DefaultItemAnimator

Kotlin |Java

open class DefaultItemAnimator : SimpleItemAnimator

kotlin.Any
↳	androidx.recyclerview.widget.RecyclerView.ItemAnimator
	↳	androidx.recyclerview.widget.SimpleItemAnimator
		↳	androidx.recyclerview.widget.DefaultItemAnimator

This implementation of RecyclerView.ItemAnimator provides basic animations on remove, add, and move events that happen to the items in a RecyclerView. RecyclerView uses a DefaultItemAnimator by default.

Summary

Inherited constants

From class ItemAnimator

`Int`	`FLAG_APPEARED_IN_PRE_LAYOUT` This ViewHolder was not laid out but has been added to the layout in pre-layout state by the `LayoutManager`. This means that the item was already in the Adapter but invisible and it may become visible in the post layout phase. LayoutManagers may prefer to add new items in pre-layout to specify their virtual location when they are invisible (e.g. to specify the item should animate in from below the visible area).
`Int`	`FLAG_CHANGED` The Item represented by this ViewHolder is updated.
`Int`	`FLAG_INVALIDATED` Adapter `Adapter#notifyDataSetChanged()` has been called and the content represented by this ViewHolder is invalid.
`Int`	`FLAG_MOVED` The position of the Item represented by this ViewHolder has been changed. This flag is not bound to `Adapter#notifyItemMoved(int, int)`. It might be set in response to any adapter change that may have a side effect on this item. (e.g. The item before this one has been removed from the Adapter).
`Int`	`FLAG_REMOVED` The Item represented by this ViewHolder is removed from the adapter.

Public constructors
`<init>()` This implementation of `RecyclerView.ItemAnimator` provides basic animations on remove, add, and move events that happen to the items in a RecyclerView.

Public methods
open Boolean	`animateAdd(holder: RecyclerView.ViewHolder!)`
open Boolean	`animateChange(oldHolder: RecyclerView.ViewHolder!, newHolder: RecyclerView.ViewHolder!, fromX: Int, fromY: Int, toX: Int, toY: Int)`
open Boolean	`animateMove(holder: RecyclerView.ViewHolder!, fromX: Int, fromY: Int, toX: Int, toY: Int)`
open Boolean	`animateRemove(holder: RecyclerView.ViewHolder!)`
open Boolean	`canReuseUpdatedViewHolder(@NonNull viewHolder: RecyclerView.ViewHolder, @NonNull payloads: MutableList<Any!>)` When an item is changed, ItemAnimator can decide whether it wants to re-use the same ViewHolder for animations or RecyclerView should create a copy of the item and ItemAnimator will use both to run the animation (e.g. cross-fade).
open Unit	`endAnimation(item: RecyclerView.ViewHolder)`
open Unit	`endAnimations()`
open Boolean	`isRunning()`
open Unit	`runPendingAnimations()`

