Develop Reference

Searching in android with Firebase

I'm using the library Material Search Bar to search my Firebase Database, but it doesn't work.
Right here is the layout and it is assumed that when I click on the search bar should give me some suggestions and also to look for products but it is not
View
My Firebase Database
Firebase DataBase
Here is my Home.java where i put the searchBar
public class Home extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {
FirebaseDatabase database;
DatabaseReference product;
TextView userName;
RecyclerView recycler_prod;
RecyclerView.LayoutManager layoutManager;
FirebaseRecyclerAdapter<Product,ProductViewHolder> adapter;
FirebaseRecyclerAdapter<Product, ProductViewHolder> searchadapter;
MaterialSearchBar searchBar;
String ProductId = "";
List<String> suggestList = new ArrayList<>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
database=FirebaseDatabase.getInstance();
product=database.getReference("Product");
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.addDrawerListener(toggle);
toggle.syncState();
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
View headerView = navigationView.getHeaderView(0);
userName= headerView.findViewById(R.id.idUserName);
userName.setText(Common.currentuser.getName());
recycler_prod = findViewById(R.id.recycler_card);
recycler_prod.setHasFixedSize(true);
layoutManager = new LinearLayoutManager(this);
recycler_prod.setLayoutManager(layoutManager);
loadProducts();
searchBar = findViewById(R.id.searchBar);
searchBar.setPlaceHolder("Productos");
loadSuggest();
searchBar.setLastSuggestions(suggestList);
searchBar.setCardViewElevation(10);
searchBar.addTextChangeListener(new TextWatcher() {
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
List<String> suggest = new ArrayList<String>();
for (String search : suggestList) {
if (search.toLowerCase().contains(searchBar.getText().toLowerCase()))
suggest.add(search);
}
searchBar.setLastSuggestions(suggest);
}
#Override
public void afterTextChanged(Editable s) {
}
});
searchBar.setOnSearchActionListener(new MaterialSearchBar.OnSearchActionListener() {
#Override
public void onSearchStateChanged(boolean enabled) {
if (!enabled)
recycler_prod.setAdapter(adapter);
}
#Override
public void onSearchConfirmed(CharSequence text) {
startSearch(text);
}
#Override
public void onButtonClicked(int buttonCode) {
}
});
}
private void startSearch(CharSequence text) {
searchadapter = new FirebaseRecyclerAdapter<Product, ProductViewHolder>(
Product.class,
R.layout.card_item,
ProductViewHolder.class,
product.orderByChild("Name").equalTo(text.toString())
) {
#Override
protected void populateViewHolder(ProductViewHolder viewHolder, Product model, int position) {
viewHolder.txtProductName.setText(model.getName());
Picasso.get().load(model.getImage())
.into(viewHolder.imageProductView);
final Product local = model;
viewHolder.setItemClickListener(new ItemClickListener() {
#Override
public void onClick(View view, int position, boolean isLongClick) {
Intent details = new Intent(Home.this, ProductDetail.class);
details.putExtra("ProductId", searchadapter.getRef(position).getKey());
startActivity(details);
}
});
}
};
recycler_prod.setAdapter(searchadapter);
}
private void loadSuggest() {
product.orderByChild("ProductId").equalTo(ProductId)
.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
for(DataSnapshot postSnapshot:dataSnapshot.getChildren()){
Product item = postSnapshot.getValue(Product.class);
suggestList.add(item.getName());
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
}
});
}
private void loadProducts() {
adapter = new FirebaseRecyclerAdapter<Product, ProductViewHolder>(Product.class,
R.layout.card_item,
ProductViewHolder.class,
product) {
#Override
protected void populateViewHolder(ProductViewHolder holder, Product model, int position) {
holder.txtProductName.setText(model.getName());
holder.txtProductDesc.setText(model.getDescription());
holder.txtProductPrice.setText("$" + model.getPrice());
Picasso.get().load(model.getImage())
.into(holder.imageProductView);
final Product clickItem = model;
holder.setItemClickListener(new ItemClickListener() {
#Override
public void onClick(View view, int position, boolean isLongClick) {
Intent details = new Intent(Home.this, ProductDetail.class);
details.putExtra("ProductId", adapter.getRef(position).getKey());
startActivity(details);
}
});
}
};
recycler_prod.setAdapter(adapter);
}
#Override
public void onBackPressed() {
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else {
super.onBackPressed();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.home, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
#SuppressWarnings("StatementWithEmptyBody")
#Override
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
int id = item.getItemId();
if (id == R.id.nav_search) {
// Handle the camera action
} else if (id == R.id.nav_map) {
Intent mapa = new Intent(Home.this,Maps.class);
startActivity(mapa);
} else if (id == R.id.nav_log_out) {
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
}
My Product.java Model
public class Product {
private String Description, Name, Image,Price,Link;
public Product() {
}
public Product(String description, String name, String image, String price, String link) {
Description = description;
Name = name;
Image = image;
Price = price;
Link = link;
}
public String getLink() {
return Link;
}
public void setLink(String link) {
Link = link;
}
public String getDescription() {
return Description;
}
public void setDescription(String description) {
Description = description;
}
public String getName() {
return Name;
}
public void setName(String name) {
Name = name;
}
public String getImage() {
return Image;
}
public void setImage(String image) {
Image = image;
}
public String getPrice() {
return Price;
}
public void setPrice(String price) {
Price = price;
}
}
My ProductViewHolder.java
public class ProductViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
public TextView txtProductName,txtProductDesc,txtProductPrice;
public ImageView imageProductView;
private ItemClickListener itemClickListener;
public ProductViewHolder(#NonNull View itemView) {
super(itemView);
txtProductName = itemView.findViewById(R.id.name);
txtProductDesc = itemView.findViewById(R.id.description);
txtProductPrice = itemView.findViewById(R.id.price);
imageProductView = itemView.findViewById(R.id.thumbnail);
itemView.setOnClickListener(this);
}
public void setItemClickListener(ItemClickListener itemClickListener) {
this.itemClickListener = itemClickListener;
}
#Override
public void onClick(View v) {
itemClickListener.onClick(v,getAdapterPosition(),false);
}
}
Thank you for your attention

