setTaskHandler static method

void setTaskHandler(
  1. TaskHandler handler
)

Set up the task handler and start the foreground task. It must always be called from a top-level function, otherwise foreground task will not work.

Implementation

static void setTaskHandler(TaskHandler handler) {
  // Create a method channel to communicate with the platform.
  const _backgroundChannel =
      MethodChannel('flutter_foreground_task/background');

  // Binding the framework to the flutter engine.
  WidgetsFlutterBinding.ensureInitialized();

  // Set the method call handler for the background channel.
  _backgroundChannel.setMethodCallHandler((call) async {
    final timestamp = DateTime.now();
    final method = call.method;

    switch (method) {
      case 'start':
        return await handler.onStart(timestamp, _lookupPort());
      case 'event':
        return await handler.onEvent(timestamp, _lookupPort());
      case 'destroy':
        return await handler.onDestroy(timestamp);
      case 'onButtonPressed':
        return handler.onButtonPressed(call.arguments.toString());
    }
  });

  // Initializes the plug-in background channel and starts a foreground task.
  _backgroundChannel.invokeMethod('initialize');
}