eu.davidea.flexibleadapter

Class FlexibleAdapter.DiffUtilCallback<T extends IFlexible>

java.lang.Object

DiffUtil.Callback

eu.davidea.flexibleadapter.FlexibleAdapter.DiffUtilCallback<T>

Enclosing class:

FlexibleAdapter<T extends IFlexible>

public static class FlexibleAdapter.DiffUtilCallback<T extends IFlexible>
extends DiffUtil.Callback

Use setItems(List, List) to set the old and new lists, that are available as:

- protected List<T> oldItems;
- protected List<T> newItems;

Field Summary

Fields

Modifier and Type	Field and Description
protected java.util.List<T>	newItems
protected java.util.List<T>	oldItems

Constructor Summary

Constructors

Constructor and Description
DiffUtilCallback()

Method Summary

Modifier and Type	Method and Description
boolean	areContentsTheSame(int oldItemPosition, int newItemPosition) Called by the DiffUtil when it wants to check whether two items have the same data.
boolean	areItemsTheSame(int oldItemPosition, int newItemPosition) Called by the DiffUtil to decide whether two object represent the same item.
java.lang.Object	getChangePayload(int oldItemPosition, int newItemPosition) When areItemsTheSame(int, int) returns true for two items and areContentsTheSame(int, int) returns false for them, DiffUtil calls this method to get a payload about the change.
java.util.List<T>	getNewItems()
int	getNewListSize()
int	getOldListSize()
void	setItems(java.util.List<T> oldItems, java.util.List<T> newItems)

Methods inherited from class java.lang.Object

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

Field Detail

oldItems

protected java.util.List<T extends IFlexible> oldItems

newItems

protected java.util.List<T extends IFlexible> newItems

Constructor Detail

DiffUtilCallback

public DiffUtilCallback()

Method Detail

setItems

public final void setItems(java.util.List<T> oldItems,
                           java.util.List<T> newItems)

getNewItems

public final java.util.List<T> getNewItems()

getOldListSize

public final int getOldListSize()

getNewListSize

public final int getNewListSize()

areItemsTheSame

public boolean areItemsTheSame(int oldItemPosition,
                               int newItemPosition)

Called by the DiffUtil to decide whether two object represent the same item.

For example, if your items have unique ids, this method should check their id equality.

Parameters:

oldItemPosition - The position of the item in the old list

newItemPosition - The position of the item in the new list

Returns:

True if the two items represent the same object or false if they are different.

areContentsTheSame

public boolean areContentsTheSame(int oldItemPosition,
                                  int newItemPosition)

Called by the DiffUtil when it wants to check whether two items have the same data. DiffUtil uses this information to detect if the contents of an item has changed.

DiffUtil uses this method to check equality instead of Object.equals(Object) so that you can change its behavior depending on your UI. For example, if you are using DiffUtil with a RecyclerView.Adapter, you should return whether the items' visual representations are the same.

This method is called only if areItemsTheSame(int, int) returns true for these items.

Parameters:

oldItemPosition - The position of the item in the old list

newItemPosition - The position of the item in the new list which replaces the oldItem

Returns:

True if the contents of the items are the same or false if they are different.

getChangePayload

public java.lang.Object getChangePayload(int oldItemPosition,
                                         int newItemPosition)

When areItemsTheSame(int, int) returns true for two items and areContentsTheSame(int, int) returns false for them, DiffUtil calls this method to get a payload about the change.

For example, if you are using DiffUtil with RecyclerView, you can return the particular field that changed in the item and your ItemAnimator can use that information to run the correct animation.

Default implementation returns null.

Parameters:

oldItemPosition - The position of the item in the old list

newItemPosition - The position of the item in the new list

Returns:

A payload object that represents the change between the two items.