Develop Reference

How to pass data between fragments in FragmentPagerAdapter

For my academic project, I want create an application with 4 tabs. The first one will show recent games added to a list, the second one will be a search form, the third will show the search result, and the last one will show the details. I currently have created the code for TabView and the 4 tabs. The problem is that I want to perform a search to get the items I have in a list which meet the search criteria on fragment 2, but I don't know how to pass the data from fragment 2 (textView data and spinner) to fragment 3. My code is the following:
MainActivity.java:
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.design.widget.TabLayout;
import android.view.MenuInflater;
import android.view.View;
import android.support.design.widget.NavigationView;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setImageResource(R.drawable.ic_search_white_24dp);
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();
}
});
//TabLayout function call
configureTabLayout();
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);
}
#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.
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()){
case R.id.menu_exit:
finish();
return true;
case R.id.menu_settings:
Toast.makeText(this, "Under Construction", Toast.LENGTH_LONG).show();
return true;
default:
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) {
// Handle the camera action
} else if (id == R.id.nav_gallery) {
} else if (id == R.id.nav_slideshow) {
} else if (id == R.id.nav_manage) {
} else if (id == R.id.nav_share) {
} else if (id == R.id.nav_send) {
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
//Tab Layout function declaration
private void configureTabLayout() {
//Getting the tab layout
TabLayout tabLayout = findViewById(R.id.tab_layout);
//Adding Tabs
tabLayout.addTab(tabLayout.newTab().setIcon(R.drawable.ic_home_white_24dp));
tabLayout.addTab(tabLayout.newTab().setIcon(R.drawable.ic_search_white_24dp));
tabLayout.addTab(tabLayout.newTab().setIcon(R.drawable.ic_results_white_24dp));
tabLayout.addTab(tabLayout.newTab().setIcon(R.drawable.ic_details_white_24dp));
//The TabPagerAdapter instance is then
//assigned as the adapter for the ViewPager and the TabLayout component added
//to the page change listener
final ViewPager viewPager = (ViewPager) findViewById(R.id.pager);
final PagerAdapter adapter = new TabPagerAdapter
(getSupportFragmentManager(), tabLayout.getTabCount());
viewPager.setAdapter(adapter);
//Finally, the onTabSelectedListener is configured on the TabLayout instance and
//the onTabSelected() method implemented to set the current page on the
//ViewPager based on the currently selected tab number.
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
#Override
public void onTabSelected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(TabLayout.Tab tab) {
}
#Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
}
}
TabPagerAdapter.java
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
public class TabPagerAdapter extends FragmentPagerAdapter{
int tabCount;
public TabPagerAdapter(FragmentManager fm, int numberOfTabs) {
super(fm);
this.tabCount = numberOfTabs;
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return new HomeScreenFragment();
case 1:
return new SearchFormFragment();
case 2:
return new SearchResultsFragment();
case 3:
return new DetailsScreenFragment();
default:
return null;
}
}
#Override
public int getCount() {
return tabCount;
}
}
SearchFormFragment.java
package gr.pliroforiki_edu.videogamedb;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
/**
* A simple {#link Fragment} subclass.
*/
public class SearchFormFragment extends Fragment {
private Button searchButton;
private EditText gameTitleEditText;
Spinner spinnerGenre;
public SearchFormFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(final LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View searchFormView = inflater.inflate(R.layout.fragment_search_form, container, false);
searchButton = searchFormView.findViewById(R.id.searchButton);
gameTitleEditText = searchFormView.findViewById(R.id.game_title_editText);
spinnerGenre = searchFormView.findViewById(R.id.genre_spinner);
ArrayAdapter<CharSequence> genreAdapter = ArrayAdapter.createFromResource(
getActivity(),
R.array.game_genres,
android.R.layout.simple_spinner_item
);
genreAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinnerGenre.setAdapter(genreAdapter);
searchButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String filterGameTitle = gameTitleEditText.getText().toString();
int filterGenreId = spinnerGenre.getSelectedItemPosition();
String message = String.format("Game Title: %s\n Genre: %s", filterGameTitle, filterGenreId);
Toast.makeText(getActivity(),message, Toast.LENGTH_LONG).show();
}
});
// Inflate the layout for this fragment
//return inflater.inflate(R.layout.fragment_search_form, container, false);
return searchFormView;
}
}
SearchResultsFragment.java
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListView;
import android.widget.TextView;
/**
* A simple {#link Fragment} subclass.
*/
public class SearchResultsFragment extends Fragment {
TextView infoTextView;
ListView listViewGames;
public SearchResultsFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View searchResultsView = inflater.inflate(R.layout.fragment_search_results, container, false);
return searchResultsView;
}
private void findViews()
{
infoTextView = getActivity().findViewById(R.id.info_textView);
listViewGames = getActivity().findViewById(R.id.games_listView);
}
}
I want to archive the following via the fragments:
ListActivity.java
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
public class ListActivity extends AppCompatActivity {
private TextView textViewInfo;
private ListView listViewBooks;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list);
// Animation when this Activity appears
overridePendingTransition(R.anim.pull_in_from_right, R.anim.hold);
// Get user filters from Intent
Intent intent = getIntent();
String filterAuthor = intent.getStringExtra("AUTHOR");
String filterTitle = intent.getStringExtra("TITLE");
int filterGenreId = intent.getIntExtra("GENREID", 0);
findViews();
// Show user filters for information
String message = String.format("Author: %s\nTitle: %s\nGenreId: %d",
filterAuthor, filterTitle, filterGenreId);
textViewInfo.setText(message);
DataStore.LoadBooks(filterAuthor, filterTitle, filterGenreId);
//Complex Object Binding
ListAdapter booksAdapter = new SimpleAdapter(
this,
DataStore.Books,
R.layout.list_item,
new String[]{DataStore.KEY_TITLE, DataStore.KEY_AUTHOR, DataStore.KEY_GENRENAME},
new int[]{R.id.book_item_title, R.id.book_item_author, R.id.book_item_genre}
);
listViewBooks.setAdapter(booksAdapter);
listViewBooks.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Intent detailsIntent = new Intent(ListActivity.this, DetailsActivity.class);
detailsIntent.putExtra(DataStore.KEY_POSITION, position);
startActivity(detailsIntent);
}
});
}
#Override
protected void onPause(){
overridePendingTransition(R.anim.hold, R.anim.push_out_to_right);
super.onPause();
}
private void findViews(){
textViewInfo = findViewById(R.id.textViewInfo);
listViewBooks = findViewById(R.id.listViewBooks);
}
}
Mainactivity.java
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
private EditText textAuthor;
private EditText textTitle;
private EditText textGenre;
private Button buttonSearch;
private Spinner spinnerGenre;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
DataStore.Init(getApplicationContext());
textAuthor = findViewById(R.id.editTextAuthor);
textTitle= findViewById(R.id.editTextAuthor);
buttonSearch = findViewById(R.id.buttonSearch);
spinnerGenre = (Spinner) findViewById(R.id.spinnerGenre);
ArrayAdapter<CharSequence> genreAdapter = ArrayAdapter.createFromResource(
this,
R.array.book_genres,
android.R.layout.simple_spinner_item
);
genreAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinnerGenre.setAdapter(genreAdapter);
buttonSearch.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String filterAuthor = textAuthor.getText().toString();
String filterTitle = textTitle.getText().toString();
int filterGenreId = spinnerGenre.getSelectedItemPosition();
Intent intent = new Intent(MainActivity.this, ListActivity.class);
intent.putExtra("AUTHOR", filterAuthor);
intent.putExtra("TITLE", filterTitle);
intent.putExtra("GENREID", filterGenreId);
startActivity(intent);
}
});
}
}

