Auto select position of RecyclerView and highlight it

Question

Currently I have a "Playlist" of videos who I can change to the next position (video player).

The RecyclerView has this full ArrayList and scroll to the next position like this:

mLinearLayoutManager.scrollToPositionWithOffset(position, 10);

Perfect! Now, I want to AUTO SELECT (I don't want clicks here...) the current position and highlight it.

The final product should look like this:

and every time I hit next on the media player, next item (position) will scroll and highlight the background.

How do I pass the position to the Adapter to know the position to highlight/change background? Remember... there is not clicks involves in this task and the item needs to keep highlighted the whole time, only changes when the next video/item/position is selected.

---

Solved

Few changes on the Adapter to make it work

private int highlightItem = 0;

public void toggleSelection(int pos) {
   this.highlightItem = pos;
}

toggleSelection(position) will be used from my Activity where I storage the current position all the time.

After that, the final change in my Adapter was:

if (position == highlightItem) {
     holder.mMainView.setSelected(true);
} else {
     holder.mMainView.setSelected(false);
}

Answer 1

You need to change your adapter a bit. Write a toggleSelection function in your adapter and pass the position to the function. Keep the track of the position of the items in your playlist in a global array. So that, when a song is played you know its position in the RecyclerView.

I'm adding an example of an adapter. You can have your toggleSelection function customized.

public class ToggleSelectionListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

        private Cursor mCursor;
        private SparseBooleanArray selectedItems;

        public ToggleSelectionListAdapter(Cursor cursor) {
            mCursor = cursor;
            selectedItems = new SparseBooleanArray();
        }

        public void toggleSelection(int pos) {
            if (selectedItems.get(pos, false)) {
                selectedItems.delete(pos);
            } else {
                selectedItems.put(pos, true);
            }
            notifyItemChanged(pos);
        }

        public int getSelectedItemCount() {
            return selectedItems.size();
        }

        public void clearSelections() {
            selectedItems.clear();
            notifyDataSetChanged();
        }

        public class ViewHolder extends RecyclerView.ViewHolder {

            public ViewHolder(final View itemView) {
                super(itemView);

                // Initialize your items of each row here
            }

            public void bindView(int pos) {
                try {
                    if (mCursor.isClosed())
                        return;

                    mCursor.moveToPosition(pos);

                    // Maintain a checked item list so that you can have a track if the item is clicked or not
                    if (checkedItems.contains(number) itemView.setBackgroundResource(R.drawable.background_selected);
                    else itemView.setBackgroundResource(R.drawable.background_normal);

                    itemView.setOnClickListener(new View.OnClickListener() {
                        @Override
                        public void onClick(View v) {
                                    if (checkedItems.contains(number)) {
                                        checkedItems.remove(number);
                                    } else {
                                        checkedItems.add(number);
                                    }

                                // Get the index of which item should toggle the background
                                int idx = mRecyclerView.getChildAdapterPosition(v);
                                toggleSelection(idx);
                            }
                        }
                    });
            }
        }


        @Override
        public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

            View v;

            v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_row, parent, false);

            ViewHolder vh = new ViewHolder(v);

            return vh;
        }

        @Override
        public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {

            if (holder instanceof ViewHolder) {
                ViewHolder vh = (ViewHolder) holder;

                vh.bindView(position);

            }
        }

        @Override
        public int getItemCount() {

            if (mCursor == null) {
                return 0;
            }

            int n = mCursor.getCount();
            return n;
        }

        @Override
        public int getItemViewType(int position) {
            return super.getItemViewType(position);
        }

        synchronized public void swapCursor(Cursor cursor) {
            mCursor = cursor;
            notifyDataSetChanged();
        }
    }