RecyclerView Content Not Displayed When No Break Strategy

Question

RecyclerView Content Not Displayed When No Break Strategy

I have RecyclerViewone that I use to display 2 column layouts with some elements in the form of sections, using the full width. This is how I set up my own RecyclerView:

StaggeredGridLayoutManager layoutManager = new StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.VERTICAL);
layoutManager.setGapStrategy(StaggeredGridLayoutManager.GAP_HANDLING_MOVE_ITEMS_BETWEEN_SPANS);
recyclerView.setItemAnimator(null);
recyclerView.setLayoutManager(layoutManager);
recyclerView.addItemDecoration(new SpacesItemDecoration(Utils.dpToPx(8)));

Here is my class SpaceItemDecoration:

private class SpacesItemDecoration extends RecyclerView.ItemDecoration {
        private int space;

        public SpacesItemDecoration(int space) {
            this.space = space;
        }

        @Override
        public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
            int position = parent.getChildAdapterPosition(view);
            int viewType = adapter.getItemViewType(position);
            if (viewType == 1) {
                //this is the regular view type
                if (map.get(position)) {
                    //it is on the left side
                    outRect.right = space / 2;
                    outRect.left = Utils.dpToPx(12);
                    outRect.top = space / 2;
                    outRect.bottom = space / 2;
                } else {
                    //it is on the right side
                    outRect.right = Utils.dpToPx(12);
                    outRect.left = space / 2;
                    outRect.top = space / 2;
                    outRect.bottom = space / 2;
                }
            } else {
                outRect.left = 0;
                outRect.right = 0;
                outRect.top = 0;
                outRect.bottom = 0;
            }
        }
}

Basically, I check if the element is a type header / heading or is it a regular element that should appear in 2 columns. In addition, I need to know whether a regular item will be displayed on the left or right side.

Here is my method for calculating whether an element will be displayed on the left or right side:

private void prepareMapping(int start, int end) {
        LogUtil.i(TAG, "prepareMapping called");

//        LogUtil.i(TAG, "mapping from " + start + " to " + end);
        int lastHeaderPosition = -1;
        FeedItems currentItem;
        for (int i=start; i<end-1; i++) {
            currentItem = list.get(i);
            if (currentItem.getType() == 0) {
                //it is header
                lastHeaderPosition = i;
            } else if ((currentItem.getType() == 1) && ((i - lastHeaderPosition) % 2 == 0)) {
                //it is right side, put false into map
//                LogUtil.i(TAG, i + " is on right");
                map.put(i, false);
            } else if ((currentItem.getType() == 1) && ((i - lastHeaderPosition) % 2 != 0)) {
                //it is left side, put true into map
//                LogUtil.i(TAG, i + " is on right");
                map.put(i, true);
            }
        }
    }