TL;DR UIPageViewController done properly.

⭐️ Features

• Simplified data source management & enhanced delegation.
• Dynamically insert & remove pages.
• Infinite scrolling support.
• Automatic timer-based page transitioning.
• Support for custom animated page transitions.

📋 Requirements

Pageboy requires iOS 12 / tvOS 12; and is compatible with Swift 5.

📲 Installation

Swift Package Manager

Pageboy is compatible with Swift Package Manager and can be integrated via Xcode.

CocoaPods

Pageboy is also available through CocoaPods:

pod 'Pageboy', '~> 4.2'

Carthage

Pageboy is also available through Carthage:

github "uias/Pageboy" ~> 4.2

🚀 Usage

• The Basics
• PageboyViewControllerDelegate
• Navigation
• Insertion & Deletion

The Basics

1. Create an instance of a PageboyViewController and provide it with a PageboyViewControllerDataSource.

class PageViewController: PageboyViewController, PageboyViewControllerDataSource {

    override func viewDidLoad() {
        super.viewDidLoad()
        
	self.dataSource = self
    }
}

2. Implement the PageboyViewControllerDataSource functions.

func numberOfViewControllers(in pageboyViewController: PageboyViewController) -> Int {
    return viewControllers.count
}

func viewController(for pageboyViewController: PageboyViewController,
                    at index: PageboyViewController.PageIndex) -> UIViewController? {
    return viewControllers[index]
}

func defaultPage(for pageboyViewController: PageboyViewController) -> PageboyViewController.Page? {
    return nil
}

PageboyViewControllerDelegate

The delegate functions provided by a PageboyViewController are much more reliable and useful than what a raw UIPageViewController provides. You can use them to find out exactly where the current page is, and when it's moved, where it's headed.

willScrollToPageAtIndex

About to embark on a transition to a new page.

func pageboyViewController(_ pageboyViewController: PageboyViewController,
                           willScrollToPageAt index: Int,
                           direction: PageboyViewController.NavigationDirection,
                           animated: Bool)

didScrollToPosition

Scrolled to a relative position along the way transitioning to a new page.

func pageboyViewController(_ pageboyViewController: PageboyViewController,
                           didScrollTo position: CGPoint,
                           direction: PageboyViewController.NavigationDirection,
                           animated: Bool)

didScrollToPage

Successfully completed a scroll transition to a page.

func pageboyViewController(_ pageboyViewController: PageboyViewController,
                           didScrollToPageAt index: Int,
                           direction: PageboyViewController.NavigationDirection,
                           animated: Bool)

didReload

Child view controllers have been reloaded.

func pageboyViewController(_ pageboyViewController: PageboyViewController,
                           didReloadWith currentViewController: UIViewController,
                           currentPageIndex: PageIndex)

Navigation

You can navigate programmatically through a PageboyViewController using scrollToPage():

pageViewController.scrollToPage(.next, animated: true)

• Infinite scrolling can be enabled with .isInfiniteScrollEnabled.
• Interactive scrolling can also be controlled with .isScrollEnabled.

Insertion & Deletion

Pageboy provides the ability to insert and delete pages dynamically in the PageboyViewController.

func insertPage(at index: PageIndex, then updateBehavior: PageUpdateBehavior)
func deletePage(at index: PageIndex, then updateBehavior: PageUpdateBehavior)

This behaves similarly to the insertion of rows in UITableView, in the fact that you have to update the data source prior to calling any of the update functions.

Example:

let index = 2
viewControllers.insert(UIViewController(), at: index)
pageViewController.insertPage(at: index)

The default behavior after inserting or deleting a page is to scroll to the update location, this however can be configured by passing a PageUpdateBehavior value other than .scrollToUpdate.

⚡️ Other Extras

• reloadData() - Reload the view controllers in the page view controller. (Reloads the data source).
• .navigationOrientation - Whether to orientate the pages horizontally or vertically.
• .currentViewController - The currently visible view controller if it exists.
• .currentPosition - The exact current relative position of the page view controller.
• .currentIndex - The index of the currently visible page.
• .parentPageboy - Access the immediate parent PageboyViewController from any child view controller.

Animated Transitions

Pageboy also provides custom transition support for animated transitions. This can be customized via the .transition property on PageboyViewController.

pageboyViewController.transition = Transition(style: .push, duration: 1.0)

Note: By default this is set to nil, which uses the standard animation provided by UIPageViewController.

Auto Scrolling

PageboyAutoScroller is available to set up timer based automatic scrolling of the PageboyViewController:

pageboyViewController.autoScroller.enable()

Support for custom intermission duration and other scroll behaviors is also available.

👨🏻‍💻 About

• Created by Merrick Sapsford (@MerrickSapsford)
• Contributed to by a growing list of others.

❤️ Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/uias/Pageboy.

👮🏻‍♂️ License

The library is available as open source under the terms of the MIT License.