SnapHelper
abstract class SnapHelper : RecyclerView.OnFlingListener
kotlin.Any | ||
↳ | androidx.recyclerview.widget.RecyclerView.OnFlingListener | |
↳ | androidx.recyclerview.widget.SnapHelper |
Class intended to support snapping for a RecyclerView
.
SnapHelper tries to handle fling as well but for this to work properly, the RecyclerView.LayoutManager
must implement the RecyclerView.SmoothScroller.ScrollVectorProvider
interface or you should override onFling(int, int)
and handle fling manually.
Summary
Public constructors | |
---|---|
<init>() Class intended to support snapping for a |
Public methods | |
---|---|
open Unit |
attachToRecyclerView(@Nullable recyclerView: RecyclerView?) Attaches the |
abstract IntArray? |
calculateDistanceToFinalSnap(@NonNull layoutManager: RecyclerView.LayoutManager, @NonNull targetView: View) Override this method to snap to a particular point within the target view or the container view on any axis. |
open IntArray! |
calculateScrollDistance(velocityX: Int, velocityY: Int) Calculated the estimated scroll distance in each direction given velocities on both axes. |
abstract View? |
findSnapView(layoutManager: RecyclerView.LayoutManager!) Override this method to provide a particular target view for snapping. |
abstract Int |
findTargetSnapPosition(layoutManager: RecyclerView.LayoutManager!, velocityX: Int, velocityY: Int) Override to provide a particular adapter target position for snapping. |
open Boolean |
Protected methods | |
---|---|
open RecyclerView.SmoothScroller? |
createScroller(@NonNull layoutManager: RecyclerView.LayoutManager) Creates a scroller to be used in the snapping implementation. |
open LinearSmoothScroller? |
createSnapScroller(@NonNull layoutManager: RecyclerView.LayoutManager) Creates a scroller to be used in the snapping implementation. |
Public constructors
<init>
SnapHelper()
Class intended to support snapping for a RecyclerView
.
SnapHelper tries to handle fling as well but for this to work properly, the RecyclerView.LayoutManager
must implement the RecyclerView.SmoothScroller.ScrollVectorProvider
interface or you should override onFling(int, int)
and handle fling manually.
Public methods
attachToRecyclerView
open fun attachToRecyclerView(@Nullable recyclerView: RecyclerView?): Unit
Attaches the SnapHelper
to the provided RecyclerView, by calling RecyclerView#setOnFlingListener(RecyclerView.OnFlingListener)
. You can call this method with null
to detach it from the current RecyclerView.
Parameters | |
---|---|
recyclerView |
RecyclerView?: The RecyclerView instance to which you want to add this helper or null if you want to remove SnapHelper from the current RecyclerView. |
Exceptions | |
---|---|
IllegalArgumentException |
if there is already a RecyclerView.OnFlingListener attached to the provided RecyclerView . |
calculateDistanceToFinalSnap
@Nullable abstract fun calculateDistanceToFinalSnap(
@NonNull layoutManager: RecyclerView.LayoutManager,
@NonNull targetView: View
): IntArray?
Override this method to snap to a particular point within the target view or the container view on any axis.
This method is called when the SnapHelper
has intercepted a fling and it needs to know the exact distance required to scroll by in order to snap to the target view.
Parameters | |
---|---|
layoutManager |
RecyclerView.LayoutManager: the RecyclerView.LayoutManager associated with the attached RecyclerView |
targetView |
View: the target view that is chosen as the view to snap |
Return | |
---|---|
IntArray? |
the output coordinates the put the result into. out[0] is the distance on horizontal axis and out[1] is the distance on vertical axis. |
calculateScrollDistance
open fun calculateScrollDistance