bmifields.dart

RaisedButton calculateButton() {
    return RaisedButton(
      onPressed: _calculator,
      color: Colors.pinkAccent,
      child: Text(
        'Calculate',
        style: TextStyle(fontSize: 16.9),
      ),
      textColor: Colors.white70,
    );
  }

  TextFormField weightFormField() {
    return TextFormField(
      controller: _weightController,
      keyboardType: TextInputType.number,
      textInputAction: TextInputAction.done,
      focusNode: _weightFocus,
      onFieldSubmitted: (value){
        _weightFocus.unfocus();
        _calculator();
      },
      validator: (value) {
        if (value.length == 0 || double.parse(value) == 0.0) {
          return ('Weight is not valid. Weight > 0.0');
        }
      }, 
      onSaved: (value) {
        _weight = value;
      },
      decoration: InputDecoration(
          hintText: _weightMessage,
          labelText: _weightMessage,
          icon: Icon(Icons.menu),
          fillColor: Colors.white
      ),
    );
  }

  TextFormField heightFormField(BuildContext context) {
    return TextFormField(
      controller: _heightController,
      keyboardType: TextInputType.number,
      textInputAction: TextInputAction.next,
      focusNode: _heightFocus,
      onFieldSubmitted: (term) {
        _fieldFocusChange(context, _heightFocus, _weightFocus);
      },
      validator: (value) {
        if (value.length == 0 || double.parse(value) == 0.0) {
          return ('Height is not valid. Height > 0.0');
        }
      }, 
      onSaved: (value) {
        _height = value;
      },
      decoration: InputDecoration(
          hintText: _heightMessage,
          icon: Icon(Icons.assessment),
          fillColor: Colors.white,
      ),
    );
  }

  TextFormField ageFormField(BuildContext context) {
    return TextFormField(
      keyboardType: TextInputType.number,
      textInputAction: TextInputAction.next,
      focusNode: _ageFocus,
      onFieldSubmitted: (term){
        _fieldFocusChange(context, _ageFocus, _heightFocus);
      },
      validator: (value) {
        if (value.length == 0 || double.parse(value) <= 15) {
          return ('Age should be over 15 years old');
        }
      }, 
      onSaved: (value) {
        _age = value;
      },
      decoration: InputDecoration(
        hintText: 'Age',
        icon: Icon(Icons.person_outline),
        fillColor: Colors.white,
      ),
    );
  }
void _calculator() {
    if (_formKey.currentState.validate()) {
      _formKey.currentState.save();
      this.widget.presenter.onCalculateClicked(_weight, _height);
    }
  }