

/*
 * Increase tasks count.
 * If tasks == 0, show the network activity indicator.
 */

- (void)pushTask;

/*
 * Decrease tasks count.
 * If tasks == 0, hide the network activity indicator.
 */

- (void)popTask;

/*
 * Returs number of currently pushed tasks
 */

- (NSInteger)tasksCount;

@end

RDVNetworkActivityIndicatorManager.m

// RDVNetworkActivityIndicatorManager.m
//
// Copyright (c) 2013 Robert Dimitrov
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

#import "RDVNetworkActivityIndicatorManager.h"

@interface RDVNetworkActivityIndicatorManager () {
    NSInteger tasks;
}
@end

@implementation RDVNetworkActivityIndicatorManager

+ (RDVNetworkActivityIndicatorManager *)sharedManager {
    static RDVNetworkActivityIndicatorManager *_sharedManager = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        _sharedManager = [[RDVNetworkActivityIndicatorManager alloc] init];
    });
    return _sharedManager;
}

- (void)pushTask {
    void (^block)(void) = ^{
        tasks++;
        if (tasks == 1) {
            [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES];
        }
    };
    
    if ([NSThread isMainThread]) {
        block();
    } else {
        dispatch_sync(dispatch_get_main_queue(), ^{
            block();
        });
    }
}

- (void)popTask {
    if (tasks <= 0) {
        return;
    }
    
    void (^block)(void) = ^{
        tasks--;
        if (tasks == 0) {
            [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
        }
    };
    
    if ([NSThread isMainThread]) {
        block();
    } else {
        dispatch_sync(dispatch_get_main_queue(), ^{
            block();
        });
    }
}

- (NSInteger)tasksCount {
    return tasks;
}

@end