Develop Reference

Is RecyclerView refreshed when AlertDialog's positive button gets pressed

My MainActivity has a RecyclerView adapter, and data to this RecyclerView is added through a AlertDialog which passes the entered text to the MainActivity. The recycler view gets refreshed somehow when the positive button in the dialog is pressed even though I never call notifyItemInserted() or notifyDatasetChange() after passing the new input. I want to know how this happens, my guess is the recyclerview is somehow refreshed after the positive button is pressed in the dialog box
Custom AlertDialog Code:
public class CustomDialog extends AppCompatDialogFragment {
OnNoteAddedListener onNoteAddedListener;
public interface OnNoteAddedListener {
public void onClick(String note);
}
public CustomDialog(OnNoteAddedListener onNoteAddedListener) {
this.onNoteAddedListener = onNoteAddedListener;
}
#Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
// Get the layout inflater
final LayoutInflater inflater = getActivity().getLayoutInflater();
final View dialogLayout = inflater.inflate(R.layout.dialog_box, null);
// Inflate and set the layout for the dialog
// Pass null as the parent view because its going in the dialog layout
builder.setView(dialogLayout).setPositiveButton("Ok", new DialogInterface.OnClickListener() {#Override
public void onClick(DialogInterface dialog, int id) {
EditText addNote = dialogLayout.findViewById(R.id.note_text);
String note = addNote.getText().toString();
onNoteAddedListener.onClick(note);
}
}).setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
CustomDialog.this.getDialog().cancel();
}
});
return builder.create();
}
}
Adapter code:
class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.ViewHolder>
{
private static final String TAG = "RecyclerViewAdapter";
private List<String> notesList;
private Context mContext;
private SendPositionConnector sendPositionConnector;
public interface SendPositionConnector
{
public void sendPosition(int position);
}
public RecyclerViewAdapter(List<String> notesList, Context mContext)
{
this.notesList = notesList;
this.mContext = mContext;
this.sendPositionConnector = (MainActivity)mContext;
}
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType)
{
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.layout_listitem, parent, false);
ViewHolder holder = new ViewHolder(view);
return holder;
}
#Override
public void onBindViewHolder(#NonNull ViewHolder viewHolder, final int position)
{
Log.d(TAG, "onBindViewHandler: called");
viewHolder.noteContent.setText(notesList.get(position));
viewHolder.parentLayout.setOnLongClickListener(new View.OnLongClickListener(){
#Override
public boolean onLongClick(View view)
{
Log.d(TAG, "onLongClick: long clicked on");
sendPositionConnector.sendPosition(position);
return false;
}
});
}
#Override
public int getItemCount()
{
return notesList.size();
}
public class ViewHolder extends RecyclerView.ViewHolder
{
TextView noteContent;
RelativeLayout parentLayout;
ImageView bullet;
public ViewHolder(#NonNull View itemView)
{
super(itemView);
bullet = itemView.findViewById(R.id.bullet);
noteContent = itemView.findViewById(R.id.text_content);
parentLayout = itemView.findViewById(R.id.parent_layout);
}
}
}
Activity Code:
public class MainActivity extends AppCompatActivity implements RecyclerViewAdapter.SendPositionConnector
{
private static final String TAG = "MainActivity";
private List<String> notesList = new ArrayList<>();
private RecyclerView recyclerView;
private RecyclerViewAdapter adapter;