Try this
pass value between two fragment using bundle
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
public class TabPagerAdapter extends FragmentPagerAdapter{
int tabCount;
public TabPagerAdapter(FragmentManager fm, int numberOfTabs) {
super(fm);
this.tabCount = numberOfTabs;
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return new HomeScreenFragment();
case 1:
return new SearchFormFragment();
case 2:
Fragment fragment = new SearchResultsFragment()
Bundle args = new Bundle();
args.putString("Key", "Value");
fragment.setArguments(args);
return fragment;
case 3:
return new DetailsScreenFragment();
default:
return null;
}
}
#Override
public int getCount() {
return tabCount;
}
}
in your onCreateView(....) of SearchResultsFragment
String value = getArguments().getString("Key");
public class SearchResultsFragment extends Fragment {
TextView infoTextView;
ListView listViewGames;
public SearchResultsFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View searchResultsView =
inflater.inflate(R.layout.fragment_search_results, container, false);
String value = getArguments().getString("Key");
return searchResultsView;
}
private void findViews(){
infoTextView = getActivity().findViewById(R.id.info_textView);
listViewGames = getActivity().findViewById(R.id.games_listView);
}
}
hop its help you

There are many ways you can pass objects/values between fragments. In your case, the simplest solution would be to delegate those values to the holding Activity i.e MainActivity.
MainActivity:
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.design.widget.TabLayout;
import android.view.MenuInflater;
import android.view.View;
import android.support.design.widget.NavigationView;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {
//these will hold your values
String filterGameTitle;
int filterGenreId;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setImageResource(R.drawable.ic_search_white_24dp);
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();
}
});
//TabLayout function call
configureTabLayout();
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);
}
#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.
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()){
case R.id.menu_exit:
finish();
return true;
case R.id.menu_settings:
Toast.makeText(this, "Under Construction", Toast.LENGTH_LONG).show();
return true;
default:
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) {
// Handle the camera action
} else if (id == R.id.nav_gallery) {
} else if (id == R.id.nav_slideshow) {
} else if (id == R.id.nav_manage) {
} else if (id == R.id.nav_share) {
} else if (id == R.id.nav_send) {
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
//Tab Layout function declaration
private void configureTabLayout() {
//Getting the tab layout
TabLayout tabLayout = findViewById(R.id.tab_layout);
//Adding Tabs
tabLayout.addTab(tabLayout.newTab().setIcon(R.drawable.ic_home_white_24dp));
tabLayout.addTab(tabLayout.newTab().setIcon(R.drawable.ic_search_white_24dp));
tabLayout.addTab(tabLayout.newTab().setIcon(R.drawable.ic_results_white_24dp));
tabLayout.addTab(tabLayout.newTab().setIcon(R.drawable.ic_details_white_24dp));
//The TabPagerAdapter instance is then
//assigned as the adapter for the ViewPager and the TabLayout component added
//to the page change listener
final ViewPager viewPager = (ViewPager) findViewById(R.id.pager);
final PagerAdapter adapter = new TabPagerAdapter
(getSupportFragmentManager(), tabLayout.getTabCount());
viewPager.setAdapter(adapter);
//Finally, the onTabSelectedListener is configured on the TabLayout instance and
//the onTabSelected() method implemented to set the current page on the
//ViewPager based on the currently selected tab number.
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
#Override
public void onTabSelected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(TabLayout.Tab tab) {
}
#Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
}
}
SearchFormFragment:
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
/**
* A simple {#link Fragment} subclass.
*/
public class SearchFormFragment extends Fragment {
private Button searchButton;
private EditText gameTitleEditText;
Spinner spinnerGenre;
public SearchFormFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(final LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View searchFormView = inflater.inflate(R.layout.fragment_search_form, container, false);
searchButton = searchFormView.findViewById(R.id.searchButton);
gameTitleEditText = searchFormView.findViewById(R.id.game_title_editText);
spinnerGenre = searchFormView.findViewById(R.id.genre_spinner);
ArrayAdapter<CharSequence> genreAdapter = ArrayAdapter.createFromResource(
getActivity(),
R.array.game_genres,
android.R.layout.simple_spinner_item
);
genreAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinnerGenre.setAdapter(genreAdapter);
searchButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String filterGameTitle = gameTitleEditText.getText().toString();
int filterGenreId = spinnerGenre.getSelectedItemPosition();
((MainActivity)getActivity()).filterGameTitle = filterGameTitle;
((MainActivity)getActivity()).filterGenreId = filterGenreId;
String message = String.format("Game Title: %s\n Genre: %s", filterGameTitle, filterGenreId);
Toast.makeText(getActivity(),message, Toast.LENGTH_LONG).show();
}
});
// Inflate the layout for this fragment
//return inflater.inflate(R.layout.fragment_search_form, container, false);
return searchFormView;
}
}
SearchResultFragment:
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListView;
import android.widget.TextView;
/**
* A simple {#link Fragment} subclass.
*/
public class SearchResultsFragment extends Fragment {
TextView infoTextView;
ListView listViewGames;
String filterGameTitle;
int filterGenreId;
public SearchResultsFragment() {
// Required empty public constructor
}
#Override
public void onAttach(Context context)
{
filterGameTitle = ((MainActivity)getActivity()).filterGameTitle;
filterGenreId = ((MainActivity)getActivity()).filterGenreId;
super.onAttach(context);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View searchResultsView = inflater.inflate(R.layout.fragment_search_results, container, false);
return searchResultsView;
}
private void findViews()
{
infoTextView = getActivity().findViewById(R.id.info_textView);
listViewGames = getActivity().findViewById(R.id.games_listView);
}
}

