belongs to Maven artifact com.android.support:recyclerview-v7:28.0.0-alpha1
SortedList.Callback
public
static
abstract
class
SortedList.Callback
extends Object
implements
Comparator<T2>,
ListUpdateCallback
| java.lang.Object | |
| ↳ | android.support.v7.util.SortedList.Callback<T2> |
Known Direct Subclasses
|
The class that controls the behavior of the SortedList.
It defines how items should be sorted and how duplicates should be handled.
SortedList calls the callback methods on this class to notify changes about the underlying data.
Summary
Public constructors | |
|---|---|
SortedList.Callback()
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Public methods | |
|---|---|
abstract
boolean
|
areContentsTheSame(T2 oldItem, T2 newItem)
Called by the SortedList when it wants to check whether two items have the same data or not. |
abstract
boolean
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areItemsTheSame(T2 item1, T2 item2)
Called by the SortedList to decide whether two objects represent the same Item or not. |
abstract
int
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compare(T2 o1, T2 o2)
Similar to |
Object
|
getChangePayload(T2 item1, T2 item2)
When |
void
|
onChanged(int position, int count, Object payload)
Called when |
abstract
void
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onChanged(int position, int count)
Called by the SortedList when the item at the given position is updated. |
Inherited methods | |
|---|---|
From
class
java.lang.Object
| |
From
interface
java.util.Comparator
| |
From
interface
android.support.v7.util.ListUpdateCallback
| |
Public constructors
Public methods
areContentsTheSame
boolean areContentsTheSame (T2 oldItem,
T2 newItem)Called by the SortedList when it wants to check whether two items have the same data
or not. SortedList uses this information to decide whether it should call
onChanged(int, int) or not.
SortedList uses this method to check equality instead of equals(Object)
so
that you can change its behavior depending on your UI.
For example, if you are using SortedList with a
RecyclerView.Adapter, you should
return whether the items' visual representations are the same or not.
| Parameters | |
|---|---|
oldItem |
T2: The previous representation of the object. |
newItem |
T2: The new object that replaces the previous one. |
| Returns | |
|---|---|
boolean |
True if the contents of the items are the same or false if they are different. |
areItemsTheSame
boolean areItemsTheSame (T2 item1,
T2 item2)Called by the SortedList to decide whether two objects represent the same Item or not.
For example, if your items have unique ids, this method should check their equality.
| Parameters | |
|---|---|
item1 |
T2: The first item to check. |
item2 |
T2: The second item to check. |
| Returns | |
|---|---|
boolean |
True if the two items represent the same object or false if they are different. |
compare
int compare (T2 o1,
T2 o2)Similar to compare(Object, Object), should compare two and
return how they should be ordered.
| Parameters | |
|---|---|
o1 |
T2: The first object to compare. |
o2 |
T2: The second object to compare. |
| Returns | |
|---|---|
int |
a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second. |
getChangePayload
Object getChangePayload (T2 item1,
T2 item2)When areItemsTheSame(T2, T2) returns true for two items and
areContentsTheSame(T2, T2) returns false for them, SortedList.Callback calls this
method to get a payload about the change.
For example, if you are using SortedList.Callback 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 | |
|---|---|
item1 |
T2: The first item to check. |
item2 |
T2: The second item to check. |
| Returns | |
|---|---|
Object |
A payload object that represents the changes between the two items. |
onChanged
void onChanged (int position,
int count,
Object payload)Called when count number of items are updated at the given position.
| Parameters | |
|---|---|
position |
int: The position of the item which has been updated. |
count |
int: The number of items which has changed.
|
payload |
Object |
onChanged
void onChanged (int position,
int count)Called by the SortedList when the item at the given position is updated.
| Parameters | |
|---|---|
position |
int: The position of the item which has been updated. |
count |
int: The number of items which has changed.
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