In your startSearch method, replace your .equalto with .startAt. See if it works

Calling a class object for each item of recycler view android

There is a situation, I have an activity having recycler view and I have its adapter, there is a model class for three Text Views of a recycler view location,latitude,longitude that comes from database. Now I want the fourth field of recycler view the distance. distance is calculated by another class and return distance in a callback function. where do I initialize the object of that class in recyclerview so that it updates the distance continuously against the lat and long of each item.
Code that return distance for single lat,long
compassManager = new CompassManager(getApplicationContext(), this);
if (isLocationServiceEnabled()) {
Log.i("FloatingViewServie","Location Service Enabled");
// i want to pass latitude and longitude of UserLocations below to
// get distance on each row
compassManager.startNavigating(33.69206669, 73.03208828);
compassManager.getLocation().getLatitude();
compassManager.getLocation().getLongitude();
}
callback method that return continusly updated distance
#Override
public void onDistanceUpdate(float distance) {
//this distance need to be on recyclerview for each row
}
Recyclerview Adapter
public class ActiveLocationsAdapter extends RecyclerView.Adapter<ActiveLocationsAdapter.MyViewHolder> {
public interface OverflowOptions
{
public void edit(int position,UserLocations userLocations);
public void delete();
}
private List<UserLocations> userLocationsList;
FirebaseDatabase database;
DatabaseReference rootRef;
private FirebaseAuth mAuth;
FirebaseUser user;
Context context;
OverflowOptions overflowOptionsCallback;
public ActiveLocationsAdapter(Context context,List<UserLocations> locationsList,OverflowOptions callback) {
this.userLocationsList = locationsList;
database = FirebaseDatabase.getInstance();
rootRef = database.getReference();
mAuth = FirebaseAuth.getInstance();
user = mAuth.getCurrentUser();
this.context=context;
overflowOptionsCallback=callback;
}
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.row_active_locations, parent, false);
return new MyViewHolder(itemView);
}
#Override
public void onBindViewHolder(final MyViewHolder holder, int position) {
// model class that have latitude and longitude for each row
final UserLocations userLocations = userLocationsList.get(position);
Log.i("aaposition",String.valueOf(holder.getAdapterPosition()));
holder.name.setText(userLocations.getName());
// holder.distance.setText(String.valueOf(userLocations.getLatitude()));
// holder.direction.setText(String.valueOf(userLocations.getLongitude()));
holder.overflow.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//creating a popup menu
PopupMenu popup = new PopupMenu(context, holder.overflow);
//inflating menu from xml resource
popup.inflate(R.menu.locations_overflow_menu);
//adding click listener
popup.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
#Override
public boolean onMenuItemClick(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_edit:
overflowOptionsCallback.edit(holder.getAdapterPosition(), userLocations);
break;
case R.id.action_delete:
break;
}
return false;
}
});
//displaying the popup
popup.show();
}
});
}
#Override
public int getItemCount() {
return userLocationsList.size();
}
public class MyViewHolder extends RecyclerView.ViewHolder {
public TextView name, distance, direction;
public ImageView overflow;
public MyViewHolder(View view) {
super(view);
name = (TextView) view.findViewById(R.id.name);
distance = (TextView) view.findViewById(R.id.distance);
direction = (TextView) view.findViewById(R.id.direction);
overflow = (ImageView) view.findViewById(R.id.overflow);
}
}
}
Model Class
public class UserLocations {
String id;
String name;
double latitude;
double longitude;
String status;
public UserLocations() {
}
public UserLocations(String id, String name, double latitude, double longitude, String status) {
this.id=id;
this.name = name;
this.latitude = latitude;
this.longitude = longitude;
this.status = status;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getLatitude() {
return latitude;
}
public void setLatitude(double latitude) {
this.latitude = latitude;
}
public double getLongitude() {
return longitude;
}
public void setLongitude(double longitude) {
this.longitude = longitude;
}
public String getStatus() {return status;}
public void setStatus(String status) {this.status = status;}
}
Row of Recyclerview
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:focusable="true"
android:paddingLeft="16dp"
android:paddingRight="16dp"
android:paddingTop="10dp"
android:paddingBottom="10dp"
android:clickable="true"
android:background="?android:attr/selectableItemBackground"
android:orientation="vertical">
<TextView
android:id="#+id/name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:textColor="#color/heading"
android:textSize="16dp"
android:textStyle="bold" />
<TextView
android:id="#+id/distance_lable"
android:layout_below="#id/name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#color/subheading"
android:text="Distance : "/>
<!-- To display distance-->
<TextView
android:id="#+id/distance"
android:layout_below="#id/name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#color/subheading"
android:layout_toRightOf="#+id/distance_lable"
/>
<TextView
android:layout_below="#id/name"
android:id="#+id/direction_lable"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="#id/distance"
android:textColor="#color/subheading"
android:text=" Direction : "/>
<!-- To display direction-->
<TextView
android:id="#+id/direction"
android:layout_below="#id/name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#color/subheading"
android:layout_toEndOf="#+id/direction_lable"/>
<ImageButton
android:id="#+id/overflow"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_marginRight="5dp"
android:background="#drawable/ic_more_vert_black_24dp"
/>
</RelativeLayout>
Main Activity that have recyclerview
public class MainActivity extends AppCompatActivity
implements CurrentLocationManager.ResultSupplier,NavigationView.OnNavigationItemSelectedListener,ActiveLocationsAdapter.OverflowOptions{
private static final int CODE_DRAW_OVER_OTHER_APP_PERMISSION = 2084;
public static final int REQUEST_FINE_LOCATION = 1;
public static final String TAG= MainActivity.class.getSimpleName();
private PrefManager prefManager;
CurrentLocationManager currentLocationManager;;
private List<UserLocations> userLocationsList = new ArrayList<>();
private RecyclerView recyclerView;
private ActiveLocationsAdapter mAdapter;
FirebaseDatabase database;
DatabaseReference rootRef;
private FirebaseAuth mAuth;
FirebaseUser user;
ProgressDialog progressDoalog;
Context context,interfaceContext;