You can use interface to send your search string to your activity from fragment 2, and from their you can call all methods in your fragment 3 as fragment3 object will be available to you in your activity, you can make performSearch() in your fragment3 and call it from your activity.
Alternatively you can use something like event bus to avoid the boiler plate code needed to setup interface.
Have a look at this event bus repo https://github.com/greenrobot/EventBus
Register event bus where you want the search string, in your case register the event bus in Fragment3 like this
#Override
public void onStart() {
super.onStart();
EventBus.getDefault().register(this);
}
#Override
public void onStop() {
super.onStop();
EventBus.getDefault().unregister(this);
}
In your Fragment 3 create a function like this
#Subscribe
public void onSearchEvent(String searchString){
//you will get your search string here
}
Now comeback to fragment2 from where you want to send the searchString, you have to put below code from where you want to send searchString, and this posted searchString will be received by fragment 3 in its onSearchEvent method
EventBus.getDefault().post(searchString);

Everytime I have to change something to reflect [closed]

Closed. This question needs details or clarity. It is not currently accepting answers.
Want to improve this question? Add details and clarify the problem by editing this post.
Closed 4 years ago.
Improve this question
In my chat App FriendsFragment is shwoing blank. If I want to reflect that then, I have run the app, open the Friends tab in my app and after Instant run in Android studio and it will reflect. If it will not, then I have to add Log statement anywhere in my FriendsFragment, and run Instant run with exctly the open tab of friendsfragmet.
Why I'm telling you to add Log statement is necessary because I found this bug that whenever I change something on my Friends Fragment and then run Instant run, then only it will show the Fragment part. And I have to do this every time, otherwise it won't show. Add Log statement and remove second time, or change tag or change message, do something that makes the changes, and must run Instant run (that Yellow symbol like booster).
NOTE: I'm still doing this thing, I observe this problem by myself and I also don't know why I have to change something every time to show this Fragment? I also built the similar fragment in this same app, but for that there is no problem!
FriendFragment
package com.jimmytrivedi.lapitchat;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.Fragment;
import android.support.v7.app.AlertDialog;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.firebase.ui.database.FirebaseRecyclerOptions;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.Query;
import com.google.firebase.database.ValueEventListener;
import com.squareup.picasso.Picasso;
import de.hdodenhof.circleimageview.CircleImageView;
public class FriendsFragment extends Fragment {
private RecyclerView FriendRecyclerView;
private DatabaseReference databaseReference, UsersDatabaseReference;
private FirebaseAuth mAuth;
private String currentUID;
private View MainView;
public FriendsFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
MainView = inflater.inflate(R.layout.fragment_friend, container, false);
FriendRecyclerView = MainView.findViewById(R.id.FriendRecyclerView);
mAuth = FirebaseAuth.getInstance();
if (mAuth.getCurrentUser() != null) {
currentUID = mAuth.getCurrentUser().getUid();
databaseReference = FirebaseDatabase.getInstance().getReference().child("Friends").child(currentUID);
databaseReference.keepSynced(true);
UsersDatabaseReference = FirebaseDatabase.getInstance().getReference().child("Users");
UsersDatabaseReference.keepSynced(true);
}
FriendRecyclerView.setHasFixedSize(true);
FriendRecyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
Log.d("wihddiewd", "Is it going?");
return MainView;
}
#Override
public void onStart() {
super.onStart();
Query query = FirebaseDatabase. getInstance()
.getReference()
.child("Friends")
.limitToLast(50);
FirebaseRecyclerOptions<Friends> options = new FirebaseRecyclerOptions.Builder<Friends>()
.setQuery(query, Friends.class)
.build();
final FirebaseRecyclerAdapter<Friends, FriendsViewHolder> FriendsRecyclerViewAdapter = new
FirebaseRecyclerAdapter<Friends, FriendsViewHolder>(options) {
#Override
protected void onBindViewHolder(#NonNull final FriendsViewHolder holder, int position, #NonNull Friends model) {
holder.setDate(model.getDate());
final String listUID = getRef(position).getKey();
UsersDatabaseReference.child(listUID).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
final String userName = dataSnapshot.child("Name").getValue().toString();
String thumbImage = dataSnapshot.child("thumbImage").getValue().toString();
String userOnline = dataSnapshot.child("Online").getValue().toString();
holder.setName(userName);
holder.setThumbImage(thumbImage, getContext());
holder.setUserOnline(userOnline);
holder.mView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
CharSequence options[] = new CharSequence[]{"Open profile", "Send message"};
AlertDialog.Builder builder = new AlertDialog.Builder(getContext());
builder.setTitle("Select Options");
builder.setItems(options, new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
if (which == 0) {
Intent intent = new Intent(getContext(), ProfileActivity.class);
intent.putExtra("userID", listUID);
startActivity(intent);
}
if (which == 1) {
Intent intent = new Intent(getContext(), ChatActivity.class);
intent.putExtra("userID", listUID);
intent.putExtra("userName", userName);
startActivity(intent);
}
}
});
builder.show();
}
});
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
}
});
}
#NonNull
#Override
public FriendsViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.users_single_layout, parent, false);
return new FriendsViewHolder(view);
}
};
FriendRecyclerView.setAdapter(FriendsRecyclerViewAdapter);
FriendsRecyclerViewAdapter.startListening();
}
public static class FriendsViewHolder extends RecyclerView.ViewHolder {
View mView;
public FriendsViewHolder(View itemView) {
super(itemView);
mView = itemView;
}
public void setDate(String date) {
TextView userStatusView = mView.findViewById(R.id.userStatus);
userStatusView.setText(date);
}
public void setName(String name) {
TextView userNameView = mView.findViewById(R.id.userName);
userNameView.setText(name);
}
public void setThumbImage(String thumbImage, Context context) {
CircleImageView circleImageView = mView.findViewById(R.id.userImage);
Picasso.get().load(thumbImage).placeholder(R.drawable.defaultimage)
.into(circleImageView);
}
public void setUserOnline(String online) {
ImageView userOnline = mView.findViewById(R.id.online);
if (online.equals("true")) {
userOnline.setVisibility(View.VISIBLE);
} else {
userOnline.setVisibility(View.INVISIBLE);
}
}
}
}
Update
I know this is weird bug. But basically when I open my app and in app firends tab (which is FriendsFragment.java), it is showing blank. So I tried to debug that is there any mistake on my code or not? But I didn't find. But while debugging time, when I go to my firends tab in my mobile app, and put any log statement in Android Studio (because when I add/remove something so Android Studio will understand that some changes made happen, and then I run Instant run(not normal run) then FriendFragment will reflect and it shows the user list.
And I have to do this every time, (means I have to add something/remove something, that consider changes for Android Studio) then only FriendsFragment will show the users list. And even if I not open my Friends tab, but open something else in app and than run (instant run) that is also not work! Only when I just go to friends tab (that time it is showing blank, but that is okay) and run Instant run, then only it will reflect.
fragment_friends.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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=".FriendsFragment">
<android.support.v7.widget.RecyclerView
android:id="#+id/FriendRecyclerView"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</android.support.v7.widget.RecyclerView>
</RelativeLayout>
users_single_layout.xml
<?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">
<de.hdodenhof.circleimageview.CircleImageView
android:id="#+id/userImage"
android:layout_width="64dp"
android:layout_height="64dp"
android:layout_marginBottom="15dp"
android:layout_marginLeft="15dp"
android:layout_marginTop="15dp"
android:src="#drawable/defaultimage" />
<TextView
android:id="#+id/userName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignTop="#+id/userImage"
android:layout_marginStart="99dp"
android:text="Display Name"
android:textColor="#000000"
android:textSize="18dp" />
<TextView
android:id="#+id/userStatus"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignStart="#+id/userName"
android:layout_below="#+id/userName"
android:text="User default Status"
android:textSize="15dp" />
<ImageView
android:id="#+id/online"
android:layout_width="8dp"
android:layout_height="wrap_content"
android:layout_alignTop="#+id/userName"
android:layout_marginLeft="10dp"
android:layout_toEndOf="#+id/userName"
android:visibility="invisible"
android:src="#drawable/online" />
</RelativeLayout>
Another Fragment ChatFragment, which is similar to this and working pretty fine).
ChatFragment.java
package com.jimmytrivedi.lapitchat;
import android.content.Context;
import android.content.Intent;
import android.graphics.Typeface;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.firebase.ui.database.FirebaseRecyclerOptions;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.ChildEventListener;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.Query;
import com.google.firebase.database.ValueEventListener;
import com.squareup.picasso.Picasso;
import de.hdodenhof.circleimageview.CircleImageView;
public class ChatFragment extends Fragment {
private RecyclerView ConversationList;
private DatabaseReference ConversationRef, MessageRef, UserRef;
private FirebaseAuth mAuth;
private String currentUID;
private View MainView;
public ChatFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
MainView = inflater.inflate(R.layout.fragment_chat, container, false);
ConversationList = MainView.findViewById(R.id.ConversationList);
mAuth = FirebaseAuth.getInstance();
currentUID = mAuth.getCurrentUser().getUid();
ConversationRef = FirebaseDatabase.getInstance().getReference().child("Chat").child(currentUID);
ConversationRef.keepSynced(true);
UserRef = FirebaseDatabase.getInstance().getReference().child("Users");
UserRef.keepSynced(true);
MessageRef = FirebaseDatabase.getInstance().getReference().child("Messages").child(currentUID);
LinearLayoutManager layoutManager = new LinearLayoutManager(getContext());
layoutManager.setReverseLayout(true);
layoutManager.setStackFromEnd(true);
ConversationList.setHasFixedSize(true);
ConversationList.setLayoutManager(layoutManager);
return MainView;
}
#Override
public void onStart() {
super.onStart();
Query conversationQuery = ConversationRef.orderByChild("timestamp");
Query query = FirebaseDatabase.getInstance()
.getReference()
.child("Chat")
.limitToLast(50);
FirebaseRecyclerOptions<Conversation> options = new FirebaseRecyclerOptions.Builder<Conversation>()
.setQuery(query, Conversation.class)
.build();
FirebaseRecyclerAdapter<Conversation, ConversationViewHolder> ConversationRecyclerViewAdapter = new
FirebaseRecyclerAdapter<Conversation, ConversationViewHolder>(options) {
#Override
protected void onBindViewHolder(#NonNull final ConversationViewHolder holder, int position, #NonNull final Conversation model) {
