Package com.firebase.ui.database

Class FirebaseRecyclerAdapter<T,VH extends androidx.recyclerview.widget.RecyclerView.ViewHolder>

java.lang.Object

androidx.recyclerview.widget.RecyclerView.Adapter<VH>

com.firebase.ui.database.FirebaseRecyclerAdapter<T,VH>

Type Parameters:

T - The Java class that maps to the type of objects stored in the Firebase location.

VH - The RecyclerView.ViewHolder class that contains the Views in the layout that is shown for each object.

All Implemented Interfaces:

androidx.lifecycle.LifecycleObserver, com.firebase.ui.common.BaseChangeEventListener<com.google.firebase.database.DataSnapshot,com.google.firebase.database.DatabaseError>, ChangeEventListener

public abstract class FirebaseRecyclerAdapter<T,VH extends androidx.recyclerview.widget.RecyclerView.ViewHolder>
extends androidx.recyclerview.widget.RecyclerView.Adapter<VH>

This class is a generic way of backing a RecyclerView with a Firebase location. It handles all of the child events at the given Firebase location and marshals received data into the given class type.

See the README for an in-depth tutorial on how to set up the FirebaseRecyclerAdapter.

Nested Class Summary

Nested classes/interfaces inherited from class androidx.recyclerview.widget.RecyclerView.Adapter

androidx.recyclerview.widget.RecyclerView.Adapter.StateRestorationPolicy

Constructor Summary

Constructors

Constructor	Description
FirebaseRecyclerAdapter(FirebaseRecyclerOptions<T> options)	Initialize a RecyclerView.Adapter that listens to a Firebase query.

Method Summary

Modifier and Type	Method	Description
T	getItem(int position)
int	getItemCount()
com.google.firebase.database.DatabaseReference	getRef(int position)
ObservableSnapshotArray<T>	getSnapshots()
void	onBindViewHolder(VH holder, int position)
protected abstract void	onBindViewHolder(VH holder, int position, T model)
void	onChildChanged(com.firebase.ui.common.ChangeEventType type, com.google.firebase.database.DataSnapshot snapshot, int newIndex, int oldIndex)
void	onDataChanged()
void	onError(com.google.firebase.database.DatabaseError error)
void	startListening()
void	stopListening()
void	updateOptions(FirebaseRecyclerOptions<T> options)	Re-initialize the Adapter with a new set of options.

Methods inherited from class androidx.recyclerview.widget.RecyclerView.Adapter

bindViewHolder, createViewHolder, findRelativeAdapterPositionIn, getItemId, getItemViewType, getStateRestorationPolicy, hasObservers, hasStableIds, notifyDataSetChanged, notifyItemChanged, notifyItemChanged, notifyItemInserted, notifyItemMoved, notifyItemRangeChanged, notifyItemRangeChanged, notifyItemRangeInserted, notifyItemRangeRemoved, notifyItemRemoved, onAttachedToRecyclerView, onBindViewHolder, onCreateViewHolder, onDetachedFromRecyclerView, onFailedToRecycleView, onViewAttachedToWindow, onViewDetachedFromWindow, onViewRecycled, registerAdapterDataObserver, setHasStableIds, setStateRestorationPolicy, unregisterAdapterDataObserver

Methods inherited from class java.lang.Object

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

Constructor Detail

FirebaseRecyclerAdapter

public FirebaseRecyclerAdapter(@NonNull
                               FirebaseRecyclerOptions<T> options)

Initialize a RecyclerView.Adapter that listens to a Firebase query. See FirebaseRecyclerOptions for configuration options.

Method Detail

startListening

public void startListening()

stopListening

public void stopListening()

onChildChanged

public void onChildChanged(@NonNull
                           com.firebase.ui.common.ChangeEventType type,
                           @NonNull
                           com.google.firebase.database.DataSnapshot snapshot,
                           int newIndex,
                           int oldIndex)

Specified by:

onChildChanged in interface com.firebase.ui.common.BaseChangeEventListener<T,VH extends androidx.recyclerview.widget.RecyclerView.ViewHolder>

onDataChanged

public void onDataChanged()

Specified by:

onDataChanged in interface com.firebase.ui.common.BaseChangeEventListener<T,VH extends androidx.recyclerview.widget.RecyclerView.ViewHolder>

onError

public void onError(@NonNull
                    com.google.firebase.database.DatabaseError error)

Specified by:

onError in interface com.firebase.ui.common.BaseChangeEventListener<T,VH extends androidx.recyclerview.widget.RecyclerView.ViewHolder>

getSnapshots

@NonNull
public ObservableSnapshotArray<T> getSnapshots()

getItem

@NonNull
public T getItem(int position)

getRef

@NonNull
public com.google.firebase.database.DatabaseReference getRef(int position)

getItemCount

public int getItemCount()

Specified by:

getItemCount in class androidx.recyclerview.widget.RecyclerView.Adapter<VH extends androidx.recyclerview.widget.RecyclerView.ViewHolder>

updateOptions

public void updateOptions(@NonNull
                          FirebaseRecyclerOptions<T> options)

Re-initialize the Adapter with a new set of options. Can be used to change the query without re-constructing the entire adapter.

onBindViewHolder

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

Specified by:

onBindViewHolder in class androidx.recyclerview.widget.RecyclerView.Adapter<VH extends androidx.recyclerview.widget.RecyclerView.ViewHolder>

onBindViewHolder

protected abstract void onBindViewHolder(@NonNull
                                         VH holder,
                                         int position,
                                         @NonNull
                                         T model)

Parameters:

model - the model object containing the data that should be used to populate the view.

See Also:

onBindViewHolder(RecyclerView.ViewHolder, int)