- (IBAction)playButton:(id)sender {

    NSLog(@"play Button clicked");
    if(self.mainloop)
    {
        [self.mainloop invalidate];
        self.mainloop = nil;
        [_animationView stopAnimating];
    }
    else{
        self.mainloop = [NSTimer scheduledTimerWithTimeInterval:0.5
                                                         target:self
                                                       selector:@selector(mainloop:)
                                                       userInfo:nil
                                                        repeats:YES];
    }

}

-(void)mainloop:(NSTimer *)timer
{
    [self flashEffect:timer];
    [self animatioEffect:timer];
}

-(void)animatioEffect:(NSTimer *)timer
{

        NSArray *animationImagesArray = @[[UIImage imageNamed:@"1.jpg"],
                                          [UIImage imageNamed:@"2.jpg"],
                                          [UIImage imageNamed:@"3.jpg"],
                                          [UIImage imageNamed:@"4.jpg"]];

        _animationView.animationImages = animationImagesArray;
        _animationView.animationDuration =  4 ;
        [_animationView startAnimating];
}