com.globusltd.recyclerview

Class Adapter<E,VH extends RecyclerView.ViewHolder>

java.lang.Object

<any>

com.globusltd.recyclerview.Adapter<E,VH>

All Implemented Interfaces:

DatasourceSwappable<E>, Swappable<Datasource<? extends E>>

@MainThread
public abstract class Adapter<E,VH extends RecyclerView.ViewHolder>
extends <any>
implements DatasourceSwappable<E>

Base RecyclerView.Adapter that holds a reference to the Datasource object.

Notice that you should always detach adapter from RecyclerView when view is destroyed to avoid possible memory leaks. Detaching the adapter from RecyclerView guarantees that all ViewHolders will be recycled. Please see a code snippet below:

Constructor Summary

Constructors

Constructor and Description
Adapter()
Adapter(Datasource<? extends E> datasource)
Adapter(Datasource<? extends E> datasource, DiffCallbackFactory<E> diffCallbackFactory)

Method Summary

Modifier and Type	Method and Description
Datasource<? extends E>	getDatasource()
int	getItemCount()
void	onAttachedToRecyclerView(RecyclerView recyclerView)
abstract void	onBindViewHolder(VH holder, E item, int position) Called by RecyclerView to display the data at the specified position.
void	onBindViewHolder(VH holder, E item, int position, List<Object> payloads) Called by RecyclerView to display the data at the specified position.
void	onBindViewHolder(VH holder, int position)
void	onBindViewHolder(VH holder, int position, List<Object> payloads)
abstract VH	onCreateViewHolder(LayoutInflater inflater, ViewGroup parent, int viewType) Called when RecyclerView needs a new RecyclerView.ViewHolder of the given type to represent an item.
VH	onCreateViewHolder(ViewGroup parent, int viewType)
void	onDetachedFromRecyclerView(RecyclerView recyclerView)
Datasource<? extends E>	swap(Datasource<? extends E> datasource) Performs swapping the internal components and returns the previous component.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Adapter

public Adapter()

Adapter

public Adapter(@NonNull
               Datasource<? extends E> datasource)

Adapter

public Adapter(@NonNull
               Datasource<? extends E> datasource,
               @Nullable
               DiffCallbackFactory<E> diffCallbackFactory)

Method Detail

onAttachedToRecyclerView

@CallSuper
public void onAttachedToRecyclerView(RecyclerView recyclerView)

onDetachedFromRecyclerView

@CallSuper
public void onDetachedFromRecyclerView(RecyclerView recyclerView)

swap

@Nullable
public final Datasource<? extends E> swap(@NonNull
                                                     Datasource<? extends E> datasource)

Performs swapping the internal components and returns the previous component.

Specified by:

swap in interface Swappable<Datasource<? extends E>>

Parameters:

datasource - The new component that should replace the old one.

Returns:

The previous component.

getDatasource

@NonNull
public Datasource<? extends E> getDatasource()

getItemCount

public int getItemCount()

onCreateViewHolder

public final VH onCreateViewHolder(@NonNull
                                   ViewGroup parent,
                                   int viewType)

onCreateViewHolder

@NonNull
public abstract VH onCreateViewHolder(@NonNull
                                                LayoutInflater inflater,
                                                @NonNull
                                                ViewGroup parent,
                                                int viewType)

Called when RecyclerView needs a new RecyclerView.ViewHolder of the given type to represent an item.

This new ViewHolder should be constructed with a new View that can represent the items of the given type. You can either create a new View manually or inflate it from an XML layout file.

The new ViewHolder will be used to display items of the adapter using onBindViewHolder(RecyclerView.ViewHolder, int, List). Since it will be re-used to display different items in the data set, it is a good idea to cache references to sub views of the View to avoid unnecessary View.findViewById(int) calls.

Parameters:

inflater - LayoutInflater to inflate views from XML.

parent - The ViewGroup into which the new View will be added after it is bound to an adapter position.

viewType - The view type of the new View.

Returns:

A new ViewHolder that holds a View of the given view type.

See Also:

#getItemViewType(int), onBindViewHolder(RecyclerView.ViewHolder, int)

onBindViewHolder

public final void onBindViewHolder(VH holder,
                                   int position)

onBindViewHolder

public abstract void onBindViewHolder(@NonNull
                                      VH holder,
                                      @NonNull
                                      E item,
                                      int position)

Called by RecyclerView to display the data at the specified position. This method should update the contents of the RecyclerView.ViewHolder#itemView to reflect the item at the given position.

Note that unlike ListView, RecyclerView will not call this method again if the position of the item changes in the data set unless the item itself is invalidated or the new position cannot be determined. For this reason, you should only use the position parameter while acquiring the related data item inside this method and should not keep a copy of it. If you need the position of an item later on (e.g. in a click listener), use RecyclerView.ViewHolder#getAdapterPosition() which will have the updated adapter position.

Parameters:

holder - The ViewHolder which should be updated to represent the contents of the item at the given position in the data set.

item - The item at the given position in the data set.

position - The position of the item within the adapter's data set.

onBindViewHolder

public final void onBindViewHolder(VH holder,
                                   int position,
                                   List<Object> payloads)

onBindViewHolder

public void onBindViewHolder(@NonNull
                             VH holder,
                             @NonNull
                             E item,
                             int position,
                             List<Object> payloads)

Called by RecyclerView to display the data at the specified position. This method should update the contents of the RecyclerView.ViewHolder#itemView to reflect the item at the given position.

Note that unlike ListView, RecyclerView will not call this method again if the position of the item changes in the data set unless the item itself is invalidated or the new position cannot be determined. For this reason, you should only use the position parameter while acquiring the related data item inside this method and should not keep a copy of it. If you need the position of an item later on (e.g. in a click listener), use RecyclerView.ViewHolder#getAdapterPosition() which will have the updated adapter position.

Partial bind vs full bind:

The payloads parameter is a merge list from #notifyItemChanged(int, Object) or #notifyItemRangeChanged(int, int, Object). If the payloads list is not empty, the ViewHolder is currently bound to old data and Adapter may run an efficient partial update using the payload info. If the payload is empty, Adapter must run a full bind. Adapter should not assume that the payload passed in notify methods will be received by onAttachViewHolder(). For example when the view is not attached to the screen, the payload in notifyItemChange() will be simply dropped.

Parameters:

holder - The ViewHolder which should be updated to represent the contents of the item at the given position in the data set.

position - The position of the item within the adapter's data set.

payloads - A non-null list of merged payloads. Can be empty list if requires full update.