final String listUID = getRef(position).getKey();
Query lastMessageQuery = MessageRef.child(listUID).limitToLast(1);
lastMessageQuery.addChildEventListener(new ChildEventListener() {
#Override
public void onChildAdded(#NonNull DataSnapshot dataSnapshot, #Nullable String s) {
String data = dataSnapshot.child("message").getValue().toString();
holder.setMassage(data, model.isSeen());
}
#Override
public void onChildChanged(#NonNull DataSnapshot dataSnapshot, #Nullable String s) {
}
#Override
public void onChildRemoved(#NonNull DataSnapshot dataSnapshot) {
}
#Override
public void onChildMoved(#NonNull DataSnapshot dataSnapshot, #Nullable String s) {
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
}
});
UserRef.child(listUID).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
final String userName = dataSnapshot.child("Name").getValue().toString();
String userThumb = dataSnapshot.child("thumbImage").getValue().toString();
if (dataSnapshot.hasChild("Online")) {
String userOnline = dataSnapshot.child("Online").getValue().toString();
holder.setUserOnline(userOnline);
}
holder.setName(userName);
holder.setUserImage(userThumb, getContext());
holder.mView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(getContext(), ChatActivity.class);
intent.putExtra("userID", listUID);
intent.putExtra("userName", userName);
startActivity(intent);
}
});
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
}
});
}
#NonNull
#Override
public ConversationViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.users_single_layout, parent, false);
return new ConversationViewHolder(view);
}
};
ConversationList.setAdapter(ConversationRecyclerViewAdapter);
ConversationRecyclerViewAdapter.startListening();
}
public static class ConversationViewHolder extends RecyclerView.ViewHolder {
View mView;
public ConversationViewHolder(View itemView) {
super(itemView);
mView = itemView;
}
public void setMassage(String message, boolean isSeen) {
TextView userStatusView = mView.findViewById(R.id.userStatus);
userStatusView.setText(message);
if (!isSeen) {
userStatusView.setTypeface(userStatusView.getTypeface(), Typeface.BOLD);
} else {
userStatusView.setTypeface(userStatusView.getTypeface(), Typeface.NORMAL);
}
}
public void setUserOnline(String online) {
ImageView userOnlineView = mView.findViewById(R.id.online);
if (online.equals("true")) {
userOnlineView.setVisibility(View.VISIBLE);
} else {
userOnlineView.setVisibility(View.INVISIBLE);
}
}
public void setName(String userName) {
TextView userNameView = mView.findViewById(R.id.userName);
userNameView.setText(userName);
}
public void setUserImage(String userThumb, Context context) {
CircleImageView userImageView = mView.findViewById(R.id.userImage);
Picasso.get().load(userThumb).placeholder(R.drawable.defaultimage).into(userImageView);
}
}
}
Friends.java
package com.jimmytrivedi.lapitchat;
public class Friends {
public String date;
public Friends() {
}
public Friends(String date) {
this.date = date;
}
public String getDate() {
return date;
}
public void setDate(String date) {
this.date = date;
}
}
SectionPagerAdapter.java
package com.jimmytrivedi.lapitchat;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
RequestFragment requestFragment = new RequestFragment();
return requestFragment;
case 1:
ChatFragment chatFragment = new ChatFragment();
return chatFragment;
case 2:
FriendsFragment friendFragment = new FriendsFragment();
return friendFragment;
default:
return null;
}
}
#Override
public int getCount() {
return 3;
}
#Nullable
#Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0:
return "Requests";
case 1:
return "Chats";
case 2:
return "Friends";
default:
return null;
}
}
}
MainActivity.java
package com.jimmytrivedi.lapitchat;
import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.TabLayout;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import com.facebook.login.LoginManager;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ServerValue;
public class MainActivity extends AppCompatActivity {
private FirebaseAuth mAuth;
private FirebaseUser currentUser;
private Toolbar toolbar;
private ViewPager viewPager;
private SectionsPagerAdapter sectionsPagerAdapter;
private TabLayout tabLayout;
private DatabaseReference UserDatabaseReference;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mAuth = FirebaseAuth.getInstance();
currentUser = mAuth.getCurrentUser();
if (currentUser == null) {
sendTostart();
} else {
UserDatabaseReference = FirebaseDatabase.getInstance().getReference().child("Users").child(mAuth.getCurrentUser().getUid());
UserDatabaseReference.child("Online").setValue("true");
}
viewPager = findViewById(R.id.viewPager);
sectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(sectionsPagerAdapter);
toolbar = findViewById(R.id.mainToolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setTitle("Home");
tabLayout = findViewById(R.id.tabLayout);
tabLayout.setupWithViewPager(viewPager);
}
#Override
protected void onPause() {
super.onPause();
if (currentUser != null) {
UserDatabaseReference.child("Online").setValue(ServerValue.TIMESTAMP);
}
}
private void sendTostart() {
startActivity(new Intent(MainActivity.this, StartActivity.class));
finish();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
getMenuInflater().inflate(R.menu.main_menu, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
super.onOptionsItemSelected(item);
if (item.getItemId() == R.id.logout) {
FirebaseAuth.getInstance().signOut();
LoginManager.getInstance().logOut();
sendTostart();
}
if (item.getItemId() == R.id.settings) {
startActivity(new Intent(MainActivity.this, SettingsActivity.class));
}
if (item.getItemId() == R.id.allUsers) {
startActivity(new Intent(MainActivity.this, UsersActivity.class));
}
return true;
}
}

