android - RecyclerView adapter taking wrong values

Question

I have a RecyclerView which shows two kinds of Views one represents an User publication and another that represents an Event publication. Both have elements in common, for example a TextView that shows a time stamp. So I created a PublicationViewHolder that takes this TextView time stamp into a variable and load it. My issue is that the adapter, initially, load the right values, but when I scroll down, and scroll up again, the values in the positions are changed by values from another positions. Here is the code:

public class PublicationViewHolder extends RecyclerView.ViewHolder {

    private TextView vTimeStamp;

    public PublicationViewHolder(View itemView) {
        super(itemView);
        this.vTimeStamp = (TextView) itemView.findViewById(R.id.txt_view_publication_timestamp);
    }

    public void load(Publication publication, int i) {
        load(publication);
        try {
            if (Publication.TYPE_USER_PUBLICATION == publication.getType()) {
                load((UserPublication) publication);
            } else if (Publication.TYPE_EVENT_PUBLICATION == publication.getType()) {
                load((EventPublication) publication);
            }
        } catch (ClassCastException e) {
            throw new RuntimeException("Publication type cast fail. See PublicationViewHolder.");
        }
    }

    public void load(Publication publication) {
        vTimeStamp.setText(DateFormatter.getTimeAgo(publication.getTimeStamp()));
    }

    public void load( UserPublication publication) {
        //This method is override by UserPublicationViewHolder
    };

    public void load( EventPublication publication) {
        //This method is override by EventPublicationViewHolder
    };

}

Now I will make my UserPublicationViewHolder for users publications only.

public class UserPublicationViewHolder extends PublicationViewHolder {
    private  ImageView vImageView, vLikeButton, vDislikeButton, vFavButton, vEditPost, vDeletePost;
    private  TextView vText, vUsername, vLikeCount, vDislikeCount, vFavCount;
    private  PostImagesLayout vImagesContainer;
    private TagCloudLocationFriends tagsView;

    public UserPublicationViewHolder(View itemView) {
        super(itemView);
        vImageView = (ImageView) itemView.findViewById(R.id.img_view_publication_user);
        vText = (TextView) itemView.findViewById(R.id.txt_view_publication_text);

        vLikeCount = (TextView) itemView.findViewById(R.id.txt_view_like_count);
        vFavCount = (TextView) itemView.findViewById(R.id.txt_view_fav_count);
        vDislikeCount = (TextView) itemView.findViewById(R.id.txt_view_dislike_count);

        vUsername = (TextView) itemView.findViewById(R.id.txt_view_publication_user_name);
        vLikeButton = (ImageView) itemView.findViewById(R.id.img_view_like);
        vDislikeButton  = (ImageView) itemView.findViewById(R.id.img_view_dislike);
        vFavButton  = (ImageView) itemView.findViewById(R.id.img_view_fav);
        vImagesContainer = (PostImagesLayout) itemView.findViewById(R.id.container_post_images);

        tagsView = (TagCloudLocationFriends) itemView.findViewById(R.id.location_friends_tag);

        // edit - remove icons
        vDeletePost = (ImageView) itemView.findViewById(R.id.img_view_delete_post);
        vEditPost = (ImageView) itemView.findViewById(R.id.img_view_edit_post);
    }


    @Override
    public void load(UserPublication publication) {
        //Load the UserPublicationViewHolder specific views.
    }
}

Now I will do the same but for the Event publications

public class EventPublicationViewHolder extends PublicationViewHolder {

    private TextView vTextViewTitle;
    private TextView vTextViewText;

    public EventPublicationViewHolder(View itemView) {
        super(itemView);
        vTextViewTitle = (TextView) itemView.findViewById(R.id.txt_view_publication_event_title);
        vTextViewText = (TextView) itemView.findViewById(R.id.txt_view_publication_event_text);
    }

    @Override
    public void load(EventPublication publication) {
        //Load the EventPublicationViewHolder specifics views
    }
}

Now here is my RecyclerView adapter:

public class PublicationAdapter extends RecyclerView.Adapter<PublicationViewHolder> {

    public static final int USER_PUBLICATION_TYPE = 1;
    public static final int EVENT_PUBLICATION_TYPE = 2;
    private List<Publication> publications = new ArrayList<Publication>();

    public List<Publication> getPublications() {
        return publications;
    }

    public void setPublications(List<Publication> publications) {
        this.publications = publications;
    }

    @Override
    public int getItemViewType(int position) {
        if (publications.get(position) instanceof UserPublication) {
            return USER_PUBLICATION_TYPE;
        }
        if (publications.get(position) instanceof EventPublication) {
            return EVENT_PUBLICATION_TYPE;
        }
        throw new RuntimeException("Unknown view type in PublicationAdapter");
    }

    @Override
    public PublicationViewHolder onCreateViewHolder(ViewGroup viewGroup, int type) {
        View v;
        switch (type) {
            case USER_PUBLICATION_TYPE:
                v = LayoutInflater.from(getActivity()).inflate(R.layout.view_holder_user_publication, viewGroup, false);
                return new UserPublicationViewHolder(v);
            case EVENT_PUBLICATION_TYPE:
                v = LayoutInflater.from(getActivity()).inflate(R.layout.view_holder_event_publication, viewGroup, false);
                return new EventPublicationViewHolder(v);
        }
        return null;
    }

    @Override
    public void onBindViewHolder(PublicationViewHolder aPublicationHolder, int i) {
        aPublicationHolder.load(publications.get(i), i);
    }

    @Override
    public long getItemId(int position) {
        //Here I tried returning only position or 0 without luck.
        //The id is unique BTW
        return publications.get(position).getId();
    }

    @Override
    public int getItemCount() {
        return publications.size();
    }

}

I don't know what can be wrong, UserPublication and EventPublication both extends from Publication. I'm not doing some request or reloading the adapter. I only load the adapter once.

