LayoutManager

LayoutManager is a software abstraction used in graphical user interfaces to manage the size and position of child components within a container. It encapsulates the layout policy, enabling the container to delegate measurement, arrangement, and sometimes visibility decisions to a dedicated object. By separating concerns, it supports flexible and adaptive user interfaces across different screen sizes and orientations.

In Android, the RecyclerView widget uses a LayoutManager to control how item views are laid out and recycled. The LayoutManager is an abstract class with methods to measure, position, and recycle items, as well as to handle scrolling. Common concrete managers include LinearLayoutManager for vertical or horizontal lists, GridLayoutManager for grid-based layouts, and StaggeredGridLayoutManager for masonry-style grids. Developers can implement custom layout managers to realize specialized arrangements or performance optimizations.

In Java Swing and similar frameworks, layout management is provided by a LayoutManager interface (and related helpers) that designers implement to arrange components within a container. Examples include BorderLayout, FlowLayout, and GridLayout, each enforcing a different strategy for adding, sizing, and placing child components.

Design considerations include consistency with platform guidelines, responsiveness to container size changes, support for dynamic content, and performance implications for large or frequently changing layouts.