com.hannesdorfmann.adapterdelegates4

Class AdapterDelegatesManager<T>

java.lang.Object

com.hannesdorfmann.adapterdelegates4.AdapterDelegatesManager<T>

Type Parameters:

T - The type of the datasource of the adapter

public class AdapterDelegatesManager<T>
extends java.lang.Object

This class is the element that ties RecyclerView.Adapter together with AdapterDelegate.

So you have to add / register your AdapterDelegates to this manager by calling addDelegate(AdapterDelegate)

Next you have to add this AdapterDelegatesManager to the RecyclerView.Adapter by calling corresponding methods:

• getItemViewType(Object, int): Must be called from RecyclerView.Adapter#getItemViewType(int)
• onCreateViewHolder(ViewGroup, int): Must be called from RecyclerView.Adapter#onCreateViewHolder(ViewGroup, int)
• onBindViewHolder(Object, int, RecyclerView.ViewHolder): Must be called from RecyclerView.Adapter#onBindViewHolder(RecyclerView.ViewHolder, int)

You can also set a fallback AdapterDelegate by using setFallbackDelegate(AdapterDelegate) that will be used if no AdapterDelegate is responsible to handle a certain view type. If no fallback is specified, an Exception will be thrown if no AdapterDelegate is responsible to handle a certain view type

Field Summary

Fields

Modifier and Type	Field and Description
protected androidx.collection.SparseArrayCompat<AdapterDelegate<T>>	delegates Map for ViewType to AdapterDelegate
static int	FALLBACK_DELEGATE_VIEW_TYPE ViewType for the fallback delegate
protected AdapterDelegate<T>	fallbackDelegate

Constructor Summary

Constructors

Constructor and Description
AdapterDelegatesManager()

Method Summary

Modifier and Type	Method and Description
AdapterDelegatesManager<T>	addDelegate(AdapterDelegate<T> delegate) Adds an AdapterDelegate.
AdapterDelegatesManager<T>	addDelegate(int viewType, AdapterDelegate<T> delegate) Adds an AdapterDelegate with the specified view type.
AdapterDelegatesManager<T>	addDelegate(int viewType, boolean allowReplacingDelegate, AdapterDelegate<T> delegate) Adds an AdapterDelegate.
AdapterDelegate<T>	getDelegateForViewType(int viewType) Get the AdapterDelegate associated with the given view type integer
AdapterDelegate<T>	getFallbackDelegate() Get the fallback delegate
int	getItemViewType(T items, int position) Must be called from RecyclerView.Adapter#getItemViewType(int).
int	getViewType(AdapterDelegate<T> delegate) Get the view type integer for the given AdapterDelegate
void	onBindViewHolder(T items, int position, androidx.recyclerview.widget.RecyclerView.ViewHolder holder) Must be called from RecyclerView.Adapter#onBindViewHolder(RecyclerView.ViewHolder, int, List)
void	onBindViewHolder(T items, int position, androidx.recyclerview.widget.RecyclerView.ViewHolder holder, java.util.List payloads) Must be called fromRecyclerView.Adapter#onBindViewHolder(RecyclerView.ViewHolder, int, List)
androidx.recyclerview.widget.RecyclerView.ViewHolder	onCreateViewHolder(android.view.ViewGroup parent, int viewType) This method must be called in RecyclerView.Adapter#onCreateViewHolder(ViewGroup, int)
boolean	onFailedToRecycleView(androidx.recyclerview.widget.RecyclerView.ViewHolder holder) Must be called from RecyclerView.Adapter#onFailedToRecycleView(RecyclerView.ViewHolder)
void	onViewAttachedToWindow(androidx.recyclerview.widget.RecyclerView.ViewHolder holder) Must be called from RecyclerView.Adapter#onViewAttachedToWindow(RecyclerView.ViewHolder)
void	onViewDetachedFromWindow(androidx.recyclerview.widget.RecyclerView.ViewHolder holder) Must be called from RecyclerView.Adapter#onViewDetachedFromWindow(RecyclerView.ViewHolder)
void	onViewRecycled(androidx.recyclerview.widget.RecyclerView.ViewHolder holder) Must be called from RecyclerView.Adapter#onViewRecycled(RecyclerView.ViewHolder)
AdapterDelegatesManager<T>	removeDelegate(AdapterDelegate<T> delegate) Removes a previously registered delegate if and only if the passed delegate is registered (checks the reference of the object).
AdapterDelegatesManager<T>	removeDelegate(int viewType) Removes the adapterDelegate for the given view types.
AdapterDelegatesManager<T>	setFallbackDelegate(AdapterDelegate<T> fallbackDelegate) Set a fallback delegate that should be used if no AdapterDelegate has been found that can handle a certain view type.