ImageButton imgBtnSaveLocation;
private double lattitude,longitude;
Switch toggle;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
checkPermissions(this);
permissionCheck();
context=getApplicationContext();
imgBtnSaveLocation=(ImageButton)findViewById(R.id.main_activity_save_btn) ;
progressDoalog = new ProgressDialog(MainActivity.this);
recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
toggle=(Switch)findViewById(R.id.active_locations_switch);
mAdapter = new ActiveLocationsAdapter(getApplicationContext(),userLocationsList,this);
prefManager = new PrefManager(this);
prefManager.setFirstTimeLaunch(false);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
//database reference pointing to root of database
database = FirebaseDatabase.getInstance();
rootRef = database.getReference();
// gives current authenticated user
mAuth = FirebaseAuth.getInstance();
user = mAuth.getCurrentUser();
RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getApplicationContext());
recyclerView.setLayoutManager(mLayoutManager);
recyclerView.setItemAnimator(new DefaultItemAnimator());
recyclerView.addItemDecoration(new DividerItemDecoration(this, LinearLayoutManager.VERTICAL));
recyclerView.setAdapter(mAdapter);
progressDoalog.setMessage("Fetching Data. . .");
progressDoalog.show();
// get and update data on View on any change in database
rootRef.child(user.getDisplayName()).child("active_locations").addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot noteDataSnapshot : dataSnapshot.getChildren()) {
UserLocations locations = noteDataSnapshot.getValue(UserLocations.class);
if(locations.getStatus().equals("active")) {
if (!contains((ArrayList<UserLocations>) userLocationsList, locations)) {
userLocationsList.add(locations);
}
}
}
mAdapter.notifyDataSetChanged();
progressDoalog.dismiss();
}
#Override
public void onCancelled(DatabaseError error) {
// Failed to read value
}
});
// button click that get current location and save to database
imgBtnSaveLocation.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Log.i(TAG,"onclick");
getLocation();
}
});
// turn the tracking on and off
toggle.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
if(isChecked)
Toast.makeText(context, "Toggle on", Toast.LENGTH_SHORT).show();
else
Toast.makeText(context, "Toggle off", Toast.LENGTH_SHORT).show();
}
});
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.setDrawerListener(toggle);
toggle.syncState();
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
}
public void permissionCheck()
{
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && !Settings.canDrawOverlays(getApplicationContext())) {
//If the draw over permission is not available open the settings screen
//to grant the permission.
Intent intent = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION,
Uri.parse("package:" + getPackageName()));
startActivityForResult(intent, CODE_DRAW_OVER_OTHER_APP_PERMISSION);
} else {
}
}
private void requestPermissions(Context context) {
ActivityCompat.requestPermissions((Activity) context,
new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION,android.Manifest.permission.ACCESS_COARSE_LOCATION},
REQUEST_FINE_LOCATION);
}
private boolean checkPermissions(Context context) {
if (ContextCompat.checkSelfPermission(context, android.Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(context, android.Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
return true;
} else {
requestPermissions(context);
return false;
}
}
#Override
public void onBackPressed() {
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else {
super.onBackPressed();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
#SuppressWarnings("StatementWithEmptyBody")
#Override
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
int id = item.getItemId();
if (id == R.id.nav_active_locations) {
startActivity(new Intent(getApplicationContext(),ActiveLocationsActivity.class));
} else if (id == R.id.nav_tracked_locations) {
startActivity(new Intent(getApplicationContext(),TrackedLocationsActivity.class));
} else if (id == R.id.nav_slideshow) {
} else if (id == R.id.nav_manage) {
} else if (id == R.id.nav_share) {
AuthUI.getInstance()
.signOut(this)
.addOnCompleteListener(new OnCompleteListener<Void>() {
public void onComplete(#NonNull Task<Void> task) {
// user is now signed out
startActivity(new Intent(getApplicationContext(), SignUpActivity.class));
finish(); }
});
} else if (id == R.id.nav_send) {
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
public void getLocation()
{
currentLocationManager = new CurrentLocationManager(context,this);
currentLocationManager.getUpdatedLocation();
}
/**
* Compares two array list
* #param list
* #param locations
* #return
*/
boolean contains(ArrayList<UserLocations> list, UserLocations locations) {
for (UserLocations item : list) {
if (item.getId().equals(locations.getId())&&item.getName().equals(locations.getName())&&item.getLatitude()==locations.getLatitude()&&item.getLongitude()==locations.getLongitude()&&item.getStatus().equals(locations.getStatus())) {
return true;
}
}
return false;
}
#Override
public void result(double lat, double longi) {
lattitude=lat;
longitude=longi;
Log.i("callback result",String.valueOf(lat)+","+String.valueOf(longi));
}
#Override
public void edit(final int position, final UserLocations userLocations) {
AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(this);
LayoutInflater inflater = this.getLayoutInflater();
final View dialogView = inflater.inflate(R.layout.dialog_edit_location_name, null);
dialogBuilder.setView(dialogView);
final EditText rename = (EditText) dialogView.findViewById(R.id.name);
dialogBuilder.setTitle("Rename Location");
//dialogBuilder.setMessage("hello");
dialogBuilder.setPositiveButton("Done", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
renameLocation(userLocations.getName(),rename.getText().toString());
userLocations.setName(rename.getText().toString());
userLocationsList.set(position, userLocations);
}
});
dialogBuilder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
//pass
}
});
AlertDialog b = dialogBuilder.create();
b.show();
}
#Override
public void delete() {
}
public void renameLocation(final String name, final String renameLocation) {
Log.i("Interface","renameLocation");
Query renameQuery= rootRef.child(user.getDisplayName()).child("active_locations").orderByChild("name").equalTo(name);
renameQuery.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot child : dataSnapshot.getChildren()) {
String child_name = (String) child.child("name").getValue();
if (child_name.equals(name)){
child.getRef().child("name").setValue(renameLocation);
Log.i("Rename Location","child renamed");
}
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
}

