@Override
    public void onShowPress(MotionEvent ev) {
        // do nothing
    }
Checks for the touch of an item's drag handle (specified by
{@link #setDragHandleId(int)}), and returns that item's position
if a drag handle touch was detected.

@param ev The ACTION_DOWN MotionEvent.
@return The list position of the item whose drag handle was
touched; MISS if unsuccessful.
third_party/DragSortListView/src/com/mobeta/android/dslv/DragSortController.java