I have one weird case where UIImagePickerController will not present.
Context: I'm using UIImagePicker to let a user pick a profile image from their photos. They tap to add a profile image and initially a modal is triggered where they can pick between using their local photos and their facebook profile photo.
This modal delegates back to the profile view controller where all the functions below exist. The modal fires didSelectProfilePhotoOption - in this case with .fromPhotos.
func didSelectProfilePhotoOption(photoSource: PhotoSource) {
switch photoSource {
case .fromFacebook:
useFacebookPhotoForProfile()
case .fromPhotos:
selectProfileImageFromPhotoLibrary()
}
}
This is important, because I have tried just triggering selectProfileImageFromPhotoLibrary from the view controller (rather than the modal delegate) and the UIImagePickerController shows every time.
func selectProfileImageFromPhotoLibrary() {
let status = PHPhotoLibrary.authorizationStatus()
handleImageAuthStatus(status: status)
}
func handleImageAuthStatus(status: PHAuthorizationStatus) {
switch status {
case .authorized:
presentImagePicker()
case .denied:
//show an error message
case .notDetermined:
PHPhotoLibrary.requestAuthorization( { status in
self.handleImageAuthStatus(status: status)
})
case .restricted:
//show an error message
}
}
func presentImagePicker() {
let imagePicker = UIImagePickerController()
imagePicker.delegate = self
imagePicker.allowsEditing = false
imagePicker.sourceType = .photoLibrary
self.present(imagePicker, animated: true, completion: nil)
}
The added weirdness is that UIImagePickerController will show when it's chained as part of requesting the photo permissions.
So in the case:
didSelectProfilePhotoOption(photoSource: .fromPhotos) >>> selectProfileImageFromPhotoLibrary >>> handleImageAuthStatus(status: .notDetermined) >>> (grant permissions) >>> handleImageAuthStatus(status: .authorized)
...UIImagePickerController shows every time.
Any ideas what's going on here? Many thanks in advance!
Related
I am exploring the MPMediaPickerController for the first time, and I don't see anything when my button is pushed. The MPMediaPickerController.view has a frame after it is presented but it is not visible at all, nor does it appear in the view hierarchy. I am just using a simple fresh POC application with a ViewController and a IBOutlet button constrained to center vertical and horizontal, that calls this function:
func checkMediaAccess() {
let status = MPMediaLibrary.authorizationStatus()
switch status {
case .authorized:
showMediaPicker()
case .notDetermined:
MPMediaLibrary.requestAuthorization() { status in
if status == .authorized {
DispatchQueue.main.async {
self.showMediaPicker()
}
}
}
break
case .denied:
print("Denied")
break
case .restricted:
break
#unknown default:
break
}
}
Which then calls this function on authorized:
func showMediaPicker() {
print("SHOWING")
let picker = MPMediaPickerController(mediaTypes: .music)
picker.allowsPickingMultipleItems = false
picker.popoverPresentationController?.sourceView = pickerButton
picker.showsCloudItems = true
picker.delegate = self
self.present(picker, animated: true, completion: nil)
print(picker.view.frame )
}
"SHOWING" is printed, but again I don't see anything. I don't get anything else printed either.
I have all the info.plist descriptions for Media and Music access in. I also do get the prompt to allow the first time, and again "SHOWING" is printed. I have the delegates implemented, but they are never fired, because I don't see the view.
Nothing happens visually when I tap the button, and I can tap the button again.
What am i missing?
maybe the music app not installed!
I really hope I'm not making a duplicate - but I read a ton different camera-questions inhere and implemented all of their answers, with the same result: Nothing happens!
No errors, the app doesn't crash, no problems whatsoever - only there is no sign of the camera, which should be activated! My goal is to get it activated in viewDidAppear or viewDidLoad, but I also tried testing it by connecting the code to a button - same result; nothing. Both on my own device and on the simulator: nothing!
What am i getting wrong in this simple code?? - Or which setting do I need to change? I have tried playing with the "data protection": nothing!
