SwiftCarousel

SwiftCarousel is a lightweight, written natively in Swift, circular UIScrollView.
So what is there more to that than just a circular scroll view? You can spin it like a real carousel!

Requirements

Swift 2.0, iOS 9

Installation

SwiftCarousel is available through CocoaPods. To install it, simply add the following line to your Podfile:

pod "SwiftCarousel"

Then run pod install and it should be 🔥 Also remember to add import SwiftCarousel in your project.

Examples

You can use Examples directory for examples with creating SwiftCarousel using IB or code.

Basic usage using Interface Builder (Storyboard/xibs)

First, create UIView object and assign SwiftCarousel class to it. Then we need to assign some selectable UIViews. It might be UILabels, UIImageViews etc. The last step would be setting correct resizeType parameter which contains:

public enum SwiftCarouselResizeType {
    // WithoutResizing is adding frames as they are.
    // Parameter = spacing between UIViews.
    // !!You need to pass correct frame sizes as items!!
    case WithoutResizing(CGFloat)

    // VisibleItemsPerPage will try to fit the number of items you specify
    // in the whole screen (will resize them of course).
    // Parameter = number of items visible on screen.
    case VisibleItemsPerPage(Int)

    // FloatWithSpacing will use sizeToFit() on your views to correctly place images
    // It is helpful for instance with UILabels (Example1 in Examples folder).
    // Parameter = spacing between UIViews.
    case FloatWithSpacing(CGFloat)
}

Basic setup would look like:

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    items = ["Elephants", "Tigers", "Chickens", "Owls", "Rats", "Parrots", "Snakes"]
    itemsViews = items!.map { labelForString($0) }
    carousel.items = itemsViews!
    carousel.resizeType = .VisibleItemsPerPage(3)
    carousel.defaultSelectedIndex = 3 // Select default item at start
    carousel.delegate = self
}

func labelForString(string: String) -> UILabel {
    let text = UILabel()
    text.text = string
    text.textColor = .blackColor()
    text.textAlignment = .Center
    text.font = .systemFontOfSize(24.0)
    text.numberOfLines = 0

    return text
}

Basic usage using pure code

Here we use itemsFactory(itemsCount:facory:) method. This method allows you to setup your carousel using closure rather than static array of views. Why would we want to use that? In case of quite complicated logic. E.g. if you want to have CALayer properties all across the carousel.

let carouselFrame = CGRect(x: view.center.x - 200.0, y: view.center.y - 100.0, width: 400.0, height: 200.0)
carouselView = SwiftCarousel(frame: carouselFrame)
try! carouselView.itemsFactory(itemsCount: 5) { choice in
    let imageView = UIImageView(image: UIImage(named: "puppy\(choice+1)"))
    imageView.frame = CGRect(origin: CGPointZero, size: CGSize(width: 200.0, height: 200.0))

    return imageView
}
carouselView.resizeType = .WithoutResizing(10.0)
carouselView.delegate = self
carouselView.defaultSelectedIndex = 2
view.addSubview(carouselView)

Additional methods, properties & delegate

You can use method selectItem(_:animated:) to programmatically select your item:

carousel.selectItem(1, animated: true)

Or you can set default selected item:

carousel.defaultSelectedIndex = 3

You can disable selecting item by tapping it (its enabled by default):

carousel.selectByTapEnabled = false

You can also get current selected index:

let selectedIndex = carousel.selectedIndex

You can implement SwiftCarouselDelegate protocol:

@objc public protocol SwiftCarouselDelegate {
    optional func didSelectItem(item item: UIView, index: Int, tapped: Bool) -> UIView?
    optional func didDeselectItem(item item: UIView, index: Int) -> UIView?
    optional func didScroll(toOffset offset: CGPoint) -> Void
    optional func willBeginDragging(withOffset offset: CGPoint) -> Void
    optional func didEndDragging(withOffset offset: CGPoint) -> Void
}

Then you need to set the delegate property:

carousel.delegate = self

If you need more, basic usages in Example1 project in directory Examples.

Known limitations

The original views are internally copied to using the copyView method defined in the UIView+SwiftCarousel extension when using the items property. This performs a shallow copy of the view using NSKeyedUnarchiver and NSKeyedArchiver. So, if a custom UIView subclass with references to external objects is used, those references might be nil when didSelectItem and didDeselectItem delegate methods are called. To avoid this situation, the itemsFactory method can be used instead of the items property to setup the carousel.

Contributing

Feel free to make issues/pull requests if you have some questions, ideas for improvement, or maybe bugs you've found. After some contribution I'm giving write access as a thank you 🎉

Author

Sunshinejr, [email protected], @thesunshinejr

License

SwiftCarousel is available under the MIT license. See the LICENSE file for more info.