universum.studios.android.widget.adapter

Class BaseRecyclerAdapter<Item,VH extends RecyclerView.ViewHolder>

java.lang.Object

android.support.v7.widget.RecyclerView.Adapter<VH>

universum.studios.android.widget.adapter.BaseRecyclerAdapter<Item,VH>

Type Parameters:

Item - Type of the item presented within a data set of a subclass of this BaseRecyclerAdapter.

VH - Type of the view holder used within a subclass of this BaseRecyclerAdapter.

All Implemented Interfaces:

DataSet<Item>, DataSetAdapter<Item>

Direct Known Subclasses:

SimpleRecyclerAdapter

public abstract class BaseRecyclerAdapter<Item,VH extends RecyclerView.ViewHolder>
extends RecyclerView.Adapter<VH>
implements DataSetAdapter<Item>

Extended version of RecyclerView.Adapter that provides API of DataSetAdapter.

Author:

Martin Albedinsky

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BaseRecyclerAdapter.SimpleViewHolder Simple RecyclerView.ViewHolder implementation used as default holder for purpose of onCreateViewHolder(ViewGroup, int) method.

Field Summary

Fields

Modifier and Type	Field and Description
protected Context	mContext Context in which will be this adapter used.
protected LayoutInflater	mLayoutInflater Layout inflater used to inflate new views for this adapter.
protected Resources	mResources Application resources that may be used to obtain strings, texts, drawables, ...

Fields inherited from interface universum.studios.android.widget.adapter.DataSet

NO_ID, NO_POSITION

Constructor Summary

Constructors

Constructor and Description
BaseRecyclerAdapter(Context context) Creates a new instance of BaseAdapter within the given context.

Method Summary

Modifier and Type	Method and Description
long	getItemId(int position) Return the stable ID for the item at position.
protected View	inflate(int resource, ViewGroup parent) Inflates a new view hierarchy from the given xml resource.
boolean	isEmpty() Returns a boolean flag indicating whether this data set is empty or not.
boolean	isEnabled(int position) Returns a boolean flag indicating whether an item at the specified position is enabled or not.
protected boolean	notifyDataSetActionSelected(int action, int position, Object payload) Notifies that the given action has been performed for the specified position.
abstract void	onBindViewHolder(VH viewHolder, int position) Called by RecyclerView to display the data at the specified position.
abstract VH	onCreateViewHolder(ViewGroup parent, int viewType) Called when RecyclerView needs a new RecyclerView.ViewHolder of the given type to represent an item.
protected boolean	onDataSetActionSelected(int action, int position, Object payload) Invoked immediately after notifyDataSetActionSelected(int, int, Object) was called.
void	registerOnDataChangeListener(OnDataChangeListener listener) Registers a callback to be invoked when a data change occurs in this data set.
void	registerOnDataSetActionListener(OnDataSetActionListener listener) Registers a callback to be invoked when a specific data set action is selected within this data set.
void	registerOnDataSetListener(OnDataSetListener listener) Registers a callback to be invoked when a data set event occurs.
void	restoreInstanceState(Parcelable savedState) Restores the previous state, saved via DataSetAdapter.saveInstanceState(), of this adapter.
Parcelable	saveInstanceState() Saves the current state of this adapter.
void	unregisterOnDataChangeListener(OnDataChangeListener listener) Unregisters the given callback from the data change listeners, so it will not receive any callbacks further.
void	unregisterOnDataSetActionListener(OnDataSetActionListener listener) Unregisters the given callback from the data set action listeners, so it will not receive any callbacks further.
void	unregisterOnDataSetListener(OnDataSetListener listener) Unregisters the given callback from the data set listeners, so it will not receive any callbacks further.

