androidview

Androidview is a core concept in the Android framework referring to the user interface components provided by the android.view package. In code, it is typically referred to as android.view, but in documentation and discussions it is often described as the foundational UI namespace for constructing screens and interactions.

The UI in Android is represented as a tree of View objects. Each View has layout properties, visibility, and state, while ViewGroups act as containers that manage child views and define layout behavior. The rendering pipeline follows a measure, layout, and draw sequence, where the system calls onMeasure to decide size, onLayout to position children, and onDraw to render content onto the screen.

Input and interaction are handled through events such as MotionEvent and KeyEvent, delivered by the window manager to the appropriate View. Views process input in methods like onTouchEvent and onKeyDown, and considerations for accessibility, focus handling, and drawing order are part of the lifecycle managed within the android.view framework.

Custom views can extend View or ViewGroup to implement specialized visuals or behaviors. Developers override methods such as onDraw for custom rendering, onMeasure for sizing, and onLayout for arranging children when creating custom view groups. Efficiency is a key consideration, and complex interfaces are often composed from multiple lightweight views rather than a single monolithic component.

The androidview namespace is part of the classic Android UI toolkit. It coexists with newer UI paradigms such as Jetpack Compose, which offers a declarative alternative. For existing apps, android.view remains a foundational reference point for UI construction, rendering, and event handling.

See also: android.widget, android.graphics, MotionEvent, KeyEvent.