Annotate/Draw on PDF in Swift - ios

Question

I am writing an app that will contain multiple PDF documents that I will display on screen depending on the user's input.
Once displayed, I would like to allow the user to draw/annotate on the PDF. I would then like to save the PDF with the drawings/annotations on for later use.
I have searched endlessly for tutorials on annotating a PDF but I am coming back with not much at all!
I have found a cocoapod on GitHub called 'UXMPDF'. Has anyone used this?
Any information on performing this type of operation would be hugely appreciated! Thanks

Answer 1

First Create PDFView and Load pdfFile:
override func viewDidLoad() {
super.viewDidLoad()
let pdfView = PDFView(frame: CGRect(x: 0, y: 0, width: UIScreen.main.bounds.size.width, height: UIScreen.main.bounds.size.height))
guard let document = PDFDocument(url: YOUR_FILE_PATH) else {
return
}
pdfView.document = document
pdfView.displayMode = .singlePageContinuous
pdfView.autoScales = true
pdfView.displayDirection = .horizontal
pdfView.autoresizingMask = [.flexibleWidth, .flexibleHeight, .flexibleTopMargin, .flexibleBottomMargin]
pdfView.maxScaleFactor = 4
pdfView.delegate = self
pdfView.minScaleFactor = pdfView.scaleFactorForSizeToFit
pdfView.usePageViewController(true, withViewOptions: nil)
pdfView.translatesAutoresizingMaskIntoConstraints = false
self.view.addSubview(pdfView)
self.pdfView = pdfView
self.pdfDocument = document
let highLightItem = UIMenuItem(title:"Highlight"), action: #selector(highlightFromMenuItem))
}
you can use pdfAnnotation from UIMenuItem like that:
#objc func highlightFromMenuItem() {
if let document = self.pdfDocument {
let pdfSelection : PDFSelection = PDFSelection(document: document)
pdfSelection.add((self.pdfView?.currentSelection)!)
let arrayByLines = self.pdfView?.currentSelection?.selectionsByLine()
arrayByLines?.forEach({ (selection) in
let annotation = PDFAnnotation(bounds: selection.bounds(for: (self.pdfView?.currentPage)!), forType: .highlight, withProperties: nil)
annotation.color = .yellow
self.pdfView?.currentPage?.addAnnotation(annotation)
})
}
}
If you want to save what did you did:
self.pdfView.document.write(to:YOUR_FILE_URL)
other pdfAnnotation you can use:
.underline
.strikeOut
.circle
.square