AnchoredDraggableState

@ExperimentalFoundationApi
fun <T : Any> Saver(
    snapAnimationSpec: AnimationSpec<Float>,
    decayAnimationSpec: DecayAnimationSpec<Float>,
    positionalThreshold: (distance: Float) -> Float,
    velocityThreshold: () -> Float,
    confirmValueChange: (T) -> Boolean = { true }
): Saver<AnchoredDraggableState<T>, T>

The default Saver implementation for AnchoredDraggableState.

<T : Any?> AnchoredDraggableState(
    initialValue: T,
    positionalThreshold: (totalDistance: Float) -> Float,
    velocityThreshold: () -> Float,
    snapAnimationSpec: AnimationSpec<Float>,
    decayAnimationSpec: DecayAnimationSpec<Float>,
    confirmValueChange: (newValue) -> Boolean = { true }
)

@ExperimentalFoundationApi
<T : Any?> AnchoredDraggableState(
    initialValue: T,
    anchors: DraggableAnchors<T>,
    positionalThreshold: (totalDistance: Float) -> Float,
    velocityThreshold: () -> Float,
    snapAnimationSpec: AnimationSpec<Float>,
    decayAnimationSpec: DecayAnimationSpec<Float>,
    confirmValueChange: (newValue) -> Boolean = { true }
)

Construct an AnchoredDraggableState instance with anchors.

suspend fun anchoredDrag(
    dragPriority: MutatePriority = MutatePriority.Default,
    block: suspend AnchoredDragScope.(anchors: DraggableAnchors<T>) -> Unit
): Unit

Call this function to take control of drag logic and perform anchored drag with the latest anchors.

All actions that change the offset of this AnchoredDraggableState must be performed within an anchoredDrag block (even if they don't call any other methods on this object) in order to guarantee that mutual exclusion is enforced.

If anchoredDrag is called from elsewhere with the dragPriority higher or equal to ongoing drag, the ongoing drag will be cancelled.

If the anchors change while the block is being executed, it will be cancelled and re-executed with the latest anchors and target. This allows you to target the correct state.

suspend fun anchoredDrag(
    targetValue: T,
    dragPriority: MutatePriority = MutatePriority.Default,
    block: suspend AnchoredDragScope.(anchor: DraggableAnchors<T>, targetValue) -> Unit
): Unit

Call this function to take control of drag logic and perform anchored drag with the latest anchors and target.

All actions that change the offset of this AnchoredDraggableState must be performed within an anchoredDrag block (even if they don't call any other methods on this object) in order to guarantee that mutual exclusion is enforced.

This overload allows the caller to hint the target value that this anchoredDrag is intended to arrive to. This will set AnchoredDraggableState.targetValue to provided value so consumers can reflect it in their UIs.

If the anchors or AnchoredDraggableState.targetValue change while the block is being executed, it will be cancelled and re-executed with the latest anchors and target. This allows you to target the correct state.

If anchoredDrag is called from elsewhere with the dragPriority higher or equal to ongoing drag, the ongoing drag will be cancelled.

fun dispatchRawDelta(delta: Float): Float

Drag by the delta, coerce it in the bounds and dispatch it to the AnchoredDraggableState.

fun progress(from: T, to: T): @FloatRange(from = 0.0, to = 1.0) Float

The fraction of the offset between from and to, as a fraction between 0f..1f, or 1f if from is equal to to.

fun requireOffset(): Float

Require the current offset.

suspend fun settle(velocity: Float): Float

Find the closest anchor, taking into account the velocityThreshold and positionalThreshold, and settle at it with an animation.

If the velocity is lower than the velocityThreshold, the closest anchor by distance and positionalThreshold will be the target. If the velocity is higher than the velocityThreshold, the positionalThreshold will not be considered and the next anchor in the direction indicated by the sign of the velocity will be the target.

Based on the velocity, either snapAnimationSpec or decayAnimationSpec will be used to animate towards the target.

fun updateAnchors(
    newAnchors: DraggableAnchors<T>,
    newTarget: T = if (!offset.isNaN()) {
            newAnchors.closestAnchor(offset) ?: targetValue
        } else targetValue
): Unit

Update the anchors. If there is no ongoing anchoredDrag operation, snap to the newTarget, otherwise restart the ongoing anchoredDrag operation (e.g. an animation) with the new anchors.

If your anchors depend on the size of the layout, updateAnchors should be called in the layout (placement) phase, e.g. through Modifier.onSizeChanged. This ensures that the state is set up within the same frame. For static anchors, or anchors with different data dependencies, updateAnchors is safe to be called from side effects or layout.

val anchors: DraggableAnchors<T>

val currentValue: T

The current value of the AnchoredDraggableState.

That is the closest anchor point that the state has passed through.

val decayAnimationSpec: DecayAnimationSpec<Float>

The animation spec that will be used when flinging with a large enough velocity to reach or cross the target state.

val isAnimationRunning: Boolean

Whether an animation is currently in progress.

val lastVelocity: Float

The velocity of the last known animation. Gets reset to 0f when an animation completes successfully, but does not get reset when an animation gets interrupted. You can use this value to provide smooth reconciliation behavior when re-targeting an animation.

val offset: Float

The current offset, or Float.NaN if it has not been initialized yet.

The offset will be initialized when the anchors are first set through updateAnchors.

Strongly consider using requireOffset which will throw if the offset is read before it is initialized. This helps catch issues early in your workflow.

val progress: Float

The fraction of the progress going from settledValue to targetValue, within 0f..1f bounds, or 1f if the AnchoredDraggableState is in a settled state.

val settledValue: T

The value the AnchoredDraggableState is currently settled at.

When progressing through multiple anchors, e.g. A -> B -> C, settledValue will stay the same until settled at an anchor, while currentValue will update to the closest anchor.

val snapAnimationSpec: AnimationSpec<Float>

The default animation spec that will be used to animate to a new state.

val targetValue: T

The target value. This is the closest value to the current offset. If no interactions like animations or drags are in progress, this will be the current value.

@ExperimentalFoundationApi
suspend fun <T : Any?> AnchoredDraggableState<T>.animateTo(targetValue: T): Unit

Animate to a targetValue. If the targetValue is not in the set of anchors, the AnchoredDraggableState.currentValue will be updated to the targetValue without updating the offset.

@ExperimentalFoundationApi
suspend fun <T : Any?> AnchoredDraggableState<T>.animateToWithDecay(
    targetValue: T,
    velocity: Float
): Float

Attempt to animate using decay Animation to a targetValue. If the velocity is high enough to get to the target offset, we'll use AnchoredDraggableState.decayAnimationSpec to get to that offset and return the consumed velocity. If the velocity is not high enough, we'll use AnchoredDraggableState.snapAnimationSpec to reach the target offset.

If the targetValue is not in the set of anchors, AnchoredDraggableState.currentValue will be updated ro the targetValue without updating the offset.

@ExperimentalFoundationApi
suspend fun <T : Any?> AnchoredDraggableState<T>.snapTo(targetValue: T): Unit

Snap to a targetValue without any animation. If the targetValue is not in the set of anchors, the AnchoredDraggableState.currentValue will be updated to the targetValue without updating the offset.