android - recycleView item on drop is not getting sorted properly with sqlite

Question

I have implemented a recycle view On drag & drop the sorting item in the recycle view. But sorting is not accurate, sorting not working properly. I tried write below code

Answer 1

I guess the problem is that the order value of ExerciseDetails has never been updated in addition to some confusion in changing orders. However, I have changed your code a bit to fix these issues.

As both updateOrder and updateSortID exactly execute the same query, so I use only updateOrder and it seems that orderNewValue should be long (not String).

public void updateOrder(Long orderNewValue, Long rowId) {
    String query = "Update " + DBHelper.TABLE_EXERCISE_DETAILS + " Set " + DBHelper.COLUMN_ORDER_ID + " = " + orderNewValue +  " Where " + DBHelper.COLUMN_EX_DETAILS_ID + " = " + rowId;
    mDatabase.execSQL(query);
}

and onDrop becomes like following:

@Override
void onDrop(int from, int to) {
    // retain order of `to` item before changing orders:
    long orderTo = items.get(to).getOrder();

    // swap order values for `to` item and other middle items (except `from` item):
    if (from < to) {
        for (int i = to; i > from; i--) {
            ExerciseDetails item = items.get(i);
            long newOrder = items.get(i - 1).getOrder();
            item.setOrder(newOrder);
            exercisesDAO.updateOrder(newOrder, item.getExDetailsId());
        }
    } else {
        for (int i = to; i < from; i++) {
            ExerciseDetails item = items.get(i);
            long newOrder = items.get(i + 1).getOrder();
            item.setOrder(newOrder);
            exercisesDAO.updateOrder(newOrder, item.getExDetailsId());
        }
    }

    // set order for `from` item after swaping orders:
    ExerciseDetails itemFrom = items.get(from);
    itemFrom.setOrder(orderTo);
    exercisesDAO.updateOrder(orderTo, itemFrom.getExDetailsId());
}

After all, note that you should never do an I/O job in the main thread. So, consider to run updateOrder in another thread somehow based on your app structure.

Answer 2

@Overid
private void onDrop(int from, int to) {   // this listener only calls when item Droped after drag
    ExerciseDetails moveItem = items.remove(from);
    items.add(moveItem, to)
    int minPosition = from > to ? to : from;
    int maxPosition = from > to ? from : to;
    // now the item index is the sort index of ExerciseDetails
    for (int i = minPosition; i <= maxPosition; i++) {
        ExerciseDetails item = items.get(i);
        item.setOrder(i);
        exercisesDAO.updateOrder(i, item.getExDetailsId());
    }
    // notify recyclerview to refresh the position of item dragged
    adapter.notifyItemMoved(from, to)
}