universum.studios.android.recycler.helper

Class ItemSwipeHelper

java.lang.Object

androidx.recyclerview.widget.RecyclerView.ItemDecoration

androidx.recyclerview.widget.ItemTouchHelper

universum.studios.android.recycler.helper.RecyclerViewItemHelper<ItemSwipeHelper.Interactor>

universum.studios.android.recycler.helper.ItemSwipeHelper

All Implemented Interfaces:

androidx.recyclerview.widget.RecyclerView.OnChildAttachStateChangeListener

public final class ItemSwipeHelper
extends RecyclerViewItemHelper<ItemSwipeHelper.Interactor>

A RecyclerViewItemHelper that may be used to support swipe feature for items displayed in a RecyclerView widget. Instance of this helper may be simply created via ItemSwipeHelper() constructor.

In order to support swipe feature for a desired adapter, such adapter must implement ItemSwipeHelper.SwipeAdapter interface and needs to be attached to its corresponding RecyclerView before call to RecyclerViewItemHelper.attachToRecyclerView(RecyclerView) which will attach such adapter to the swipe helper automatically. Also all ViewHolders of that adapter of which item views are desired to be swiped, must implement ItemSwipeHelper.SwipeViewHolder interface as other view holder implementations will be ignored by the ItemSwipeHelper API. When the ItemSwipeHelper.SwipeAdapter is properly attached, the item helper will delegate to it all swipe gesture related callbacks/events whenever appropriate via the adapter's interface.

Swipe Callbacks

A ItemSwipeHelper.OnSwipeListener may be registered for the helper's ItemSwipeHelper.Interactor via ItemSwipeHelper.Interactor#addOnSwipeListener(OnSwipeListener) in order to receive callbacks about started, finished or canceled swipe gesture for a particular ViewHolder. If the listener is no more needed it should be unregistered via ItemSwipeHelper.Interactor#removeOnSwipeListener(OnSwipeListener).

Since:

1.0

Author:

Martin Albedinsky

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ItemSwipeHelper.Interactor A ItemInteractor implementation used by ItemSwipeHelper to handle swipe gesture related callbacks and to delegate swipe events to the view holder that is being swiped.
static interface	ItemSwipeHelper.OnSwipeListener Listener which may be used to receive callbacks about started, finished or canceled swipe gesture for a specific RecyclerView.ViewHolder instance.
static interface	ItemSwipeHelper.SwipeAdapter Required interface for adapters which want to support swipe feature for theirs ViewHolders.
static class	ItemSwipeHelper.SwipeItemAnimator A DefaultItemAnimator extension which overrides default implementation of ItemSwipeHelper.SwipeItemAnimator.animateChange(RecyclerView.ViewHolder, RecyclerView.ViewHolder, int, int, int, int) in a way that does not cause any drawing artifacts to occur when state of item view for swiped view holder is about to be restored via restoreHolder(RecyclerView.ViewHolder, int, Runnable).
static interface	ItemSwipeHelper.SwipeViewHolder Required interface for all ViewHolders which want to support swipe feature for theirs corresponding item views.

Nested classes/interfaces inherited from class universum.studios.android.recycler.helper.RecyclerViewItemHelper

RecyclerViewItemHelper.Direction, RecyclerViewItemHelper.Interaction, RecyclerViewItemHelper.InteractiveViewHolder, RecyclerViewItemHelper.ItemInteractor, RecyclerViewItemHelper.Movement

Nested classes/interfaces inherited from class androidx.recyclerview.widget.ItemTouchHelper

androidx.recyclerview.widget.ItemTouchHelper.Callback, androidx.recyclerview.widget.ItemTouchHelper.SimpleCallback, androidx.recyclerview.widget.ItemTouchHelper.ViewDropHandler

Field Summary

Fields

Modifier and Type	Field and Description
static int	INTERACTION Interaction constant specific for ItemSwipeHelper.
static long	RESTORE_HOLDER_ANIMATION_DURATION Default duration for animation used to restore position of the holder's item view.
static float	SWIPE_THRESHOLD Default swipe threshold for the swipe gesture.

Fields inherited from class androidx.recyclerview.widget.ItemTouchHelper

ACTION_STATE_DRAG, ACTION_STATE_IDLE, ACTION_STATE_SWIPE, ANIMATION_TYPE_DRAG, ANIMATION_TYPE_SWIPE_CANCEL, ANIMATION_TYPE_SWIPE_SUCCESS, DOWN, END, LEFT, RIGHT, START, UP

Constructor Summary

Constructors

Constructor and Description
ItemSwipeHelper() Creates a new instance of ItemSwipeHelper.

