Listbox

A listbox is a graphical user interface control that presents a list of items from which the user can select one or more entries. It is typically displayed as a rectangular area with a vertical list and an optional scrollbar for navigating long lists. Users interact with listboxes using the mouse or keyboard, and the control can be configured to allow single or multiple selections.

In single selection mode, only one item can be highlighted at a time. In multiple selection mode, users can select several items, typically by holding modifier keys (such as Ctrl or Shift) to make non-contiguous or contiguous selections, or by toggling check boxes next to items in some variants. Some implementations also support item activation, where selecting an item triggers a default action.

Items within a listbox may be simple strings or objects that contain a display value and associated data. Frameworks often support custom rendering for items, allowing icons, check marks, or different fonts. Listboxes may be bound to a data model, and in large lists virtualization techniques can be used to render only the visible portion to improve performance.

Common platforms include Windows, macOS, GTK, and Qt, each providing its own listbox widgets or equivalents. In web contexts, a similar control is typically represented by a select element or a custom list component. Listboxes are distinct from combo boxes, which present a collapsed list that can be opened to reveal options.

Accessibility considerations include keyboard navigation (arrow keys, Home/End, Page Up/Down), focus management, and screen reader labeling to ensure items are announced appropriately.