Code:
class CreateNewPerson: UIViewController, UITextFieldDelegate, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
func viewDidAppear () {
let imagePicker = UIImagePickerController()
imagePicker.delegate = self
imagePicker.sourceType = .camera
present(imagePicker, animated: true, completion: nil)
}
private func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject]!) {
PersonPhoto.image = info[UIImagePickerControllerOriginalImage] as? UIImage
dismiss(animated: true, completion: nil)
}
Hope someone can help me!
Photo of info.plist (where I can't seem to find the camera ussage description) - maybe I'm an idiot...:
Thanks!
You need to add a Camara usage description into your info.plist file and ask permission for your app to access the camera.
Add this to your plist file:
Privacy - Camera Usage Description
With some text like
"We need your permission to access the device camera"
To request permission:
AVCaptureDevice.requestAccess(for: AVMediaType.video) { granted in
if granted {
// show the image picker
} else {
// show an error
}
}
It is usually best to check if you need permission or what state the permissions are in, so I would do it like this...
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
checkCameraPermissions()
}
private func checkCameraPermissions() {
let status = AVCaptureDevice.authorizationStatus(for: .video)
switch status {
case .authorized:
self.presentPicker()
case .notDetermined:
self.requestPermissions()
case .denied:
// user denied access
self.permissionDenied()
}
}
private func requestAccess() {
AVCaptureDevice.requestAccess(for: AVMediaType.video) { granted in
if !granted {
// show an error
}
// call it again in to recheck now that permissions have changed.
checkCameraPermissions
}
}
private func presentPicker() {
// permissions are all set, continue as planned.
}
private func permissionDenied() {
// show an alert and link to app settings to turn on
// usually I would show a view which explains they have denied permission to the camera so this functionality isn't available until they manually change the setting in the app settings.
}
You have to add CreateNewPerson in UINavigationController after that run your code.
Don't forget to add Privacy - Camera Usage Description in info.plist
I have a split view controller with the top view controller set to a table view controller that is to display a list of playlists for selection. The first time the app is loaded it asks for music access permission. Answering yes does give it permission but the table view displays no playlists. I end up having to kill the app and run it again. Am I asking for music library permission the wrong place? It is in that top view controller's viewWillAppear and store the playlists I'm using (since some are screened out) in a class of playlists.
override func viewWillAppear(_ animated: Bool) {
self.clearsSelectionOnViewWillAppear = self.splitViewController!.isCollapsed
super.viewWillAppear(animated)
checkMediaAccessAndSetup()
}
func checkMediaAccessAndSetup() {
let authorizationStatus = MPMediaLibrary.authorizationStatus()
switch authorizationStatus {
case .notDetermined:
// Show the permission prompt.
MPMediaLibrary.requestAuthorization({[weak self] (newAuthorizationStatus: MPMediaLibraryAuthorizationStatus) in
// Try again after the prompt is dismissed.
self?.checkMediaAccessAndSetup()
})
case .denied, .restricted:
// Do not use MPMediaQuery.
return
default:
// Proceed as usual.
break
}
// Do stuff with MPMediaQuery
self.setupPlaylistStore()
tableView.reloadData()
}
The chief problems with your code are
You are completely failing to grapple with the fact that the requestAuthorization completion function is called on a background thread. You need to step out to the main thread to do work on the interface.
You have omitted the all-important .authorized case. When you have work to do that depends upon your authorization status, you must do it now if you are authorized, but after authorization if you are not determined.
Thus, this is the correct scheme for a coherent authorization check (where f() is the thing you always want to do if you can):
let status = MPMediaLibrary.authorizationStatus()
switch status {
case .authorized:
f()
case .notDetermined:
MPMediaLibrary.requestAuthorization() { status in
if status == .authorized {
DispatchQueue.main.async {
f()
}
}
}
// ...
}
If you abstract this code into a utility method, where f can be anything, you can do this everywhere in your app where authorization might be necessary — not merely at startup.
