readOnly top-level property
This facet controls the value of the EditorState.readOnly getter.
Commands and extensions that implement editing functionality consult
this to determine whether they should apply. It defaults to false,
but when its highest-precedence value is true, such functionality
disables itself.
Not to be confused with EditorView.editable, which controls whether
the editor's DOM is set to be editable (and thus focusable).
Implementation
final Facet<bool, bool> readOnly = Facet.define(
FacetConfig(combine: (values) => values.isNotEmpty ? values[0] : false),
);