added in version 24.1.0
belongs to Maven artifact com.android.support:recyclerview-v7:28.0.0-alpha1

Summary: Inherited Constants | Ctors | Methods | Inherited Methods | [Expand All]

ItemTouchHelper.SimpleCallback

This package is part of the Android support library which is no longer maintained. The support library has been superseded by AndroidX which is part of Jetpack. We recommend using the AndroidX libraries in all new projects. You should also consider migrating existing projects to AndroidX. To find the AndroidX class that maps to this deprecated class, see the AndroidX support library class mappings.

public static abstract class ItemTouchHelper.SimpleCallback
extends ItemTouchHelper.Callback

java.lang.Object
↳	android.support.v7.widget.helper.ItemTouchHelper.Callback
	↳	android.support.v7.widget.helper.ItemTouchHelper.SimpleCallback

---

A simple wrapper to the default Callback which you can construct with drag and swipe directions and this class will handle the flag callbacks. You should still override onMove or onSwiped depending on your use case.

 ItemTouchHelper mIth = new ItemTouchHelper(
     new ItemTouchHelper.SimpleCallback(ItemTouchHelper.UP | ItemTouchHelper.DOWN,
         ItemTouchHelper.LEFT) {
         public abstract boolean onMove(RecyclerView recyclerView,
             ViewHolder viewHolder, ViewHolder target) {
             final int fromPos = viewHolder.getAdapterPosition();
             final int toPos = target.getAdapterPosition();
             // move item in `fromPos` to `toPos` in adapter.
             return true;// true if moved, false otherwise
         }
         public void onSwiped(ViewHolder viewHolder, int direction) {
             // remove from adapter
         }
 });
 

Summary

Inherited constants
From class android.support.v7.widget.helper.ItemTouchHelper.Callback int DEFAULT_DRAG_ANIMATION_DURATION int DEFAULT_SWIPE_ANIMATION_DURATION

Public constructors
ItemTouchHelper.SimpleCallback(int dragDirs, int swipeDirs) Creates a Callback for the given drag and swipe allowance.

Public methods
int	getDragDirs(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) Returns the drag directions for the provided ViewHolder.
int	getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) Should return a composite flag which defines the enabled move directions in each state (idle, swiping, dragging).
int	getSwipeDirs(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) Returns the swipe directions for the provided ViewHolder.
void	setDefaultDragDirs(int defaultDragDirs) Updates the default drag directions.
void	setDefaultSwipeDirs(int defaultSwipeDirs) Updates the default swipe directions.

Inherited methods
From class android.support.v7.widget.helper.ItemTouchHelper.Callback boolean canDropOver(RecyclerView recyclerView, RecyclerView.ViewHolder current, RecyclerView.ViewHolder target) Return true if the current ViewHolder can be dropped over the the target ViewHolder. RecyclerView.ViewHolder chooseDropTarget(RecyclerView.ViewHolder selected, List<RecyclerView.ViewHolder> dropTargets, int curX, int curY) Called by ItemTouchHelper to select a drop target from the list of ViewHolders that are under the dragged View. void clearView(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) Called by the ItemTouchHelper when the user interaction with an element is over and it also completed its animation. int convertToAbsoluteDirection(int flags, int layoutDirection) Converts a given set of flags to absolution direction which means START and END are replaced with LEFT and RIGHT depending on the layout direction. static int convertToRelativeDirection(int flags, int layoutDirection) Replaces a movement direction with its relative version by taking layout direction into account. long getAnimationDuration(RecyclerView recyclerView, int animationType, float animateDx, float animateDy) Called by the ItemTouchHelper when user action finished on a ViewHolder and now the View will be animated to its final position. int getBoundingBoxMargin() When finding views under a dragged view, by default, ItemTouchHelper searches for views that overlap with the dragged View. static ItemTouchUIUtil getDefaultUIUtil() Returns the ItemTouchUIUtil that is used by the ItemTouchHelper.Callback class for visual changes on Views in response to user interactions. float getMoveThreshold(RecyclerView.ViewHolder viewHolder) Returns the fraction that the user should move the View to be considered as it is dragged. abstract int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) Should return a composite flag which defines the enabled move directions in each state (idle, swiping, dragging). float getSwipeEscapeVelocity(float defaultValue) Defines the minimum velocity which will be considered as a swipe action by the user. float getSwipeThreshold(RecyclerView.ViewHolder viewHolder) Returns the fraction that the user should move the View to be considered as swiped. float getSwipeVelocityThreshold(float defaultValue) Defines the maximum velocity ItemTouchHelper will ever calculate for pointer movements. int interpolateOutOfBoundsScroll(RecyclerView recyclerView, int viewSize, int viewSizeOutOfBounds, int totalSize, long msSinceStartScroll) Called by the ItemTouchHelper when user is dragging a view out of bounds. boolean isItemViewSwipeEnabled() Returns whether ItemTouchHelper should start a swipe operation if a pointer is swiped over the View. boolean isLongPressDragEnabled() Returns whether ItemTouchHelper should start a drag and drop operation if an item is long pressed. static int makeFlag(int actionState, int directions) Shifts the given direction flags to the offset of the given action state. static int makeMovementFlags(int dragFlags, int swipeFlags) Convenience method to create movement flags. void onChildDraw(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) Called by ItemTouchHelper on RecyclerView's onDraw callback. void onChildDrawOver(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) Called by ItemTouchHelper on RecyclerView's onDraw callback. abstract boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) Called when ItemTouchHelper wants to move the dragged item from its old position to the new position. void onMoved(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, int fromPos, RecyclerView.ViewHolder target, int toPos, int x, int y) Called when onMove(RecyclerView, ViewHolder, ViewHolder) returns true. void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) Called when the ViewHolder swiped or dragged by the ItemTouchHelper is changed. abstract void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) Called when a ViewHolder is swiped by the user.
From class java.lang.Object Object clone() boolean equals(Object arg0) void finalize() final Class<?> getClass() int hashCode() final void notify() final void notifyAll() String toString() final void wait(long arg0, int arg1) final void wait(long arg0) final void wait()

