Flutter source code snippets

void _showAlertDialog() {
  const msg = '''
    The slideshow requires at least two images to run.
    Please add more images using the Manage Images screen.''';
  final msg2 = convertMultilineStringToOneParagraph(msg);

  final dialog = AlertDialog(
      title: const Text('Add More Images'),
      content: SingleChildScrollView(
        child: ListBody(
          children: <Widget>[
            Text(msg2),
          ],
        ),
      )
  );
  showDialog(
    context: context,
    builder: (BuildContext context) {
      return dialog;
    },
  );
}

Navigator.push(
  context,
  MaterialPageRoute(builder: (context) => const SomeOtherWidget())

ScaffoldMessenger.of(context).showSnackBar(const SnackBar(content: Text('Your text here')));

Widget circularProgressIndicator() {
   return const Center(child: SizedBox(width: 60, height: 60, child: CircularProgressIndicator()));
}

setState(() {
  // your model-update code here
});