private int position;
public AgentAsyncTask agentAsyncTask;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView = findViewById(R.id.my_recycler_view);
registerForContextMenu(recyclerView);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
agentAsyncTask = new AgentAsyncTask(notesList, getApplicationContext(), true, new AgentAsyncTask.OnRead(){
#Override
public void onRead(List<String> notesList)
{
if(!notesList.isEmpty())
MainActivity.this.notesList = notesList;
adapter = new RecyclerViewAdapter(notesList, MainActivity.this);
recyclerView.setAdapter(adapter);
}
});
agentAsyncTask.execute();
}
#Override
public boolean onCreateOptionsMenu(Menu menu)
{
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.add_menu, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item)
{
// Handle item selection
switch (item.getItemId())
{
case R.id.add_note:
showDialogBox(item);
return true;
default:
return super.onOptionsItemSelected(item);
}
}
#Override
protected void onStop()
{
super.onStop();
new AgentAsyncTask(notesList, getApplicationContext(), false, new AgentAsyncTask.OnRead(){
#Override
public void onRead(List<String> notesList)
{
if(!notesList.isEmpty())
MainActivity.this.notesList = notesList;
}
}).execute();
}
#Override
protected void onDestroy()
{
super.onDestroy();
}
private boolean showDialogBox(MenuItem menuItem)
{
AppCompatDialogFragment dialogFragment = new CustomDialog(new CustomDialog.OnNoteAddedListener(){
#Override
public void onClick(String note)
{
Log.d(TAG, "onClick: "+ note);
notesList.add(note);
}
});
dialogFragment.show(getSupportFragmentManager(),"Adding");
return true;
}
#Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo)
{
super.onCreateContextMenu(menu, v, menuInfo);
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.context_menu, menu);
}
#Override
public boolean onContextItemSelected(MenuItem menuItem)
{
switch(menuItem.getItemId())
{
case R.id.delete:
notesList.remove(position);
adapter.notifyItemRemoved(position);
adapter.notifyItemRangeChanged(position, notesList.size());
return true;
default:
return false;
}
}
#Override
public void sendPosition(int position)
{
this.position = position;
}
private static class AgentAsyncTask extends AsyncTask<Void, Void, List<String>>
{
private List<String> notesList;
private boolean flag;
OnRead onRead;
Context context;
AppDataBase dataBase;
private static final String TAG = "AgentAsyncTask";
public interface OnRead
{
public void onRead(List<String> notesList);
}
private AgentAsyncTask(List<String> notesList,Context context,boolean flag, OnRead onRead)
{
this.notesList = notesList;
this.onRead = onRead;
this.flag = flag;
this.context = context;
}
#Override
protected List<String> doInBackground(Void... params)
{
dataBase = Room.databaseBuilder(context, AppDataBase.class, "database-name").build();
if(!flag)
{
Gson gson = new Gson();
Type type = new TypeToken<List<String>>() {}.getType();
String json = gson.toJson(notesList, type);
Log.d(TAG, "doInBackground: "+json);
Notes notes = new Notes();
notes.setNoteContent(json);
notes.setUid(1);
dataBase.notesDao().insertNotes(notes);
return notesList;
}
else
{
Gson gson = new Gson();
String notesListContent = dataBase.notesDao().getNotes();
if(dataBase.notesDao().getCount() != 0)
{
notesList = gson.fromJson(notesListContent, new TypeToken<List<String>>()
{
}.getType());
}
else
{
return notesList;
}
return notesList;
}
}
#Override
protected void onPostExecute(List<String> notesList)
{
super.onPostExecute(notesList);
if(flag)
onRead.onRead(notesList);
}
}
}