Method Summary

Modifier and Type	Method and Description
long	getRestoreHolderAnimationDuration() Returns the duration of holder's restore animation.
android.view.animation.Interpolator	getRestoreHolderAnimationInterpolator() Returns the interpolator for holder's restore animation.
static int	makeSwipeFlags(int movementFlags) Makes movement flags for the swipe gesture.
boolean	restoreHolder(androidx.recyclerview.widget.RecyclerView.ViewHolder viewHolder, int direction) Same as restoreHolder(RecyclerView.ViewHolder, int, Runnable) with null callback.
boolean	restoreHolder(androidx.recyclerview.widget.RecyclerView.ViewHolder viewHolder, int direction, Runnable animationCallback) Restores position of the given viewHolder (of its item view) to its initial state.
void	setRestoreHolderAnimationDuration(long duration) Sets a duration for animation used to restore position of holder's item view after swipe gesture for that holder has been canceled.
void	setRestoreHolderAnimationInterpolator(android.view.animation.Interpolator interpolator) Sets an interpolator for animation used to restore position of holder's item view after swipe gesture for that holder has been canceled.

Methods inherited from class universum.studios.android.recycler.helper.RecyclerViewItemHelper

attachToRecyclerView, getInteractor

Methods inherited from class androidx.recyclerview.widget.ItemTouchHelper

getItemOffsets, onChildViewAttachedToWindow, onChildViewDetachedFromWindow, onDraw, onDrawOver, startDrag, startSwipe

Methods inherited from class androidx.recyclerview.widget.RecyclerView.ItemDecoration

getItemOffsets, onDraw, onDrawOver

Methods inherited from class java.lang.Object

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

Field Detail

INTERACTION

public static final int INTERACTION

Interaction constant specific for ItemSwipeHelper.

See Also:

ItemTouchHelper.ACTION_STATE_SWIPE, Constant Field Values

SWIPE_THRESHOLD

public static final float SWIPE_THRESHOLD

Default swipe threshold for the swipe gesture.

See Also:

Constant Field Values

RESTORE_HOLDER_ANIMATION_DURATION

public static final long RESTORE_HOLDER_ANIMATION_DURATION

Default duration for animation used to restore position of the holder's item view.

See Also:

restoreHolder(RecyclerView.ViewHolder, int, Runnable), Constant Field Values

Constructor Detail

ItemSwipeHelper

public ItemSwipeHelper()

Creates a new instance of ItemSwipeHelper.

Method Detail

makeSwipeFlags

public static int makeSwipeFlags(int movementFlags)

Makes movement flags for the swipe gesture.

Parameters:

movementFlags - The desired movement flags. One of flags defined by @Movement annotation.

Returns:

Swipe flags according to the given movement flags.

See Also:

ItemSwipeHelper.Callback#makeMovementFlags(int, int)

setRestoreHolderAnimationDuration

public void setRestoreHolderAnimationDuration(long duration)

Sets a duration for animation used to restore position of holder's item view after swipe gesture for that holder has been canceled.

Default value: RESTORE_HOLDER_ANIMATION_DURATION

Parameters:

duration - The desired duration.

See Also:

getRestoreHolderAnimationDuration(), restoreHolder(RecyclerView.ViewHolder, int, Runnable), ItemSwipeHelper.OnSwipeListener.onSwipeCanceled(ItemSwipeHelper, RecyclerView.ViewHolder)

getRestoreHolderAnimationDuration

public long getRestoreHolderAnimationDuration()

Returns the duration of holder's restore animation.

Returns:

Duration of restore animation.

See Also:

setRestoreHolderAnimationDuration(long)

setRestoreHolderAnimationInterpolator

public void setRestoreHolderAnimationInterpolator(@NonNull
                                                  android.view.animation.Interpolator interpolator)

Sets an interpolator for animation used to restore position of holder's item view after swipe gesture for that holder has been canceled.

Default value: FastOutSlowInInterpolator

Parameters:

interpolator - The desired interpolator.

See Also:

getRestoreHolderAnimationInterpolator(), ItemSwipeHelper.OnSwipeListener.onSwipeCanceled(ItemSwipeHelper, RecyclerView.ViewHolder)

getRestoreHolderAnimationInterpolator

@NonNull
public android.view.animation.Interpolator getRestoreHolderAnimationInterpolator()

Returns the interpolator for holder's restore animation.

Returns:

Animator for restore animation.

See Also:

setRestoreHolderAnimationInterpolator(Interpolator)

restoreHolder

public boolean restoreHolder(@NonNull
                             androidx.recyclerview.widget.RecyclerView.ViewHolder viewHolder,
                             int direction)

Same as restoreHolder(RecyclerView.ViewHolder, int, Runnable) with null callback.

restoreHolder

public boolean restoreHolder(@NonNull
                             androidx.recyclerview.widget.RecyclerView.ViewHolder viewHolder,
                             int direction,
                             @Nullable
                             Runnable animationCallback)

Restores position of the given viewHolder (of its item view) to its initial state.

When the restore animation finishes, the adapter of the RecyclerViewItemHelper to which is this item helper attached, will be notified via RecyclerView.Adapter#notifyItemChanged(int) with position of the restored holder.

This method should be called to restore holder's position whenever swipe gesture for such holder is canceled to prevent case when holder remains in the swiped state, that is off screen.

Parameters:

viewHolder - The view holder of which position to restore.

direction - The direction for which to restore the holder's state.

animationCallback - Callback to be fired when the restore animation finishes. May be null.

Returns:

True restoring of the holder has been performed, false otherwise.

See Also:

ItemSwipeHelper.OnSwipeListener.onSwipeCanceled(ItemSwipeHelper, RecyclerView.ViewHolder)