KeyboardListener constructor Null safety
Creates a widget that receives keyboard events.
For text entry, consider using a EditableText, which integrates with on-screen keyboards and input method editors (IMEs).
The focusNode and child arguments are required and must not be null.
The autofocus argument must not be null.
The key
is an identifier for widgets, and is unrelated to keyboards.
See Widget.key.
Implementation
const KeyboardListener({
super.key,
required this.focusNode,
this.autofocus = false,
this.includeSemantics = true,
this.onKeyEvent,
required this.child,
}) : assert(focusNode != null),
assert(autofocus != null),
assert(includeSemantics != null),
assert(child != null);