The constraints for the prefix icon.
This property is particularly useful for getting the decoration's height less than 48px. This can be achieved by setting isDense to true and setting the constraints' minimum height and width to a value lower than 48px.
TextFieldwidgets when prefixIconConstraints is set to the default value and when one is not.
The isDense property must be set to true to be able to set the constraints smaller than 48px.
If null, BoxConstraints with a minimum width and height of 48px is used.
To create a local project with this code sample, run:
flutter create --sample=material.InputDecoration.prefixIconConstraints.1 mysample
final BoxConstraints? prefixIconConstraints;