Thanks for the comments, it gave me clues of the multi-threading that was going on and I was able to fix it with a timer call if there were no playlists in the class to keep on checking and reload the table data.
override func viewWillAppear(_ animated: Bool) {
self.clearsSelectionOnViewWillAppear = self.splitViewController!.isCollapsed
super.viewWillAppear(animated)
checkMediaAccess()
self.setupPlaylistStore()
tableView.reloadData()
if store.allPlaylists.count < 1 {
playlistTimer = Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(self.playlistTimerCall), userInfo: nil, repeats: true)
}
}
#objc func playlistTimerCall() {
self.setupPlaylistStore()
if store.allPlaylists.count > 1 {
tableView.reloadData()
playlistTimer?.invalidate()
}
}
func checkMediaAccess() {
let authorizationStatus = MPMediaLibrary.authorizationStatus()
switch authorizationStatus {
case .notDetermined:
// Show the permission prompt.
MPMediaLibrary.requestAuthorization({[weak self] (newAuthorizationStatus: MPMediaLibraryAuthorizationStatus) in
// Try again after the prompt is dismissed.
self?.checkMediaAccess()
})
case .denied, .restricted:
// Do not use MPMediaQuery.
return
default:
// Proceed as usual.
break
}
}
func setupPlaylistStore() {
// purge store
store.clearAllPlaylists()
// create a query of media items in playlist
let myPlayListsQuery = MPMediaQuery.playlists()
if myPlayListsQuery.collections != nil {
playlists = myPlayListsQuery.collections!
}
// add playlists to MyPlaylist(s)
if playlists.count > 0 {
for index in 0...playlists.count - 1 {
let playlist = playlists[index]
store.addPlaylist(playlist: playlist as! MPMediaPlaylist)
}
}
var toBeRemoved = [Int]()
let defaults = UserDefaults.standard
if defaults.bool(forKey: "exclude_smart_playlists") {
//smart
for index in 0...(playlists.count - 1) {
let playlist = playlists[index]
let theAttributes = playlist.value(forProperty: MPMediaPlaylistPropertyPlaylistAttributes) as! Int
if theAttributes == 2 {
toBeRemoved.append(index)
}
}
}
if defaults.bool(forKey: "exclude_folders") {
//folders
for index in 0...(playlists.count - 1) {
let playlist = playlists[index]
let isFolder = playlist.value(forProperty: "isFolder")
let stringIsFolder = String("\(String(describing: isFolder))")
if ((stringIsFolder.range(of: "1")) != nil) {
toBeRemoved.append(index)
}
}
}
//sort from the last to the first so i don't reindex
let reverseSortedPlaylists = toBeRemoved.sorted(by: >)
// remove the unwanted playlists
for list in reverseSortedPlaylists {
store.removePlaylist(index: list)
}
}
I am using a UIImagePicker to present the users with camera to take photos which will be used in the app.
My problem is that on the first time a user opens the image picker they are presented with a prompt saying: '"my App" Would like to Access your Camera' with two options, Don't allow and OK.
My requirement is that when the user clicks Don't Allow, the Image picker gets dismissed leaving a black view. Is there a way to detect that the user has chosen Don't allow?
Here is my code to present UIImagePicker:
var PhotoPicker:UIImagePickerController = UIImagePickerController()
PhotoPicker.delegate = self
PhotoPicker.sourceType = .Camera
PhotoPicker.cameraFlashMode = .Off
PhotoPicker.showsCameraControls = false
PhotoPicker.cameraDevice = .Rear
self.presentViewController(PhotoPicker, animated: false, completion: nil)
To detect access to your library:
You need to use AssetsLibrary for that. First, import assets library framework:
import AssetsLibrary
Then, request authorization status, and if it is not determined, use blocks to catch those events, like this:
if ALAssetsLibrary.authorizationStatus() == ALAuthorizationStatus.NotDetermined {
let library = ALAssetsLibrary()
library.enumerateGroupsWithTypes(.All, usingBlock: { (group, stop) -> Void in
// User clicked ok
}, failureBlock: { (error) -> Void in
// User clicked don't allow
imagePickerController.dismissViewControllerAnimated(true, completion: nil)
})
}
To detect access to camera:
You need to use AVFoundation for that. First, import avfoundation framework:
import AVFoundation
Then, as previously, request user permission when you go to imagepicker and catch the event.
if AVCaptureDevice.authorizationStatusForMediaType(AVMediaTypeVideo) == AVAuthorizationStatus.NotDetermined {
AVCaptureDevice.requestAccessForMediaType(AVMediaTypeVideo, completionHandler: { (videoGranted: Bool) -> Void in
// User clicked ok
if (videoGranted) {
// User clicked don't allow
} else {
imagePickerController.dismissViewControllerAnimated(true, completion: nil)
}
})
}
Hope it helps!
