InfinityScrollKit Package

InfinityScrollKit is a SwiftUI package that simplifies implementing infinite scrolling for lists in iOS. The package handles loading more items as the user scrolls, while providing a customizable UI for both normal cells and the last loading/error state cell.

Features

• Infinite scrolling support for any SwiftUI list.
• Native UIKit and AppKit support with UIInfiniteScrollView and NSInfiniteScrollView.
• Customizable views for individual items and the last cell (used for progress indicators or error states).
• Support for dynamic loading through a callback for loading more items.
• Encapsulated state management for loading indicators.
• Option to provide feedback to parent views about loading state changes.
• Scroll orientation customization.
• Customizable spacing between cells.

Installation

Swift Package Manager

Add the package by going to your Xcode project:

1. Select your project in the file navigator.
2. Choose the project or target where you want to add the package.
3. Go to the Package Dependencies tab.
4. Click the + button.
5. Search for InfinityScrollKit using the repository URL:

   https://github.com/PierreJanineh-com/InfinityScrollKit

6. Follow the prompts to complete the installation.

CocoaPods

1. If you are not yet using CocoaPods in your project, first run sudo gem install cocoapods followed by pod init. (For further information on installing CocoaPods, click here.)

2. Add the following to your Podfile (inside the target section):

   pod 'InfinityScrollKit'

3. Run pod install.

Usage

Check out the full example in this repo.

SwiftUI Usage

Below is a basic usage example where we create an infinite scroll list with custom item and last cell views:

import SwiftUI
import InfinityScrollKit

struct ContentView: View {
    @State private var items: [MyItem] = []
    
    var body: some View {
        InfiniteScrollView(
            arr: $items,
            cellView: { item in
                Text(item.name) // Customize the view for each item
            }
        )
    }
}

• arr: The array of items to display.
• cellView: A ViewBuilder function to display the individual cells in the list.

UIKit Usage

For UIKit-based applications, use UIInfiniteScrollView:

import UIKit
import InfinityScrollKit

class ViewController: UIViewController {
    private var scrollView: UIInfiniteScrollView<String, ViewController>!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // Initialize with items
        scrollView = UIInfiniteScrollView(items: ["Item 1", "Item 2", "Item 3"])
        scrollView.delegate = self
        view.addSubview(scrollView)
        
        // Setup constraints
        // ...
    }
}

extension ViewController: UIInfiniteScrollViewDelegate {
    func cellFor(_ item: String, at: IndexPath.Index) -> UIView {
        let label = UILabel()
        label.text = item
        return label
    }
    
    func lastCellView() -> UIView? {
        let activityIndicator = UIActivityIndicatorView(style: .medium)
        activityIndicator.startAnimating()
        return activityIndicator
    }
    
    func emptyArrayView() -> UIView? {
        let label = UILabel()
        label.text = "No items yet..."
        return label
    }
    
    func onLoadingChanged(_ isLoading: Bool) {
        // Handle loading state changes if needed
    }
}

AppKit Usage

For macOS applications, use NSInfiniteScrollView:

import AppKit
import InfinityScrollKit

class ViewController: NSViewController {
    private var scrollView: NSInfiniteScrollView<String, ViewController>!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // Initialize with items
        scrollView = NSInfiniteScrollView(items: ["Item 1", "Item 2", "Item 3"])
        scrollView.delegate = self
        view.addSubview(scrollView)
        
        // Setup constraints
        // ...
    }
}

extension ViewController: NSInfiniteScrollViewDelegate {
    func cellFor(_ item: String, at: IndexPath.Index) -> NSView {
        NSTextField(labelWithString: item)
    }
    
    func lastCellView() -> NSView? {
        let progressIndicator = NSProgressIndicator()
        progressIndicator.style = .spinning
        progressIndicator.startAnimation(nil)
        return progressIndicator
    }
    
    func emptyArrayView() -> NSView? {
        NSTextField(labelWithString: "No items yet...")
    }
    
    func onLoadingChanged(_ isLoading: Bool) {
        // Handle loading state changes if needed
    }
}

Customization

• onLoadingChange: A closure to notify the parent view when the loading state changes.
• options: You can pass Options<T> to customize the number of items per page and handle loading more items via a callback.
• lastCellView: A ViewBuilder function for the view at the end of the list (e.g., a loading indicator or error message).
• emptyArrayView: Customize the view shown when there are no items in the list.

import SwiftUI
import InfinityScrollKit

struct ContentView: View {
    @State private var arr: [String] = []
    @State private var isLoading: Bool = false
    
    var body: some View {
        InfiniteScrollView(
            arr: $arr,
            options: options,
            onLoadingChanged: onLoadingChanged,
            cellView: CellView,
            lastCellView: LastCellView,
            emptyArrView: EmptyArrView
        )
        // You can also use ScrollView modifiers directly
        .scrollIndicators(.hidden)
    }

    private var options: Options<String> {
        .init(
            orientation: .horizontal,
            countPerPage: 2,
            paginationOptions: .init(
                onPageLoad: {
                    // Replace this with an API pagination request
                    try? await Task.sleep(nanoseconds: 5 * 1_000_000_000)
                    
                    var fetchedItems: [String]
                    // ...
                    // fetch additional items to add to the current array
                    
                    return fetchedItems
                },
                concatMode: .auto  //.auto for automatically adding pages to the array instead of passing the full array everytime.
            )
        )
    }

    private func onLoadingChanged(_ isLoading: Bool) {
        self.isLoading = isLoading
        if self.isLoading {
            // Do anything here...
        }
    }

    @ViewBuilder func CellView(_ item: String) -> some View {
        Text(item)
    }

    @ViewBuilder func LastCellView() -> some View {
        ProgressView()
            .padding()
    }

    @ViewBuilder func EmptyArrView() -> some View {
        Text("No items to display...")
    }
}

Platforms

The InfiniteScrollView package supports the following platforms:

• iOS 14.0+
• macOS 14.0+
• watchOS 7.0+
• tvOS 14.0+
• visionOS 1.0+

Contribution

Feel free to contribute by creating issues or submitting pull requests. Before submitting, make sure to:

1. Fork the repository.
2. Create your feature branch (git checkout -b feature/my-feature).
3. Commit your changes (git commit -m 'Add some feature').
4. Push to the branch (git push origin feature/my-feature).
5. Open a pull request.

License

This project is licensed under the MIT License. See the LICENSE file for more details.