The minimum number of lines to occupy when the content spans fewer lines.
If this is null (default), text container starts with enough vertical space for one line and grows to accommodate additional lines as they are entered.
This can be used in combination with maxLines for a varying set of behaviors.
If the value is set, it must be greater than zero. If the value is greater than 1, maxLines should also be set to either null or greater than this value.
Input that always occupies at least 2 lines and has an infinite max. Expands vertically as needed.
Input whose height starts from 2 lines and grows up to 4 lines at which point the height limit is reached. If additional lines are entered it will scroll vertically.
TextField(minLines:2, maxLines: 4)
Defaults to null.
final int minLines