OTActivityIndicatorView.h

#import <Foundation/Foundation.h>

@interface OTActivityIndicatorView : UIActivityIndicatorView
{

}

@end

OTActivityIndicatorView.m

#import "OTActivityIndicatorView.h"

@implementation OTActivityIndicatorView

- (void)didMoveToWindow
{
    if (self.window)
        [self startAnimating];
    else
        [self stopAnimating];
}

@end