NestedScrollConnection

Interface

Common

@JvmDefaultWithCompatibility
interface NestedScrollConnection

Interface to connect to the nested scroll system.

Pass this connection to the nestedScroll modifier to participate in the nested scroll hierarchy and to receive nested scroll events when they are dispatched by the scrolling child (scrolling child - the element that actually receives scrolling events and dispatches them via NestedScrollDispatcher).

Functions

fun onPreScroll(available: Offset, source: NestedScrollSource): Offset

Pre scroll event chain. Called by children to allow parents to consume a portion of a drag event beforehand

Parameters


available	the delta available to consume for pre scroll
source	the source of the scroll event

Returns


	the amount this connection consumed

fun onPostScroll(consumed: Offset, available: Offset, source: NestedScrollSource): Offset

Post scroll event pass. This pass occurs when the dispatching (scrolling) descendant made their consumption and notifies ancestors with what's left for them to consume.

Parameters


consumed	the amount that was consumed by all nested scroll nodes below the hierarchy
available	the amount of delta available for this connection to consume
source	source of the scroll

Returns


	the amount that was consumed by this connection

suspend fun onPreFling(available: Velocity): Velocity

Pre fling event chain. Called by children when they are about to perform fling to allow parents to intercept and consume part of the initial velocity

Parameters


available	the velocity which is available to pre consume and with which the child is about to fling

Returns


	the amount this connection wants to consume and take from the child

suspend fun onPostFling(consumed: Velocity, available: Velocity): Velocity

Post fling event chain. Called by the child when it is finished flinging (and sending onPreScroll & onPostScroll events)

Parameters


consumed	the amount of velocity consumed by the child
available	the amount of velocity left for a parent to fling after the child (if desired)

Returns


	the amount of velocity consumed by the fling operation in this connection