Multiple concurrent networkActivityIndicators

networkActivityIndicator

var applicationActivityIndicators = 0
extension UIApplication {
    func startActivityIndicator() {
        applicationActivityIndicators++
        UIApplication.sharedApplication().networkActivityIndicatorVisible = true
    }
    
    func stopActivityIndicator() {
        applicationActivityIndicators--
        if applicationActivityIndicators <= 0 {
            UIApplication.sharedApplication().networkActivityIndicatorVisible = false
            applicationActivityIndicators = 0
        }
    }
}