Use
`viewPager.setOffscreenPageLimit(3);`
after
viewPager.setAdapter(sectionsPagerAdapter);
inside MainActivity.

Use notifyDataSetChanged() after setting adapter to recyclerview.
FriendRecyclerView.setAdapter(FriendsRecyclerViewAdapter);
FriendsRecyclerViewAdapter.notifyDataSetChanged();

App crashed after adding navigation menu in Android Studio

Please take a look at my source code, my app crashed after I added the navigation Menu. Can you please tell what is wrong I have been searching all on Google and could not arrive at a solution to this issue? Thank You.
My MainActivity looks like:
package com.example.rssreader;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.SearchManager;
import android.content.Intent;
import android.content.res.Configuration;
import android.os.Bundle;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.support.v7.app.ActionBar;
import android.view.LayoutInflater;
import android.view.MenuInflater;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.Toast;
import java.util.Locale;
public class MainActivity extends AppCompatActivity {
private DrawerLayout mDrawerLayout;
private ListView mDrawerList;
private android.support.v4.app.ActionBarDrawerToggle mDrawerToggle;
private CharSequence mDrawerTitle;
private CharSequence mTitle;
private String[] mPlanetTitles;
RecyclerView recyclerView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView = (RecyclerView) findViewById(R.id.recyclerview);
ReadRss readRss = new ReadRss(this, recyclerView);
readRss.execute();
mTitle = mDrawerTitle = getTitle();
mPlanetTitles = getResources().getStringArray(R.array.contents);
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
mDrawerList = (ListView) findViewById(R.id.left_drawer);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setHomeButtonEnabled(true);
// set a custom shadow that overlays the main content when the drawer opens
mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START);
// set up the drawer's list view with items and click listener
mDrawerList.setAdapter(new ArrayAdapter<String>(this,
R.layout.drawer_list_item, mPlanetTitles));
mDrawerList.setOnItemClickListener(new DrawerItemClickListener());
// enable ActionBar app icon to behave as action to toggle nav drawer
// ActionBarDrawerToggle ties together the the proper interactions
// between the sliding drawer and the action bar app icon
mDrawerToggle = new android.support.v4.app.ActionBarDrawerToggle(
this, /* host Activity */
mDrawerLayout, /* DrawerLayout object */
R.drawable.ic_drawer, /* nav drawer image to replace 'Up' caret */
R.string.drawer_open, /* "open drawer" description for accessibility */
R.string.drawer_close /* "close drawer" description for accessibility */
) {
public void onDrawerClosed(View view) {
getActionBar().setTitle(mTitle);
invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
}
public void onDrawerOpened(View drawerView) {
getActionBar().setTitle(mDrawerTitle);
invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
}
};
mDrawerLayout.setDrawerListener(mDrawerToggle);
if (savedInstanceState == null) {
selectItem(0);
}
getWindow().setNavigationBarColor(getResources().getColor(R.color.colorPrimary));
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.layout.main, menu);
return super.onCreateOptionsMenu(menu);
}
/* Called whenever we call invalidateOptionsMenu() */
#Override
public boolean onPrepareOptionsMenu(Menu menu) {
// If the nav drawer is open, hide action items related to the content view
boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
menu.findItem(R.id.action_websearch).setVisible(!drawerOpen);
return super.onPrepareOptionsMenu(menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// The action bar home/up action should open or close the drawer.
// ActionBarDrawerToggle will take care of this.
if (mDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
// Handle action buttons
switch(item.getItemId()) {
case R.id.action_websearch:
// create intent to perform web search for this planet
Intent intent = new Intent(Intent.ACTION_WEB_SEARCH);
// catch event that there's no activity to handle intent
if (intent.resolveActivity(getPackageManager()) != null) {
startActivity(intent);
} else {
Toast.makeText(this, R.string.app_not_available, Toast.LENGTH_LONG).show();
}
return true;
default:
return super.onOptionsItemSelected(item);
}
}
/* The click listner for ListView in the navigation drawer */
private class DrawerItemClickListener implements ListView.OnItemClickListener {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
selectItem(position);
}
}
private void selectItem(int position) {
// update the main content by replacing fragments
Fragment fragment = new PlanetFragment();
Bundle args = new Bundle();
args.putInt(PlanetFragment.ARG_CONTENT_NUMBER, position);
fragment.setArguments(args);
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();
// update selected item and title, then close the drawer
mDrawerList.setItemChecked(position, true);
setTitle(mPlanetTitles[position]);
mDrawerLayout.closeDrawer(mDrawerList);
}
#Override
public void setTitle(CharSequence title) {
mTitle = title;
getActionBar().setTitle(mTitle);
}
/**
* When using the ActionBarDrawerToggle, you must call it during
* onPostCreate() and onConfigurationChanged()...
*/
#Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
// Sync the toggle state after onRestoreInstanceState has occurred.
mDrawerToggle.syncState();
}
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
// Pass any configuration change to the drawer toggls
mDrawerToggle.onConfigurationChanged(newConfig);
}
/**
* Fragment that appears in the "content_frame", shows a planet
*/
public static class PlanetFragment extends Fragment {
public static final String ARG_CONTENT_NUMBER = "planet_number";
public PlanetFragment() {
// Empty constructor required for fragment subclasses
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_content, container, false);
int i = getArguments().getInt(ARG_CONTENT_NUMBER);
String planet = getResources().getStringArray(R.array.contents)[i];
int imageId = getResources().getIdentifier(planet.toLowerCase(Locale.getDefault()),
"drawable", getActivity().getPackageName());
((ImageView) rootView.findViewById(R.id.image)).setImageResource(imageId);
getActivity().setTitle(planet);
return rootView;
}
}
}
My Activity_main.xml looks like:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<FrameLayout
android:id="#+id/content_frame"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<ListView
android:id="#+id/left_drawer"
android:layout_width="240dp"
android:layout_height="match_parent"
android:layout_gravity="start"
android:choiceMode="singleChoice"
android:divider="#android:color/transparent"
android:dividerHeight="0dp"
android:background="#ccc"/>
</android.support.v4.widget.DrawerLayout>
Drawer_list_item.xml looks like:
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#android:id/text1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceListItemSmall"
android:gravity="center_vertical"
android:paddingLeft="16dp"
android:paddingRight="16dp"
android:textColor="#113d5e"
android:background="?android:attr/activatedBackgroundIndicator"
android:minHeight="?android:attr/listPreferredItemHeightSmall"/>
Fragment_content.xml looks like:
<ImageView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/image"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#000000"
android:gravity="center"
android:padding="32dp" />
Main.xml looks like:
<ImageView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/image"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#000000"
android:gravity="center"
android:padding="32dp" />
Thank You

