List a collection of items in a horizontally scrolling view

Circular-Carousel

List a collection of items in a horizontally scrolling view. A scaling factor controls the size of the items relative to the center.

Requirements

• iOS 12.0+
• Xcode 10.2+
• Swift 5.0+

Installation

Just add the CircularCarousel directory to your project.

or use CocoaPods with Podfile:

pod 'CircularCarousel'

or just drag and drop the CircularCarousel directory to your project

Usage

1. Create a custom view that will be used as a carousel item. In this tutorial we will just use a blank UIView.

2. Create a view controller or container view that handles datasource and delegate responses for the contained Carousel.

	final class ContainerView : UITableViewCell, CircularCarouselDataSource, CircularCarouselDelegate {

	}

2.1) Add a reference to the carousel control and the selection of a delegate and datasource to your Carousel control.

	private weak var _carousel : CircularCarousel!
    @IBOutlet var carousel : CircularCarousel! {
        set {
            _carousel = newValue
            _carousel.delegate = self
            _carousel.dataSource = self
        }
        
        get {
            return _carousel
        }
    }

3. Implement the DataSource and Delegate functions. Some of the key functions are listed below.

3.1) Datasource

	func numberOfItems(inCarousel carousel: CircularCarousel) -> Int {
        return /* Number of carousel items */
    }

	func carousel(_: CircularCarousel, viewForItemAt indexPath: IndexPath, reuseView view: UIView?) -> UIView {
    	var view = view as? UIVIew

    	if view == nil {
    		view = UIView(frame: CGRect(x: 0, y: 0, width: 50, height: 50))
    	}

    	return view
    }

	func startingItemIndex(inCarousel carousel: CircularCarousel) -> Int {
        return /* Insert starting item index */
    }

3.2) Delegate

Select how you want the carousel to operate based on the control variables specified below :

	func carousel<CGFloat>(_ carousel: CircularCarousel, valueForOption option: CircularCarouselOption, withDefaultValue defaultValue: CGFloat) -> CGFloat {
	    switch option {
        case .itemWidth:
            return /* Select item width for carousel */
        /*  Insert one of the following handlers :
			case spacing
			case fadeMin
			case fadeMax
			case fadeRange
			case fadeMinAlpha
			case offsetMultiplier
			case itemWidth
			case scaleMultiplier
			case minScale
			case maxScale
        */
        default:
            return defaultValue
        }
	}

Handle the selection of a particular carousel item :

	func carousel(_ carousel: CircularCarousel, didSelectItemAtIndex index: Int) {
        /* Handle selection of the selected carousel item */
    }

Handle will begin scrolling :

	func carousel(_ carousel: CircularCarousel, willBeginScrollingToIndex index: Int) {

	}

To handle spacing between items depending on their offst from the center :

	func carousel(_ carousel: CircularCarousel, spacingForOffset offset: CGFloat) -> CGFloat {        
        return /* Based on the offset from center, adjust the spacing of the item */
    }

That's it, the Carousel is good to go!

GitHub