rsrbk/HidingNavigationBar

Easily hide and show a view controller's navigation bar (and tab bar) as a user scrolls

HidingNavigationBar

An easy to use library (written in Swift) that manages hiding and showing a navigation bar as a user scrolls.

• Features
• Usage
• Customization
• Installation

#Features

HidingNavigationBar supports hiding/showing of the following view elements:

• UINavigationBar
• UINavigationBar and an extension UIView
• UINavigationBar and a UIToolbar
• UINavigationBar and a UITabBar

###UINavigationBar ###UINavigationBar and an extension UIView ###UINavigationBar and a UIToolbar ###A UINavigationBar and a UITabBar

#Usage

1. Import HidingNavigationBar
2. Include a member variable of type HidingNavigationBarManager in your UIViewController subclass.
3. Initialize the variable in viewDidLoad function, passing in the UIViewController instance and the UIScrollView instance that will control the hiding/showing of the navigation bar.
4. Relay the following UIViewController lifecycle functions to the HidingNavigationBarManager variable:

override func viewWillAppear(animated: Bool)
override func viewWillDisappear(animated: Bool)
override func viewDidLayoutSubviews() //Only necessary when adding the extension view

And finally relay the following UIScrollViewDelegate function:

func scrollViewShouldScrollToTop(scrollView: UIScrollView) -> Bool

Below is an example of how your UIViewController subclass should look:

import HidingNavigationBar

class MyViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

	var hidingNavBarManager: HidingNavigationBarManager?
	@IBOutlet weak var tableView: UITableView!

    override func viewDidLoad() {
        super.viewDidLoad()

		hidingNavBarManager = HidingNavigationBarManager(viewController: self, scrollView: tableView)
    }
	
	override func viewWillAppear(animated: Bool) {
		super.viewWillAppear(animated)
		
		hidingNavBarManager?.viewWillAppear(animated)
	}
	
	override func viewDidLayoutSubviews() {
		super.viewDidLayoutSubviews()
		
		hidingNavBarManager?.viewDidLayoutSubviews()
	}
	
	override func viewWillDisappear(animated: Bool) {
		super.viewWillDisappear(animated)
		
		hidingNavBarManager?.viewWillDisappear(animated)
	}

	//// TableView datasoure and delegate 

	func scrollViewShouldScrollToTop(scrollView: UIScrollView) -> Bool {
		hidingNavBarManager?.shouldScrollToTop()
		
		return true
	}
	
	...
}

Note: HidingNavigationBar only works with UINavigationBars that have translucent set to true.

#Customization

###Add an extension view to the UINavigationBar

let extensionView = // load your a UIView to use as an extension
hidingNavBarManager?.addExtensionView(extensionView)

###Hide and show a UITabBar or UIToolbar

if let tabBar = navigationController?.tabBarController?.tabBar {
	hidingNavBarManager?.manageBottomBar(tabBar)
}

###Hide/Show/Do Nothing when App is Foregrounded

	hidingNavBarManager?.onForegroundAction = .Default	//Do nothing, state of bars will remain the same as when backgrounded
	hidingNavBarManager?.onForegroundAction = .Hide		//Always hide on foreground
	hidingNavBarManager?.onForegroundAction = .Show 	//Always show on foreground

###Expansion Resistance When the navigation bar is hidden, you can some 'resitance' which adds a delay before the navigation bar starts to expand when scrolling. The resistance value is the distance that the user needs to scroll before the navigation bar starts to expand.

hidingNavBarManager?.expansionResistance = 150

###UIRefreshControl

If you are using a UIRefreshControl with your scroll view, it is important to let the HidingNavigationBarManager know about it:

hidingNavBarManager?.refreshControl = refreshControl

#Installation

If your using Carthage, add the following line to your Cartfile:

github "tristanhimmelman/HidingNavigationBar" ~> 1.0

If you are using CocoaPods, add the following line to your Podfile:

pod 'HidingNavigationBar', '~> 1.0'

Otherwise, include the following files directly to your project:

• HidingNavigationBarManager.swift
• HidingViewController.swift