How to animate add UISearchBar on top of UINavigationBar

Question

If I set the displaysSearchBarInNavigationBar = YES in viewDidLoad, the search bar will be in navigation bar when the view show up. But I want to s

Answer 1

Following Nick's answer, I made a similar one on Xcode 7.1 -swift 2.0.

Note:
To the Navigation Bar, I added

(a) UIBarButtons( Drag& Drop) - menuButton & searchButton
(b) UIBarButtons (programatically) - leftSearchBarButtonItem & rightSearchBarButtonItem.

The common methods are : 
(a) showSearchBar(), hideSearchBar()
(b) revealToggle: - It is connected to SWRevealController for Slider Menu.

//  DashBoardViewController.swift

import UIKit

class DashBoardViewController: UIViewController,UISearchBarDelegate,SWRevealViewControllerDelegate {

    //MARK:- STORYBOARD REFERENCE
    @IBOutlet weak var menuButton: UIBarButtonItem!
    @IBOutlet weak var searchButtton: UIBarButtonItem!

    //Making secondary Searchbar
    var searchBar = UISearchBar()
    var leftSearchBarButtonItem: UIBarButtonItem?
    var rightSearchBarButtonItem: UIBarButtonItem?
    var logoImageView   : UIImageView!

    override func viewDidLoad() {

        super.viewDidLoad()
        self.activateInitialUISetUp()
        //    self.revealViewController().delegate = self
        makeTopNavigationSearchbar()


    }
    override func viewWillAppear(animated: Bool) {
        makeTopNavigationSearchbar()
        activateInitialUISetUp()        

    }
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }

    //MARK:- SEARCHBAR METHODS
    func searchBarSearchButtonClicked(searchBar: UISearchBar) {
        hideSearchBar()
        searchBar.resignFirstResponder()
    }
    func searchBarTextDidBeginEditing(searchBar: UISearchBar) {

    }
    func searchBarCancelButtonClicked(searchBar: UISearchBar) {
        hideSearchBar()
    }

    //Search Bar Appear & Disappear
    func showSearchBar() {
        searchBar.hidden =  false
        searchBar.alpha = 0
        navigationItem.titleView = searchBar
        navigationItem.setLeftBarButtonItem(nil, animated: true)
        navigationItem.setRightBarButtonItem(nil, animated: true)

        UIView.animateWithDuration(0.5, animations: {
            self.searchBar.alpha = 1
            }, completion: { finished in
                self.searchBar.becomeFirstResponder()
        })
    }

    func hideSearchBar() {
        hideSearchBarAndMakeUIChanges()
        logoImageView.alpha = 0
        UIView.animateWithDuration(0.3, animations: {

            self.logoImageView.alpha = 1
            }, completion: { finished in

        })
    }
    //Making secondary Searchbar
    func makeTopNavigationSearchbar()
    {
        let logoImage = UIImage(named: "password")!
        logoImageView = UIImageView(frame: CGRect(x: 0, y: 0, width: logoImage.size.width, height: logoImage.size.height))
        logoImageView.image = logoImage
        searchButtton.customView?.addSubview(logoImageView)

        searchBar.delegate = self
        searchBar.searchBarStyle = UISearchBarStyle.Minimal

        leftSearchBarButtonItem = navigationItem.leftBarButtonItem
        rightSearchBarButtonItem =  navigationItem.rightBarButtonItem

        leftSearchBarButtonItem?.tintColor =  UIColor.whiteColor()
        rightSearchBarButtonItem?.tintColor =  UIColor.whiteColor()

    }

    //Adding secondary uibar butttons to navigation bar
    func hideSearchBarAndMakeUIChanges ()
    {
        searchBar.hidden =  true

        //Adding secondary uibarbuttons to the nav bar and revoke its methods
        navigationItem.setLeftBarButtonItem(leftSearchBarButtonItem, animated: true)
        navigationItem.setRightBarButtonItem(rightSearchBarButtonItem, animated: true)

        leftSearchBarButtonItem?.title = "Menu"
        leftSearchBarButtonItem?.target = self.revealViewController()
        leftSearchBarButtonItem?.action = "revealToggle:"

        rightSearchBarButtonItem?.title = "Search"
        rightSearchBarButtonItem?.target = self
        rightSearchBarButtonItem?.action = "showSearchBar"


        //Adding Title Label
        var navigationTitlelabel = UILabel(frame: CGRectMake(0, 0, 200, 21))
        navigationTitlelabel.center = CGPointMake(160, 284)
        navigationTitlelabel.textAlignment = NSTextAlignment.Center
        navigationTitlelabel.textColor  = UIColor.whiteColor()
        navigationTitlelabel.text = "WORK ORDER"
        self.navigationController!.navigationBar.topItem!.titleView = navigationTitlelabel

    }    

    //UI-Related Methods
    func activateInitialUISetUp()
    {
        self.navigationController?.navigationBarHidden =  false
        self.navigationController?.navigationBar.barStyle = UIBarStyle.BlackOpaque
        self.navigationController?.navigationBar.translucent =  true
        self.navigationController?.navigationBar.backgroundColor =  UIColor.redColor()

        //Nav Bar Searchbar
        searchBar.delegate = self
        searchBar.placeholder = "Start Your Search Here"
        searchButtton.action = "showSearchBar"
        searchButtton.target = self

        //searchbar Text Color
        var textFieldInsideSearchBar = searchBar.valueForKey("searchField") as? UITextField
        textFieldInsideSearchBar?.textColor = UIColor.whiteColor()


        //Nav Bar Title
        self.title = "WORK ORDER"

        if self.revealViewController() != nil {
            menuButton.target = self.revealViewController()
            menuButton.action = "revealToggle:"

            self.view.addGestureRecognizer(self.revealViewController().panGestureRecognizer())
            self.revealViewController().rearViewRevealWidth = self.view.frame.width / 2
            self.revealViewController().rearViewRevealOverdraw = 0.0
            self.view.addGestureRecognizer(self.revealViewController().tapGestureRecognizer())
        }
    }    

    func revealController(revealController: SWRevealViewController!, didMoveToPosition position: FrontViewPosition) {
        if(position.rawValue == 3)
        {


        }
        else
        {

        }
        print("position\(position)")

    }    
}