ItemTouchHelper

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)

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.

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.

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.

onChildViewAttachedToWindow

void onChildViewAttachedToWindow (View view)

Called when a view is attached to the RecyclerView.

onChildViewDetachedFromWindow

void onChildViewDetachedFromWindow (View view)

Called when a view is detached from 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.

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.

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.

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

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.

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