Android - CardView doesn't show up on RecyclerView connected to Firebase

I'm building a RecyclerView in a Fragment, which brings in data from Firebase database and suppose to show them on a CardView. I wrote all the code as shown below but all that appears upon running is an empty RecyclerView Fragment with the method getItemCount() returning always 0.
card_item.xml
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:id="#+id/cardView"
android:layout_width="match_parent"
android:layout_height="200dp"
android:layout_margin="10dp"
android:orientation="horizontal"
card_view:cardCornerRadius="5dp"
card_view:cardElevation="5dp">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/colorPrimary">
<TextView
android:id="#+id/primaryText"
android:layout_width="300dp"
android:layout_height="60dp"
android:textColor="#color/colorPrimary"
android:textSize="24sp" />
<TextView
android:id="#+id/subText"
android:layout_width="300dp"
android:layout_height="60dp"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_centerVertical="true"
android:textColor="#color/colorPrimary"
android:textSize="14sp" />
<TextView
android:id="#+id/rateValue"
android:layout_width="300dp"
android:layout_height="60dp"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_below="#+id/subText"
android:textColor="#color/colorPrimary"
android:textSize="24sp" />
</RelativeLayout>
fragment_profile.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#F1F1F1"
android:orientation="vertical">
<android.support.v7.widget.RecyclerView
android:id="#+id/placesRecycler"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
PlacesModel.java
public class PlaceModel {
private String mPrimaryText, mSubText, mRateValue;
public PlaceModel() {
}
public PlaceModel(String mCardImage, String mPrimaryText,
String mSubText, String mRateValue) {
//this.mCardImageURL = mCardImage;
this.mPrimaryText = mPrimaryText;
this.mSubText = mSubText;
this.mRateValue = mRateValue;
}
public void setmPrimaryText(String mPrimaryText) {
this.mPrimaryText = mPrimaryText;
}
public void setmSubText(String mSubText) {
this.mSubText = mSubText;
}
public void setmRateValue(String mRateValue) {
this.mRateValue = mRateValue;
}
public String getmPrimaryText() {
return mPrimaryText;
}
public String getmSubText() {
return mSubText;
}
public String getmRateValue() {
return mRateValue;
}}
PlacesAdapter.java
public class PlacesAdapter extends RecyclerView.Adapter<PlacesAdapter.PlacesViewHolder> {
private ArrayList<PlaceModel> cardContents;
private Context context;
public PlacesAdapter(Context context, ArrayList<PlaceModel> cardContents) {
this.cardContents = cardContents;
this.context = context;
}
#Override
public PlacesViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(context).inflate(R.layout.card_item, parent, false);
return new PlacesViewHolder(view);
}
#Override
public void onBindViewHolder(PlacesViewHolder holder, int position) {
PlaceModel place = cardContents.get(position);
holder.primaryText.setText(place.getmPrimaryText());
holder.subText.setText(place.getmSubText());
holder.rateValue.setText(place.getmRateValue());
}
#Override
public int getItemCount() {
return cardContents.size();
}
public class PlacesViewHolder extends RecyclerView.ViewHolder {
CardView cardView;
public TextView primaryText, subText, rateValue;
public PlacesViewHolder(View itemView) {
super(itemView);
cardView = (CardView) itemView.findViewById(R.id.cardView);
primaryText = (TextView) itemView.findViewById(R.id.primaryText);
subText = (TextView) itemView.findViewById(R.id.subText);
rateValue = (TextView) itemView.findViewById(R.id.rateValue);
}
}}
FirebaseConnector.java
public class FirebaseConnector {
DatabaseReference db;
PlaceModel placeModel = new PlaceModel();
ArrayList<PlaceModel> cardContent = new ArrayList<>();
public FirebaseConnector(DatabaseReference db) {
this.db = db;
}
public ArrayList<PlaceModel> retrieve() {
db.addChildEventListener(new ChildEventListener() {
#Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
fetchData(dataSnapshot);
}
#Override
public void onChildChanged(DataSnapshot dataSnapshot, String s) {
fetchData(dataSnapshot);
}
#Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
}
#Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
return cardContent;
}
private void fetchData(DataSnapshot dataSnapshot) {
cardContent.clear(); //clear card content from last usage
for (DataSnapshot ds : dataSnapshot.getChildren()) {
placeModel = ds.child("Place Model").getValue(PlaceModel.class);
cardContent.add(placeModel);
}
}}
ProfileFragment.java
public class ProfileFragment extends Fragment {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
/////////////////////////////////////////////////////////////
private FirebaseAuth mAuth;
private FirebaseAuth.AuthStateListener mAuthListener;
private RecyclerView placesRecycler;
private PlacesAdapter placesAdapter;
private FirebaseConnector connector;
private DatabaseReference ref;
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
public ProfileFragment() {
// Required empty public constructor
}
// TODO: Rename and change types and number of parameters
public static ProfileFragment newInstance(String param1, String param2) {
ProfileFragment fragment = new ProfileFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View v = inflater.inflate(R.layout.fragment_profile, container, false);
mAuth = FirebaseAuth.getInstance();
//Initialize Database..
ref = FirebaseDatabase.getInstance().getReference();
connector = new FirebaseConnector(ref);
//Initialize RecyclerView
placesRecycler = (RecyclerView)v.findViewById(R.id.placesRecycler);
placesRecycler.setLayoutManager(new LinearLayoutManager(this.getActivity()));
//Adapter
placesAdapter = new PlacesAdapter(this.getActivity(), connector.retrieve());
placesRecycler.setAdapter(placesAdapter);
Toast.makeText(getActivity(), "We have "+placesAdapter.getItemCount()+" cards", Toast.LENGTH_LONG).show();
return v;
}
#Override
public void onStart() {
super.onStart();
if (mAuth.getCurrentUser() == null) {
startActivity(new Intent(getActivity(), LoginActivity.class));
}
}
public void updateUI() {
if (mAuth.getCurrentUser() == null) {
startActivity(new Intent(getActivity(), LoginActivity.class));
}
}}
Database trial structure
Database trial structure

