Snappable

A set of SwiftUI custom modifiers to make the ScrollView snappable.

The goal of this library is to provide an easy way to implement Views such as carousels and slideshows.

Demo

Requirements

• iOS 14.0+
• Swift 5.3+

Note

Snappable includes the copied code from Introspect for SwiftUI (#17) due to detect the behavior of scrolling from UIScrollView. So this library would be fragile on iOS or SwiftUI updates.

Installation

Swift Package Manager

.package(
  url: "https://github.com/hugehoge/Snappable.git",
  .upToNextMinor(from: "0.3.0")
)

CocoaPods

pod 'Snappable', '~> 0.3.0'

Usage

Basic

struct ContentView: View {
  @State private var items: [Item]

  var body: some View {
    ScrollView(.horiaontal) {
      LazyHStack {
        ForEach(items, id: \.self) { item in
          ItemView(item)
            .snapID(item)  // Step 1
        }
      }
    }
    .snappable()  // Step 2
  }
}

1. Added .snapID(_:) modifier to items in ScrollView
   • snapID applies .id(_:) modifier internally
2. Added .snappable(_:mode:) modifier to ScrollView

Options

Alignment

The snap anchor point can be set as an option.

.snappable(alignment: .leading)

Available alignment parameters are below:

• .top
• .leading
• .center
• .trailing
• .bottom

SnapMode

You can determine the snap timing after the end of the drag with following parameters.

• .afterScrolling
• .immediately

Both parameters are set together with scrolling deceleration rate.

.snappable(alignment: .center, mode: .afterScolling(decelerationRate: .fast))

.snappable(alignment: .center, mode: .immediately(decelerationRate: .normal, withFlick: false))