Using Flutter, how can I trigger onSubmitted() of TextField on iOS?

Please take a look at the following Flutter code snippet: it creates a `TextField` that is intended as a single line input field tat will submit its value when Return is pressed: ``` child: new TextField( decoration: _deco, maxLines: 1, autofocus: true, onSubmitted: (newValue) {print(newValue);}, onChanged: (newValue) { setState(() { strTemperature = newValue.trim(); }); })), ``` On the iOS Simulator the corresponding app looks as follows: As you can see the widget is configured with `maxLines = 1`, but when I click the Return key on the onscreen keyboard, line feeds are insert. Please spot the narrow blue cursor a couple of lines below the widget. Also, I see no console output, which should be the case because of my `onSubmitted()` lambda. Am I configuring the text field correctly, or am I missing something?