ConcatAdapter

@SafeVarargs
public ConcatAdapter(@NonNull RecyclerView.Adapter[] adapters)

Creates a ConcatAdapter with DEFAULT and the given adapters in the given order.

public ConcatAdapter(
    @NonNull List<RecyclerView.Adapter<RecyclerView.ViewHolder>> adapters
)

Creates a ConcatAdapter with DEFAULT and the given adapters in the given order.

@SafeVarargs
public ConcatAdapter(
    @NonNull ConcatAdapter.Config config,
    @NonNull RecyclerView.Adapter[] adapters
)

Creates a ConcatAdapter with the given config and the given adapters in the given order.

public ConcatAdapter(
    @NonNull ConcatAdapter.Config config,
    @NonNull List<RecyclerView.Adapter<RecyclerView.ViewHolder>> adapters
)

Creates a ConcatAdapter with the given config and the given adapters in the given order.

public boolean addAdapter(
    @NonNull RecyclerView.Adapter<RecyclerView.ViewHolder> adapter
)

Appends the given adapter to the existing list of adapters and notifies the observers of this ConcatAdapter.

public boolean addAdapter(
    int index,
    @NonNull RecyclerView.Adapter<RecyclerView.ViewHolder> adapter
)

Adds the given adapter to the given index among other adapters that are already added.

public int findRelativeAdapterPositionIn(
    @NonNull RecyclerView.Adapter<RecyclerView.ViewHolder> adapter,
    @NonNull RecyclerView.ViewHolder viewHolder,
    int localPosition
)

Returns the position of the given ViewHolder in the given Adapter. If the given Adapter is not part of this ConcatAdapter, NO_POSITION is returned.

public @NonNull List<RecyclerView.Adapter<RecyclerView.ViewHolder>> getAdapters()

Returns an unmodifiable copy of the list of adapters in this ConcatAdapter. Note that this is a copy hence future changes in the ConcatAdapter are not reflected in this list.

public int getItemCount()

Returns the total number of items in the data set held by the adapter.

public long getItemId(int position)

Return the stable ID for the item at position. If hasStableIds would return false this method should return NO_ID. The default implementation of this method returns NO_ID.

public int getItemViewType(int position)

Return the view type of the item at position for the purposes of view recycling.

The default implementation of this method returns 0, making the assumption of a single view type for the adapter. Unlike ListView adapters, types need not be contiguous. Consider using id resources to uniquely identify item view types.

public @NonNull Pair<RecyclerView.Adapter<RecyclerView.ViewHolder>, Integer> getWrappedAdapterAndPosition(int globalPosition)

Retrieve the adapter and local position for a given position in this ConcatAdapter. This allows for retrieving wrapped adapter information in situations where you don't have a ViewHolder, such as within a androidx.recyclerview.widget.GridLayoutManager.SpanSizeLookup in which you want to look up information from the source adapter.

public void onAttachedToRecyclerView(@NonNull RecyclerView recyclerView)

Called by RecyclerView when it starts observing this Adapter.

Keep in mind that same adapter may be observed by multiple RecyclerViews.

public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position)

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

Note that unlike android.widget.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 getBindingAdapterPosition which will have the updated adapter position. Override onBindViewHolder instead if Adapter can handle efficient partial bind.

public @NonNull RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType)

Called when RecyclerView needs a new 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. 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 findViewById calls.

public void onDetachedFromRecyclerView(@NonNull RecyclerView recyclerView)

Called by RecyclerView when it stops observing this Adapter.

public boolean onFailedToRecycleView(@NonNull RecyclerView.ViewHolder holder)

Called by the RecyclerView if a ViewHolder created by this Adapter cannot be recycled due to its transient state. Upon receiving this callback, Adapter can clear the animation(s) that effect the View's transient state and return true so that the View can be recycled. Keep in mind that the View in question is already removed from the RecyclerView.

In some cases, it is acceptable to recycle a View although it has transient state. Most of the time, this is a case where the transient state will be cleared in onBindViewHolder call when View is rebound to a new position. For this reason, RecyclerView leaves the decision to the Adapter and uses the return value of this method to decide whether the View should be recycled or not.

Note that when all animations are created by RecyclerView.ItemAnimator, you should never receive this callback because RecyclerView keeps those Views as children until their animations are complete. This callback is useful when children of the item views create animations which may not be easy to implement using an ItemAnimator.

You should never fix this issue by calling holder.itemView.setHasTransientState(false); unless you've previously called holder.itemView.setHasTransientState(true);. Each View.setHasTransientState(true) call must be matched by a View.setHasTransientState(false) call, otherwise, the state of the View may become inconsistent. You should always prefer to end or cancel animations that are triggering the transient state instead of handling it manually.

public void onViewAttachedToWindow(@NonNull RecyclerView.ViewHolder holder)

Called when a view created by this adapter has been attached to a window.

This can be used as a reasonable signal that the view is about to be seen by the user. If the adapter previously freed any resources in onViewDetachedFromWindow those resources should be restored here.

public void onViewDetachedFromWindow(@NonNull RecyclerView.ViewHolder holder)

Called when a view created by this adapter has been detached from its window.

Becoming detached from the window is not necessarily a permanent condition; the consumer of an Adapter's views may choose to cache views offscreen while they are not visible, attaching and detaching them as appropriate.

public void onViewRecycled(@NonNull RecyclerView.ViewHolder holder)

Called when a view created by this adapter has been recycled.

A view is recycled when a LayoutManager decides that it no longer needs to be attached to its parent RecyclerView. This can be because it has fallen out of visibility or a set of cached views represented by views still attached to the parent RecyclerView. If an item view has large or expensive data bound to it such as large bitmaps, this may be a good place to release those resources.

RecyclerView calls this method right before clearing ViewHolder's internal data and sending it to RecycledViewPool. This way, if ViewHolder was holding valid information before being recycled, you can call getBindingAdapterPosition to get its adapter position.

public boolean removeAdapter(
    @NonNull RecyclerView.Adapter<RecyclerView.ViewHolder> adapter
)

Removes the given adapter from the adapters list if it exists

public void setHasStableIds(boolean hasStableIds)

Calling this method is an error and will result in an UnsupportedOperationException. You should use the Config object passed into the ConcatAdapter to configure this behavior.

public void setStateRestorationPolicy(
    @NonNull RecyclerView.Adapter.StateRestorationPolicy strategy
)

Calling this method is an error and will result in an UnsupportedOperationException. ConcatAdapter infers this value from added Adapters.