universum.studios.android.recycler.helper

Class ItemDragHelper.Interactor

java.lang.Object

android.support.v7.widget.helper.ItemTouchHelper.Callback

universum.studios.android.recycler.helper.RecyclerViewItemHelper.ItemInteractor

universum.studios.android.recycler.helper.ItemDragHelper.Interactor

Enclosing class:

ItemDragHelper

public static final class ItemDragHelper.Interactor
extends RecyclerViewItemHelper.ItemInteractor

A ItemInteractor implementation used by ItemDragHelper to handle drag gesture related callbacks and to delegate drag events to the view holder that is being dragged and also to it parent adapter in order to properly move dragged items in the adapter's data set.

Since:

1.0

Author:

Martin Albedinsky

Field Summary

Fields inherited from class android.support.v7.widget.helper.ItemTouchHelper.Callback

DEFAULT_DRAG_ANIMATION_DURATION, DEFAULT_SWIPE_ANIMATION_DURATION

Method Summary

Modifier and Type	Method and Description
void	addOnDragListener(ItemDragHelper.OnDragListener listener) Registers a callback to be invoked whenever drag gesture is started, finished or canceled for a specific RecyclerView.ViewHolder instance.
protected boolean	canAttachAdapter(RecyclerView.Adapter adapter) Called by the parent helper to check if the given adapter may be attached to this interactor instance.
boolean	canDropOver(RecyclerView recyclerView, RecyclerView.ViewHolder current, RecyclerView.ViewHolder target)
void	clearView(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder)
float	getDragThreshold() Returns the fraction that the user should move the holder's View to be considered as it is dragged.
int	getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder)
float	getMoveThreshold(RecyclerView.ViewHolder viewHolder)
boolean	isActive() Returns boolean flag indicating whether this interactor is currently active.
boolean	isLongPressDragEnabled()
protected void	onAdapterAttached(RecyclerView.Adapter adapter) Invoked whenever a new adapter is attached to this interactor instance.
protected void	onAdapterDetached(RecyclerView.Adapter adapter) Invoked before a new adapter is attached to this interactor instance if there is already previous adapter attached.
boolean	onMove(RecyclerView recyclerView, RecyclerView.ViewHolder current, RecyclerView.ViewHolder target)
void	onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState)
void	onSwiped(RecyclerView.ViewHolder viewHolder, int direction)
void	removeOnDragListener(ItemDragHelper.OnDragListener listener) Removes the given drag listener from the registered listeners.
void	setDragThreshold(float threshold) Sets a fraction that the user should move the holder's View to be considered as it is dragged.
void	setEnabled(boolean enabled) Sets a boolean flag indicating whether this interactor should be enabled or not.
void	setLongPressDragEnabled(boolean enabled) Sets a boolean flag indicating whether the drag should be started whenever an item view is long pressed or not.
protected boolean	shouldHandleInteraction(RecyclerView.ViewHolder viewHolder) Checks whether this interactor should handle interaction for the specified viewHolder due to received callback from the parent helper.

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

isEnabled, onAttachedToHelper, onChildDraw, onChildDrawOver, shouldHandleInteraction

Methods inherited from class android.support.v7.widget.helper.ItemTouchHelper.Callback

chooseDropTarget, convertToAbsoluteDirection, convertToRelativeDirection, getAnimationDuration, getBoundingBoxMargin, getDefaultUIUtil, getSwipeEscapeVelocity, getSwipeThreshold, getSwipeVelocityThreshold, interpolateOutOfBoundsScroll, isItemViewSwipeEnabled, makeFlag, makeMovementFlags, onMoved

Methods inherited from class java.lang.Object

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

Method Detail

setLongPressDragEnabled

public void setLongPressDragEnabled(boolean enabled)

Sets a boolean flag indicating whether the drag should be started whenever an item view is long pressed or not.

If disabled, a drag for a particular view holder needs to be started via ItemTouchHelper.startDrag(RecyclerView.ViewHolder) manually.

Default value: true

Parameters:

enabled - True to enable automatic drag on long press, false to disable it.

See Also:

isLongPressDragEnabled()

isLongPressDragEnabled

public boolean isLongPressDragEnabled()

Overrides:

isLongPressDragEnabled in class ItemTouchHelper.Callback

setDragThreshold

public void setDragThreshold(float threshold)

Sets a fraction that the user should move the holder's View to be considered as it is dragged.

Default value: ItemDragHelper.MOVE_THRESHOLD

Parameters:

threshold - The desired threshold from the range [0.0, 1.0].

See Also:

getDragThreshold(), getMoveThreshold(RecyclerView.ViewHolder), getMoveThreshold(RecyclerView.ViewHolder)

getDragThreshold

public float getDragThreshold()

Returns the fraction that the user should move the holder's View to be considered as it is dragged.

Returns:

The drag threshold from the range [0.0, 1.0].

See Also:

setDragThreshold(float)

getMoveThreshold

public float getMoveThreshold(@NonNull
                              RecyclerView.ViewHolder viewHolder)

Overrides:

getMoveThreshold in class ItemTouchHelper.Callback

addOnDragListener

public void addOnDragListener(@NonNull
                              ItemDragHelper.OnDragListener listener)

Registers a callback to be invoked whenever drag gesture is started, finished or canceled for a specific RecyclerView.ViewHolder instance.

Parameters:

listener - The desired listener callback to add.

