How does uniapp determine whether mobile phone positioning is enabled?

/**检查是否打开GPS功能（android）**/
export const checkOpenGPSServiceByAndroid = () => {
  let system = uni.getSystemInfoSync();// 获取系统信息
  if (system.platform === 'android') { // 判断平台
    var context = plus.android.importClass("android.content.Context");
    var locationManager = plus.android.importClass("android.location.LocationManager");
    var main = plus.android.runtimeMainActivity();
    var mainSvr = main.getSystemService(context.LOCATION_SERVICE);
    if (!mainSvr.isProviderEnabled(locationManager.GPS_PROVIDER)) {
      uni.showModal({
        title: '提示',
        content: '请打开定位服务功能',
        showCancel: false, // 不显示取消按钮
        success() {
          if (!mainSvr.isProviderEnabled(locationManager.GPS_PROVIDER)) {
            var Intent = plus.android.importClass('android.content.Intent');
            var Settings = plus.android.importClass('android.provider.Settings');
            var intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS); 
            main.startActivity(intent); // 打开系统设置GPS服务页面
          } else {
            console.log('GPS功能已开启');
          }
        }
      });
    }
  } 
}