I see that retrieve method will return empty array list because it won't wait for the listener to finish (note that listener works in another thread)
You may make move the listener to the profile fragment and every time you update the ArrayList write
placesRecycler.notifydatasetchanged();

Recycle View row image not showing up

i am building a simple recycle view with a custom adapter, i already set the position of all of my elements, but somehow the image of my row the main one is not showing up and i don't know why.
Before i changed the xml it was showing up, so basicly i have my main activity:
public class PlantFeed extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener,PlantFeedAdapter.OnItemClickListener {
//initialize fields
String token;
ArrayList<PlantPhotoUser> photos = new ArrayList<>();
VolleyService mVolleyService;
IResult mResultCallback = null;
final String GETREQUEST = "GETCALL";
String connectionTxt;
String URL;
String date;
String lat;
String lon;
String alt;
PlantFeedAdapter plantFeedAdapter;
RecyclerView recyclerView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_plant_feed);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
connectionString connection = ((connectionString) getApplicationContext());
connectionTxt = connection.getGlobalVarValue();
URL = connectionTxt + "/fotos";
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent i = new Intent(PlantFeed.this,CameraCapture.class);
startActivity(i);
}
});
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.setDrawerListener(toggle);
toggle.syncState();
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
recyclerView = (RecyclerView)findViewById(R.id.recycleView2);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
plantFeedAdapter = new PlantFeedAdapter(getApplicationContext(), photos,PlantFeed.this);
recyclerView.setAdapter(plantFeedAdapter);
token = checkForToken();
initVolleyCallback();
mVolleyService = new VolleyService(mResultCallback,this);
mVolleyService.getDataVolley(GETREQUEST,URL,token);
}
void initVolleyCallback(){
mResultCallback = new IResult() {
#Override
public void notifySuccess(String requestType,JSONObject response) {
Log.d("HELLL","hi1");
}
#Override
public void notifySuccess(String requestType, JSONArray response) {
PlantPhotoUser plantPhotoUser;
Log.d("HELLLL","hi");
for (int i=0; i < response.length(); i++) {
try {
JSONObject object = response.getJSONObject(i);
Log.d("objeto",object.toString());
int userId = object.getInt("userId");
Log.d("objeto",String.valueOf(userId));
String username = object.getJSONObject("user").getString("username");
Log.d("objeto",String.valueOf(username));
int plantId = object.getInt("plantId");
Log.d("objeto",String.valueOf(plantId));
String specie = object.getJSONObject("plant").getString("specie");
Log.d("objeto",String.valueOf(specie));
String path = object.getString("image");
Log.d("objeto",String.valueOf(path));
int fotoId = object.getInt("id");
if(object.getString("date") != null){
date = object.getString("date");
}
if(object.getString("lat") != null){
lat = object.getString("lat");
}
if(object.getString("lon") != null){
lon = object.getString("lon");
}
if(object.getString("altitude") != null){
alt = object.getString("altitude");
}
plantPhotoUser = new PlantPhotoUser(fotoId,plantId,userId,path,specie,date,lat,lon,alt,username);
photos.add(plantPhotoUser);
} catch (JSONException e) {
e.printStackTrace();
}
}
plantFeedAdapter.notifyDataSetChanged();
}
#Override
public void notifyError(String requestType,VolleyError error) {
Log.d("FAIL",error.toString());
}
};
}
public String checkForToken() {
SharedPreferences sharedPref = getSharedPreferences("user", MODE_PRIVATE);
String tokenKey = getResources().getString(R.string.token);
String token = sharedPref.getString(getString(R.string.token), tokenKey); // take the token
return token;
}
#Override
public void onBackPressed() {
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else {
super.onBackPressed();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.plant_feed, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.Perfil) {
return true;
}
return super.onOptionsItemSelected(item);
}
#SuppressWarnings("StatementWithEmptyBody")
#Override
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
int id = item.getItemId();
if (id == R.id.nav_camera) {
Intent i = new Intent(PlantFeed.this,CameraCapture.class);
startActivity(i);
} else if (id == R.id.nav_gallery) {
Intent i = new Intent(PlantFeed.this,PlantFeed.class);
startActivity(i);
} else if (id == R.id.nav_slideshow) {
Intent i = new Intent(PlantFeed.this,FamilyLibrary.class);
startActivity(i);
} else if (id == R.id.nav_manage) {
} else if (id == R.id.nav_share) {
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
#Override
public void onRowClick(int position, String name, int id, View view) {
}
#Override
public void onTitleClicked(int position, int id, View clickedview) {
Intent i = new Intent(this,PhotosForPlant.class);
i.putExtra("plantId",String.valueOf(id));
startActivity(i);
}
#Override
public void onImageClicked(int position, int id, View clickedview) {
Intent i = new Intent(this,PhotosForPlant.class);
i.putExtra("plantId",String.valueOf(id));
startActivity(i);
}
#Override
public void onReportClicked(int position, int id, String name, View clickedview) {
Log.d("HELLLO","HELLOO");
showDialogReport(id,name);
}
#Override
public void onUserIconClicked(int position, int id, View clickedview) {
Intent i = new Intent(this,UserProfile.class);
i.putExtra("userId",id);
startActivity(i);
}
#Override
public void onUsernameClicked(int position, int id, View clickedview) {
Intent i = new Intent(this,UserProfile.class);
i.putExtra("userId",id);
startActivity(i);
}
#Override
public void onAvaliationClicked(int position, int id, String name, View clickedview) {
}
private void showDialogReport(int id, String name) {
Log.d("HELLLO","HELLOO");
AlertDialog.Builder builder = new AlertDialog.Builder(PlantFeed.this);
builder.setTitle(name);
