[Ink Recognition] Crash when attempting to run on iOS

[luanemanuel]

Title: Crash when attempting to run on iOS.

Describe the bug I'm using the ink_recognition library, but it's crashing when trying to download the model on iOS 12 with an iPhone 6 (physical device) and when attempting to run recognition on iOS 16 with an iPhone 14 Pro Max (simulator). I'm using the "pt-BR" model, but the same issue occurs with the "en-US" model. When testing on Android, the model downloads and runs without any issues.

To Reproduce Steps to reproduce the behavior:

1. Try to download the model in iOS 12.
2. Try to recognize a draw in any iOS version.

Expected behavior The drawing should be recognized without any issues.

Platform (please complete the following information):

• OS: iOS
• Device: iPhone 6 (physical device) and iPhone 14 Pro Max (simulator)
• OS: iOS 12.5.5 and iOS 16
• Flutter/Dart Version: Flutter 3.13.1, Dart 3.1.0

Additional context Download Method:

final _modelIdentifier = 'pt-BR';
Future<void> downloadInkRecognitionModel() async {
    try {
      await _modelManager.downloadModel(
        _modelIdentifier,
        isWifiRequired: false,
      );
    } catch (e) {
      rethrow;
    }
  }

Crash log:

2023-08-30 15:54:31.909774-0300 Runner[27258:1239673] *** Terminating app
due to uncaught exception 'NSInvalidArgumentException', reason: '*** -
[__NSCFConstantString stringByAppendingString:]: nil argument'
*** First throw call stack:
(
0 CoreFoundation 0x000000010f7058ab
__exceptionPreprocess + 242
1 libobjc.A.dylib 0x000000010d3dbba3
objc_exception_throw + 48
2 Foundation 0x0000000111b26242 -[NSString
stringByAppendingFormat:] + 0
3 Runner 0x0000000102e52889 -
[MLKDigitalInkRecognitionModel initWithModelIdentifier:] + 87
4 Runner 0x00000001035617c2 -
[GoogleMlKitDigitalInkRecognitionPlugin handleDetection:result:] + 206
5 Runner 0x0000000103561613 -
[GoogleMlKitDigitalInkRecognitionPlugin handleMethodCall:result:] + 220
6 Flutter 0x00000001160b56bd __45-
[FlutterMethodChannel setMethodCallHandler:]_block_invoke + 168
7 Flutter 0x0000000115a77f52
___ZN7flutter25PlatformMessageHandlerIos21HandlePlatformMessageENSt21
+ 94
8 libdispatch.dylib 0x000000010f465d18
_dispatch_call_block_and_release + 12
9 libdispatch.dylib 0x000000010f466f5b
_dispatch_client_callout + 8
10 libdispatch.dylib 0x000000010f477d55
_dispatch_main_queue_drain + 1463
11 libdispatch.dylib 0x000000010f477790
_dispatch_main_queue_callback_4CF + 31
12 CoreFoundation 0x000000010f664b1f
__CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 9
13 CoreFoundation 0x000000010f65f436 __CFRunLoopRun
+ 2482
14 CoreFoundation 0x000000010f65e6a7
CFRunLoopRunSpecific + 560
15 GraphicsServices 0x000000011159128a
GSEventRunModal + 139
16 UIKitCore 0x00000001296d9ad3 -[UIApplication _run]
+ 994
17 UIKitCore 0x00000001296de9ef UIApplicationMain +
123
18 Runner 0x0000000102cde89f main + 63
19 dyld 0x000000010c5772bf start_sim + 10
20 ??? 0x0000000203dfd52e 0x0 + 8654935342
21 ??? 0x0000000203df8000 0x0 + 8654913536
)

libc++abi: terminating with uncaught exception of type NSException
*** Terminating app due to uncaught exception 'NSInvalidArgumentException',
reason: '*** -[__NSCFConstantString stringByAppendingString:]: nil argument'
terminating with uncaught exception of type NSException
CoreSimulator 857.14 - Device: iPhone 14 Pro (10D7DFC9-26BD-4669-9F40-
B5F023DA9FE4) - Runtime: iOS 16.2 (20C52) - DeviceType: iPhone 14 Pro

[Sneh-Paghdal]

I am getting same in android also.

[lurongshuang]

I am getting same in android also.

[lurongshuang]

@fbernaly

[lurongshuang]

At present, I can only modify the code as follows to ensure normal operation;

Annotate all if (! GenericModelManager. isModelDownloaded (model))

Only judge on the Flutter platform first

public void isModelDownloaded(RemoteModel model, @NonNull final MethodChannel.Result result) {

// IsModelDownloaded myCallable = new IsModelDownloaded(remoteModelManager.isModelDownloaded(model)); // Future taskResult = executorService.submit(myCallable); // try { // return taskResult.get(); // } catch (InterruptedException | ExecutionException e) { // e.printStackTrace(); // } // return null; try { remoteModelManager.isModelDownloaded(model) .addOnSuccessListener(new OnSuccessListener() { @Override public void onSuccess(@NonNull Boolean isDownloaded) { result.success(isDownloaded); } }) .addOnFailureListener(new OnFailureListener() { @Override public void onFailure(@NonNull Exception e) { result.error("Check model failed!", e.getMessage(), e); } }); } catch (Exception e) { result.error("Exception", e.getMessage(), e); } }

[fbernaly]

Thanks, will take a look

[luanemanuel]

I implemented some changes in my project by switching the language model exclusively to 'pt'. Consequently, ink_recognition is now functional on iOS again, albeit exclusively for iOS 14 and later versions. I conducted tests on the following platforms:

• iPhone 6 Plus (Physical device) with iOS 12.5.7
• iPhone XR (Physical device) with iOS 13.7
• iPhone 8 (Virtual device) with iOS 14.0.1
• iPhone 14 Plus (Virtual device) with iOS 16.4

Out of these devices, only the virtual ones with iOS 14+ operated smoothly. Earlier versions resulted in the app abruptly closing without generating a crash log on Crashlytics. Unfortunately, I lack an adapter to connect the physical iPhone to my Mac for conducting development tests, so I do not possess a detailed log of the incident.

[MatthiasKi]

@fbernaly any updates on this? I would really appreciate a fix for this, because currently, I can not use this package on iOS at all due to this crash.

[github-actions[bot]]

This issue is stale because it has been open for 30 days with no activity.