ViewDropHandler

Kotlin |Java

interface ViewDropHandler

androidx.recyclerview.widget.ItemTouchHelper.ViewDropHandler

Known Direct Subclasses

LinearLayoutManager

A RecyclerView.LayoutManager implementation which provides similar functionality to android.widget.ListView.

Known Indirect Subclasses

GridLayoutManager, WearableLinearLayoutManager

GridLayoutManager	A `RecyclerView.LayoutManager` implementations that lays out items in a grid.
WearableLinearLayoutManager	This wear-specific implementation of `LinearLayoutManager` provides basic offsetting logic for updating child layout.

An interface which can be implemented by LayoutManager for better integration with ItemTouchHelper.

Summary

Public methods
abstract Unit	`prepareForDrop(@NonNull view: View, @NonNull target: View, x: Int, y: Int)` Called by the `ItemTouchHelper` after a View is dropped over another View.

Public methods

prepareForDrop

abstract fun prepareForDrop(
    @NonNull view: View, 
    @NonNull target: View, 
    x: Int, 
    y: Int
): Unit

Called by the ItemTouchHelper after a View is dropped over another View.

A LayoutManager should implement this interface to get ready for the upcoming move operation.

For example, LinearLayoutManager sets up a "scrollToPositionWithOffset" calls so that the View under drag will be used as an anchor View while calculating the next layout, making layout stay consistent.

Parameters
`view`	View: The View which is being dragged. It is very likely that user is still dragging this View so there might be other calls to `prepareForDrop()` after this one.
`target`	View: The target view which is being dropped on.
`x`	Int: The `left` offset of the View that is being dragged. This value includes the movement caused by the user.
`y`	Int: The `top` offset of the View that is being dragged. This value includes the movement caused by the user.