builder.setMessage("Tem a certeza que pretende reportar a fotografia?");
builder.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
//TODO reportar base de dados
}
});
builder.setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.dismiss();
}
});
AlertDialog dialog = builder.create();
dialog.show();
}
}
and then i have my customer adapter like this:
public class PlantFeedAdapter extends RecyclerView.Adapter<PlantFeedAdapter.ViewHolder> {
private OnItemClickListener listener;
public interface OnItemClickListener {
void onRowClick(int position, String name, int id, View view);
void onTitleClicked(int position, int id, View clickedview);
void onImageClicked(int position,int id, View clickedview);
void onReportClicked(int position, int id,String name, View clickedview);
void onUserIconClicked(int position, int id, View clickedview);
void onUsernameClicked(int position, int id, View clickedview);
void onAvaliationClicked(int position, int id,String name, View clickedview);
}
private ArrayList<PlantPhotoUser> photos;
private Context context;
public PlantFeedAdapter(Context context, ArrayList<PlantPhotoUser> photos, OnItemClickListener listener) {
this.photos = photos;
this.context = context;
this.listener = listener;
}
#Override
public PlantFeedAdapter.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.plant_feed_row, viewGroup, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(final PlantFeedAdapter.ViewHolder viewHolder, final int i) {
viewHolder.name.setText(photos.get(i).getSpecie());
viewHolder.username.setText(photos.get(i).getUsernName());
viewHolder.data.setText(photos.get(i).getDate().split("T")[0]);
Log.d("data123",(photos.get(i).getDate().toString()));
String urlFoto = "http://fe1b7efd.ngrok.io/" + photos.get(i).getPath();
if(urlFoto.toLowerCase().contains("public/")){
urlFoto = urlFoto.replace("public/","");
}
viewHolder.userIcon.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (listener != null) {
listener.onUserIconClicked(viewHolder.getAdapterPosition(), photos.get(i).getUserId(), view);
}
}
});
viewHolder.username.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (listener != null) {
listener.onUsernameClicked(viewHolder.getAdapterPosition(),photos.get(i).getUserId(), view);
}
}
});
viewHolder.plantImg.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (listener != null) {
listener.onImageClicked(viewHolder.getAdapterPosition(), photos.get(i).getIdPlant(), view);
}
}
});
viewHolder.name.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(listener != null){
listener.onTitleClicked(viewHolder.getAdapterPosition(),photos.get(i).getIdPlant(),v);
}
}
});
viewHolder.reportImage.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(listener != null){
listener.onReportClicked(viewHolder.getAdapterPosition(),photos.get(i).getIdPlant(),photos.get(i).getSpecie(),v);
}
}
});
/*viewHolder.avaliationFoto.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(listener != null){
listener.onAvaliationClicked(viewHolder.getAdapterPosition(),photos.get(i).getIdPlant(),photos.get(i).getSpecie(),v);
}
}
});*/
Picasso.with(context)
.load(urlFoto)
.resize(300, 300)
.into(viewHolder.plantImg);
}
#Override
public int getItemCount() {
return photos.size();
}
public class ViewHolder extends RecyclerView.ViewHolder{
private TextView name;
private ImageView userIcon;
private TextView avaliationFoto;
private ImageView plantImg;
private ImageView foto;
private TextView username;
private ImageView reportImage;
private TextView data;
public ViewHolder(View view) {
super(view);
data = (TextView)view.findViewById(R.id.data);
name = (TextView) view.findViewById(R.id.plantName);
userIcon = (ImageView)view.findViewById(R.id.userIcon);
plantImg = (ImageView)view.findViewById(R.id.plantPhoto);;
username = (TextView)view.findViewById(R.id.password);
reportImage = (ImageView)view.findViewById(R.id.cameraForbiden);
}
}
}
finally my row xml, wher i think there is the problem
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#cfcfcf">
<LinearLayout
android:layout_margin="10dp"
android:background="#ffffff"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.android.volley.toolbox.NetworkImageView
android:layout_weight="1"
android:layout_width="120dp"
android:layout_height="100dp"
android:padding="0dp"
app:srcCompat="#mipmap/ic_launcher"
android:id="#+id/plantPhoto"
android:background="#c7c7c7"
/>
<LinearLayout
android:layout_weight="20"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="#+id/plantName"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="right"
android:padding="15dp"
android:text="TextView"
android:textColor="#000"
android:textSize="20dp" />
<ImageView
android:id="#+id/starIcon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="15dp"
android:gravity="right"
android:src="#drawable/ic_star" />
</RelativeLayout>
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:padding="15dp">
<com.example.afcosta.inesctec.pt.android.Helpers.NexusBoldTextView
android:id="#+id/data"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toStartOf="#+id/cameraForbiden"
android:text="TextView"
android:textColor="#color/base" />
<ImageView
android:id="#+id/cameraForbiden"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_alignParentEnd="true"
android:src="#drawable/ic_no_photos" />
<ImageView
android:id="#+id/userIcon"
android:layout_width="15dp"
android:layout_height="15dp"
android:gravity="left"
android:layout_alignParentBottom="true"
android:src="#drawable/ic_user" />
<com.example.afcosta.inesctec.pt.android.Helpers.NexusBoldTextView
android:id="#+id/password"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="#+id/userIcon"
android:text="Filipe"
android:textColor="#color/base" />
</RelativeLayout>
</LinearLayout>
</LinearLayout>
the problem is on this element:
<com.android.volley.toolbox.NetworkImageView
android:layout_weight="1"
android:layout_width="120dp"
android:layout_height="100dp"
android:padding="0dp"
app:srcCompat="#mipmap/ic_launcher"
android:id="#+id/plantPhoto"
android:background="#c7c7c7"
/>

