ScrollVectorProvider
interface ScrollVectorProvider
androidx.recyclerview.widget.RecyclerView.SmoothScroller.ScrollVectorProvider |
An interface which is optionally implemented by custom RecyclerView.LayoutManager
to provide a hint to a SmoothScroller
about the location of the target position.
Summary
Public methods | |
---|---|
abstract PointF? |
computeScrollVectorForPosition(targetPosition: Int) Should calculate the vector that points to the direction where the target position can be found. |
Public methods
computeScrollVectorForPosition
@Nullable abstract fun computeScrollVectorForPosition(targetPosition: Int): PointF?
Should calculate the vector that points to the direction where the target position can be found.
This method is used by the LinearSmoothScroller
to initiate a scroll towards the target position.
The magnitude of the vector is not important. It is always normalized before being used by the LinearSmoothScroller
.
LayoutManager should not check whether the position exists in the adapter or not.
Parameters | |
---|---|
targetPosition |
Int: the target position to which the returned vector should point |
Return | |
---|---|
PointF? |
the scroll vector for a given position. |