Pick and play a video in SwiftUI — how convert from UIKit code? - swift

Question

I'm working on a camera app and I've got a problem.
I've never used UIKit to build an app, but a lot of the reference code does.
So I tried to convert it using swiftUI but I failed.
There is UIKit code which I want to convert to SwiftUI.
static func startMediaBrowser(
delegate: UIViewController & UINavigationControllerDelegate & UIImagePickerControllerDelegate,
sourceType: UIImagePickerController.SourceType
) {
guard UIImagePickerController.isSourceTypeAvailable(sourceType)
else { return }
let mediaUI = UIImagePickerController()
mediaUI.sourceType = sourceType
mediaUI.mediaTypes = [kUTTypeMovie as String]
mediaUI.allowsEditing = true
mediaUI.delegate = delegate
delegate.present(mediaUI, animated: true, completion: nil)
}
import AVKit
import MobileCoreServices
import UIKit
class PlayVideoViewController: UIViewController {
#IBAction func playVideo(_ sender: AnyObject) {
VideoHelper.startMediaBrowser(delegate: self, sourceType: .savedPhotosAlbum)
}
}
// MARK: - UIImagePickerControllerDelegate
extension PlayVideoViewController: UIImagePickerControllerDelegate {
func imagePickerController(
_ picker: UIImagePickerController,
didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey: Any]
) {
guard
let mediaType = info[UIImagePickerController.InfoKey.mediaType] as? String,
mediaType == (kUTTypeMovie as String),
let url = info[UIImagePickerController.InfoKey.mediaURL] as? URL
else { return }
dismiss(animated: true) {
let player = AVPlayer(url: url)
let vcPlayer = AVPlayerViewController()
vcPlayer.player = player
self.present(vcPlayer, animated: true, completion: nil)
}
}
}
// MARK: - UINavigationControllerDelegate
extension PlayVideoViewController: UINavigationControllerDelegate {
}
Here's what I've tried, and the compilation passes, but it only does UIImagePickerController() , and the delegate function I wrote doesn't work.
import SwiftUI
import AVKit
import MobileCoreServices
import UIKit
struct ContentView: View {
#State private var isShowVideoLibrary = false
#State private var image = UIImage()
#State private var isShowCamara = false
var body: some View {
VStack {
HStack{
Button {
isShowVideoLibrary.toggle()
} label: {
Text("Play video")
}
}
}
.sheet(isPresented: $isShowVideoLibrary) {
VideoPicker(sourceType: .photoLibrary)
}
}
struct VideoPicker: UIViewControllerRepresentable {
var sourceType: UIImagePickerController.SourceType = .photoLibrary
#Environment(\.presentationMode) private var presentationMode
func makeUIViewController(context: UIViewControllerRepresentableContext<VideoPicker>) -> UIViewController {
let mediaUI = UIImagePickerController()
mediaUI.sourceType = sourceType
mediaUI.mediaTypes = [kUTTypeMovie as String]
mediaUI.allowsEditing = true
mediaUI.delegate = context.coordinator
return mediaUI
}
func updateUIViewController(_ uiViewController: UIViewControllerType, context: Context) {
}
final class Coordinator : NSObject, UIImagePickerControllerDelegate, UINavigationControllerDelegate{
var parent: VideoPicker
init(_ parent: VideoPicker) {
self.parent = parent
}
private func imagePickerController(
_ picker: UIImagePickerController,
didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey: Any]) -> UIViewController {
guard
let mediaType = info[UIImagePickerController.InfoKey.mediaType] as? String,
mediaType == (kUTTypeMovie as String),
let url = info[UIImagePickerController.InfoKey.mediaURL] as? URL
else { return AVPlayerViewController()}
// 2
parent.presentationMode.wrappedValue.dismiss()
//3
let player = AVPlayer(url: url)
let vcPlayer = AVPlayerViewController()
vcPlayer.player = player
return vcPlayer
}
}
func makeCoordinator() -> Coordinator {
Coordinator(self)
}
}

Answer 1

The problem you have is that you haven't implemented the correct UIImagePickerControllerDelegate function signature.
Your Coordinator has:
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey: Any]) -> UIViewController
while the correct method is:
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any])
The method won't get called unless the signature matches exactly.
A solution
The UIImagePickerController is just used to select the image or video, you'll need additional cod to play the selected video. Luckily SwiftUI has a VideoPlayer that makes it easy:
import UniformTypeIdentifiers
struct ContentView: View {
#State private var isShowVideoLibrary = false
#State private var url: URL?
var body: some View {
Group {
if let url {
VideoPlayer(player: AVPlayer(url: url))
} else {
VStack {
HStack{
Button {
isShowVideoLibrary.toggle()
} label: {
Text("Play video")
}
}
}
}
}
.sheet(isPresented: $isShowVideoLibrary) {
VideoPicker(sourceType: .photoLibrary) { url in
self.url = url
isShowVideoLibrary = false
}
}
}
}
struct VideoPicker: UIViewControllerRepresentable {
var sourceType: UIImagePickerController.SourceType = .photoLibrary
let didFinish: (URL?) -> Void
func makeUIViewController(context: UIViewControllerRepresentableContext<VideoPicker>) -> UIViewController {
let mediaUI = UIImagePickerController()
mediaUI.sourceType = sourceType
mediaUI.mediaTypes = [UTType.movie.identifier]
mediaUI.allowsEditing = true
mediaUI.delegate = context.coordinator
return mediaUI
}
func updateUIViewController(_ uiViewController: UIViewControllerType, context: Context) {
}
final class Coordinator : NSObject, UIImagePickerControllerDelegate, UINavigationControllerDelegate{
let didFinish: (URL?) -> Void
init(didFinish: #escaping (URL?) -> Void) {
self.didFinish = didFinish
}
// This func passes the URL back to the calling View
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
guard
let mediaType = info[UIImagePickerController.InfoKey.mediaType] as? String,
mediaType == UTType.movie.identifier,
let url = info[UIImagePickerController.InfoKey.mediaURL] as? URL
else {
didFinish(nil)
return
}
didFinish(url)
}
}
func makeCoordinator() -> Coordinator {
Coordinator(didFinish: didFinish)
}
}