What's probably happening is that when the dialog returns, it causes a re-layout of the RecyclerView, which rebinds the views. This is prone to bugs though, since it may not have updated the recycler about stuff like the list length or item view types, etc, so the appropriate notify method should always be used.

When you get the text from the dialog to main activity after pressing the positive button.
Append your list with that new text that you are passing to adapter and call method
adapter.notifyDataSetChanged();

How to change Tabs of a TabLayout from Navigation Drawer

Currently I'm changing Tabs from NavigationDrawer but it's not a right way and it takes too long to change tabs from NavigationDrawer becuase I'm replacing Main Fragment of Tabs each time and I don't want it. For more
NavigationDrawerAdapter.java
public class NavDrawerListAdapter extends BaseAdapter {
public Context context;
public MainActivity activity;
public MainTabFragment fragment;
int currentSelectedPostion;
LayoutInflater mInflater;
TextView tv_signup;
SharedPreferences share;
boolean cbc = false;
String fis = "", las = "";
int group_id = 0;
private String[] titles;
private int[] images;
private int[] selectedposition;
public NavDrawerListAdapter(Context context, int[] selectedposition, boolean cb, String fis, String las) {
this.context = context;
this.images = images;
this.cbc = cb;
this.fis = fis;
this.las = las;
share = context.getSharedPreferences("sharePref", 0);
group_id = share.getInt("group_id", 0);
this.selectedposition = selectedposition;
mInflater = (LayoutInflater) context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
}
#Override
public int getCount() {
return 1;
}
#Override
public Object getItem(int position) {
return position;
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
if (convertView == null) {
convertView = mInflater.inflate(com.cws.advisorymandi.R.layout.drawer_list_item, null);
}
LinearLayout ll_contact_us = (LinearLayout) convertView.findViewById(com.cws.advisorymandi.R.id.contact_item);
RelativeLayout ll_login = (RelativeLayout) convertView.findViewById(com.cws.advisorymandi.R.id.signup_item);
LinearLayout ll_equity = (LinearLayout) convertView.findViewById(com.cws.advisorymandi.R.id.equity_item);
LinearLayout ll_indices = (LinearLayout) convertView.findViewById(com.cws.advisorymandi.R.id.indices_item);
if (cbc) {
tv_signup.setText("Welcome " + fis + " " + las);
tv_logout.setVisibility(View.VISIBLE);
tv_edit.setVisibility(View.VISIBLE);
}
ll_equity.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
MainActivity.getInstance().displayView(3, 0, 0);
}
});
ll_indices.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
MainActivity.getInstance().displayView(3, 0, 1);
}
});
});
return convertView;
}
}
MainActivity.java
public class MainActivity extends AppCompatActivity {
public ListView mDrawerList;
NavDrawerListAdapter adapter;
public static MainActivity getInstance() {
return sMainActivity;
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(com.cws.advisorymandi.R.layout.activity_main)
mDrawerList = (ListView) findViewById(com.cws.advisorymandi.R.id.list_slidermenu);
adapter = new NavDrawerListAdapter(getApplicationContext(), selectedposition, cb, firstName, lastName);
mDrawerList.setAdapter(adapter);
}
/**
* Diplaying fragment view for selected nav drawer list item
*/
public int displayView(int position, int position2, int position3) {
// update the main content by replacing fragments
first_position = position;
second_position = position2;
third_position = position3;
fragment = null;
switch (position) {
case 0:
sharedPreferences = getSharedPreferences("sharePref", 0);
cb = sharedPreferences.getBoolean("ConfirmLogin", false);
if (cb) {
} else new Handler().postDelayed(new Runnable() {
#Override
public void run() {
fragment = new LoginActivity();
changeFragments3();
}
}, 150);
mDrawerLayout.closeDrawer(mDrawerList);
break;
case 3:
// fragment = new MainTabFragment();
/* new Handler().postDelayed(new Runnable() {
#Override
public void run() {*/
fragment = new MainTabFragment();
changeFragments();
/*}
}, 150);
mDrawerLayout.closeDrawer(mDrawerList);*/
break;
}
return 0;
}
}
Note: I created each drawer item without using an array or arrayList so onItemClickListener isn't also working in it.

