core/androidx.core.widget/NestedScrollView/dispatchNestedPreScroll

dispatchNestedPreScroll

open fun dispatchNestedPreScroll(dx: Int, dy: Int, @Nullable consumed: Array<Int>, @Nullable offsetInWindow: Array<Int>, type: Int): Boolean(source)

Dispatch one step of a nested scroll in progress before this view consumes any portion of it.

Nested pre-scroll events are to nested scroll events what touch intercept is to touch. dispatchNestedPreScroll offers an opportunity for the parent view in a nested scrolling operation to consume some or all of the scroll operation before the child view consumes it.

Return

true if the parent consumed some or all of the scroll delta

Parameters

dx

Horizontal scroll distance in pixels

dy

Vertical scroll distance in pixels

consumed

Output. If not null, consumed[0] will contain the consumed component of dx and consumed[1] the consumed dy.

offsetInWindow

Optional. If not null, on return this will contain the offset in local view coordinates of this view from before this operation to after it completes. View implementations may use this to adjust expected input coordinate tracking.

type

the type of input which cause this scroll event

See also

open fun dispatchNestedPreScroll(dx: Int, dy: Int, @Nullable consumed: Array<Int>, @Nullable offsetInWindow: Array<Int>): Boolean(source)