I was able to fix that issue by creating a separate class for the navigation drawer. However, I am facing another issue with the RssFeeds.
public class ReadRss extends AsyncTask and recyclerView.setLayoutManager(new LinearLayoutManager(context) is where the error is pointing to when the app crashed when running the debug.
Here is the ReadRss.java:
package tk.mattercast.myapplication;
import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
public class ReadRss extends AsyncTask<Void, Void, Void> {
Context context;
String address = "http://www.oecd.org/corruption/index.xml";
ProgressDialog progressDialog;
ArrayList<FeedItem>feedItems;
RecyclerView recyclerView;
URL url;
public ReadRss(Context context,RecyclerView recyclerView) {
this.recyclerView=recyclerView;
this.context = context;
progressDialog = new ProgressDialog(context);
progressDialog.setMessage("Fetching Data...");
}
#Override
protected void onPreExecute() {
progressDialog.show();
super.onPreExecute();
}
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
progressDialog.dismiss();
MyAdapter adapter=new MyAdapter(context,feedItems);
recyclerView.setLayoutManager(new LinearLayoutManager(context) {
#Override
public RecyclerView.LayoutParams generateDefaultLayoutParams() {
return null;
}
});
recyclerView.addItemDecoration(new VerticalSpace(50));
recyclerView.setAdapter(adapter);
}
#Override
protected Void doInBackground(Void... params) {
ProcessXml(Getdata());
return null;
}
private void ProcessXml(Document data) {
if (data != null) {
feedItems=new ArrayList<>();
Element root = data.getDocumentElement();
Node channel = root.getChildNodes().item(1);
NodeList items = channel.getChildNodes();
for (int i = 0; i < items.getLength(); i++) {
Node cureentchild = items.item(i);
if (cureentchild.getNodeName().equalsIgnoreCase("item")) {
FeedItem item=new FeedItem();
NodeList itemchilds = cureentchild.getChildNodes();
for (int j = 0; j < itemchilds.getLength(); j++) {
Node cureent = itemchilds.item(j);
if (cureent.getNodeName().equalsIgnoreCase("title")){
item.setTitle(cureent.getTextContent());
}else if (cureent.getNodeName().equalsIgnoreCase("description")){
item.setDescription(cureent.getTextContent());
}else if (cureent.getNodeName().equalsIgnoreCase("pubDate")){
item.setPubDate(cureent.getTextContent());
}else if (cureent.getNodeName().equalsIgnoreCase("link")){
item.setLink(cureent.getTextContent());
}
}
feedItems.add(item);
}
}
}
}
public Document Getdata() {
try {
url = new URL(address);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
InputStream inputStream = connection.getInputStream();
DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = builderFactory.newDocumentBuilder();
Document xmlDoc = builder.parse(inputStream);
return xmlDoc;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
}

A populated RecyclerView is empty

The data model:
public class Information {
String title;}
The adapter:
import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.Collections;
import java.util.List;
/**
* Created by anish on 29/12/14.
*/
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {
private LayoutInflater inflator;
List<Information> data = Collections.emptyList();
public MyAdapter(Context context, List<Information> data)
{
inflator = LayoutInflater.from(context);
this.data=data;
}
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = inflator.inflate(R.layout.custom_row, parent, false);
MyViewHolder holder = new MyViewHolder(view);
return holder;
}
#Override
public void onBindViewHolder(MyViewHolder holder, int position) {
Information current = data.get(position);
holder.text.setText(current.title);
}
#Override
public int getItemCount() {
return data.size();
}
class MyViewHolder extends RecyclerView.ViewHolder{
TextView text;
public MyViewHolder(View itemView) {
super(itemView);
text = (TextView) itemView.findViewById(R.id.listText);
}
}
}
The navigation drawer fragment:
import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import java.util.ArrayList;
import java.util.List;
/**
* A simple {#link Fragment} subclass.
*/
public class NavigationDrawerFragment extends Fragment {
private RecyclerView recyclerView;
private ActionBarDrawerToggle mDrawerToggle;
private DrawerLayout mDrawerLayout;
private boolean mUserLearnedDrawer;
private boolean mFromSavedInstanceState;
public static final String PREF_FILE_NAME="testpref";
public static final String KEY_USER_LEARNED_DRAWER="user_learned_drawer";
private View containerView;
private MyAdapter adapter;
public NavigationDrawerFragment() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
mUserLearnedDrawer = Boolean.getBoolean(readFromPreferences(getActivity(),KEY_USER_LEARNED_DRAWER,"false"));
if(savedInstanceState!=null) mFromSavedInstanceState = true;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View layout = inflater.inflate(R.layout.fragment_navigation_drawer, container, false);
recyclerView = (RecyclerView) layout.findViewById(R.id.drawer_list);
adapter = new MyAdapter(getActivity(),getData());
recyclerView.setAdapter(adapter);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
// Inflate the layout for this fragment
return layout;
}
public static List<Information> getData()
{
List<Information> data = new ArrayList<>();
//int icons[]={R.drawable.abc_ic_ab_back_mtrl_am_alpha, R.drawable.abc_ab_share_pack_holo_dark, R.drawable.abc_btn_radio_to_on_mtrl_000};
String[] title = {"Microsoft","Yahoo","Google"};
for(int i=0; i<title.length; i++)
{
Information current = new Information();
//current.iconId = icons[i];
current.title = title[i];
data.add(current);
}
return data;
}
public void setUp(int fragmentID, DrawerLayout drawerLayout, final Toolbar toolbar) {
containerView = getActivity().findViewById(fragmentID);
mDrawerLayout = drawerLayout;
mDrawerToggle=new ActionBarDrawerToggle(getActivity(),drawerLayout,toolbar, R.string.drawer_open, R.string.drawer_close) {
#Override
public void onDrawerOpened(View drawerView) {
if(!mUserLearnedDrawer)
{
mUserLearnedDrawer=true;
saveToPreferences(getActivity(),KEY_USER_LEARNED_DRAWER,mUserLearnedDrawer+"");
}
getActivity().invalidateOptionsMenu();
super.onDrawerOpened(drawerView);
}
#Override
public void onDrawerClosed(View drawerView) {
getActivity().invalidateOptionsMenu();
super.onDrawerClosed(drawerView);
}
#Override
public void onDrawerSlide(View drawerView, float slideOffset) {
if(slideOffset<0.6)
{
toolbar.setAlpha(1-slideOffset);
}
}
};
if(!mUserLearnedDrawer && !mFromSavedInstanceState)
{
mDrawerLayout.openDrawer(containerView);
}
mDrawerLayout.setDrawerListener(mDrawerToggle);
mDrawerLayout.post(new Runnable() {
#Override
public void run() {
mDrawerToggle.syncState();
}
});
}
public static void saveToPreferences(Context context, String preferenceName, String preferenceValue)
{
SharedPreferences sharedPreferences = context.getSharedPreferences(PREF_FILE_NAME, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString(preferenceName, preferenceValue);
editor.apply();
}
public static String readFromPreferences(Context context, String preferenceName, String defaultValue)
{
SharedPreferences sharedPreferences = context.getSharedPreferences(PREF_FILE_NAME, Context.MODE_PRIVATE);
return sharedPreferences.getString(preferenceName, defaultValue);
}
}
The XML for an individual row I am populating:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<TextView
android:id="#+id/listText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Dummy Text"
android:gravity="center"
android:textColor="#0000"
android:paddingTop="5dp"
/>
</LinearLayout>
When I run the app, the NavigationDrawer is blank. I first thought of using an ImageView, but then for debugging purposes, I thought of using text only. I did everything I could. Please help.