Methods inherited from class java.lang.Object

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

Field Detail

FALLBACK_DELEGATE_VIEW_TYPE

public static final int FALLBACK_DELEGATE_VIEW_TYPE

ViewType for the fallback delegate

See Also:

Constant Field Values

delegates

protected androidx.collection.SparseArrayCompat<AdapterDelegate<T>> delegates

Map for ViewType to AdapterDelegate

fallbackDelegate

protected AdapterDelegate<T> fallbackDelegate

Constructor Detail

AdapterDelegatesManager

public AdapterDelegatesManager()

Method Detail

addDelegate

public AdapterDelegatesManager<T> addDelegate(@NonNull
                                              AdapterDelegate<T> delegate)

Adds an AdapterDelegate. This method automatically assign internally the view type integer by using the next unused

Internally calls addDelegate(int, boolean, AdapterDelegate) with allowReplacingDelegate = false as parameter.

Parameters:

delegate - the delegate to add

Returns:

self

Throws:

java.lang.NullPointerException - if passed delegate is null

See Also:

addDelegate(int, AdapterDelegate), addDelegate(int, boolean, AdapterDelegate)

addDelegate

public AdapterDelegatesManager<T> addDelegate(int viewType,
                                              @NonNull
                                              AdapterDelegate<T> delegate)

Adds an AdapterDelegate with the specified view type.

Internally calls addDelegate(int, boolean, AdapterDelegate) with allowReplacingDelegate = false as parameter.

Parameters:

viewType - the view type integer if you want to assign manually the view type. Otherwise use addDelegate(AdapterDelegate) where a viewtype will be assigned automatically.

delegate - the delegate to add

Returns:

self

Throws:

java.lang.NullPointerException - if passed delegate is null

See Also:

addDelegate(AdapterDelegate), addDelegate(int, boolean, AdapterDelegate)

addDelegate

public AdapterDelegatesManager<T> addDelegate(int viewType,
                                              boolean allowReplacingDelegate,
                                              @NonNull
                                              AdapterDelegate<T> delegate)

Adds an AdapterDelegate.

Parameters:

viewType - The viewType id

allowReplacingDelegate - if true, you allow to replacing the given delegate any previous delegate for the same view type. if false, you disallow and a IllegalArgumentException will be thrown if you try to replace an already registered AdapterDelegate for the same view type.

delegate - The delegate to add

Throws:

java.lang.IllegalArgumentException - if allowReplacingDelegate is false and an AdapterDelegate is already added (registered) with the same ViewType.

java.lang.IllegalArgumentException - if viewType is FALLBACK_DELEGATE_VIEW_TYPE which is reserved

See Also:

addDelegate(AdapterDelegate), addDelegate(int, AdapterDelegate), setFallbackDelegate(AdapterDelegate)

removeDelegate

public AdapterDelegatesManager<T> removeDelegate(@NonNull
                                                 AdapterDelegate<T> delegate)

Removes a previously registered delegate if and only if the passed delegate is registered (checks the reference of the object). This will not remove any other delegate for the same viewType (if there is any).

Parameters:

delegate - The delegate to remove

Returns:

self

removeDelegate

public AdapterDelegatesManager<T> removeDelegate(int viewType)

Removes the adapterDelegate for the given view types.

Parameters:

viewType - The Viewtype

Returns:

self

getItemViewType

public int getItemViewType(@NonNull
                           T items,
                           int position)

Must be called from RecyclerView.Adapter#getItemViewType(int). Internally it scans all the registered AdapterDelegate and picks the right one to return the ViewType integer.