Inherited functions

From class SimpleItemAnimator

`Boolean`	`animateAppearance(@NonNull viewHolder: RecyclerView.ViewHolder, @Nullable preLayoutInfo: RecyclerView.ItemAnimator.ItemHolderInfo?, @NonNull postLayoutInfo: RecyclerView.ItemAnimator.ItemHolderInfo)`
`Boolean`	`animateChange(@NonNull oldHolder: RecyclerView.ViewHolder, @NonNull newHolder: RecyclerView.ViewHolder, @NonNull preInfo: RecyclerView.ItemAnimator.ItemHolderInfo, @NonNull postInfo: RecyclerView.ItemAnimator.ItemHolderInfo)`
`Boolean`	`animateDisappearance(@NonNull viewHolder: RecyclerView.ViewHolder, @NonNull preLayoutInfo: RecyclerView.ItemAnimator.ItemHolderInfo, @Nullable postLayoutInfo: RecyclerView.ItemAnimator.ItemHolderInfo?)`
`Boolean`	`animatePersistence(@NonNull viewHolder: RecyclerView.ViewHolder, @NonNull preInfo: RecyclerView.ItemAnimator.ItemHolderInfo, @NonNull postInfo: RecyclerView.ItemAnimator.ItemHolderInfo)`
`Boolean`	`canReuseUpdatedViewHolder(@NonNull viewHolder: RecyclerView.ViewHolder)` When an item is changed, ItemAnimator can decide whether it wants to re-use the same ViewHolder for animations or RecyclerView should create a copy of the item and ItemAnimator will use both to run the animation (e.g. cross-fade). Note that this method will only be called if the `ViewHolder` still has the same type (`Adapter#getItemViewType(int)`). Otherwise, ItemAnimator will always receive both `ViewHolder`s in the `animateChange(ViewHolder, ViewHolder, ItemHolderInfo, ItemHolderInfo)` method. If your application is using change payloads, you can override `canReuseUpdatedViewHolder(ViewHolder, List)` to decide based on payloads.
`Unit`	`dispatchAddFinished(item: RecyclerView.ViewHolder!)` Method to be called by subclasses when an add animation is done.
`Unit`	`dispatchAddStarting(item: RecyclerView.ViewHolder!)` Method to be called by subclasses when an add animation is being started.
`Unit`	`dispatchChangeFinished(item: RecyclerView.ViewHolder!, oldItem: Boolean)` Method to be called by subclasses when a change animation is done.
`Unit`	`dispatchChangeStarting(item: RecyclerView.ViewHolder!, oldItem: Boolean)` Method to be called by subclasses when a change animation is being started.
`Unit`	`dispatchMoveFinished(item: RecyclerView.ViewHolder!)` Method to be called by subclasses when a move animation is done.
`Unit`	`dispatchMoveStarting(item: RecyclerView.ViewHolder!)` Method to be called by subclasses when a move animation is being started.
`Unit`	`dispatchRemoveFinished(item: RecyclerView.ViewHolder!)` Method to be called by subclasses when a remove animation is done.
`Unit`	`dispatchRemoveStarting(item: RecyclerView.ViewHolder!)` Method to be called by subclasses when a remove animation is being started.
`Boolean`	`getSupportsChangeAnimations()` Returns whether this ItemAnimator supports animations of change events.
`Unit`	`onAddFinished(item: RecyclerView.ViewHolder!)` Called when an add animation has ended on the given ViewHolder. The default implementation does nothing. Subclasses may wish to override this method to handle any ViewHolder-specific operations linked to animation lifecycles.
`Unit`	`onAddStarting(item: RecyclerView.ViewHolder!)` Called when an add animation is being started on the given ViewHolder. The default implementation does nothing. Subclasses may wish to override this method to handle any ViewHolder-specific operations linked to animation lifecycles.
`Unit`	`onChangeFinished(item: RecyclerView.ViewHolder!, oldItem: Boolean)` Called when a change animation has ended on the given ViewHolder. The default implementation does nothing. Subclasses may wish to override this method to handle any ViewHolder-specific operations linked to animation lifecycles.
`Unit`	`onChangeStarting(item: RecyclerView.ViewHolder!, oldItem: Boolean)` Called when a change animation is being started on the given ViewHolder. The default implementation does nothing. Subclasses may wish to override this method to handle any ViewHolder-specific operations linked to animation lifecycles.
`Unit`	`onMoveFinished(item: RecyclerView.ViewHolder!)` Called when a move animation has ended on the given ViewHolder. The default implementation does nothing. Subclasses may wish to override this method to handle any ViewHolder-specific operations linked to animation lifecycles.
`Unit`	`onMoveStarting(item: RecyclerView.ViewHolder!)` Called when a move animation is being started on the given ViewHolder. The default implementation does nothing. Subclasses may wish to override this method to handle any ViewHolder-specific operations linked to animation lifecycles.
`Unit`	`onRemoveFinished(item: RecyclerView.ViewHolder!)` Called when a remove animation has ended on the given ViewHolder. The default implementation does nothing. Subclasses may wish to override this method to handle any ViewHolder-specific operations linked to animation lifecycles.
`Unit`	`onRemoveStarting(item: RecyclerView.ViewHolder!)` Called when a remove animation is being started on the given ViewHolder. The default implementation does nothing. Subclasses may wish to override this method to handle any ViewHolder-specific operations linked to animation lifecycles.
`Unit`	`setSupportsChangeAnimations(supportsChangeAnimations: Boolean)` Sets whether this ItemAnimator supports animations of item change events. If you set this property to false, actions on the data set which change the contents of items will not be animated. What those animations do is left up to the discretion of the ItemAnimator subclass, in its `animateChange(RecyclerView.ViewHolder, RecyclerView.ViewHolder, int, int, int, int)` implementation. The value of this property is true by default.

