Most visited

Recently visited

Results for

ItemTouchHelper

public class ItemTouchHelper
extends RecyclerView.ItemDecoration implements RecyclerView.OnChildAttachStateChangeListener

java.lang.Object
↳	android.support.v7.widget.RecyclerView.ItemDecoration
	↳	android.support.v7.widget.helper.ItemTouchHelper

This is a utility class to add swipe to dismiss and drag & drop support to RecyclerView.

It works with a RecyclerView and a Callback class, which configures what type of interactions are enabled and also receives events when user performs these actions.

Depending on which functionality you support, you should override onMove(RecyclerView, ViewHolder, ViewHolder) and / or onSwiped(ViewHolder, int).

This class is designed to work with any LayoutManager but for certain situations, it can be optimized for your custom LayoutManager by extending methods in the ItemTouchHelper.Callback class or implementing ItemTouchHelper.ViewDropHandler interface in your LayoutManager.

By default, ItemTouchHelper moves the items' translateX/Y properties to reposition them. On platforms older than Honeycomb, ItemTouchHelper uses canvas translations and View's visibility property to move items in response to touch events. You can customize these behaviors by overriding onChildDraw(Canvas, RecyclerView, ViewHolder, float, float, int, boolean) or onChildDrawOver(Canvas, RecyclerView, ViewHolder, float, float, int, boolean).

Most of the time, you only need to override onChildDraw but due to limitations of platform prior to Honeycomb, you may need to implement onChildDrawOver as well.

Summary

Nested classes
`class`	`ItemTouchHelper.Callback` This class is the contract between ItemTouchHelper and your application.
`class`	`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.
`interface`	`ItemTouchHelper.ViewDropHandler` An interface which can be implemented by LayoutManager for better integration with `ItemTouchHelper`.

Constants
`int`	`ACTION_STATE_DRAG` A View is currently being dragged.
`int`	`ACTION_STATE_IDLE` ItemTouchHelper is in idle state.
`int`	`ACTION_STATE_SWIPE` A View is currently being swiped.
`int`	`ANIMATION_TYPE_DRAG` Animation type for views that were dragged and now will animate to their final position.
`int`	`ANIMATION_TYPE_SWIPE_CANCEL` Animation type for views which are not completely swiped thus will animate back to their original position.
`int`	`ANIMATION_TYPE_SWIPE_SUCCESS` Animation type for views which are swiped successfully.
`int`	`DOWN` Down direction, used for swipe & drag control.
`int`	`END` Horizontal end direction.
`int`	`LEFT` Left direction, used for swipe & drag control.
`int`	`RIGHT` Right direction, used for swipe & drag control.
`int`	`START` Horizontal start direction.
`int`	`UP` Up direction, used for swipe & drag control.

Public constructors
`ItemTouchHelper(ItemTouchHelper.Callback callback)` Creates an ItemTouchHelper that will work with the given Callback.

Public methods
`void`	`attachToRecyclerView(RecyclerView recyclerView)` Attaches the ItemTouchHelper to the provided RecyclerView.
`void`	`getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state)` Retrieve any offsets for the given item.
`void`	`onChildViewAttachedToWindow(View view)` Called when a view is attached to the RecyclerView.
`void`	`onChildViewDetachedFromWindow(View view)` Called when a view is detached from RecyclerView.
`void`	`onDraw(Canvas c, RecyclerView parent, RecyclerView.State state)` Draw any appropriate decorations into the Canvas supplied to the RecyclerView.
`void`	`onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state)` Draw any appropriate decorations into the Canvas supplied to the RecyclerView.
`void`	`startDrag(RecyclerView.ViewHolder viewHolder)` Starts dragging the provided ViewHolder.
`void`	`startSwipe(RecyclerView.ViewHolder viewHolder)` Starts swiping the provided ViewHolder.

Inherited methods

From class


  
    android.support.v7.widget.RecyclerView.ItemDecoration

From class


  
    java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long millis, int nanos)` Causes the current thread to wait until another thread invokes the `notify()` method or the `notifyAll()` method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed.
`final void`	`wait(long millis)` Causes the current thread to wait until either another thread invokes the `notify()` method or the `notifyAll()` method for this object, or a specified amount of time has elapsed.
`final void`	`wait()` Causes the current thread to wait until another thread invokes the `notify()` method or the `notifyAll()` method for this object.

