Expand description
CheckState — tri-state checkbox value shared by the data layer and widgets.
Represents the three visual states of a checkbox: unchecked, checked, and
indeterminate (partial — some but not all descendants are checked). Lives in
teksilo-data rather than teksilo-widgets so that crate::TreeCheckedModel
can produce Signal<CheckState> values without inverting the dependency graph.
From<bool> converts a plain two-state boolean (e.g. from a filter predicate)
into Unchecked or Checked, making it easy to bridge non-tristate sources.
let state = CheckState::Indeterminate;
assert!(state.is_filled());
assert_eq!(state.next_tristate(), CheckState::Unchecked);
assert_eq!(CheckState::from(true), CheckState::Checked);