From class ItemAnimator

`Boolean`	`canReuseUpdatedViewHolder(@NonNull viewHolder: RecyclerView.ViewHolder, @NonNull payloads: MutableList<Any!>)` When an item is changed, ItemAnimator can decide whether it wants to re-use the same ViewHolder for animations or RecyclerView should create a copy of the item and ItemAnimator will use both to run the animation (e.g. cross-fade). Note that this method will only be called if the `ViewHolder` still has the same type (`Adapter#getItemViewType(int)`). Otherwise, ItemAnimator will always receive both `ViewHolder`s in the `animateChange(ViewHolder, ViewHolder, ItemHolderInfo, ItemHolderInfo)` method.
`Unit`	`dispatchAnimationFinished(@NonNull viewHolder: RecyclerView.ViewHolder)` Method to be called by subclasses when an animation is finished. For each call RecyclerView makes to `animateAppearance()`, `animatePersistence()`, or `animateDisappearance()`, there should be a matching `dispatchAnimationFinished(ViewHolder)` call by the subclass. For `animateChange()`, subclass should call this method for both the `oldHolder` and `newHolder` (if they are not the same instance).
`Unit`	`dispatchAnimationStarted(@NonNull viewHolder: RecyclerView.ViewHolder)` Method to be called by subclasses when an animation is started. For each call RecyclerView makes to `animateAppearance()`, `animatePersistence()`, or `animateDisappearance()`, there should be a matching `dispatchAnimationStarted(ViewHolder)` call by the subclass. For `animateChange()`, subclass should call this method for both the `oldHolder` and `newHolder` (if they are not the same instance). If your ItemAnimator decides not to animate a ViewHolder, it should call `dispatchAnimationFinished(ViewHolder)` without calling `dispatchAnimationStarted(ViewHolder)`.
`Unit`	`dispatchAnimationsFinished()` This method should be called by ItemAnimator implementations to notify any listeners that all pending and active item animations are finished.
`Unit`	`endAnimation(@NonNull item: RecyclerView.ViewHolder)` Method called when an animation on a view should be ended immediately. This could happen when other events, like scrolling, occur, so that animating views can be quickly put into their proper end locations. Implementations should ensure that any animations running on the item are canceled and affected properties are set to their end values. Also, `dispatchAnimationFinished(ViewHolder)` should be called for each finished animation since the animations are effectively done when this method is called.
`Unit`	`endAnimations()` Method called when all item animations should be ended immediately. This could happen when other events, like scrolling, occur, so that animating views can be quickly put into their proper end locations. Implementations should ensure that any animations running on any items are canceled and affected properties are set to their end values. Also, `dispatchAnimationFinished(ViewHolder)` should be called for each finished animation since the animations are effectively done when this method is called.
`Long`	`getAddDuration()` Gets the current duration for which all add animations will run.
`Long`	`getChangeDuration()` Gets the current duration for which all change animations will run.
`Long`	`getMoveDuration()` Gets the current duration for which all move animations will run.
`Long`	`getRemoveDuration()` Gets the current duration for which all remove animations will run.
`Boolean`	`isRunning()` Method which returns whether there are any item animations currently running. This method can be used to determine whether to delay other actions until animations end.
`Boolean`	`isRunning(@Nullable listener: RecyclerView.ItemAnimator.ItemAnimatorFinishedListener?)` Like `isRunning()`, this method returns whether there are any item animations currently running. Additionally, the listener passed in will be called when there are no item animations running, either immediately (before the method returns) if no animations are currently running, or when the currently running animations are `finished`. Note that the listener is transient - it is either called immediately and not stored at all, or stored only until it is called when running animations are finished sometime later.
`RecyclerView.ItemAnimator.ItemHolderInfo`	`obtainHolderInfo()` Returns a new `ItemHolderInfo` which will be used to store information about the ViewHolder. This information will later be passed into `animate**` methods. You can override this method if you want to extend `ItemHolderInfo` and provide your own instances.
`Unit`	`onAnimationFinished(@NonNull viewHolder: RecyclerView.ViewHolder)` Called after `dispatchAnimationFinished(ViewHolder)` is called by the ItemAnimator.
`Unit`	`onAnimationStarted(@NonNull viewHolder: RecyclerView.ViewHolder)` Called when a new animation is started on the given ViewHolder.
`RecyclerView.ItemAnimator.ItemHolderInfo`	`recordPostLayoutInformation(@NonNull state: RecyclerView.State, @NonNull viewHolder: RecyclerView.ViewHolder)` Called by the RecyclerView after the layout is complete. Item animator should record necessary information about the View's final state. The data returned from this method will be passed to the related `animate**` methods. The default implementation returns an `ItemHolderInfo` which holds the bounds of the View.
`RecyclerView.ItemAnimator.ItemHolderInfo`	`recordPreLayoutInformation(@NonNull state: RecyclerView.State, @NonNull viewHolder: RecyclerView.ViewHolder, changeFlags: Int, @NonNull payloads: MutableList<Any!>)` Called by the RecyclerView before the layout begins. Item animator should record necessary information about the View before it is potentially rebound, moved or removed. The data returned from this method will be passed to the related `animate**` methods. Note that this method may be called after pre-layout phase if LayoutManager adds new Views to the layout in pre-layout pass. The default implementation returns an `ItemHolderInfo` which holds the bounds of the View and the adapter change flags.
`Unit`	`runPendingAnimations()` Called when there are pending animations waiting to be started. This state is governed by the return values from `animateAppearance()`, `animateChange()` `animatePersistence()`, and `animateDisappearance()`, which inform the RecyclerView that the ItemAnimator wants to be called later to start the associated animations. runPendingAnimations() will be scheduled to be run on the next frame.
`Unit`	`setAddDuration(addDuration: Long)` Sets the duration for which all add animations will run.
`Unit`	`setChangeDuration(changeDuration: Long)` Sets the duration for which all change animations will run.
`Unit`	`setMoveDuration(moveDuration: Long)` Sets the duration for which all move animations will run.
`Unit`	`setRemoveDuration(removeDuration: Long)` Sets the duration for which all remove animations will run.

