Firebase RecyclerView+ViewHolder. How save state ativity

Question

everyone. Hello. I’ve created android application. I am retrieving data from real-time database and also using recycle view + view holder. But when I go to another activity and then go back - my list oh view holder items was reset. How I can save state view holder and restore them? I looked at various topics on the site, but not one answer did not help me. My Pojo Class

public class Post {
private String  post_id;
private String  post_title;
private long  post_date;
private long  post_desc;
public Post(String post_id, String post_title, long post_date,  String post_desc) {
    this.post_id = post_id;
    this.post_title = post_title;
    this.comments_count = comments_count;
    this.post_date = post_date;
    this.post_desc = post_desc;
}     
public void setPost_id(String post_id) {
    this.post_id = post_id;
}
public String getPost_title() {
    return post_title;
}

public void setPost_title(String post_title) {
    this.post_title = post_title;
}

public String getPost_date() {
    String month = new java.text.SimpleDateFormat("MM").
            format(new java.util.Date(post_date * 1000));
    int monthnumber = Integer.parseInt(month);

    String value = new java.text.SimpleDateFormat("dd ").
            format(new java.util.Date(post_date * 1000));
    value +=MonthName[monthnumber-1];
    value+= new java.text.SimpleDateFormat(" HH:mm").
            format(new java.util.Date(post_date * 1000));
    return value;
}

public void setPost_date(long post_date) {
    this.post_date = post_date;
}

public String getPost_desc() {
    return post_desc;
}

public void setPost_desc(String post_desc) {
    this.post_desc = post_desc;
}}

ViewHolderClass

public static class PostViewHolder extends  RecyclerView.ViewHolder {
    public PostViewHolder(View itemView) {
        super(itemView); }
   public void setTitle(String title) {
        titleViewPost.setText(title);
    }
    public void setDate(String date) {
        dateViewPost.setText(date);
    }
    public void setDesc(String desc) {
        descViewPost.setText(desc);
    }}}

FirebaseRecyleAdapter

firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<Post, PostViewHolder >(
                Post.class,
                R.layout.post_row,
                PostViewHolder.class,
                mDatabase
        ) {@Override    
            protected void populateViewHolder(final PostViewHolder viewHolder,      
Post model, final int position) {     
  viewHolder.mCommentButton.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        Intent commentActivity  = new Intent(MainActivity.this, CommentActivity.class);
                        commentActivity.putExtra("post_id", post_key);
                        if(mUserId != null) {
                            commentActivity.putExtra("user_id", mUserId);
                        }
                        startActivity(commentActivity);
                    }
                });

As I understand, the whole problem is that my adapter is reused and I can not return to that position in the tape - where I was before.

Its my app.https://play.google.com/store/apps/details?id=dev.arounda.chesnock I want fix thiw trouble for this application

@Linxy, no. Im seeting my adapter on onCreate(). I tried to save both the adapter and the LinearLayoutManager in the object of the Parcelable class, and restore it to the onResume() - but it did not work out( — Alexey Karlov, Mar 21 '18 at 20:44
Does the adapter reset to the top, or is completely recreated? Is just scrolling to the previous position what you need or the problem is the adapter goes away? — cutiko, Mar 21 '18 at 20:53
@cutiko reset to the top. Any attempts to scroll or display the element that was before the previous activity, nothing gives. — Alexey Karlov, Mar 21 '18 at 20:56
@Linxy current activity -> new activity(finish())->previous activity. I hope you understand what I mean — Alexey Karlov, Mar 21 '18 at 21:00
[This](https://stackoverflow.com/questions/49383687/how-can-i-retrieve-data-from-firebase-to-my-adapter/49384849) is how you can display data from Firebase Realtime database in a RecyclerView using a FirebaseRecyclerAdapter. — Alex Mamo, Mar 22 '18 at 11:36

score 0 · Accepted Answer · answered Mar 26 '18 at 20:14

0

Try to call firebaseRecyclerAdapter.startListening(); in onCreate() instead of onStart and firebaseRecyclerAdapter.stopListening(); in onDestroy() instead of onStop()

answered Mar 26 '18 at 20:14

Karim Karimov

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14

whats is this method? i got cannot resolve method startListening() – Alexey Karlov Mar 26 '18 at 21:02
Which version of FirebaseRecyclerAdapter are you using? Is it a recent one? – Karim Karimov Mar 26 '18 at 21:13
If I understood you correctly, then that's what I'm using compile 'com.google.firebase:firebase-database:10.2.4' compile 'com.google.firebase:firebase-storage:10.2.4' implementation 'com.google.firebase:firebase-core:10.2.4' compile 'com.firebaseui:firebase-ui-database:1.2.0' – Alexey Karlov Mar 26 '18 at 21:15
I recommend you to switch FirebaseUI v3.2.2 – Karim Karimov Mar 26 '18 at 21:43
Thank, I will try – Alexey Karlov Mar 26 '18 at 21:56

Firebase RecyclerView+ViewHolder. How save state ativity

1 Answers1