Public constructors

ItemTouchHelper.SimpleCallback

added in version 24.1.0

ItemTouchHelper.SimpleCallback (int dragDirs, 
                int swipeDirs)

Creates a Callback for the given drag and swipe allowance. These values serve as defaults and if you want to customize behavior per ViewHolder, you can override getSwipeDirs(RecyclerView, ViewHolder) and / or getDragDirs(RecyclerView, ViewHolder).

Parameters
dragDirs	int: Binary OR of direction flags in which the Views can be dragged. Must be composed of LEFT, RIGHT, START, END, UP and DOWN.
swipeDirs	int: Binary OR of direction flags in which the Views can be swiped. Must be composed of LEFT, RIGHT, START, END, UP and DOWN.

Public methods

getDragDirs

added in version 24.1.0

int getDragDirs (RecyclerView recyclerView, 
                RecyclerView.ViewHolder viewHolder)

Returns the drag directions for the provided ViewHolder. Default implementation returns the drag directions that was set via constructor or setDefaultDragDirs(int).

Parameters
recyclerView	RecyclerView: The RecyclerView to which the ItemTouchHelper is attached to.
viewHolder	RecyclerView.ViewHolder: The ViewHolder for which the swipe direction is queried.

Returns
int	A binary OR of direction flags.

getMovementFlags

added in version 24.1.0

int getMovementFlags (RecyclerView recyclerView, 
                RecyclerView.ViewHolder viewHolder)

Should return a composite flag which defines the enabled move directions in each state (idle, swiping, dragging).

Instead of composing this flag manually, you can use makeMovementFlags(int, int) or makeFlag(int, int).

This flag is composed of 3 sets of 8 bits, where first 8 bits are for IDLE state, next 8 bits are for SWIPE state and third 8 bits are for DRAG state. Each 8 bit sections can be constructed by simply OR'ing direction flags defined in ItemTouchHelper.

For example, if you want it to allow swiping LEFT and RIGHT but only allow starting to swipe by swiping RIGHT, you can return:

      makeFlag(ACTION_STATE_IDLE, RIGHT) | makeFlag(ACTION_STATE_SWIPE, LEFT | RIGHT);
 

This means, allow right movement while IDLE and allow right and left movement while swiping.

Parameters
recyclerView	RecyclerView: The RecyclerView to which ItemTouchHelper is attached.
viewHolder	RecyclerView.ViewHolder: The ViewHolder for which the movement information is necessary.

Returns
int	flags specifying which movements are allowed on this ViewHolder.

getSwipeDirs

added in version 24.1.0

int getSwipeDirs (RecyclerView recyclerView, 
                RecyclerView.ViewHolder viewHolder)

Returns the swipe directions for the provided ViewHolder. Default implementation returns the swipe directions that was set via constructor or setDefaultSwipeDirs(int).

Parameters
recyclerView	RecyclerView: The RecyclerView to which the ItemTouchHelper is attached to.
viewHolder	RecyclerView.ViewHolder: The ViewHolder for which the swipe direction is queried.

Returns
int	A binary OR of direction flags.

setDefaultDragDirs

added in version 24.1.0

void setDefaultDragDirs (int defaultDragDirs)

Updates the default drag directions. For example, you can use this method to toggle certain directions depending on your use case.

Parameters
defaultDragDirs	int: Binary OR of directions in which the ViewHolders can be dragged.

setDefaultSwipeDirs

added in version 24.1.0

void setDefaultSwipeDirs (int defaultSwipeDirs)

Updates the default swipe directions. For example, you can use this method to toggle certain directions depending on your use case.

Parameters
defaultSwipeDirs	int: Binary OR of directions in which the ViewHolders can be swiped.

• Interfaces

  • ItemTouchHelper.ViewDropHandler
  • ItemTouchUIUtil

• Classes

  • ItemTouchHelper
  • ItemTouchHelper.Callback
  • ItemTouchHelper.SimpleCallback