Android Music Player inside a fragment

I am implementing a music player app. I am able to fetch the songs from the sd card. But stuck in something from hours i.e. I am unable to make the songs play inside the fragment.
Here is the MainActivity class which is having 3 tab fragments.
public class MainActivity extends AppCompatActivity {
private final String[] TITLES = {"Now playing", "Library", "Groups"};
private static boolean isInForeground = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//if (savedInstanceState == null) {}
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
// Initialize the ViewPager and set an adapter
ViewPager pager = (ViewPager) findViewById(R.id.pager);
pager.setAdapter(new PagerAdapter(getSupportFragmentManager(), getBaseContext()));
// Bind the tabs to the ViewPager
PagerSlidingTabStrip tabs = (PagerSlidingTabStrip) findViewById(R.id.tabs);
tabs.setShouldExpand(true);
tabs.setViewPager(pager);
//Whenever the user changes tab, we want the title to change too
tabs.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrollStateChanged(int arg0) {
// TODO Auto-generated method stub
}
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
// TODO Auto-generated method stub
}
#Override
public void onPageSelected(int position) {
setTitle(TITLES[position]);
}
});
//We want to have the library as default view
pager.setCurrentItem(1);
setTitle(TITLES[1]);
}
#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_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);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class MainFragment extends Fragment {
public MainFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_song_library, container, false);
return view;
}
}
public class PagerAdapter extends FragmentPagerAdapter
implements PagerSlidingTabStrip.CustomTabProvider {
private ArrayList<Integer> tab_icon = new ArrayList<Integer>();
Context myContext;
public PagerAdapter(FragmentManager fm, Context context) {
super(fm);
myContext = context;
tab_icon.add(context.getResources().getIdentifier("ic_play_arrow_white_36dp", "drawable", context.getPackageName()));
tab_icon.add(context.getResources().getIdentifier("ic_list_white_36dp", "drawable", context.getPackageName()));
tab_icon.add(context.getResources().getIdentifier("ic_group_white_36dp", "drawable", context.getPackageName()));
}
#Override
public CharSequence getPageTitle(int position) {
return TITLES[position];
}
#Override
public int getCount() {
return TITLES.length;
}
#Override
public Fragment getItem(int position) {
if(position == 0){
return SongNowPlayingFragment.newInstance();
} else if (position == 1){
return SongLibraryFragment.newInstance();
} else if(position == 2){
return GroupFragment.newInstance();
}
System.err.println("Invalid tab fragment!");
return new Fragment();
}
#Override
public View getCustomTabView(ViewGroup viewGroup, int position) {
LinearLayout imageView = (LinearLayout) LayoutInflater.from(myContext)
.inflate(R.layout.tab_layout, null, false);
ImageView tabImage = (ImageView) imageView.findViewById(R.id.tabImage);
tabImage.setImageResource(tab_icon.get(position));
return imageView;
}
}
#Override
protected void onResume()
{
super.onResume();
isInForeground = true;
}
#Override
protected void onPause()
{
super.onPause();
isInForeground = false;
}
static boolean isInForeground(){
return isInForeground;
}
}
This is the SongLibraryFragment in which I have added the songs from the user device. Now I want to play those songs.
public class SongLibraryFragment extends Fragment implements MediaPlayerControl {
private ArrayList<SongItem> songList;
private ListView songView;
private MusicService musicSrv;
private Intent playIntent;
private boolean musicBound=false;
private MusicController controller;
private boolean paused=false, playbackPaused=false;
private MainActivity mainActivity = null;
public static SongLibraryFragment newInstance() {
SongLibraryFragment f = new SongLibraryFragment();
Bundle b = new Bundle();
f.setArguments(b);
return f;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_song_library, container, false);
return rootView;
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
mainActivity = (MainActivity) SongLibraryFragment.this.getActivity();
songView = (ListView) getView().findViewById(R.id.library_song_list);
songList = new ArrayList<SongItem>();
getSongList();
SongAdapter songAdt = new SongAdapter(getActivity(), songList);
songView.setAdapter(songAdt);
Collections.sort(songList, new Comparator<SongItem>() {
public int compare(SongItem a, SongItem b) {
return a.getTitle().compareTo(b.getTitle());
}
});
setController();
}
//connect to the service
private ServiceConnection musicConnection = new ServiceConnection(){
#Override
public void onServiceConnected(ComponentName name, IBinder service) {
MusicBinder binder = (MusicBinder)service;
//get service
musicSrv = binder.getService();
//pass list
musicSrv.setList(songList);
musicBound = true;
}
#Override
public void onServiceDisconnected(ComponentName name) {
musicBound = false;
}
};
#Override
public void onStart() {
super.onStart();
if(playIntent==null){
playIntent = new Intent(getActivity(), MusicService.class);
this.getActivity().bindService(playIntent, musicConnection, Context.BIND_AUTO_CREATE);
this.getActivity().startService(playIntent);
