iOS-image-picker.swift

import UIKit

class ViewController: UIViewController {
    
    @IBOutlet weak var imageView: UIImageView!
    var imagePicker: UIImagePickerController!
    
    enum ImageSource {
        case photoLibrary
        case camera
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
    }
    
    @IBAction func onBtnClicked(_ sender: UIButton){
        
        if sender.tag == 0 { // Photo Gallery...
            PermissionManager.shared.requestAccess(vc: self, .photoLibraryUsage) { (isGranted) in
                if isGranted{
                    self.selectImageFrom(.photoLibrary)
                }
            }
            
        }else if sender.tag == 1 { // CAMERA...
            if UIImagePickerController.isSourceTypeAvailable(.camera){
                PermissionManager.shared.requestAccess(vc: self, .cameraUsage) { (isGranted) in
                    self.selectImageFrom(.camera)
                }
            }else{
                let alert = UIAlertController(title: "Error", message: "You have no camera to capture image.", preferredStyle: .alert)
                alert.addAction(UIAlertAction(title: "Ok", style: .default, handler: nil))
                self.present(alert, animated: true, completion: nil)
            }
        }else if (sender.tag == 3){   // Save Image to Photo Library
            guard let image = imageView.image else { return}
            UIImageWriteToSavedPhotosAlbum(image, self, #selector(image(_:didFinishSavingWithError:contextInfo:)), nil)
        }
    }
    

    func selectImageFrom(_ source: ImageSource){
        imagePicker =  UIImagePickerController()
        imagePicker.delegate = self
        imagePicker.allowsEditing = false
        
        switch source {
        case .camera:
            imagePicker.sourceType = .camera
            imagePicker.cameraCaptureMode = .photo
        case .photoLibrary:
            imagePicker.sourceType = .photoLibrary
        }
        present(imagePicker, animated: true, completion: nil)
    }
}


extension ViewController: UIImagePickerControllerDelegate, UINavigationControllerDelegate{
    
    @objc func image(_ image: UIImage, didFinishSavingWithError error: Error?, contextInfo: UnsafeRawPointer) {
        if let error = error {
            let ac = UIAlertController(title: "Save error", message: error.localizedDescription, preferredStyle: .alert)
            ac.addAction(UIAlertAction(title: "OK", style: .default))
            present(ac, animated: true)
        } else {
            let ac = UIAlertController(title: "Saved!", message: "Your altered image has been saved to your photos.", preferredStyle: .alert)
            ac.addAction(UIAlertAction(title: "OK", style: .default))
            present(ac, animated: true)
        }
    }
    
    
    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
        picker.dismiss(animated: true, completion: nil)
        guard let selectedImage = info[UIImagePickerControllerOriginalImage] as? UIImage else {
            print("Image not found!")
            return
        }
        imageView.image = selectedImage
    }
}


////////////////////////////////////////////// Permission Manager ////////////////////////////////////


enum Permission {
    case cameraUsage
    case contactUsage
    case photoLibraryUsage
    case microphoneUsage
}

class PermissionManager {

    private init(){}
    public static let shared = PermissionManager()
    
    let PHOTO_LIBRARY_PERMISSION: String = "Require access to Photo library to proceed. Would you like to open settings and grant permission to photo library?"
    let CAMERA_USAGE_PERMISSION: String = "Require access to Camera to proceed. Would you like to open settings and grant permission to camera ?"
    let CONTACT_USAGE_ALERT: String = "Require access to Contact to proceed. Would you like to open Settings and grant permission to Contact?"
    let MICROPHONE_USAGE_ALERT: String = "Require access to microphone to proceed. Would you like to open Settings and grant permissiont to Microphone?"
    
    
    
    func requestAccess(vc: UIViewController,
                       _ permission: Permission,
                       completionHandler: @escaping (_ accessGranted: Bool) -> Void){
        
        switch permission {
  
        case .cameraUsage: ////////////////// Camera
            switch AVCaptureDevice.authorizationStatus(for: .video) {
            case .authorized:
                completionHandler(true)
            case .denied:
                showSettingsAlert(controller: vc, msg: CAMERA_USAGE_PERMISSION, completionHandler)
            case .restricted, .notDetermined:
                AVCaptureDevice.requestAccess(for: .video) { granted in
                    if granted {
                        completionHandler(true)
                    } else {
                        DispatchQueue.main.async {
                            self.showSettingsAlert(controller: vc, msg: self.CAMERA_USAGE_PERMISSION, completionHandler)
                        }
                    }
                }
            }
            break
            
            
        case .contactUsage: ///////////////////// Contact
            switch CNContactStore.authorizationStatus(for: .contacts) {
            case .authorized:
                completionHandler(true)
            case .denied:
                showSettingsAlert(controller: vc, msg: CONTACT_USAGE_ALERT, completionHandler)
            case .restricted, .notDetermined:
                CNContactStore.init().requestAccess(for: .contacts) { granted, error in
                    if granted {
                        completionHandler(true)
                    } else {
                        DispatchQueue.main.async {
                            self.showSettingsAlert(controller: vc, msg: self.CONTACT_USAGE_ALERT, completionHandler)
                        }
                    }
                }
            }
            break
            
            
        case .photoLibraryUsage: ///////////////////// Photo library
            switch PHPhotoLibrary.authorizationStatus() {
            case .authorized:
                completionHandler(true)
            case .denied:
                showSettingsAlert(controller: vc, msg: PHOTO_LIBRARY_PERMISSION, completionHandler)
            case .restricted, .notDetermined:
                PHPhotoLibrary.requestAuthorization { (status) in
                    if status == .authorized{
                        completionHandler(true)
                    }else{
                        DispatchQueue.main.async {
                            self.showSettingsAlert(controller: vc, msg: self.PHOTO_LIBRARY_PERMISSION, completionHandler)
                        }
                    }
                }
            }
            break
            
        case .microphoneUsage:  //////////////////////// Microphone usage
            switch AVAudioSession.sharedInstance().recordPermission(){
            case .granted:
                completionHandler(true)
                break
            case .denied:
                showSettingsAlert(controller: vc, msg: MICROPHONE_USAGE_ALERT, completionHandler)
                break
            case .undetermined:
                AVAudioSession.sharedInstance().requestRecordPermission({ (granted) in
                    if granted{
                        completionHandler(true)
                    }else{
                        DispatchQueue.main.async {
                            self.showSettingsAlert(controller: vc, msg: self.MICROPHONE_USAGE_ALERT, completionHandler)
                        }
                    }
                })
                break
            }
        }
    }
    
    
    
    private func showSettingsAlert(controller: UIViewController ,
                                   msg: String,
                                   _ completionHandler: @escaping (_ accessGranted: Bool) -> Void) {
        
        let alert = UIAlertController(title: nil, message: msg, preferredStyle: .alert)
        alert.addAction(UIAlertAction(title: "Open Settings", style: .default) { action in
            completionHandler(false)
            
            if let settingsUrl = URL(string: UIApplicationOpenSettingsURLString) {
                if UIApplication.shared.canOpenURL(settingsUrl){
                    if #available(iOS 10.0, *) {
                        UIApplication.shared.open(settingsUrl)
                    } else {
                        UIApplication.shared.openURL(settingsUrl)
                    }
                }
            }
        })
        alert.addAction(UIAlertAction(title: "Cancel", style: .cancel) { action in
            completionHandler(false)
        })
        controller.present(alert, animated: true)
    }
}


/////////////////////////////////////////////////////////////////////////
/////// Don't forget to add permission in info.plist from privacy ///////
/////////////////////////////////////////////////////////////////////////