In iOS 10, use:
import Photos
let authStatus = PHPhotoLibrary.authorizationStatus()
if authStatus == .notDetermined || authStatus == .denied {
PHPhotoLibrary.requestAuthorization({ (status) in
if status == PHAuthorizationStatus.authorized {
} else {
imagePickerController.dismissViewControllerAnimated(true, completion: nil)
}
})
}
Check out this for detecting camera permission
Presenting camera permission dialog in iOS 8
Use this when user picks Don't Allow.
PhotoPicker.dismissViewControllerAnimated(false, completion: nil)
I am developing a very simple video app. I use the official control: UIImagePickerController.
Here is the problem. When presenting the UIImagePickerController for the first time, the iOS will ask for the permission. The user can click yes or no. If the user clicks no, the control is not dismissed. Instead, if the user keeps clicking the start button, the timers go on while the screen is always black, and the user can't stop the timers or go back. The only thing the user can do is to kill the app. The next time the UIImagePickerController is presented, it is still a black screen and the user can't go back if clicking start.
I was wondering if it's a bug. Is there any way we can detect the permission of the camera so that we can decide to show the UIImagePickerController or not?
Check the AVAuthorizationStatus and handle the cases properly.
NSString *mediaType = AVMediaTypeVideo;
AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:mediaType];
if(authStatus == AVAuthorizationStatusAuthorized) {
// do your logic
} else if(authStatus == AVAuthorizationStatusDenied){
// denied
} else if(authStatus == AVAuthorizationStatusRestricted){
// restricted, normally won't happen
} else if(authStatus == AVAuthorizationStatusNotDetermined){
// not determined?!
[AVCaptureDevice requestAccessForMediaType:mediaType completionHandler:^(BOOL granted) {
if(granted){
NSLog(#"Granted access to %#", mediaType);
} else {
NSLog(#"Not granted access to %#", mediaType);
}
}];
} else {
// impossible, unknown authorization status
}
Swift 4 and newer
Make sure to:
import AVFoundation
The code below checks for all possible permission states:
let cameraMediaType = AVMediaType.video
let cameraAuthorizationStatus = AVCaptureDevice.authorizationStatus(for: cameraMediaType)
switch cameraAuthorizationStatus {
case .denied: break
case .authorized: break
case .restricted: break
case .notDetermined:
// Prompting user for the permission to use the camera.
AVCaptureDevice.requestAccess(for: cameraMediaType) { granted in
if granted {
print("Granted access to \(cameraMediaType)")
} else {
print("Denied access to \(cameraMediaType)")
}
}
}
Since iOS 10 you need to specify
NSCameraUsageDescription key in your Info.plist to be able ask for camera access, otherwise your app will crash at runtime. See APIs Requiring Usage Descriptions.
An interesting sidenote from Apple Developer forum:
The system actually kills your app if the user toggles your app's
access to camera in Settings. The same applies to any protected
dataclass in the Settings→Privacy section.
Swift Solution
extension AVCaptureDevice {
enum AuthorizationStatus {
case justDenied
case alreadyDenied
case restricted
case justAuthorized
case alreadyAuthorized
case unknown
}
class func authorizeVideo(completion: ((AuthorizationStatus) -> Void)?) {
AVCaptureDevice.authorize(mediaType: AVMediaType.video, completion: completion)
}
class func authorizeAudio(completion: ((AuthorizationStatus) -> Void)?) {
AVCaptureDevice.authorize(mediaType: AVMediaType.audio, completion: completion)
}
private class func authorize(mediaType: AVMediaType, completion: ((AuthorizationStatus) -> Void)?) {
let status = AVCaptureDevice.authorizationStatus(for: mediaType)
switch status {
case .authorized:
completion?(.alreadyAuthorized)
case .denied:
completion?(.alreadyDenied)
case .restricted:
completion?(.restricted)
case .notDetermined:
AVCaptureDevice.requestAccess(for: mediaType, completionHandler: { (granted) in
DispatchQueue.main.async {
if granted {
completion?(.justAuthorized)
} else {
completion?(.justDenied)
}
}
})
#unknown default:
completion?(.unknown)
}
}
}
And then in order to use it you do
AVCaptureDevice.authorizeVideo(completion: { (status) in
//Your work here
})
As an addition to the answer from #Raptor the following should be mentioned. You may receive the following error starting with iOS 10: This application is modifying the autolayout engine from a background thread after the engine was accessed from the main thread. This can lead to engine corruption and weird crashes.
