MotionLayout

MotionLayout is a layout class in Android's ConstraintLayout library designed to manage motion and widget animation across layout states. It coordinates multiple child views by using a MotionScene that describes transitions between two constraint sets (start and end). This enables coordinated changes in position, size, and other properties of several views as a single animated sequence.

A MotionLayout instance relies on a MotionScene XML resource. The scene defines two ConstraintSets for the start and end states, a Transition that specifies which state to which state to animate and how the animation should proceed, and optional Keyframes (such as KeyAttribute, KeyPosition, and KeyCycle) to customize properties at specific progress values. The layout can respond to user input through swipe gestures (OnSwipe) or be driven programmatically by adjusting the progress value.

Usage notes: MotionLayout is part of ConstraintLayout 2.x. To use it, add the ConstraintLayout dependency in your project, declare MotionLayout in your layout, and reference the MotionScene via app:layoutDescription="@xml/motion_scene". The MotionScene file defines the constraint sets and transitions, using ids like @id/start and @id/end to describe the positions of child views.

Impact and usage: MotionLayout enables complex, fluid motion for onboarding, transitions, or interactive UI while remaining constraint-centric. It is suitable for coordinating animations across multiple views and can integrate with various Android components. While powerful, it adds complexity and may incur performance considerations on low-end devices if overused.