}
}
public void songPicked(View view){
musicSrv.setSong(Integer.parseInt(view.getTag().toString()));
musicSrv.playSong();
if(playbackPaused){
setController();
playbackPaused=false;
}
controller.show(0);
}
public void getSongList() {
//retrieve song info
ContentResolver musicResolver = getActivity().getContentResolver();
Uri musicUri = android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
Cursor musicCursor = musicResolver.query(musicUri, null, null, null, null);
if(musicCursor!=null && musicCursor.moveToFirst()){
//get columns
int titleColumn = musicCursor.getColumnIndex
(android.provider.MediaStore.Audio.Media.TITLE);
int idColumn = musicCursor.getColumnIndex
(android.provider.MediaStore.Audio.Media._ID);
int artistColumn = musicCursor.getColumnIndex
(android.provider.MediaStore.Audio.Media.ARTIST);
//add songs to list
do {
long thisId = musicCursor.getLong(idColumn);
String thisTitle = musicCursor.getString(titleColumn);
String thisArtist = musicCursor.getString(artistColumn);
songList.add(new SongItem(thisId, thisTitle, thisArtist));
}
while (musicCursor.moveToNext());
}
}
#Override
public boolean canPause() {
return true;
}
#Override
public boolean canSeekBackward() {
return true;
}
#Override
public boolean canSeekForward() {
return true;
}
#Override
public int getAudioSessionId() {
return 0;
}
#Override
public int getBufferPercentage() {
return 0;
}
#Override
public int getCurrentPosition() {
if(musicSrv!=null && musicBound && musicSrv.isPng())
return musicSrv.getPosn();
else return 0;
}
#Override
public int getDuration() {
if(musicSrv!=null && musicBound && musicSrv.isPng())
return musicSrv.getDur();
else return 0;
}
#Override
public boolean isPlaying() {
if(musicSrv!=null && musicBound)
return musicSrv.isPng();
return false;
}
#Override
public void pause() {
playbackPaused=true;
musicSrv.pausePlayer();
}
#Override
public void seekTo(int pos) {
musicSrv.seek(pos);
}
#Override
public void start() {
musicSrv.go();
}
private void setController(){
//set the controller up
controller = new MusicController(getActivity());
controller.setPrevNextListeners(new View.OnClickListener() {
#Override
public void onClick(View v) {
playNext();
}
}, new View.OnClickListener() {
#Override
public void onClick(View v) {
playPrev();
}
});
controller.setMediaPlayer(this);
controller.setAnchorView(getActivity().findViewById(R.id.library_song_list));
controller.setEnabled(true);
}
//play next
private void playNext(){
musicSrv.playNext();
if(playbackPaused){
setController();
playbackPaused=false;
}
controller.show(0);
}
//play previous
private void playPrev(){
musicSrv.playPrev();
if(playbackPaused){
setController();
playbackPaused=false;
}
controller.show(0);
}
#Override
public void onPause(){
super.onPause();
paused=true;
}
#Override
public void onResume(){
super.onResume();
if(paused){
setController();
paused=false;
}
}
#Override
public void onStop() {
controller.hide();
super.onStop();
}
#Override
public void onDestroy() {
this.getActivity().stopService(playIntent);
musicSrv=null;
super.onDestroy();
}
SongAdapter class
public class SongAdapter extends BaseAdapter {
private ArrayList<SongItem> songs;
private LayoutInflater songInf;
public SongAdapter(Context c, ArrayList<SongItem> theSongs){
songs=theSongs;
songInf=LayoutInflater.from(c);
}
#Override
public int getCount() {
// TODO Auto-generated method stub
return songs.size();
}
#Override
public Object getItem(int arg0) {
// TODO Auto-generated method stub
return null;
}
#Override
public long getItemId(int arg0) {
// TODO Auto-generated method stub
return 0;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
//map to song layout
LinearLayout songLay = (LinearLayout)songInf.inflate
(R.layout.song, parent, false);
//get title and artist views
TextView songView = (TextView)songLay.findViewById(R.id.song_title);
TextView artistView = (TextView)songLay.findViewById(R.id.song_artist);
//ImageView imageView = (ImageView)songLay.findViewById(R.id.song_image);
//get song using position
SongItem currSong = songs.get(position);
//get title and artist strings
songView.setText(currSong.getTitle());
artistView.setText(currSong.getArtist());
//imageView.setImage(currSong.getImage());
//set position as tag
songLay.setTag(position);
return songLay;
}
Song.xml file
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="5dp"
android:onClick="songPicked">
<TextView
android:id="#+id/song_title"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
style="#style/Base.TextAppearance.AppCompat.Title"
android:textColor="#color/primary_text_default_material_light"/>
<TextView
android:id="#+id/song_artist"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
style="#style/Base.TextAppearance.AppCompat.Subhead"
android:textColor="#color/secondary_text_default_material_light"/>
</LinearLayout>
Error
java.lang.IllegalStateException: Could not find a method
songPicked(View) in the activity class
co.adrianblan.noraoke.MainActivity for onClick handler on view class
android.widget.LinearLayout
So the main problem is with the songPicked method inside SongFragmentLibrary. I have added the onClick: songPicked in the song.xml file but it is searching for the songPicked method inside the MainActivity. I am not getting what is the problem.
Please can anyone help me with this?

