UISearchControllerDelegate

UISearchControllerDelegateExtension.swift

extension ViewController: UISearchControllerDelegate {
    func willPresentSearchController(searchController: UISearchController) {
        tabBarController?.tabBar.hidden = true
        searchBarBackground(true)
        dimmingBackground(true)
    }
    
    func willDismissSearchController(searchController: UISearchController) {
        tabBarController?.tabBar.hidden = false
        searchBarBackground(false)
        dimmingBackground(false)
    }
    
    // For animate
    func searchBarBackground(on: Bool) {
        let onAlpha: CGFloat = 0.95
        let offAlpha: CGFloat = 0
        let barBackgroundView = searchController.view?.subviews
            .filter { $0.frame.height < 100 }.first
        barBackgroundView?.alpha = on ? offAlpha : onAlpha
        UIView.animateWithDuration(0.3) { barBackgroundView?.alpha = on ? onAlpha : offAlpha }
    }
    
    func dimmingBackground(on: Bool) {
        let onColor = UIColor.blackColor().colorWithAlphaComponent(0.5)
        let offColor = UIColor.blackColor().colorWithAlphaComponent(0)
        let backgroundView = searchController.view?.subviews
            .filter { $0.frame.height == UIScreen.mainScreen().bounds.height }.first
        backgroundView?.backgroundColor = on ? offColor : onColor
        UIView.animateWithDuration(0.3) {
            backgroundView?.backgroundColor = on ? onColor : offColor
        }
    }
}