---
title: "TargetBasedAnimation"
description: "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."
type: "class"
---

<div class='type'>Class</div>


<a id='references'></a>

<div class='sourceset sourceset-common'>Common</div>


```kotlin
public class TargetBasedAnimation<T, V : AnimationVector>
internal constructor(
    internal val animationSpec: VectorizedAnimationSpec<V>,
    override val typeConverter: TwoWayConverter<T, V>,
    initialValue: T,
    targetValue: T,
    initialVelocityVector: V? = null,
) : Animation<T, V>
```


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.

#### Parameters

| | |
| --- | --- |
| animationSpec | the `VectorizedAnimationSpec` that will be used to calculate value/velocity |
| initialValue | the start value of the animation |
| targetValue | the end value of the animation |
| typeConverter | the `TwoWayConverter` that is used to convert animation type `T` from/to `V` |
| initialVelocityVector | the start velocity of the animation in the form of `AnimationVector` |



## Secondary Constructors

```kotlin
public constructor(
    animationSpec: AnimationSpec<T>,
    typeConverter: TwoWayConverter<T, V>,
    initialValue: T,
    targetValue: T,
    initialVelocityVector: V? = null,
) : this(
    animationSpec.vectorize(typeConverter),
    typeConverter,
    initialValue,
    targetValue,
    initialVelocityVector,
)
```


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