ActionLists

ActionLists are a design construct used in software to group and present a set of actions (commands) to the user as a list, menu, or palette. They encapsulate a collection of actions and their presentation rules, enabling consistent access to functionality across the application. ActionLists typically support static lists, which are defined at design time, and dynamic lists, which are built at runtime from application state or context.

A typical ActionList consists of Action items and optional groupings. An Action carries properties such as an identifier, label, icon, keyboard shortcut, enabled state, visibility, and a handler function that executes the command. Groups and separators help organize actions for readability and usability. Dynamic behavior may show, hide, or reorder actions based on context such as user selection, mode, permissions, or localization.

Usage and benefits: ActionLists promote modularity by decoupling the command logic from its presentation. They support consistent styling and behavior across menus, toolbars, palettes, and contextual panels. They enable context-sensitive interfaces where only relevant actions are shown. They also facilitate extension and customization, as new actions can be added to existing lists without altering other UI components.

Relation to other concepts: ActionLists relate to the Command pattern and to UI constructs like menus and toolbars. They are implemented in various frameworks under different names, such as action managers, action groups, or command sets, but share the core idea of organizing and presenting related actions in a cohesive, interactive unit.