Find root view window

    self.rootView = [self.window.subviews objectAtIndex:0];
    if (!self.rootView) {
        self.rootView = self;
        while (self.rootView.superview != nil) {
            self.rootView = self.rootView.superview;
        }
    }

- (void)willMoveToWindow:(UIWindow *)newWindow {
    if(newWindow == nil){
        //the view is being removed
        [self stopAnimation];
        return;
    }

}