animateFloatAsState

Composable Function

Common

@Composable
public fun animateFloatAsState(
    targetValue: Float,
    animationSpec: AnimationSpec<Float> = defaultAnimation,
    visibilityThreshold: Float = 0.01f,
    label: String = "FloatAnimation",
    finishedListener: ((Float) -> Unit)? = null,
): State<Float>

Fire-and-forget animation function for Float. This Composable function is overloaded for different parameter types such as Dp, Color, Offset, etc. When the provided targetValue is changed, the animation will run automatically. If there is already an animation in-flight when targetValue changes, the on-going animation will adjust course to animate towards the new target value.

animateFloatAsState returns a State object. The value of the state object will continuously be updated by the animation until the animation finishes.

Note, animateFloatAsState cannot be canceled/stopped without removing this composable function from the tree. See Animatable for cancelable animations.

Parameters


targetValue	Target value of the animation
animationSpec	The animation that will be used to change the value through time. `spring` will be used by default.
visibilityThreshold	An optional threshold for deciding when the animation value is considered close enough to the targetValue.
label	An optional label to differentiate from other animations in Android Studio.
finishedListener	An optional end listener to get notified when the animation is finished.

Returns


	A `State` object, the value of which is updated by animation.

Common

Deprecated animate*AsState APIs now have a new label parameter added.

@Composable
public fun animateFloatAsState(
    targetValue: Float,
    animationSpec: AnimationSpec<Float> = defaultAnimation,
    visibilityThreshold: Float = 0.01f,
    finishedListener: ((Float) -> Unit)? = null,
): State<Float>

Code Examples

AlphaAnimationSample

@Composable
fun AlphaAnimationSample() {
    @Composable
    fun alphaAnimation(visible: Boolean) {
        // Animates to 1f or 0f based on [visible].
        // This [animateState] returns a State<Float> object. The value of the State object is
        // being updated by animation. (This method is overloaded for different parameter types.)
        // Here we use the returned [State] object as a property delegate.
        val alpha: Float by animateFloatAsState(if (visible) 1f else 0f)
        // Updates the alpha of a graphics layer with the float animation value. It is more
        // performant to modify alpha in a graphics layer than using `Modifier.alpha`. The former
        // limits the invalidation scope of alpha change to graphicsLayer's draw stage (i.e. no
        // recomposition would be needed). The latter triggers recomposition on each animation
        // frame.
        Box(modifier = Modifier.graphicsLayer { this.alpha = alpha }.background(Color.Red))
    }
}