There is Problem in your Model Class. You should use getter and setter method in model class. The following code may help you.
public class Information {
private String title;
public Model( String title) {
super();
this.title = title;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
}
In MainActivity.java, set the title in the MainActivity

In my case, i realized that getItemCount() method of the adapter is never called. In this case, setting layoutmanager of recyclerView is solved my problem.
recyclerView.layoutManager = LinearLayoutManager(mainActivity)

(JAVA) I faced a similar issue and the following code worked for me.
The Adapter Functions were not being called for some reasons.
recyclerView.setLayoutManager(new LinearLayoutManager(this));

Launch a activity with button click using a FragmentActivity

Hey guys I need help I'm making a launcher that needs to have a button that when clicked it opens the AllApps.class activity witch shows a list of all installed apps
The other button needs to open a installed app that is on the device
and the last button needs to open the default web browser and open google.com
Here's my code!
Home.java:
package com.dva.schooltoolshome;
import java.util.Locale;
import android.app.ActionBar;
import android.app.FragmentTransaction;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageButton;
import android.widget.TextView;
public class Home extends FragmentActivity implements ActionBar.TabListener {
SectionsPagerAdapter mSectionsPagerAdapter;
ViewPager mViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
final ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
actionBar.setDisplayShowHomeEnabled(false);
actionBar.setDisplayOptions(actionBar.getDisplayOptions()
^ ActionBar.DISPLAY_SHOW_TITLE);
mSectionsPagerAdapter = new SectionsPagerAdapter(
getSupportFragmentManager());
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
mViewPager
.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
#Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
});
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
if (mSectionsPagerAdapter.getPageTitle(i).toString()
.equalsIgnoreCase("calc")) {
actionBar.addTab(actionBar.newTab()
.setIcon(R.drawable.calendar)
.setTabListener(this));
} else if (mSectionsPagerAdapter.getPageTitle(i).toString()
.equalsIgnoreCase("home")) {
actionBar.addTab(actionBar.newTab().setIcon(R.drawable.home)
.setTabListener(this));
} else if (mSectionsPagerAdapter.getPageTitle(i).toString()
.equalsIgnoreCase("drive")) {
actionBar.addTab(actionBar.newTab().setIcon(R.drawable.folder)
.setTabListener(this));
}
}
mViewPager.setCurrentItem(1);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.home, menu);
return true;
}
#Override
public void onTabSelected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
mViewPager.setCurrentItem(tab.getPosition());
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_settings:
startActivity(new Intent(android.provider.Settings.ACTION_APPLICATION_SETTINGS));
return true;
default:
return super.onOptionsItemSelected(item);
}
}
#Override
public void onTabUnselected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
}
#Override
public void onTabReselected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
}
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
Fragment fragment = null;
switch (position) {
case 0:
fragment = new CalcFragment();
break;
case 1:
fragment = new HomeFragment();
break;
case 2:
fragment = new DriveFragment();
break;
}
return fragment;
}
#Override
public int getCount() {
return 3;
}
#Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return getString(R.string.title_section1).toUpperCase(l);
case 1:
return getString(R.string.title_section2).toUpperCase(l);
case 2:
return getString(R.string.title_section3).toUpperCase(l);
}
return null;
}
}
public static class HomeFragment extends Fragment {
public static final String ARG_SECTION_NUMBER = "section_number";
public HomeFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.activity_homebar,
container, false);
return rootView;
}
}
public static class CalcFragment extends Fragment {
public static final String ARG_SECTION_NUMBER = "section_number";
public CalcFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.activity_calculator,
container, false);
return rootView;
}
}
public static class DriveFragment extends Fragment {
public static final String ARG_SECTION_NUMBER = "section_number";
public DriveFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_home_dummy,
container, false);
TextView dummyTextView = (TextView) rootView
.findViewById(R.id.section_label);
dummyTextView.setText("DRIVE");
return rootView;
}
}
}
activity_homebar
<RelativeLayout 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="#drawable/bg"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".HomeBar" >
<ImageButton
android:id="#+id/apps"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:background="#drawable/appdrawer"
android:src="#drawable/appdrawer" />
<ImageButton
android:id="#+id/wbrowser"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignTop="#+id/apps"
android:src="#drawable/browser" />
</RelativeLayout>
AllApps.java:
package com.dva.schooltoolshome;
import android.app.LauncherActivity;
import android.content.Intent;
public class AllApps extends LauncherActivity {
#Override
protected Intent getTargetIntent () {
// just a example, you should replace the method yourself
Intent intent = new Intent();
intent.setAction(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_LAUNCHER);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
return intent;
}
}
I'm am still learning so please don't judge
Thanks in advance
Regards
Rapsong11

You can easily find the answer to your question with a bit of googling. It has been asked many times before. I will point you in the right direction.
To add functionality to a button you have to first make the button (view) aware it can be clicked. This can be done in java programatically (research this yourself) or in the xml like so:
android:onClick="onClickDoStuff"
Then you have to implement the onClickDoStuff method which will look like:
public void onClickDoStuff(View view) {
//Do stuff on click
}
You wanted the button to open a new activity onClick to do that you would require an intent have a look here for futher guidance