onCustomPermissionRequest

import 'dart:io';

import 'package:flutter/material.dart';
import 'package:permission_handler/permission_handler.dart';

void onCustomPermissionRequest(
    {required Permission permission,
    VoidCallback? onGranted,
    required VoidCallback onFinish,
    VoidCallback? onIosPermanentlyDenied,
    VoidCallback? onAndroidPermanentlyDenied}) {
  if (Platform.isIOS) {
    permission.status.then((value) {
      if (value.isDenied) {
        permission.request().then((value) {
          if (value.isGranted && onGranted != null) {
            onGranted();
          }
        });
      } else if (value.isPermanentlyDenied && onIosPermanentlyDenied != null) {
        onIosPermanentlyDenied();
      } else if (value.isGranted && onGranted != null) {
        onGranted();
      }
      onFinish();
    });
  } else {
    /// [isRequestRationale] flag for checking already requested
    permission.shouldShowRequestRationale.then((isRequestRationale) {
      permission.request().then((value) {
        if (value.isGranted && onGranted != null) {
          onGranted();
        } else if (value.isPermanentlyDenied &&
            onAndroidPermanentlyDenied != null &&
            !isRequestRationale) {
          onAndroidPermanentlyDenied();
        }
        onFinish();
      });
    });
  }
}