使用SpannedGridLayoutManager的ItemTouchHelper-RecyclerView问题

Question

I am facing an issue with ItemTouchHelper in combination with SpannedGridLayoutManager in my RecyclerView, drag is ended prematurely when dragging to the item next to the dragged one. I know it is glitchy layout manager, because it works with other layout managers without any issues.

Did somebody worked this out already?

Answer 1

The onSelectedChanged(RecyclerView.ViewHolder, int) callback provides information about the current actionState: - ACTION_STATE_IDLE: - ACTION_STATE_DRAG - ACTION_STATE_SWIPE

So you could keep track whether the order changed, and when the state changes to ACTION_STATE_IDLE, you can do what you need to do!

Implement a callback class like this.

class CardsTouchHelperCallback extends ItemTouchHelper.Callback {

...
@Override
    public boolean onMove(RecyclerView recyclerView, 
RecyclerView.ViewHolder viewHolder,
                      RecyclerView.ViewHolder target) {

    int fromPosition = viewHolder.getAdapterPosition();
    int toPosition = target.getAdapterPosition();

    dragFrom =  fromPosition;
    dragTo = toPosition;

    mOrderChanged = true;

    return false;
}

@Override
public void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) {
    super.onSelectedChanged(viewHolder, actionState);

    if (actionState == ItemTouchHelper.ACTION_STATE_IDLE && mOrderChanged) {
        //doSomething();
        touchHelperAdapter.onItemMove(dragFrom, dragTo);
        mOrderChanged = false;
    }
 }
}