To fix this, make sure you handle the results from the main thread as follows (Swift 3):
private func showCameraPermissionPopup() {
let cameraMediaType = AVMediaTypeVideo
let cameraAuthorizationStatus = AVCaptureDevice.authorizationStatus(forMediaType: cameraMediaType)
switch cameraAuthorizationStatus {
case .denied:
NSLog("cameraAuthorizationStatus=denied")
break
case .authorized:
NSLog("cameraAuthorizationStatus=authorized")
break
case .restricted:
NSLog("cameraAuthorizationStatus=restricted")
break
case .notDetermined:
NSLog("cameraAuthorizationStatus=notDetermined")
// Prompting user for the permission to use the camera.
AVCaptureDevice.requestAccess(forMediaType: cameraMediaType) { granted in
DispatchQueue.main.sync {
if granted {
// do something
} else {
// do something else
}
}
}
}
}
Specify NSCameraUsageDescription key in Info.plist first.
Then check AVAuthorizationStatus if Authorised then present the UIImagePickerController. It will work.
Swift: Using AVFoundation
Add AVFoundation to Target -> Build Phases -> Link Binary with Libraries.
import AVFoundation on ViewController.
On Info.plist, Add the following:
On View Controller:
#IBAction func cameraButtonClicked(sender: AnyObject) {
let authorizationStatus = AVCaptureDevice.authorizationStatusForMediaType(AVMediaTypeVideo)
print(authorizationStatus.rawValue)
if AVCaptureDevice.authorizationStatusForMediaType(AVMediaTypeVideo) == AVAuthorizationStatus.Authorized{
self.openCameraAfterAccessGrantedByUser()
}
else
{
print("No Access")
dispatch_async(dispatch_get_main_queue()) { [unowned self] in
AVCaptureDevice.requestAccessForMediaType(AVMediaTypeVideo, completionHandler: { (granted :Bool) -> Void in
if granted == true
{
// User granted
self.openCameraAfterAccessGrantedByUser()
}
else
{
// User Rejected
alertToEncourageCameraAccessWhenApplicationStarts()
}
});
}
}
//Open camera
func openCameraAfterAccessGrantedByUser()
{
if(UIImagePickerController .isSourceTypeAvailable(UIImagePickerControllerSourceType.Camera)){
self.cameraAndGalleryPicker!.sourceType = UIImagePickerControllerSourceType.Camera
cameraAndGalleryPicker?.delegate = self
cameraAndGalleryPicker?.allowsEditing = false
cameraAndGalleryPicker!.cameraCaptureMode = .Photo
cameraAndGalleryPicker!.modalPresentationStyle = .FullScreen
presentViewController(self.cameraAndGalleryPicker!, animated: true, completion: nil)
}
else
{
}
}
//Show Camera Unavailable Alert
func alertToEncourageCameraAccessWhenApplicationStarts()
{
//Camera not available - Alert
let cameraUnavailableAlertController = UIAlertController (title: "Camera Unavailable", message: "Please check to see if it is disconnected or in use by another application", preferredStyle: .Alert)
let settingsAction = UIAlertAction(title: "Settings", style: .Destructive) { (_) -> Void in
let settingsUrl = NSURL(string:UIApplicationOpenSettingsURLString)
if let url = settingsUrl {
dispatch_async(dispatch_get_main_queue()) {
UIApplication.sharedApplication().openURL(url)
}
}
}
let cancelAction = UIAlertAction(title: "Okay", style: .Default, handler: nil)
cameraUnavailableAlertController .addAction(settingsAction)
cameraUnavailableAlertController .addAction(cancelAction)
self.window?.rootViewController!.presentViewController(cameraUnavailableAlertController , animated: true, completion: nil)
}