flagsImGuiMultiSelectFlags options controlling this operation; combine compatible flag bits with |.
Borrowed multi-selection IO containing requests to apply before submitting items. Always pair with EndMultiSelect(), and apply its requests too.
This enables standard multi-selection/range-selection idioms (CTRL+Mouse/Keyboard, SHIFT+Mouse/Keyboard, etc.) in a way that also allow a clipper to be used.
ImGuiSelectionUserData is often used to store your item index within the current view (but may store something else).
Read comments near ImGuiMultiSelectIO for instructions/details and see 'Demo->Widgets->Selection State & Multi-Select' for demo.
TreeNode() is technically supported but... using this correctly is more complicated. You need some sort of linear/random access to your tree, which is suited to advanced trees setups already implementing filters and clipper. We will work simplifying the current demo.
'selection_size' and 'items_count' parameters are optional and used by a few features. If they are costly for you to compute, you may avoid them.
Implied selection_size = -1, items_count = -1
Begin a multi-selection scope.