/*
* Copyright 2016 Google Inc. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.firebase.samples.apps.friendlypix;
import android.content.Context;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.Fragment;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.text.format.DateUtils;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.firebase.ui.database.FirebaseRecyclerOptions;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.firebase.database.ChildEventListener;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.Query;
import com.google.firebase.database.ValueEventListener;
import com.google.firebase.samples.apps.friendlypix.Models.Author;
import com.google.firebase.samples.apps.friendlypix.Models.Post;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
/**
* Shows a list of posts.
*/
public class PostsFragment extends Fragment {
public static final String TAG = "PostsFragment";
private static final String KEY_LAYOUT_POSITION = "layoutPosition";
private static final String KEY_TYPE = "type";
public static final int TYPE_HOME = 1001;
public static final int TYPE_FEED = 1002;
private int mRecyclerViewPosition = 0;
private OnPostSelectedListener mListener;
private RecyclerView mRecyclerView;
private RecyclerView.Adapter<PostViewHolder> mAdapter;
public PostsFragment() {
// Required empty public constructor
}
public static PostsFragment newInstance(int type) {
PostsFragment fragment = new PostsFragment();
Bundle args = new Bundle();
args.putInt(KEY_TYPE, type);
fragment.setArguments(args);
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_posts, container, false);
rootView.setTag(TAG);
mRecyclerView = (RecyclerView) rootView.findViewById(R.id.my_recycler_view);
return rootView;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getActivity());
linearLayoutManager.setReverseLayout(true);
linearLayoutManager.setStackFromEnd(true);
mRecyclerView.setLayoutManager(linearLayoutManager);
if (savedInstanceState != null) {
// Restore saved layout manager type.
mRecyclerViewPosition = (int) savedInstanceState
.getSerializable(KEY_LAYOUT_POSITION);
mRecyclerView.scrollToPosition(mRecyclerViewPosition);
// TODO: RecyclerView only restores position properly for some tabs.
}
switch (getArguments().getInt(KEY_TYPE)) {
case TYPE_FEED:
Log.d(TAG, "Restoring recycler view position (all): " + mRecyclerViewPosition);
Query allPostsQuery = FirebaseUtil.getPostsRef();
mAdapter = getFirebaseRecyclerAdapter(allPostsQuery);
mAdapter.registerAdapterDataObserver(new RecyclerView.AdapterDataObserver() {
@Override
public void onItemRangeInserted(int positionStart, int itemCount) {
super.onItemRangeInserted(positionStart, itemCount);
// TODO: Refresh feed view.
}
});
break;
case TYPE_HOME:
Log.d(TAG, "Restoring recycler view position (following): " + mRecyclerViewPosition);
FirebaseUtil.getCurrentUserRef().child("following").addChildEventListener(new ChildEventListener() {
@Override
public void onChildAdded(final DataSnapshot followedUserSnapshot, String s) {
String followedUserId = followedUserSnapshot.getKey();
String lastKey = "";
if (followedUserSnapshot.getValue() instanceof String) {
lastKey = followedUserSnapshot.getValue().toString();
}
Log.d(TAG, "followed user id: " + followedUserId);
Log.d(TAG, "last key: " + lastKey);
FirebaseUtil.getPeopleRef().child(followedUserId).child("posts")
.orderByKey().startAt(lastKey).addChildEventListener(new ChildEventListener() {
@Override
public void onChildAdded(final DataSnapshot postSnapshot, String s) {
HashMap<String, Object> addedPost = new HashMap<String, Object>();
addedPost.put(postSnapshot.getKey(), true);
FirebaseUtil.getFeedRef().child(FirebaseUtil.getCurrentUserId())
.updateChildren(addedPost).addOnSuccessListener(new OnSuccessListener<Void>() {
@Override
public void onSuccess(Void aVoid) {
FirebaseUtil.getCurrentUserRef().child("following")
.child(followedUserSnapshot.getKey())
.setValue(postSnapshot.getKey());
}
});
}
@Override
public void onChildChanged(DataSnapshot dataSnapshot, String s) {
}
@Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
}
@Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
@Override
public void onChildChanged(DataSnapshot dataSnapshot, String s) {
