時刻（時間）をドラムロールで入力したいけれど出来ない、flutter

Widget timeField4(isEditable, TextEditingController jt, String lbl, fn,
    {DateTime? initialValue} //add 2023-12-14 初期値指定
    ) =>
    Container(
        padding: const EdgeInsets.all(0),
        child: DateTimeField(
            enabled: isEditable,
            controller: jt,
            keyboardType: TextInputType.datetime,
            textAlign: TextAlign.center,
            format: DateFormat("HH:mm"),
            decoration: InputDecoration(
              // contentPadding:EdgeInsets.zero,
                labelText: lbl,
                border: const OutlineInputBorder(),
                contentPadding:
                const EdgeInsets.only(top: 0, bottom: 0, left: 5),
                isDense: true,
                suffixIcon: IconButton(
                    icon: const Icon(Icons.clear),
//                      onPressed: () => jt.text=''
                    onPressed: () {
                      jt.text = '';
                      fn('');
                    })),
            onChanged: (DateTime? newValue) {
              if (newValue != null) {
                fn('');
              }
            },
            onShowPicker: (context, _) async {
              final time = await showTimePicker(
                initialEntryMode: TimePickerEntryMode.wheel,
                context: context,
                initialTime:
                TimeOfDay.fromDateTime(initialValue ?? DateTime(0,0,0,0)), //mod 2023-12-14 初期値指定
              );
              return DateTimeField.convert(time);
            }));