Flutter custom dialog with radio button lists

Custom language selection popup

Create class for list item having text and radio button. I have created statelesswidget CustomRow and CustomRowModel.

class CustomRowModel {
  bool selected;
  String title;
  CustomRowModel({this.selected, this.title});
}

class CustomRow extends StatelessWidget {
 final CustomRowModel model;
 CustomRow(this.model);

 @override
  Widget build(BuildContext context) {
 return Padding(
      padding:
 const EdgeInsets.only(left: 8.0, right: 8.0, top: 3.0, bottom: 3.0),
      child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceBetween,
        children: <Widget>[
// I have used my own CustomText class to customise TextWidget.
          CustomText(       
            label: model.title,
          ),
 this.model.selected
              ? Icon(
                  Icons.radio_button_checked,
                  color: Colors.amber,
                )
              : Icon(Icons.radio_button_unchecked),
        ],
      ),
    );
  }
}

Now create dialog design. In my dialog, having cancel icon, heading, custom listview and button 'Submit'.

dialogContent(BuildContext context) {
 return Container(
      child: Column(
        children: <Widget>[
          Container(
            margin: EdgeInsets.all(5.0),
            alignment: Alignment.topRight,
            child: Icon(
              Icons.close,
              color: Colors.grey,
              size: 20.0,
            ),
          ),
          Container(
            margin: EdgeInsets.only(top: 5.0, bottom: 5.0),
            color: Colors.white,
            child: CustomText(
              fontSize: 16.0,
              label: "Select your preferred language",
              labelColor: AppColors.dialogTitleColor,
              fontWeight: FontWeight.bold,
            ),
          ),
          Flexible(
            child: new MyDialogContent(),//Custom ListView
          ),
          SizedBox(
            height: 50,
            width: double.infinity,
            child: FlatButton(
              shape: RoundedRectangleBorder(
                borderRadius: BorderRadius.only(
                  bottomLeft: Radius.circular(20.0),
                  bottomRight: Radius.circular(20.0),
                ),
              ),
              onPressed: () {},
              color: AppColors.dialogTitleColor,
              textColor: Colors.black,
              child: CustomText(
                label: "Submit",
                fontWeight: FontWeight.bold,
                fontSize: 16.0,
              ),
            ),
          ),
        ],
      ),
    );
  }

Now to Create LanguageSelection statefulwidget to show our customised dialog.

class LanguageSelection extends StatefulWidget {
 @override
  State<StatefulWidget> createState() {
 return LanguageSelectionState();
  }
}

class LanguageSelectionState extends State<LanguageSelection> {
 @override
 void initState() {
 super.initState();
  }

@override
  Widget build(BuildContext context) {
 return Container(
      margin: EdgeInsets.only(top: 50.0, bottom: 50.0),
      alignment: Alignment.center,
      child: Dialog(
        shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.all(
            Radius.circular(20.0),
          ),
        ),
        elevation: 25.0,
        backgroundColor: Colors.white,
        child: dialogContent(context),
      ),
    );
  }
}

MyDialogContent statefulwidget I have create list item and handle state of after clicking on radio button to show selected/deselected.

class MyDialogContent extends StatefulWidget {
 @override
  _MyDialogContentState createState() => new _MyDialogContentState();
}

class _MyDialogContentState extends State<MyDialogContent> {
  List<CustomRowModel> sampleData = new List<CustomRowModel>();

 @override
 void initState() {
 super.initState();
    sampleData.add(CustomRowModel(title: "Marathi", selected: false));
    sampleData.add(CustomRowModel(title: "English", selected: false));
    sampleData.add(CustomRowModel(title: "Hindi", selected: false));
    sampleData.add(CustomRowModel(title: "Kannada", selected: false));
    sampleData.add(CustomRowModel(title: "Telugu", selected: false));
    sampleData.add(CustomRowModel(title: "Gujarathi", selected: false);
    sampleData.add(CustomRowModel(title: "Rajsthani", selected: false);
    sampleData.add(CustomRowModel(title: "Punjabi", selected: false));
  }

 @override
  Widget build(BuildContext context) {
 return sampleData.length == 0
        ? Container()
        : Container(
            child: ListView.separated(
              separatorBuilder: (context, index) => Divider(
                color: Colors.grey,
              ),
              scrollDirection: Axis.vertical,
              shrinkWrap: true,
              itemCount: sampleData.length,
              itemBuilder: (BuildContext context, int index) {
 return new InkWell(
 //highlightColor: Colors.red,
 //splashColor: Colors.blueAccent,
                  onTap: () {
                    setState(() {
                      sampleData.forEach((element) => element.selected = false);
                      sampleData[index].selected = true;
                    });
                  },
                  child: new CustomRow(sampleData[index]),
                );
              },
            ),
          );
  }
}