dejanskledar

class CollectionViewRow {
    ...
  
    var rowWidth: CGFloat {
        return attributes.reduce(0, { result, attribute -> CGFloat in
            return result + attribute.frame.width
        }) + CGFloat(attributes.count - 1) * spacing
    }
    
    func centerLayout(collectionViewWidth: CGFloat) {

dejanskledar

override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
    ...
    var rows = [CollectionViewRow]()
    var currentRowY: CGFloat = -1

    for attribute in attributes {
        if currentRowY != attribute.frame.origin.y {
            currentRowY = attribute.frame.origin.y
            rows.append(CollectionViewRow(spacing: 10))
        }

dejanskledar

class CollectionViewRow {
    var attributes = [UICollectionViewLayoutAttributes]()
    var spacing: CGFloat = 0

    init(spacing: CGFloat) {
        self.spacing = spacing
    }

    func add(attribute: UICollectionViewLayoutAttributes) {
        attributes.append(attribute)

dejanskledar

override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
    guard let attributes = super.layoutAttributesForElements(in: rect) else {
        return nil
    }
    ...
}

dejanskledar

let layout = UICollectionViewFlowLayout()
layout.estimatedItemSize = CGSize(width: 140, height: 40)
collectionView.collectionViewLayout = layout

dejanskledar

guard let data = self.pdfDocument.dataRepresentation() else { return }
let activityController = UIActivityViewController(activityItems: [data], applicationActivities: nil)
self.present(activityController, animated: true, completion: nil)

dejanskledar

open func dataRepresentation() -> Data?

dejanskledar

open func insert(_ page: PDFPage, at index: Int)

open func removePage(at index: Int)

open func exchangePage(at indexA: Int, withPageAt indexB: Int)

dejanskledar

guard let url = URL(string:"www.your_pdf_url.com") else { return }

let pdfView = PDFView(frame: view.frame)
let pdfDocument = PDFDocument(url: url)
pdfView.document = pdfDocument
view.addSubview(pdfView)

dejanskledar

UIView.animateKeyframes(withDuration: 5.0, delay: 0, options: [.calculationModeCubic], animations: {
    // Add animations
    UIView.addKeyframe(withRelativeStartTime: 0, relativeDuration: 1.0/5.0, animations: {
        view.frame.origin.x += 200
    })
    UIView.addKeyframe(withRelativeStartTime: 1.0/5.0, relativeDuration: 1.0/5.0, animations: {
        view.backgroundColor = .green
    })
    UIView.addKeyframe(withRelativeStartTime: 2.0/5.0, relativeDuration: 1.0/5.0, animations: {
        view.frame.origin.y += 200