TargetBasedAnimation

Artifact: androidx.compose.animation:animation-core

View Source

Added in 1.0.0

Common/All

• Cmn

  class TargetBasedAnimation<T : Any?, V : AnimationVector> : Animation

---

This is a convenient animation wrapper class that works for all target based animations, i.e. animations that has a pre-defined end value, unlike decay.

It assumes that the starting value and velocity, as well as ending value do not change throughout the animation, and cache these values. This caching enables much more convenient query for animation value and velocity (where only playtime needs to be passed into the methods).

Note: When interruptions happen to the TargetBasedAnimation, a new instance should be created that use the current value and velocity as the starting conditions. This type of interruption handling is the default behavior for both Animatable and Transition. Consider using those APIs for the interruption handling, as well as built-in animation lifecycle management.

See also
Transition
rememberTransition
updateTransition
Animatable

Summary

Public constructors
<T : Any?, V : AnimationVector> TargetBasedAnimation(     animationSpec: AnimationSpec<T>,     typeConverter: TwoWayConverter<T, V>,     initialValue: T,     targetValue: T,     initialVelocityVector: V? ) Creates a TargetBasedAnimation with the given start/end conditions of the animation, and the provided animationSpec.	Cmn

Public functions
open T	getValueFromNanos(playTimeNanos: Long) Returns the value of the animation at the given play time.	Cmn
open V	getVelocityVectorFromNanos(playTimeNanos: Long) Returns the velocity (in AnimationVector form) of the animation at the given play time.	Cmn
open String	toString()	Cmn

Public properties
open Long	durationNanos This amount of time in nanoseconds that the animation will run before it finishes	Cmn
T	initialValue	Cmn
open Boolean	isInfinite Whether or not the Animation represents an infinite animation.	Cmn
open T	targetValue This is the value that the Animation will reach when it finishes uninterrupted.	Cmn
open TwoWayConverter<T, V>	typeConverter the TwoWayConverter that is used to convert animation type T from/to V	Cmn

Inherited functions
From androidx.compose.animation.core.Animation open Boolean isFinishedFromNanos(playTimeNanos: Long) Returns whether the animation is finished at the given play time. Cmn

Public constructors

TargetBasedAnimation

Cmn

<T : Any?, V : AnimationVector> TargetBasedAnimation(
    animationSpec: AnimationSpec<T>,
    typeConverter: TwoWayConverter<T, V>,
    initialValue: T,
    targetValue: T,
    initialVelocityVector: V? = null
)

Creates a TargetBasedAnimation with the given start/end conditions of the animation, and the provided animationSpec.

The resulting Animation assumes that the start value and velocity, as well as end value do not change throughout the animation, and cache these values. This caching enables much more convenient query for animation value and velocity (where only playtime needs to be passed into the methods).

Note: When interruptions happen to the TargetBasedAnimation, a new instance should be created that use the current value and velocity as the starting conditions. This type of interruption handling is the default behavior for both Animatable and Transition. Consider using those APIs for the interruption handling, as well as built-in animation lifecycle management.

Parameters
animationSpec: AnimationSpec<T>	the AnimationSpec that will be used to calculate value/velocity
typeConverter: TwoWayConverter<T, V>	the TwoWayConverter that is used to convert animation type T from/to V
initialValue: T	the start value of the animation
targetValue: T	the end value of the animation
initialVelocityVector: V? = null	the start velocity vector, null by default (meaning 0 velocity).

Public functions

getValueFromNanos

Cmn

Added in 1.8.0-alpha07

open fun getValueFromNanos(playTimeNanos: Long): T

Returns the value of the animation at the given play time.

Parameters
playTimeNanos: Long	the play time that is used to determine the value of the animation.

getVelocityVectorFromNanos

Cmn

Added in 1.8.0-alpha07

open fun getVelocityVectorFromNanos(playTimeNanos: Long): V

Returns the velocity (in AnimationVector form) of the animation at the given play time.

Parameters
playTimeNanos: Long	the play time that is used to calculate the velocity of the animation.

toString

Cmn

open fun toString(): String

Public properties

durationNanos

Cmn

Added in 1.8.0-alpha07

open val durationNanos: Long

This amount of time in nanoseconds that the animation will run before it finishes

initialValue

Cmn

Added in 1.0.0

val initialValue: T

isInfinite

Cmn

Added in 1.8.0-alpha07

open val isInfinite: Boolean

Whether or not the Animation represents an infinite animation. That is, one that will not finish by itself, one that needs an external action to stop. For examples, an indeterminate progress bar, which will only stop when it is removed from the composition.

targetValue

Cmn

Added in 1.8.0-alpha07

open val targetValue: T

This is the value that the Animation will reach when it finishes uninterrupted.

typeConverter

Cmn

Added in 1.8.0-alpha07

open val typeConverter: TwoWayConverter<T, V>

the TwoWayConverter that is used to convert animation type T from/to V