Update:

BTW I'm using this RecyclerView inside a Fragment which is loaded in a PageAdapter which is loaded in a ViewPager that is inside a Fragment, maybe is this the issue?

Update: This is the other binding code.

This is the load method of the UserPublicationViewHolder.

    @Override
    public void load(UserPublication publication) {
        PicassoHelper.publicationUser(getActivity(), publication.getUser().getAvatarUrl(),
                vImageView);
        vText.setText(publication.getText());
        vUsername.setText(publication.getUser().getName());
        boolean hasLocation = false;
        if (publication.getImages().length > 0) {
            vImagesContainer.setImages(publication.getImages());
        } else {
            vImagesContainer.setVisibility(View.GONE);
        }
        tagsView.setTags(new ArrayList<MinikastTag>());
        tagsView.drawTags();

        if(publication.getLocation() != null || publication.getTaggedFriends().size() > 0){
            if(publication.getLocation() != null){
                hasLocation = true;
                tagsView.add(new MinikastTag(1,"Post from ",1));
                tagsView.add(new MinikastTag(2, publication.getLocation().getName(), 2));
            }
            if(publication.getTaggedFriends().size() > 0){
                if(hasLocation)
                    tagsView.add(new MinikastTag(3," with ",1));
                else
                    tagsView.add(new MinikastTag(3,"With ",1));

                int i = 0;
                for(User aUser: publication.getTaggedFriends()){
                    MinikastTag aTag;
                    if(i == publication.getTaggedFriends().size() - 1 ) {
                        aTag = new MinikastTag(4, aUser.getName(), 3);
                        aTag.setUserID(aUser.getId());
                        aTag.setUserName(aUser.getName());
                        tagsView.add(aTag);
                    } else {
                        aTag = new MinikastTag(4, aUser.getName() + ", ", 3);
                        aTag.setUserID(aUser.getId());
                        aTag.setUserName(aUser.getName());
                        tagsView.add(aTag);
                    }
                    i = i+1;
                }
            }
        }
        tagsView.drawTags();

        // likes, dislikes, favs
        if(publication.getLikesAmount() > 0)
            vLikeCount.setText(String.valueOf(publication.getLikesAmount()));

        if(publication.getDislikesAmount() > 0)
            vDislikeCount.setText(String.valueOf(publication.getDislikesAmount()));

        if(publication.getLovesAmount() > 0)
            vFavCount.setText(String.valueOf(publication.getLovesAmount()));

        // reset buttons
        vFavButton.setPressed(false);
        vDislikeButton.setPressed(false);
        vLikeButton.setPressed(false);

        if(publication.getRelationship().equals("LOVE"))
            vFavButton.setPressed(true);
        else if (publication.getRelationship().equals("LIKE"))
            vLikeButton.setPressed(true);
        else if (publication.getRelationship().equals("DISLIKE"))
            vDislikeButton.setPressed(true);

        // edit - remove icons

        if(String.valueOf(publication.getUser().getId()).equals(StartupSharedPreferences.getProfileId())){
            vEditPost.setVisibility(View.VISIBLE);
            vDeletePost.setVisibility(View.VISIBLE);
        }else{
            vEditPost.setVisibility(View.INVISIBLE);
            vDeletePost.setVisibility(View.INVISIBLE);
        }
    }
}

And this is the load method of the EventPublicationViewHolder:

@Override
public void load(EventPublication publication) {
    vTimeStamp.setVisibility(View.GONE);
    itemView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            //GoTo.eventDetail(getActivity(), publication);
        }
    });
    vTextViewTitle.setText(publication.getTitle());
    vTextViewText.setText(publication.getText());
}

I commented some code just because I was testing, but as you can see, I only do setTexts and assing some images.

And this is how I set the adapter, LinearLayoutManager, etc. In the onViewCreated method of the fragment.

vRecyclerView = (FixedRecyclerView) view.findViewById(R.id.recycler_view_publications);
        vSwipeRefresh = (SwipeRefreshLayout) view.findViewById(R.id.swipe_container);
        mFeedCallback.onScrollReady(vRecyclerView);
        mLayoutManager = buildLayoutManager();
        vRecyclerView.setLayoutManager(mLayoutManager);
        vRecyclerView.addItemDecoration(new DividerItemDecoration(getActivity(), DividerItemDecoration.VERTICAL_LIST));
        mAdapter = new PublicationAdapter();
        vSwipeRefresh.setOnRefreshListener(this);
        vSwipeRefresh.setColorSchemeResources(R.color._SWIPER_COLOR_1, R.color._SWIPER_COLOR_2,
                R.color._SWIPER_COLOR_3,

Answer 1

This usually happens when you have something like "if (field != null) holder.setField(field)", without an else. The holder is recycled, this means that it will have values there, so you need to clean or replace EVERY value, if it's null you should nullit, if it's not, you should write it, ALWAYS. It's late, but, as an answer for others.