Methods inherited from class android.support.v7.widget.RecyclerView.Adapter

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

Methods inherited from class java.lang.Object

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

Methods inherited from interface universum.studios.android.widget.adapter.DataSetAdapter

hasStableIds

Methods inherited from interface universum.studios.android.widget.adapter.DataSet

getItem, getItemCount, hasItemAt

Field Detail

mContext

protected final Context mContext

Context in which will be this adapter used.

mLayoutInflater

protected final LayoutInflater mLayoutInflater

Layout inflater used to inflate new views for this adapter.

mResources

protected final Resources mResources

Application resources that may be used to obtain strings, texts, drawables, ... and other resources.

Constructor Detail

BaseRecyclerAdapter

public BaseRecyclerAdapter(@NonNull
                           Context context)

Creates a new instance of BaseAdapter within the given context.

Parameters:

context - Context in which will be this adapter used.

Method Detail

registerOnDataChangeListener

public void registerOnDataChangeListener(@NonNull
                                         OnDataChangeListener listener)

Description copied from interface: DataSet

Registers a callback to be invoked when a data change occurs in this data set.

Specified by:

registerOnDataChangeListener in interface DataSet<Item>

Parameters:

listener - The desired listener callback to register.

See Also:

DataSet.unregisterOnDataChangeListener(OnDataChangeListener)

unregisterOnDataChangeListener

public void unregisterOnDataChangeListener(@NonNull
                                           OnDataChangeListener listener)

Description copied from interface: DataSet

Unregisters the given callback from the data change listeners, so it will not receive any callbacks further.

Specified by:

unregisterOnDataChangeListener in interface DataSet<Item>

Parameters:

listener - The desired listener callback to unregister.

See Also:

DataSet.registerOnDataChangeListener(OnDataChangeListener)

registerOnDataSetListener

public void registerOnDataSetListener(@NonNull
                                      OnDataSetListener listener)

Description copied from interface: DataSet

Registers a callback to be invoked when a data set event occurs. The occurred event may be a local change in the data set, or an invalidation of the data set.

Specified by:

registerOnDataSetListener in interface DataSet<Item>

Parameters:

listener - The desired listener callback to register.

See Also:

DataSet.unregisterOnDataSetListener(OnDataSetListener)

unregisterOnDataSetListener

public void unregisterOnDataSetListener(@NonNull
                                        OnDataSetListener listener)

Description copied from interface: DataSet

Unregisters the given callback from the data set listeners, so it will not receive any callbacks further.

Specified by:

unregisterOnDataSetListener in interface DataSet<Item>

Parameters:

listener - The desired listener callback to unregister.

See Also:

DataSet.registerOnDataSetListener(OnDataSetListener)

registerOnDataSetActionListener

public void registerOnDataSetActionListener(@NonNull
                                            OnDataSetActionListener listener)

Description copied from interface: DataSet

Registers a callback to be invoked when a specific data set action is selected within this data set.

Specified by:

registerOnDataSetActionListener in interface DataSet<Item>

Parameters:

listener - The desired listener callback to register.

See Also:

DataSet.unregisterOnDataSetActionListener(OnDataSetActionListener)

notifyDataSetActionSelected

protected boolean notifyDataSetActionSelected(int action,
                                              int position,
                                              @Nullable
                                              Object payload)

Notifies that the given action has been performed for the specified position.

If onDataSetActionSelected(int, int, Object) will not process this call, the registered OnDataSetActionListeners will be notified.

Note, that invoking this method with 'invalid' position, out of bounds of the current data set, will be ignored.

Parameters:

action - The action that was selected.

position - The position for which was the specified action selected.

payload - Additional payload data for the selected action. May be null if no payload has been specified.

Returns:

True if the action has been handled internally by this adapter or by one of the registers listeners, false otherwise.

onDataSetActionSelected

protected boolean onDataSetActionSelected(int action,
                                          int position,
                                          @Nullable
                                          Object payload)

Invoked immediately after notifyDataSetActionSelected(int, int, Object) was called.

