RecyclerView.ViewCacheExtension

public static abstract class RecyclerView.ViewCacheExtension
extends Object

java.lang.Object
   ↳ androidx.recyclerview.widget.RecyclerView.ViewCacheExtension


ViewCacheExtension is a helper class to provide an additional layer of view caching that can be controlled by the developer.

When RecyclerView.Recycler.getViewForPosition(int) is called, Recycler checks attached scrap and first level cache to find a matching View. If it cannot find a suitable View, Recycler will call the getViewForPositionAndType(Recycler, int, int) before checking RecyclerView.RecycledViewPool.

Note that, Recycler never sends Views to this method to be cached. It is developers responsibility to decide whether they want to keep their Views in this custom cache or let the default recycling policy handle it.

Summary

Public constructors

RecyclerView.ViewCacheExtension()

Public methods

abstract View getViewForPositionAndType(RecyclerView.Recycler recycler, int position, int type)

Returns a View that can be binded to the given Adapter position.

Inherited methods

Public constructors

RecyclerView.ViewCacheExtension

public RecyclerView.ViewCacheExtension ()

Public methods

getViewForPositionAndType

public abstract View getViewForPositionAndType (RecyclerView.Recycler recycler, 
                int position, 
                int type)

Returns a View that can be binded to the given Adapter position.

This method should not create a new View. Instead, it is expected to return an already created View that can be re-used for the given type and position. If the View is marked as ignored, it should first call RecyclerView.LayoutManager.stopIgnoringView(View) before returning the View.

RecyclerView will re-bind the returned View to the position if necessary.

Parameters
recycler RecyclerView.Recycler: The Recycler that can be used to bind the View

position int: The adapter position

type int: The type of the View, defined by adapter

Returns
View A View that is bound to the given position or NULL if there is no View to re-use