Module selection_model 

SelectionModel — index-based selection state for collection widgets.

SelectionModel manages which flat indices are selected in a ListView, TreeView, TableView, or GridView. It is a share-by-clone handle (Rc<RefCell<…>> internally): pass a clone to each view that should share selection state. The current selection is exposed as a reactive Signal<BTreeSet<usize>> so widgets can bind to it without polling.

Three selection behaviours are available via SelectionMode: None (read-only / no interaction), Single (at most one item), and Multi (Ctrl+click toggle + Shift+click range extension via an internal anchor). Mutators automatically notify all Signal observers after every change, and the helper methods adjust_for_insert / adjust_for_remove / adjust_for_move keep selected indices consistent when the underlying source mutates.

When to use SelectionModel vs KeyedSelectionModel

Use SelectionModel (this type) for views that are backed by a plain ListModel<T> or a SortFilterListModel<T> where position is the natural identity. Use crate::KeyedSelectionModel when items carry a stable app-defined key (e.g. a NodeId or a UUID) and selection must survive sort/filter rebuilds or window slides that renumber visible indices.

let sel = SelectionModel::new(SelectionMode::Multi);
sel.select(2);         // clear-and-select index 2, anchor = 2
sel.toggle(5);         // add index 5 (Ctrl+click behaviour)
sel.extend_to(8);      // extend from anchor 5 to 8 (Shift+click behaviour)
assert!(sel.is_selected(2));
assert_eq!(sel.count(), 5); // 2, 5, 6, 7, 8
sel.clear();
assert_eq!(sel.count(), 0);

Structs

SelectionModel

Manages selection state for a collection widget.

Enums

SelectionMode

Selection behavior mode.