Returns:

True to indicate that this event was processed here, false to dispatch this event to the registered OnDataSetActionListeners.

unregisterOnDataSetActionListener

public void unregisterOnDataSetActionListener(@NonNull
                                              OnDataSetActionListener listener)

Description copied from interface: DataSet

Unregisters the given callback from the data set action listeners, so it will not receive any callbacks further.

Specified by:

unregisterOnDataSetActionListener in interface DataSet<Item>

Parameters:

listener - The desired listener callback to unregister.

See Also:

DataSet.registerOnDataSetActionListener(OnDataSetActionListener)

isEmpty

public boolean isEmpty()

Description copied from interface: DataSet

Returns a boolean flag indicating whether this data set is empty or not.

Specified by:

isEmpty in interface DataSet<Item>

Returns:

True if cursor attached to this data set has no rows or it is null, false otherwise.

See Also:

DataSet.getItemCount()

getItemId

public long getItemId(int position)

Description copied from class: android.support.v7.widget.RecyclerView.Adapter

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

Specified by:

getItemId in interface DataSet<Item>

Overrides:

getItemId in class RecyclerView.Adapter<VH extends RecyclerView.ViewHolder>

Parameters:

position - Adapter position to query

Returns:

the stable ID of the item at position

See Also:

DataSet.hasItemAt(int), DataSet.getItem(int)

isEnabled

public boolean isEnabled(int position)

Description copied from interface: DataSetAdapter

Returns a boolean flag indicating whether an item at the specified position is enabled or not.

Specified by:

isEnabled in interface DataSetAdapter<Item>

Parameters:

position - The position of item to check.

Returns:

True if the item is enabled, false otherwise.

onCreateViewHolder

public abstract VH onCreateViewHolder(ViewGroup parent,
                                      int viewType)

Description copied from class: android.support.v7.widget.RecyclerView.Adapter

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(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.

Specified by:

onCreateViewHolder in class RecyclerView.Adapter<VH extends RecyclerView.ViewHolder>

Parameters:

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:

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

inflate

@NonNull
protected View inflate(@LayoutRes
                                 int resource,
                                 @NonNull
                                 ViewGroup parent)

Inflates a new view hierarchy from the given xml resource.

Parameters:

resource - Resource id of a view to inflate.

parent - A parent view, to resolve correct layout params for the newly creating view.

Returns:

The root view of the inflated view hierarchy.

See Also:

LayoutInflater.inflate(int, ViewGroup)

onBindViewHolder

public abstract void onBindViewHolder(@NonNull
                                      VH viewHolder,
                                      int position)

Description copied from class: android.support.v7.widget.RecyclerView.Adapter

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. Override #onBindViewHolder(ViewHolder, int, List) instead if Adapter can handle efficient partial bind.

Specified by:

onBindViewHolder in class RecyclerView.Adapter<VH extends RecyclerView.ViewHolder>

Parameters:

viewHolder - 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.

saveInstanceState

@NonNull
 @CallSuper
public Parcelable saveInstanceState()

Description copied from interface: DataSetAdapter

Saves the current state of this adapter.

If you decide to override this method, do not forget to call super.saveInstanceState() and pass the obtained super state to the corresponding constructor of your saved state implementation to ensure the state of all classes along the chain is properly saved.

Specified by:

saveInstanceState in interface DataSetAdapter<Item>

Returns:

Saved state of this adapter or an empty state if this adapter does not need to save its state.

restoreInstanceState

@CallSuper
public void restoreInstanceState(@NonNull
                                             Parcelable savedState)

Description copied from interface: DataSetAdapter

Restores the previous state, saved via DataSetAdapter.saveInstanceState(), of this adapter.

If you decide to override this method, do not forget to call super.restoreInstanceState(Parcelable) and pass there the parent state obtained from your saved state implementation to ensure the state of all classes along the chain is properly restored.

Specified by:

restoreInstanceState in interface DataSetAdapter<Item>

Parameters:

savedState - Should be the same state as obtained via DataSetAdapter.saveInstanceState() before.