}
@Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
}
@Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
FirebaseUtil.getFeedRef().child(FirebaseUtil.getCurrentUserId())
.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
final List<String> postPaths = new ArrayList<>();
for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
Log.d(TAG, "adding post key: " + snapshot.getKey());
postPaths.add(snapshot.getKey());
}
mAdapter = new FirebasePostQueryAdapter(postPaths,
new FirebasePostQueryAdapter.OnSetupViewListener() {
@Override
public void onSetupView(PostViewHolder holder, Post post, int position, String postKey) {
setupPost(holder, post, position, postKey);
}
});
}
@Override
public void onCancelled(DatabaseError firebaseError) {
}
});
break;
default:
throw new RuntimeException("Illegal post fragment type specified.");
}
mRecyclerView.setAdapter(mAdapter);
}
private FirebaseRecyclerAdapter<Post, PostViewHolder> getFirebaseRecyclerAdapter(Query query) {
FirebaseRecyclerOptions<Post> options = new FirebaseRecyclerOptions.Builder<Post>()
.setLifecycleOwner(this)
.setQuery(query, Post.class)
.build();
return new FirebaseRecyclerAdapter<Post, PostViewHolder>(options) {
@Override
protected void onBindViewHolder(@NonNull PostViewHolder postViewHolder,
int position,
@NonNull Post post) {
setupPost(postViewHolder, post, position, null);
}
@Override
public PostViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.post_item, parent, false);
return new PostViewHolder(view);
}
};
}
private void setupPost(final PostViewHolder postViewHolder, final Post post, final int position, final String inPostKey) {
postViewHolder.setPhoto(post.getThumb_url());
postViewHolder.setText(post.getText());
postViewHolder.setTimestamp(DateUtils.getRelativeTimeSpanString(
(long) post.getTimestamp()).toString());
final String postKey;
if (mAdapter instanceof FirebaseRecyclerAdapter) {
postKey = ((FirebaseRecyclerAdapter) mAdapter).getRef(position).getKey();
} else {
postKey = inPostKey;
}
Author author = post.getAuthor();
postViewHolder.setAuthor(author.getFull_name(), author.getUid());
postViewHolder.setIcon(author.getProfile_picture(), author.getUid());
ValueEventListener likeListener = new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
postViewHolder.setNumLikes(dataSnapshot.getChildrenCount());
if (dataSnapshot.hasChild(FirebaseUtil.getCurrentUserId())) {
postViewHolder.setLikeStatus(PostViewHolder.LikeStatus.LIKED, getActivity());
} else {
postViewHolder.setLikeStatus(PostViewHolder.LikeStatus.NOT_LIKED, getActivity());
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
};
FirebaseUtil.getLikesRef().child(postKey).addValueEventListener(likeListener);
postViewHolder.mLikeListener = likeListener;
postViewHolder.setPostClickListener(new PostViewHolder.PostClickListener() {
@Override
public void showComments() {
Log.d(TAG, "Comment position: " + position);
mListener.onPostComment(postKey);
}
@Override
public void toggleLike() {
Log.d(TAG, "Like position: " + position);
mListener.onPostLike(postKey);
}
});
}
@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
// Save currently selected layout manager.
int recyclerViewScrollPosition = getRecyclerViewScrollPosition();
Log.d(TAG, "Recycler view scroll position: " + recyclerViewScrollPosition);
savedInstanceState.putSerializable(KEY_LAYOUT_POSITION, recyclerViewScrollPosition);
super.onSaveInstanceState(savedInstanceState);
}
private int getRecyclerViewScrollPosition() {
int scrollPosition = 0;
// TODO: Is null check necessary?
if (mRecyclerView != null && mRecyclerView.getLayoutManager() != null) {
scrollPosition = ((LinearLayoutManager) mRecyclerView.getLayoutManager())
.findFirstCompletelyVisibleItemPosition();
}
return scrollPosition;
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p/>
*/
public interface OnPostSelectedListener {
void onPostComment(String postKey);
void onPostLike(String postKey);
}
@Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof OnPostSelectedListener) {
mListener = (OnPostSelectedListener) context;
} else {
throw new RuntimeException(context.toString()
+ " must implement OnPostSelectedListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
}