Parameters:

items - Adapter's data source

position - the position in adapters data source

Returns:

the ViewType (integer). Returns FALLBACK_DELEGATE_VIEW_TYPE in case that the fallback adapter delegate should be used

Throws:

java.lang.NullPointerException - if no AdapterDelegate has been found that is responsible for the given data element in data set (No AdapterDelegate for the given ViewType)

java.lang.NullPointerException - if items is null

onCreateViewHolder

@NonNull
public androidx.recyclerview.widget.RecyclerView.ViewHolder onCreateViewHolder(@NonNull
                                                                                        android.view.ViewGroup parent,
                                                                                        int viewType)

This method must be called in RecyclerView.Adapter#onCreateViewHolder(ViewGroup, int)

Parameters:

parent - the parent

viewType - the view type

Returns:

The new created ViewHolder

Throws:

java.lang.NullPointerException - if no AdapterDelegate has been registered for ViewHolders viewType

onBindViewHolder

public void onBindViewHolder(@NonNull
                             T items,
                             int position,
                             @NonNull
                             androidx.recyclerview.widget.RecyclerView.ViewHolder holder,
                             java.util.List payloads)

Must be called fromRecyclerView.Adapter#onBindViewHolder(RecyclerView.ViewHolder, int, List)

Parameters:

items - Adapter's data source

position - the position in data source

holder - the ViewHolder to bind

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

Throws:

java.lang.NullPointerException - if no AdapterDelegate has been registered for ViewHolders viewType

onBindViewHolder

public void onBindViewHolder(@NonNull
                             T items,
                             int position,
                             @NonNull
                             androidx.recyclerview.widget.RecyclerView.ViewHolder holder)

Must be called from RecyclerView.Adapter#onBindViewHolder(RecyclerView.ViewHolder, int, List)

Parameters:

items - Adapter's data source

position - the position in data source

holder - the ViewHolder to bind

Throws:

java.lang.NullPointerException - if no AdapterDelegate has been registered for ViewHolders viewType

onViewRecycled

public void onViewRecycled(@NonNull
                           androidx.recyclerview.widget.RecyclerView.ViewHolder holder)

Must be called from RecyclerView.Adapter#onViewRecycled(RecyclerView.ViewHolder)

Parameters:

holder - The ViewHolder for the view being recycled

onFailedToRecycleView

public boolean onFailedToRecycleView(@NonNull
                                     androidx.recyclerview.widget.RecyclerView.ViewHolder holder)

Must be called from RecyclerView.Adapter#onFailedToRecycleView(RecyclerView.ViewHolder)

Parameters:

holder - The ViewHolder containing the View that could not be recycled due to its transient state.

Returns:

True if the View should be recycled, false otherwise. Note that if this method returns true, RecyclerView will ignore the transient state of the View and recycle it regardless. If this method returns false, RecyclerView will check the View's transient state again before giving a final decision. Default implementation returns false.

onViewAttachedToWindow

public void onViewAttachedToWindow(@NonNull
                                   androidx.recyclerview.widget.RecyclerView.ViewHolder holder)

Must be called from RecyclerView.Adapter#onViewAttachedToWindow(RecyclerView.ViewHolder)

Parameters:

holder - Holder of the view being attached

onViewDetachedFromWindow

public void onViewDetachedFromWindow(@NonNull
                                     androidx.recyclerview.widget.RecyclerView.ViewHolder holder)

Must be called from RecyclerView.Adapter#onViewDetachedFromWindow(RecyclerView.ViewHolder)

Parameters:

holder - Holder of the view being attached

setFallbackDelegate

public AdapterDelegatesManager<T> setFallbackDelegate(@Nullable
                                                      AdapterDelegate<T> fallbackDelegate)

Set a fallback delegate that should be used if no AdapterDelegate has been found that can handle a certain view type.

Parameters:

fallbackDelegate - The AdapterDelegate that should be used as fallback if no other AdapterDelegate has handled a certain view type. null you can set this to null if you want to remove a previously set fallback AdapterDelegate

getViewType

public int getViewType(@NonNull
                       AdapterDelegate<T> delegate)

Get the view type integer for the given AdapterDelegate

Parameters:

delegate - The delegate we want to know the view type for

Returns:

-1 if passed delegate is unknown, otherwise the view type integer

getDelegateForViewType

@Nullable
public AdapterDelegate<T> getDelegateForViewType(int viewType)

Get the AdapterDelegate associated with the given view type integer

Parameters:

viewType - The view type integer we want to retrieve the associated delegate for.

Returns:

The AdapterDelegate associated with the view type param if it exists, the fallback delegate otherwise if it is set or returns null if no delegate is associated to this viewType (and no fallback has been set).

getFallbackDelegate

@Nullable
public AdapterDelegate<T> getFallbackDelegate()

Get the fallback delegate

Returns:

The fallback delegate or null if no fallback delegate has been set

See Also:

setFallbackDelegate(AdapterDelegate)