Flutter RenderIndexedStack object was given an infinite size during layout

Question

I am battling this DropDownItem box error, everything seems to work, but pops up the yellow out of bounds while it loads. Tried several things and can not get it resolved. I have this code for my Widget.

@override
Widget build(BuildContext context) {
    var _children = <Widget>[
      !_createNew ? _referrerPractice() : _referrerCreate(),
    ];
    return new Scaffold(
        appBar: new AppBar(
          title: new Text(widget.title),
        ),
        body: new Column(
          mainAxisSize: MainAxisSize.max,
          children: _children,
        ));
  }

I then use this as one of the functions.

Widget _referrerPractice() {
assert(!_createNew);
return new Form(
  key: _formKey2,
  child: new Expanded(
    child: new ListView(
      padding: const EdgeInsets.symmetric(horizontal: 16.0),
      children: <Widget>[
        new InputDecorator(
          decoration: const InputDecoration(
            labelText: 'Referrer Practice',
            hintText: 'Choose Referrer Practice or choose new',
          ),
          isEmpty: _referPractice == null,
          child: new DropdownButton<String>(
            value: _referPractice,
            isDense: true,
            onChanged: (String newValue) {
              setState(() {
                _referPractice = newValue;
              });
            },
            items: practicelist.map((Map value) {
              return new DropdownMenuItem<String>(
                value: value['id'].toString(),
                child: new Text(value['name']),
              );
            }).toList(),
          ),
        ),
        new RaisedButton(
            child: new Text('Start'), onPressed: _startReferrer),
      ],
    ),
  ),
);

}

It seems to work on another page and I do not use a function to populate the widget, just a regular var of widgets, but seems it should be the same as the structure is the same.

Any ideas what I am missing? This is one DropDownButton, but it happens on the resulting page that has a DropDownButton as well for the other function.

EDIT********** This is the working code

final List<String> _allTypeAppt = <String>['Elective OP', 'Hospital Transfer', 'Phone Consult'];

new Form(
      key: _formKey,
      autovalidate: _autovalidate,
      onWillPop: _warnUserAboutInvalidData,
      child: new Expanded(
          child: new ListView(
            padding: const EdgeInsets.symmetric(horizontal: 16.0),
            children: <Widget>[
              new TextFormField(
                decoration: const InputDecoration(
                  icon: const Icon(Icons.person),
                  hintText: 'First Name?',
                  labelText: 'First Name *',
                ),
                controller: _fnameController,

                onSaved: (String value) { referral.fname = value; },
                validator: _validateName,
              ),

              new TextFormField(
                decoration: const InputDecoration(
                  icon: const Icon(Icons.person),
                  hintText: 'Last Name?',
                  labelText: 'Last Name *',
                ),
                controller: _lnameController,
                onSaved: (String value) { referral.lname = value; },
                validator: _validateName,
              ),

              new _DateTimePicker(
                labelText: 'DOB',
                selectedDate: _fromDate,
                selectDate: (DateTime date) {
                  setState(() {
                    _fromDate = date;
                  });
                },
              ),

              new TextFormField(
                decoration: const InputDecoration(
                    icon: const Icon(Icons.phone),
                    hintText: 'How to contact?',
                    labelText: 'Phone Number *',
                ),
                controller: _phoneController,
                keyboardType: TextInputType.phone,
                onSaved: (String value) { referral.contact = value; },
                validator: _validatePhoneNumber,
                // TextInputFormatters are applied in sequence.
                /*inputFormatters: <TextInputFormatter> [
                  WhitelistingTextInputFormatter.digitsOnly,
                  // Fit the validating format.
                  _phoneNumberFormatter,
                ],*/
              ),

              new TextFormField(
                decoration: const InputDecoration(
                  icon: const Icon(Icons.phone),
                  hintText: 'Alt contact?',
                  labelText: 'Alt Phone Number *',
                ),
                controller: _altPhoneController,
                keyboardType: TextInputType.phone,
                onSaved: (String value) { referral.altcontact = value; },
                validator: _validatePhoneNumber,
                // TextInputFormatters are applied in sequence.
                /*inputFormatters: <TextInputFormatter> [
                  WhitelistingTextInputFormatter.digitsOnly,
                  // Fit the validating format.
                  _phoneNumberFormatter,
                ],*/
              ),

              new TextFormField(
                decoration: const InputDecoration(
                  icon: const Icon(Icons.email),
                  hintText: 'Patien Email?',
                  labelText: 'Patient Email *',
                ),
                controller: _emailController,
                onSaved: (String value) { referral.altcontact = value; },
                //validator: _validatePhoneNumber,
                // TextInputFormatters are applied in sequence.
                /*inputFormatters: <TextInputFormatter> [
                  WhitelistingTextInputFormatter.digitsOnly,
                  // Fit the validating format.
                  _phoneNumberFormatter,
                ],*/
              ),

