A custom UINavigationController that enables the scrolling of the navigation bar alongside the scrolling of an observed content view

Version 2.x is written as a subclass of UINavigationController, in Swift. If you are looking for the category implementation in Objective-C, make sure to checkout version 1.x and prior, although the 2.x is recomended.

Screenshot

Setup with Cocoapods

pod 'AMScrollingNavbar', `~> 2.0.0`

use_frameworks!

Setup with Carthage

github "andreamazz/AMScrollingNavbar"

Usage

Make sure to use a subclass of ScrollingNavigationController for your UINavigationController.

Use followScrollView(_: delay:) to start following the scrolling of a scrollable view (e.g.: a UIScrollView or UITableView).

override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(animated)

    if let navigationController = self.navigationController as? ScrollingNavigationController {
        navigationController.followScrollView(tableView, delay: 50.0)
    }
}

Use stopFollowingScrollview() to stop the behaviour. Remember to call this function on disappear:

override func viewDidDisappear(animated: Bool) {
    super.viewDidDisappear(animated)

    if let navigationController = self.navigationController as? ScrollingNavigationController {
        navigationController.stopFollowingScrollView()
    }
}

ScrollingNavigationViewController

To DRY things up you can let your view controller subclass ScrollingNavigationViewController, which provides the base setup implementation. You will just need to call followScrollView(_: delay:):

override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(animated)

    if let navigationController = self.navigationController as? ScrollingNavigationController {
        navigationController.followScrollView(tableView, delay: 50.0)
    }
}

ScrollingNavigationControllerDelegate

You can set a delegate to receive a call when the state of the navigation bar changes:

if let navigationController = self.navigationController as? ScrollingNavigationController {
    navigationController.scrollingNavbarDelegate = self
}

Delegate function:

func scrollingNavigationController(controller: ScrollingNavigationController, didChangeState state: NavigationBarState) {
    switch state {
    case .Collapsed:
        println("navbar collapsed")
    case .Expanded:
        println("navbar expanded")
    case .Scrolling:
        println("navbar is moving")
    }
}

Check out the sample project for more details.

Author

Andrea Mazzini

MIT License

The MIT License (MIT)

Copyright (c) 2015 Andrea Mazzini

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.