See Also:

#removeOnDragListener(OnDragListener)

removeOnDragListener

public void removeOnDragListener(@NonNull
                                 ItemDragHelper.OnDragListener listener)

Removes the given drag listener from the registered listeners.

Parameters:

listener - The desired listener to remove.

See Also:

#addOnDragListener(OnDragListener)

canAttachAdapter

protected boolean canAttachAdapter(@NonNull
                                   RecyclerView.Adapter adapter)

Description copied from class: RecyclerViewItemHelper.ItemInteractor

Called by the parent helper to check if the given adapter may be attached to this interactor instance.

If this method returns true, RecyclerViewItemHelper.ItemInteractor.onAdapterAttached(RecyclerView.Adapter) will follow. If this interactor has attached any previous adapter, such adapter will be detached via RecyclerViewItemHelper.ItemInteractor.onAdapterDetached(RecyclerView.Adapter) before the new one is attached.

Specified by:

canAttachAdapter in class RecyclerViewItemHelper.ItemInteractor

Parameters:

adapter - The adapter to be checked if it may be attached.

Returns:

True if the parent helper may attach the adapter to this interactor, false otherwise.

onAdapterAttached

protected void onAdapterAttached(@NonNull
                                 RecyclerView.Adapter adapter)

Description copied from class: RecyclerViewItemHelper.ItemInteractor

Invoked whenever a new adapter is attached to this interactor instance.

This method is called as result of call to RecyclerViewItemHelper.attachToRecyclerView(RecyclerView) for the parent helper.

Overrides:

onAdapterAttached in class RecyclerViewItemHelper.ItemInteractor

Parameters:

adapter - The adapter of the associated RecyclerView to which is the parent helper attached.

See Also:

RecyclerViewItemHelper.ItemInteractor.onAdapterDetached(RecyclerView.Adapter)

onAdapterDetached

protected void onAdapterDetached(@NonNull
                                 RecyclerView.Adapter adapter)

Description copied from class: RecyclerViewItemHelper.ItemInteractor

Invoked before a new adapter is attached to this interactor instance if there is already previous adapter attached.

Overrides:

onAdapterDetached in class RecyclerViewItemHelper.ItemInteractor

Parameters:

adapter - The previous adapter that has been detached from this interactor.

See Also:

RecyclerViewItemHelper.ItemInteractor.onAdapterAttached(RecyclerView.Adapter)

setEnabled

public void setEnabled(boolean enabled)

Description copied from class: RecyclerViewItemHelper.ItemInteractor

Sets a boolean flag indicating whether this interactor should be enabled or not.

Overrides:

setEnabled in class RecyclerViewItemHelper.ItemInteractor

Parameters:

enabled - True to enable this interactor, false otherwise.

See Also:

RecyclerViewItemHelper.ItemInteractor.isEnabled()

isActive

public boolean isActive()

Description copied from class: RecyclerViewItemHelper.ItemInteractor

Returns boolean flag indicating whether this interactor is currently active.

Specified by:

isActive in class RecyclerViewItemHelper.ItemInteractor

Returns:

True if this interactor performs some interaction logic at this time, false otherwise.

getMovementFlags

public int getMovementFlags(@NonNull
                            RecyclerView recyclerView,
                            @NonNull
                            RecyclerView.ViewHolder viewHolder)

Specified by:

getMovementFlags in class ItemTouchHelper.Callback

onSelectedChanged

public void onSelectedChanged(@Nullable
                              RecyclerView.ViewHolder viewHolder,
                              int actionState)

Overrides:

onSelectedChanged in class ItemTouchHelper.Callback

onMove

public boolean onMove(@NonNull
                      RecyclerView recyclerView,
                      @NonNull
                      RecyclerView.ViewHolder current,
                      @NonNull
                      RecyclerView.ViewHolder target)

Specified by:

onMove in class ItemTouchHelper.Callback

onSwiped

public void onSwiped(@NonNull
                     RecyclerView.ViewHolder viewHolder,
                     int direction)

Specified by:

onSwiped in class ItemTouchHelper.Callback

canDropOver

public boolean canDropOver(@NonNull
                           RecyclerView recyclerView,
                           @NonNull
                           RecyclerView.ViewHolder current,
                           @NonNull
                           RecyclerView.ViewHolder target)

Overrides:

canDropOver in class ItemTouchHelper.Callback

clearView

public void clearView(@NonNull
                      RecyclerView recyclerView,
                      @NonNull
                      RecyclerView.ViewHolder viewHolder)

Overrides:

clearView in class ItemTouchHelper.Callback

shouldHandleInteraction

protected boolean shouldHandleInteraction(@Nullable
                                          RecyclerView.ViewHolder viewHolder)

Description copied from class: RecyclerViewItemHelper.ItemInteractor

Checks whether this interactor should handle interaction for the specified viewHolder due to received callback from the parent helper.

This implementation only extends RecyclerViewItemHelper.ItemInteractor.shouldHandleInteraction() in a way that the view holder is checked if it is not null and has valid adapter position. Inheritance hierarchies are allowed to override this behaviour as desired.

Overrides:

shouldHandleInteraction in class RecyclerViewItemHelper.ItemInteractor

Parameters:

viewHolder - The desired view holder to be checked.

Returns:

True if RecyclerViewItemHelper.ItemInteractor.shouldHandleInteraction() returns true, view holder is not null and has valid (not RecyclerView.NO_POSITION) adapter position, false otherwise.