Add centerCrop() with Picasso
Picasso.with(context)
.load(url)
.resize(50, 50)
.centerCrop()
.into(imageView)

Change this lines in Your Adapter and in ViewHolder because type cast is wrong. :
private ImageView plantImg;
plantImg = (ImageView)view.findViewById(R.id.plantPhoto);;
to
private NetworkImageView plantImg;
plantImg= (NetworkImageView) findViewById(R.id
.plantPhoto); then set image .
Edit
`private ImageLoader mImageLoader;
mImageLoader = CustomVolleyRequestQueue.getInstance(this.getApplicationContext())
.getImageLoader();
mImageLoader.get(url, ImageLoader.getImageListener(mNetworkImageView,
R.mipmap.truiton_short, android.R.drawable
.ic_dialog_alert));
mNetworkImageView.setImageUrl(url, mImageLoader);`
use this link http://www.truiton.com/2015/03/android-volley-imageloader-networkimageview-example/ for further guide.

Recyclerview doesnt call any Adapter method :onBindViewHolder,onCreateViewHolder

Recyclerview doesnt call any Adapter method :onBindViewHolder,onCreateViewHolder therefor the adapter is empty
here is my code :
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_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) {
return new FirebaseRecyclerAdapter<Post, PostViewHolder>(
Post.class, R.layout.post_item, PostViewHolder.class, query) {
#Override
public void populateViewHolder(final PostViewHolder postViewHolder,
final Post post, final int position) {
setupPost(postViewHolder, post, position, null);
}
#Override
public void onViewRecycled(PostViewHolder holder) {
super.onViewRecycled(holder);
}
};
}
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 onDestroy() {
super.onDestroy();
if (mAdapter != null && mAdapter instanceof FirebaseRecyclerAdapter) {
((FirebaseRecyclerAdapter) mAdapter).cleanup();
}
}
#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;
}
}
the adapter class
public class FirebasePostQueryAdapter extends RecyclerView.Adapter<PostViewHolder> {
private final String TAG = "PostQueryAdapter";
private List<String> mPostPaths;
private OnSetupViewListener mOnSetupViewListener;
public FirebasePostQueryAdapter(List<String> paths, OnSetupViewListener onSetupViewListener) {
if (paths == null || paths.isEmpty()) {
mPostPaths = new ArrayList<>();
} else {
mPostPaths = paths;
}
mOnSetupViewListener = onSetupViewListener;
}
#Override
public PostViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// create a new view
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.post_item, parent, false);
return new PostViewHolder(v);
}
public void setPaths(List<String> postPaths) {
mPostPaths = postPaths;
notifyDataSetChanged();
}
public void addItem(String path) {
mPostPaths.add(path);
notifyItemInserted(mPostPaths.size());
}
#Override
public void onBindViewHolder(final PostViewHolder holder, int position) {
DatabaseReference ref = FirebaseUtil.getPostsRef().child(mPostPaths.get(position));
// TODO: Fix this so async event won't bind the wrong view post recycle.
ValueEventListener postListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
Post post = dataSnapshot.getValue(Post.class);
Log.d(TAG, "post key: " + dataSnapshot.getKey());
mOnSetupViewListener.onSetupView(holder, post, holder.getAdapterPosition(),
dataSnapshot.getKey());
}
#Override
public void onCancelled(DatabaseError firebaseError) {
Log.e(TAG, "Error occurred: " + firebaseError.getMessage());
}
};
ref.addValueEventListener(postListener);
holder.mPostRef = ref;
holder.mPostListener = postListener;
}
#Override
public void onViewRecycled(PostViewHolder holder) {
super.onViewRecycled(holder);
holder.mPostRef.removeEventListener(holder.mPostListener);
}
#Override
public int getItemCount() {
return mPostPaths.size();
}
public interface OnSetupViewListener {
void onSetupView(PostViewHolder holder, Post post, int position, String postKey);
}
}
the main class
public class FeedsActivity extends AppCompatActivity implements PostsFragment.OnPostSelectedListener {
private static final String TAG = "FeedsActivity";
private FloatingActionButton mFab;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_feeds);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
ViewPager viewPager = (ViewPager) findViewById(R.id.feeds_view_pager);
FeedsPagerAdapter adapter = new FeedsPagerAdapter(getSupportFragmentManager());
adapter.addFragment(PostsFragment.newInstance(PostsFragment.TYPE_HOME), "HOME");
adapter.addFragment(PostsFragment.newInstance(PostsFragment.TYPE_FEED), "FEED");
viewPager.setAdapter(adapter);
viewPager.setCurrentItem(1);
TabLayout tabLayout = (TabLayout) findViewById(R.id.feeds_tab_layout);
tabLayout.setupWithViewPager(viewPager);
mFab = (FloatingActionButton) findViewById(R.id.fab);
mFab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
if (user == null || user.isAnonymous()) {
Toast.makeText(FeedsActivity.this, "You must sign-in to post.", Toast.LENGTH_SHORT).show();
return;
}
Intent newPostIntent = new Intent(FeedsActivity.this, NewPostActivity.class);
startActivity(newPostIntent);
}
});
}
#Override
public void onPostComment(String postKey) {
Intent intent = new Intent(this, CommentsActivity.class);
intent.putExtra(CommentsActivity.POST_KEY_EXTRA, postKey);
startActivity(intent);
}
#Override