              new TextFormField(
                decoration: const InputDecoration(
                  hintText: 'Tell us about patient',
                  helperText: 'It does not have to be detailed yet',
                  labelText: 'Referral Details',
                ),
                controller: _detailsController,
                maxLines: 5,
              ),

              new InputDecorator(
                decoration: const InputDecoration(
                  labelText: 'Type of Appointment',
                  hintText: 'Choose an Appointment Type',
                ),
                isEmpty: _typeAppt == null,
                child: new DropdownButton<String>(
                  value: _typeAppt,
                  isDense: true,
                  onChanged: (String newValue) {
                    setState(() {
                      _typeAppt = newValue;
                    });
                  },
                  items: _allTypeAppt.map((String value) {
                    return new DropdownMenuItem<String>(
                      value: value,
                      child: new Text(value),
                    );
                  }).toList(),
                ),
              ),

              new RaisedButton(
                child: new Text('Submit Referral'),
                onPressed: _submitData,
              ),

            ],

          )
      )
  ),

Solution

I was able to reproduce your issue, I am not sure why are you building the layout this way. Your are feeding your DropDownButton as the child property for InputDecorator, which is fine. However, it is throwing this error because DropDownMenuItem is overflowing your InputDecorator. In other words, you are not only containing the DopDownButton within your InputDecorator, but also your items are trying to be contained in the same space as well. So, Flutter is confused on how to position the list of items inside the space provided by the InputDecorator.

I am really confused what kind of layout you are trying to build, why do you need a Form and an InputDecorator for?

Maybe provide a little context to your design choices so that we can help better.

I have created a simpler layout with Row and TextField widgets, it might be of help.

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => new _MyAppState();
}

class _MyAppState extends State<MyApp> {
  String _mySelection;
  String _text = "Choose";
   List<Map> _myJson = [
    {"id": "ID 1310012", "name": "Newcommer"}, {"id": "ID 0000TEMP", "name": "Temp"}];

  Widget _children() {
    TextEditingController _controller = new TextEditingController(text: _text);
    return  new Expanded(child: new ListView(
            padding: const EdgeInsets.symmetric(horizontal: 16.0),
            children: <Widget>[
              new Container (
        child: new Row(
                  children: <Widget>[
                    new Expanded(
                      child: new TextField(
                        controller: _controller,
                      ),
                    ),
                    new DropdownButton(
                      isDense: true,
                      value: _mySelection,
                      items: _myJson.map((Map map) {
                        return new DropdownMenuItem<String>(
                          value: map["id"],
                          child: new Text(
                            map["name"],
                          ),
                        );
                      }).toList(),
                      onChanged: (String newValue) {
                        setState(() {
                          _mySelection = newValue;
                          _text = newValue;
                        });
                      })
              ],),),
              new RaisedButton(
                  child: new Text('Start'), onPressed: null),

            ]
        ));
  }

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(title: new Text("Test")),
      body:  new Column(
        mainAxisSize: MainAxisSize.max,
        children: <Widget>[
           _children(),
        ],
      ),
    );
  }
}

Comments

[Robert]

So I took an example from flutter examples for dropdownbutton, I use the input decorator because it allows for icon and also the hint text and label. The only difference between the working code and the non-working is that in the non-working code, I populate the _children using a widget function with a assert to change from one form to another and the working one has a static list instead of dynamically created list of items. So its weird why it throws the error. Any other thoughts to make it work with input decorator would be great so that I can have the icon, etc...

[Shady Aziza]

Can you show me the static code that is working? also I still do not think you need an InputDecorator at all

[Shady Aziza]

Are you sure you are not getting any debug errors on the console when you open the drop down menu on the static view you just added? I mean the DropDown works I understand, but what do you see on your console?

[Robert]

I get no errors, I just ran it again, when the non-working runs I get the error I showed in the original, but the working one has no error. Thats why it makes no sense.

[Shady Aziza]

I am having this simple build and I get errors, I do not understand how it is working with you. dartpad.dartlang.org/51cc48e85041bcd53e2a2cafbc5d4aa8

[Robert]

I think I just found the problem, when I do this in the working one I have an already populated list List = ['xxxx'], when its not working I start with a List xxx = [], when I populate that with a default value, I do not get the error. It must allow for it to know how to fill it and works without the error. I guess it makes sense in some manner, thanks for helping me work through it.

[Shady Aziza]

If you finally solved it, try to add an answer to possibly help others, regardless, I suggest you rethink your widget choices in building the layout, try not to wrap your drop down inside widgets that has limited space at least. I hope it all work out for you.