Apply UIAppearance immediately on the screen

I was looking for how to apply changes made with UIAppearance’s proxy method immediately.

I found a solution in a library UISS, that handles Stylesheets written with JSON format.

UISS#refreshViews

- (void)refreshViews {
    [[NSNotificationCenter defaultCenter] postNotificationName:UISSWillRefreshViewsNotification object:self];

    for (UIWindow *window in [UIApplication sharedApplication].windows) {
        for (UIView *view in window.subviews) {
            [view removeFromSuperview];
            [window addSubview:view];
        }
    }

    [[NSNotificationCenter defaultCenter] postNotificationName:UISSDidRefreshViewsNotification object:self];
}

This code detaches all subviews of window and attach them again.

I also tried setNeedsDisplay and setNeedsLayout, but didn’t work. So I adapted this hack.

Here is Swift version.

public func resetViews() {
  let windows = UIApplication.sharedApplication().windows as [UIWindow]
  for window in windows {
    let subviews = window.subviews as [UIView]
    for v in subviews {
      v.removeFromSuperview()
      window.addSubview(v)
    }
  }
}