You are trying to set onclick listener from your fragment xml android:onClick="songPicked", you can't set onclick listener for a view which is part of fragment, in your getView() setOnClickListener:
LinearLayout songLay = (LinearLayout)songInf.inflate
(R.layout.song, parent, false);
songLay.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
//Handle click event
}
})
OR
You can simply set OnItemClickListener on your listview
list.setOnItemClickListener(this);// implement OnItemClickListener in your fragment class

How to resolve 'getData()' method in recyclerview using android studio

i have followed Slidenerd's tutorial on youtube on how to create a material design navigation drawer using android studio.
However on running the app i get this cannot resolve method getData() and on the console Error:(56, 46) error: cannot find symbol method getData() error onadapter=new AdapterClass(getActivity().getData());
There's probably somewhere i have overlooked.Any help will be appreciated.
NavigationDrawerFragment.java
public class NavigationDrawerFragment extends Fragment {
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 AdapterClass adapter;
private RecyclerView recyclerView;
public NavigationDrawerFragment() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mUserLearnedDrawer = Boolean.valueOf(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.drawerList);
adapter=new AdapterClass(getActivity().getData());
recyclerView.setAdapter(adapter);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
return layout;
}
public static List<Information> getData() {
List<Information> data = new ArrayList<>();
int[] icons = {R.drawable.ic_menu_check, R.drawable.ic_menu_check, R.drawable.ic_menu_check, R.drawable.ic_menu_check};
String[] titles = {"Notifications", "School", "What's hot", "Hit us up"};
for (int i=0;i<titles.length && i<icons.length;i++)
{
Information current=new Information();
current.iconId=icons[i];
current.title=titles[i];
data.add(current);
}
return data;
}
public void setUp(int fragmentId, DrawerLayout drawerLayout, Toolbar toolbar) {
containerView = getActivity().findViewById(fragmentId);
mDrawerLayout = drawerLayout;
mDrawerToggle = new ActionBarDrawerToggle(getActivity(), drawerLayout, toolbar, R.string.drawer_open, R.string.drawer_close) {
#SuppressLint("NewApi")
#Override
public void onDrawerOpened(View drawerView) {
super.onDrawerOpened(drawerView);
if (!mUserLearnedDrawer) {
mUserLearnedDrawer = true;
saveToPreferences(getActivity(), KEY_USER_LEARNED_DRAWER, mUserLearnedDrawer + "");
}
getActivity().invalidateOptionsMenu();
}
#SuppressLint("NewApi")
#Override
public void onDrawerClosed(View drawerView) {
super.onDrawerClosed(drawerView);
getActivity().invalidateOptionsMenu();
}
};
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);
}
}
AdapterClasss.java
public class AdapterClass extends RecyclerView.Adapter<AdapterClass.MyViewHolder> {
private LayoutInflater inflater;
List<Information>data= Collections.emptyList();
public AdapterClass(Context context,List<Information>data){
inflater= LayoutInflater.from(context);
this.data=data;
}
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view= inflater.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.title.setText(current.title);
holder.icon.setImageResource(current.iconId);
}
#Override
public int getItemCount() {
return data.size();
}
class MyViewHolder extends RecyclerView.ViewHolder{
TextView title;
ImageView icon;
public MyViewHolder(View itemView) {
super(itemView);
title=(TextView)itemView.findViewById(R.id.listText);
icon=(ImageView)itemView.findViewById(R.id.listIcon);
}
}
}

adapter = new VivzAdapter(getActivity(),getData());
use this intead
adapter=new AdapterClass(getActivity().getData());
i had the same problem. ;-)

Fixed it by doing it this way:
adapter = new AdapterClass(getActivity(), getData());
recyclerView.setAdapter(adapter);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));

