I am using PDFKit as PDFViewer for my app, but I am facing an issue while viewing PDFs. I can't scroll the page, but on the bottom side, when I press double tap, it scrolls to the bottom, or we can say the next page content. one more thing: I am using the code below for Kotlin MultiPlatform.

import UIKit
import PDFKit
import composeApp

class IOSNativeViewFactory: NativeViewFactory {
  func createPdfView(path: String) -> UIView {
    let filePath = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
      .first?.appendingPathComponent(path)
    let pdfView = PDFView()
    pdfView.autoScales = true // Enables pinch-to-zoom
    pdfView.displayMode = .singlePageContinuous // Enables scrolling
    pdfView.displayDirection = .vertical
    pdfView.minScaleFactor = 1.0
    pdfView.maxScaleFactor = 4.0 // Adjust zoom limits
    pdfView.scaleFactor = 1.5
    if let filePath {
      if let document = PDFDocument(url: filePath) {
        pdfView.document = document
      }
    }
    return pdfView
  }
}

I am using PDFKit as PDFViewer for my app, but I am facing an issue while viewing PDFs. I can't scroll the page, but on the bottom side, when I press double tap, it scrolls to the bottom, or we can say the next page content. one more thing: I am using the code below for Kotlin MultiPlatform.

import UIKit
import PDFKit
import composeApp

class IOSNativeViewFactory: NativeViewFactory {
  func createPdfView(path: String) -> UIView {
    let filePath = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
      .first?.appendingPathComponent(path)
    let pdfView = PDFView()
    pdfView.autoScales = true // Enables pinch-to-zoom
    pdfView.displayMode = .singlePageContinuous // Enables scrolling
    pdfView.displayDirection = .vertical
    pdfView.minScaleFactor = 1.0
    pdfView.maxScaleFactor = 4.0 // Adjust zoom limits
    pdfView.scaleFactor = 1.5
    if let filePath {
      if let document = PDFDocument(url: filePath) {
        pdfView.document = document
      }
    }
    return pdfView
  }
}

• ios
• swift
• flutter
• react-native
• kotlin-multiplatform

1 Answer 1

Found the Solution:

When you create a view controller in the same view. It will stick to PDF view on the same page and face a scrolling issue. But When you pass a reference of the parent view controller and add in the parent view controller, it works fine.

Below is the Code I have used in KMM.

func loadPdf(modifier: any UiModifier, name: String)-> Any {
    
    let safeAreaInset = uiViewController.view.safeAreaInsets
    let frame = CGRect(x: 0, y: safeAreaInset.top + 85, width: uiViewController.view.bounds.width, height: uiViewController.view.bounds.height-safeAreaInset.bottom)

    pdfView = PDFView(frame: frame)
    uiViewController.view.addSubview(pdfView)

    let filePath = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
      .first?.appendingPathComponent(name)
    if let filePath {
      if let document = PDFDocument(url: filePath) {
        pdfView.document = document
      }
    }

    pdfView.translatesAutoresizingMaskIntoConstraints = false
    pdfDocument = PDFDocument(url: filePath ?? URL(fileURLWithPath: ""))!
    pdfView.document = pdfDocument
    pdfView.minScaleFactor = 1.0
    pdfView.autoScales = true
    pdfView.displayMode = .singlePageContinuous
    pdfView.displayDirection = .vertical

    totalPAgeCount = 0
    if let total = pdfView.document?.pageCount {
      totalPAgeCount = total
    }
    countPages()

    return uiViewController
  }