From interface


  
    android.support.v7.widget.RecyclerView.OnChildAttachStateChangeListener

Constants

ACTION_STATE_DRAG

int ACTION_STATE_DRAG

A View is currently being dragged.

Constant Value: 2 (0x00000002)

ACTION_STATE_IDLE

int ACTION_STATE_IDLE

ItemTouchHelper is in idle state. At this state, either there is no related motion event by the user or latest motion events have not yet triggered a swipe or drag.

Constant Value: 0 (0x00000000)

ACTION_STATE_SWIPE

int ACTION_STATE_SWIPE

A View is currently being swiped.

Constant Value: 1 (0x00000001)

ANIMATION_TYPE_DRAG

int ANIMATION_TYPE_DRAG

Animation type for views that were dragged and now will animate to their final position.

Constant Value: 8 (0x00000008)

ANIMATION_TYPE_SWIPE_CANCEL

int ANIMATION_TYPE_SWIPE_CANCEL

Animation type for views which are not completely swiped thus will animate back to their original position.

Constant Value: 4 (0x00000004)

ANIMATION_TYPE_SWIPE_SUCCESS

int ANIMATION_TYPE_SWIPE_SUCCESS

Animation type for views which are swiped successfully.

Constant Value: 2 (0x00000002)

DOWN

int DOWN

Down direction, used for swipe & drag control.

Constant Value: 2 (0x00000002)

END

int END

Horizontal end direction. Resolved to LEFT or RIGHT depending on RecyclerView's layout direction. Used for swipe & drag control.

Constant Value: 32 (0x00000020)

LEFT

int LEFT

Left direction, used for swipe & drag control.

Constant Value: 4 (0x00000004)

RIGHT

int RIGHT

Right direction, used for swipe & drag control.

Constant Value: 8 (0x00000008)

START

int START

Horizontal start direction. Resolved to LEFT or RIGHT depending on RecyclerView's layout direction. Used for swipe & drag control.

Constant Value: 16 (0x00000010)

UP

int UP

Up direction, used for swipe & drag control.

Constant Value: 1 (0x00000001)

Public constructors

ItemTouchHelper

ItemTouchHelper (ItemTouchHelper.Callback callback)

Creates an ItemTouchHelper that will work with the given Callback.

You can attach ItemTouchHelper to a RecyclerView via attachToRecyclerView(RecyclerView). Upon attaching, it will add an item decoration, an onItemTouchListener and a Child attach / detach listener to the RecyclerView.

Parameters
`callback`	`ItemTouchHelper.Callback`: The Callback which controls the behavior of this touch helper.

Public methods

attachToRecyclerView

void attachToRecyclerView (RecyclerView recyclerView)

Attaches the ItemTouchHelper to the provided RecyclerView. If TouchHelper is already attached to a RecyclerView, it will first detach from the previous one. You can call this method with null to detach it from the current RecyclerView.

Parameters
`recyclerView`	`RecyclerView`: The RecyclerView instance to which you want to add this helper or `null` if you want to remove ItemTouchHelper from the current RecyclerView.

getItemOffsets

void getItemOffsets (Rect outRect, 
                View view, 
                RecyclerView parent, 
                RecyclerView.State state)

Retrieve any offsets for the given item. Each field of outRect specifies the number of pixels that the item view should be inset by, similar to padding or margin. The default implementation sets the bounds of outRect to 0 and returns.

If this ItemDecoration does not affect the positioning of item views, it should set all four fields of outRect (left, top, right, bottom) to zero before returning.

If you need to access Adapter for additional data, you can call getChildAdapterPosition(View) to get the adapter position of the View.

Parameters
`outRect`	`Rect`: Rect to receive the output.
`view`	`View`: The child view to decorate
`parent`	`RecyclerView`: RecyclerView this ItemDecoration is decorating
`state`	`RecyclerView.State`: The current state of RecyclerView.

onChildViewAttachedToWindow

void onChildViewAttachedToWindow (View view)

Called when a view is attached to the RecyclerView.

