VectorizedDecayAnimationSpec

Kotlin |Java

interface VectorizedDecayAnimationSpec<V : AnimationVector>

androidx.compose.animation.core.VectorizedDecayAnimationSpec

VectorizedDecayAnimationSpecs are stateless vector based decay animation specifications. They do not assume any starting/ending conditions. Nor do they manage a lifecycle. All it stores is the configuration that is particular to the type of the decay animation: friction multiplier for exponentialDecay. Its stateless nature allows the same VectorizedDecayAnimationSpec to be reused by a few different running animations with different starting and ending values.

Since VectorizedDecayAnimationSpecs are stateless, it requires starting value/velocity and ending value to be passed in, along with playtime, to calculate the value or velocity at that time. Play time here is the progress of the animation in terms of milliseconds, where 0 means the start of the animation and getDurationNanos returns the play time for the end of the animation.

Note: For use cases where the starting values/velocity and ending values aren't expected to change, it is recommended to use DecayAnimation that caches these static values and hence does not require them to be supplied in the value/velocity calculation.

Summary

Public methods
abstract Long	`getDurationNanos(initialValue: V, initialVelocity: V)` Returns the duration of the decay animation, in nanoseconds.
abstract V	`getTargetValue(initialValue: V, initialVelocity: V)` Returns the target value of the animation based on the initial condition of the animation ( i.
abstract V	`getValueFromNanos(playTimeNanos: Long, initialValue: V, initialVelocity: V)` Returns the value of the animation at the given time.
abstract V	`getVelocityFromNanos(playTimeNanos: Long, initialValue: V, initialVelocity: V)` Returns the velocity of the animation at the given time.

Properties
abstract Float	`absVelocityThreshold` This is the absolute value of a velocity threshold, below which the animation is considered finished.

Public methods

getDurationNanos

abstract fun getDurationNanos(
    initialValue: V, 
    initialVelocity: V
): Long

Returns the duration of the decay animation, in nanoseconds.

Parameters
initialValue: V	initialValue value of the animation
initialVelocity: V	initialValue velocity of the animation

getTargetValue

abstract fun getTargetValue(
    initialValue: V, 
    initialVelocity: V
): V

Returns the target value of the animation based on the initial condition of the animation ( i.e. initial value and initial velocity).

Parameters
initialValue: V	The initial value of the animation
initialVelocity: V	The initial velocity of the animation

getValueFromNanos

abstract fun getValueFromNanos(
    playTimeNanos: Long, 
    initialValue: V, 
    initialVelocity: V
): V

Returns the value of the animation at the given time.

Parameters
playTimeNanos: Long	The time elapsed in milliseconds since the initialValue of the animation
initialValue: V	The initialValue value of the animation
initialVelocity: V	The initialValue velocity of the animation

getVelocityFromNanos

abstract fun getVelocityFromNanos(
    playTimeNanos: Long, 
    initialValue: V, 
    initialVelocity: V
): V

Returns the velocity of the animation at the given time.

Parameters
playTimeNanos: Long	The time elapsed in milliseconds since the initialValue of the animation
initialValue: V	The initialValue value of the animation
initialVelocity: V	The initialValue velocity of the animation

Properties

absVelocityThreshold

abstract val absVelocityThreshold: Float

This is the absolute value of a velocity threshold, below which the animation is considered finished.