Public constructors

<init>

DefaultItemAnimator()

See Also

RecyclerView#setItemAnimator(RecyclerView.ItemAnimator)

Public methods

animateAdd

open fun animateAdd(holder: RecyclerView.ViewHolder!): Boolean

animateChange

open fun animateChange(oldHolder: RecyclerView.ViewHolder!, newHolder: RecyclerView.ViewHolder!, fromX: Int, fromY: Int, toX: Int, toY: Int): Boolean

animateMove

open fun animateMove(holder: RecyclerView.ViewHolder!, fromX: Int, fromY: Int, toX: Int, toY: Int): Boolean

animateRemove

open fun animateRemove(holder: RecyclerView.ViewHolder!): Boolean

canReuseUpdatedViewHolder

open fun canReuseUpdatedViewHolder(@NonNull viewHolder: RecyclerView.ViewHolder, @NonNull payloads: MutableList<Any!>): Boolean

When an item is changed, ItemAnimator can decide whether it wants to re-use the same ViewHolder for animations or RecyclerView should create a copy of the item and ItemAnimator will use both to run the animation (e.g. cross-fade).

Note that this method will only be called if the ViewHolder still has the same type (Adapter#getItemViewType(int)). Otherwise, ItemAnimator will always receive both ViewHolders in the animateChange(ViewHolder, ViewHolder, ItemHolderInfo, ItemHolderInfo) method.

If the payload list is not empty, DefaultItemAnimator returns true. When this is the case:

If you override animateChange(RecyclerView.ViewHolder, RecyclerView.ViewHolder, int, int, int, int), both ViewHolder arguments will be the same instance.
If you are not overriding animateChange(RecyclerView.ViewHolder, RecyclerView.ViewHolder, int, int, int, int), then DefaultItemAnimator will call animateMove(RecyclerView.ViewHolder, int, int, int, int) and run a move animation instead.

Parameters
`viewHolder`	RecyclerView.ViewHolder: The ViewHolder which represents the changed item's old content.
`payloads`	RecyclerView.ViewHolder: A non-null list of merged payloads that were sent with change notifications. Can be empty if the adapter is invalidated via `RecyclerView.Adapter#notifyDataSetChanged()`. The same list of payloads will be passed into `RecyclerView.Adapter#onBindViewHolder(ViewHolder, int, List)` method if this method returns `true`.

Return
Boolean: True if RecyclerView should just rebind to the same ViewHolder or false if RecyclerView should create a new ViewHolder and pass this ViewHolder to the ItemAnimator to animate. Default implementation calls `canReuseUpdatedViewHolder(ViewHolder)`.

endAnimation

open fun endAnimation(item: RecyclerView.ViewHolder): Unit

endAnimations

open fun endAnimations(): Unit

isRunning

open fun isRunning(): Boolean

runPendingAnimations

open fun runPendingAnimations(): Unit