tizen_interop_callbacks

A Flutter plugin to resolve issues related to the error message: Cannot invoke native callback outside an isolate.

This package is designed to be used with the tizen_interop package. Similarly to tizen_interop, this package has no build time dependency on a specific Tizen profile or version.

Usage

1. Add this package and tizen_interop as dependencies in your pubspec.yaml file.

   dependencies:
     ffi: ^2.0.1
     tizen_interop: ^0.4.1
     tizen_interop_callbacks: ^0.3.1
   

2. In your Dart code, import the packages:

   import 'dart:ffi';
   import 'package:tizen_interop/6.0/tizen.dart';
   import 'package:tizen_interop_callbacks/tizen_interop_callbacks.dart';
   

3. Instantiate the TizenInteropCallbacks class. This should be done in the root isolate - the thread where your main() is called.

   final callbacks = TizenInteropCallbacks();
   

4. Implement your callback in Dart and register it with TizenInteropCallbacks:

   final callback = _callbacks.register<Void Function(Int32, Pointer<Void>, Pointer<Void>)>(
     'device_changed_cb',
     Pointer.fromFunction(_batteryChanged),
   );
   

   The native function type to be used in register<>() can be obtained by checking the definition of the related callback type - the device_changed_cb in this case.

5. Pass the obtained callback pointer and user_data to the Native API function:

   Warning

   Both interopCallback and interopUserData must be passed. The callback handling implementation relies on the interopUserData. The only exceptions are a few callbacks that do not accept user_data parameters.

   final ret = tizen.device_add_callback(
     device_callback_e.DEVICE_CALLBACK_BATTERY_CAPACITY,
     callback.interopCallback,
     callback.interopUserData,
   );