Parameters
`view`	`View`: The View which is attached to the RecyclerView

onChildViewDetachedFromWindow

void onChildViewDetachedFromWindow (View view)

Called when a view is detached from RecyclerView.

Parameters
`view`	`View`: The View which is being detached from the RecyclerView

onDraw

void onDraw (Canvas c, 
                RecyclerView parent, 
                RecyclerView.State state)

Draw any appropriate decorations into the Canvas supplied to the RecyclerView. Any content drawn by this method will be drawn before the item views are drawn, and will thus appear underneath the views.

Parameters
`c`	`Canvas`: Canvas to draw into
`parent`	`RecyclerView`: RecyclerView this ItemDecoration is drawing into
`state`	`RecyclerView.State`: The current state of RecyclerView

onDrawOver

void onDrawOver (Canvas c, 
                RecyclerView parent, 
                RecyclerView.State state)

Draw any appropriate decorations into the Canvas supplied to the RecyclerView. Any content drawn by this method will be drawn after the item views are drawn and will thus appear over the views.

Parameters
`c`	`Canvas`: Canvas to draw into
`parent`	`RecyclerView`: RecyclerView this ItemDecoration is drawing into
`state`	`RecyclerView.State`: The current state of RecyclerView.

startDrag

void startDrag (RecyclerView.ViewHolder viewHolder)

Starts dragging the provided ViewHolder. By default, ItemTouchHelper starts a drag when a View is long pressed. You can disable that behavior by overriding isLongPressDragEnabled().

For this method to work:

The provided ViewHolder must be a child of the RecyclerView to which this ItemTouchHelper is attached.
ItemTouchHelper.Callback must have dragging enabled.
There must be a previous touch event that was reported to the ItemTouchHelper through RecyclerView's ItemTouchListener mechanism. As long as no other ItemTouchListener grabs previous events, this should work as expected.

For example, if you would like to let your user to be able to drag an Item by touching one of its descendants, you may implement it as follows:

     viewHolder.dragButton.setOnTouchListener(new View.OnTouchListener() {
         public boolean onTouch(View v, MotionEvent event) {
             if (MotionEventCompat.getActionMasked(event) == MotionEvent.ACTION_DOWN) {
                 mItemTouchHelper.startDrag(viewHolder);
             }
             return false;
         }
     });

Parameters
`viewHolder`	`RecyclerView.ViewHolder`: The ViewHolder to start dragging. It must be a direct child of RecyclerView.

See also:

isItemViewSwipeEnabled()

startSwipe

void startSwipe (RecyclerView.ViewHolder viewHolder)

Starts swiping the provided ViewHolder. By default, ItemTouchHelper starts swiping a View when user swipes their finger (or mouse pointer) over the View. You can disable this behavior by overriding ItemTouchHelper.Callback

For this method to work:

The provided ViewHolder must be a child of the RecyclerView to which this ItemTouchHelper is attached.
ItemTouchHelper.Callback must have swiping enabled.
There must be a previous touch event that was reported to the ItemTouchHelper through RecyclerView's ItemTouchListener mechanism. As long as no other ItemTouchListener grabs previous events, this should work as expected.

For example, if you would like to let your user to be able to swipe an Item by touching one of its descendants, you may implement it as follows:

     viewHolder.dragButton.setOnTouchListener(new View.OnTouchListener() {
         public boolean onTouch(View v, MotionEvent event) {
             if (MotionEventCompat.getActionMasked(event) == MotionEvent.ACTION_DOWN) {
                 mItemTouchHelper.startSwipe(viewHolder);
             }
             return false;
         }
     });

Parameters
`viewHolder`	`RecyclerView.ViewHolder`: The ViewHolder to start swiping. It must be a direct child of RecyclerView.

Most visited

Recently visited

Results for

ItemTouchHelper

Summary

Nested classes

Constants

Public constructors

Public methods

Inherited methods

Constants

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

Public constructors

ItemTouchHelper

Public methods

attachToRecyclerView

getItemOffsets

onChildViewAttachedToWindow

onChildViewDetachedFromWindow

onDraw

onDrawOver

startDrag

startSwipe