public void onPostLike(final String postKey) {
final String userKey = FirebaseUtil.getCurrentUserId();
final DatabaseReference postLikesRef = FirebaseUtil.getLikesRef();
postLikesRef.child(postKey).child(userKey).addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
if (dataSnapshot.exists()) {
// User already liked this post, so we toggle like off.
postLikesRef.child(postKey).child(userKey).removeValue();
} else {
postLikesRef.child(postKey).child(userKey).setValue(ServerValue.TIMESTAMP);
}
}
#Override
public void onCancelled(DatabaseError firebaseError) {
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_feeds, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
// TODO: Add settings screen.
return true;
} else if (id == R.id.action_profile) {
startActivity(new Intent(this, ProfileActivity.class));
return true;
}
return super.onOptionsItemSelected(item);
}
class FeedsPagerAdapter extends FragmentPagerAdapter {
private final List<Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();
public FeedsPagerAdapter(FragmentManager manager) {
super(manager);
}
#Override
public Fragment getItem(int position) {
return mFragmentList.get(position);
}
#Override
public int getCount() {
return mFragmentList.size();
}
public void addFragment(Fragment fragment, String title) {
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
#Override
public CharSequence getPageTitle(int position) {
return mFragmentTitleList.get(position);
}
}
}
activity_feeds.xml
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/main_content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
>
<android.support.design.widget.AppBarLayout
android:id="#+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:layout_scrollFlags="scroll|enterAlways|snap"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
<android.support.design.widget.TabLayout
android:id="#+id/feeds_tab_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="#+id/feeds_view_pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
/>
<android.support.design.widget.FloatingActionButton
android:id="#+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="end|bottom"
android:layout_margin="#dimen/fab_margin"
android:src="#android:drawable/ic_input_add"
android:tint="#android:color/white"/>
post_item.xml
<android.support.v7.widget.CardView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_margin="8dp"
android:layout_height="wrap_content" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="50dp"
android:padding="10dp">
<de.hdodenhof.circleimageview.CircleImageView
android:id="#+id/post_author_icon"
android:layout_width="#dimen/post_author_icon_size"
android:layout_height="#dimen/post_author_icon_size"
android:layout_centerVertical="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"/>
<TextView
android:id="#+id/post_author_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_toRightOf="#id/post_author_icon"
android:layout_marginLeft="4dp"
style="#style/Base.TextAppearance.AppCompat.Title"
android:textColor="#android:color/primary_text_light_nodisable"
android:text="Unknown"/>
<TextView
android:id="#+id/post_timestamp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:layout_gravity="end"
android:textColor="#android:color/primary_text_light"
android:textSize="18sp" />
</RelativeLayout>
<ImageView
android:id="#+id/post_photo"
android:layout_width="match_parent"
android:layout_height="200dp"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:scaleType="centerCrop" />
<TextView
android:id="#+id/post_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:singleLine="false"
android:layout_marginLeft="6dp"
android:layout_marginRight="6dp"
android:layout_marginTop="6dp"
android:layout_marginBottom="6dp"
android:textColor="#android:color/primary_text_light"
android:textSize="16sp"
android:ellipsize="end" />
<TextView
android:id="#+id/post_num_likes"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="6dp"
android:layout_marginRight="6dp"
android:layout_marginTop="6dp"
android:layout_marginBottom="6dp"
android:textColor="#android:color/secondary_text_light"
android:textSize="14sp" />
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="6dp">
<ImageView
android:id="#+id/post_like_icon"
android:layout_width="30dp"
android:layout_height="30dp"
android:src="#drawable/heart_full"/>
<ImageView
android:id="#+id/post_comment_icon"
android:layout_width="30dp"
android:layout_height="30dp"
android:layout_marginLeft="6dp"
android:layout_toRightOf="#id/post_like_icon"
android:src="#drawable/ic_chat_24dp"
android:tint="#color/blue_grey_500"/>
</RelativeLayout>
</LinearLayout>
fragment_posts.xml
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".PostsFragment">
<android.support.v7.widget.RecyclerView
android:id="#+id/my_recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="vertical" />

You are setting the adapter on the recyclerview before the adapter has been initialised. Try:
mAdapter = new FirebasePostQueryAdapter(postPaths,
new FirebasePostQueryAdapter.OnSetupViewListener() {
#Override
public void onSetupView(PostViewHolder holder, Post post, int position, String postKey) {
setupPost(holder, post, position, postKey);
}
});
mRecyclerView.setAdapter(mAdapter);