ViewPager/PagerAdapter: Changing The Value of a String

I have a youtube Playlist:
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.home);
final ActionBar actionBar = getActionBar();
ViewPager viewPager = (ViewPager) findViewById(R.id.view_pager);
viewPager.setAdapter(adapter);
actionBar.setCustomView(R.layout.actionbar_custom_view_home);
actionBar.setDisplayShowTitleEnabled(false);
actionBar.setDisplayShowCustomEnabled(true);
drawerListViewItems = getResources().getStringArray(R.array.items);
drawerListView = (ListView) findViewById(R.id.left_drawer);
drawerListView.setAdapter(new ArrayAdapter<String>(this,
R.layout.drawer_listview_item, drawerListViewItems));
drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
actionBarDrawerToggle = new ActionBarDrawerToggle(this, /* host Activity */
drawerLayout, /* DrawerLayout object */
R.drawable.ic_drawer, /* nav drawer icon to replace 'Up' caret */
R.string.drawer_open, /* "open drawer" description */
R.string.drawer_close /* "close drawer" description */
);
drawerLayout.setDrawerListener(actionBarDrawerToggle);
getActionBar().setDisplayHomeAsUpEnabled(true);
drawerLayout.setDrawerShadow(R.drawable.drawer_shadow,
GravityCompat.START);
listView = (VideosListView) findViewById(R.id.videosListView);
listView.setOnVideoClickListener(this);
new GetYouTubeUserVideosTask(responseHandler, PLAYLIST).execute();
}
...
and I have a ViewPager/PagerAdapter:
private class ImagePagerAdapter extends PagerAdapter {
public ImagePagerAdapter(Activity act, int[] mImages,
String[] stringArra) {
imageArray = mImages;
activity = act;
stringArray = stringArra;
}
public ImagePagerAdapter() {
super();
// setOnPageChangeListener(mPageChangeListener);
}
private int[] mImages = new int[] { R.drawable.selstation_up_btn,
R.drawable.classical_up_btn, R.drawable.country_up_btn,
R.drawable.dance_up_btn, R.drawable.hiphop_up_btn,
R.drawable.island_up_btn, R.drawable.latin_up_btn,
R.drawable.pop_up_btn, R.drawable.samba_up_btn };
private String[] stringArray = new String[] { "vevo",
"TheMozARTGROUP‎", "TimMcGrawVEVO‎", "TiestoVEVO‎",
"EminemVEVO‎" };
#Override
public int getCount() {
return mImages.length;
}
#Override
public boolean isViewFromObject(View view, Object object) {
return view == ((ImageView) object);
}
#Override
public Object instantiateItem(ViewGroup container, int position) {
Context context = Home.this;
ImageView imageView = new ImageView(context);
imageView.setScaleType(ScaleType.FIT_XY);
imageView.setImageResource(mImages[position]);
((ViewPager) container).addView(imageView, 0);
return imageView;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
((ViewPager) container).removeView((ImageView) object);
}
private final ViewPager.SimpleOnPageChangeListener mPageChangeListener = new ViewPager.SimpleOnPageChangeListener() {
#Override
public void onPageSelected(final int position) {
onTabChanged(mPager.getAdapter(), mCurrentTabPosition, position);
mCurrentTabPosition = position;
}
};
public View getView(int position, View convertView, ViewGroup parent) {
View vi=convertView;
if (convertView == null) {
convertView = LayoutInflater.from(context)
.inflate(R.layout.home, parent, false);
}
ImageView imageView = new ImageView(context);
ImageView imageView = (ImageView)vi.findViewById(R.drawable.selstation_up_btn);
imageView.setImageResource(imageView.getImage());
return convertView;
}
protected void onTabChanged(final PagerAdapter adapter,
final int oldPosition, final int newPosition) {
// Calc if swipe was left to right, or right to left
if (oldPosition > newPosition) {
// left to right
} else {
// right to left
View vg = findViewById(R.layout.home);
vg.invalidate();
}
final ViewPager viewPager = (ViewPager) findViewById(R.id.view_pager);
viewPager.setOnPageChangeListener(new OnPageChangeListener() {
int oldPos = viewPager.getCurrentItem();
#Override
public void onPageScrolled(int position, float arg1, int arg2) {
if (position > oldPos) {
// Moving to the right
} else if (position < oldPos) {
// Moving to the Left
View vg = findViewById(R.layout.home);
vg.invalidate();
}
}
#Override
public void onPageScrollStateChanged(int arg0) {
// TODO Auto-generated method stub
}
#Override
public void onPageSelected(int arg0) {
// TODO Auto-generated method stub
}
});
}
}
}
Screenshot:
Issue:
How can I connect the two - so when I swipe the ViewPager/PagerAdapter: it changes the value of: String PLAYLIST
I need to change it's value depending on the ViewPager/PagerAdapter selection.
Example:
if R.drawable.classical_up_btn {
String PLAYLIST = "TheMozARTGROUP‎";
}
or
if R.drawable.country_up_btn {
String PLAYLIST = "TimMcGrawVEVO‎";
}

If I'm understanding your question correctly, you can change a class level variable, playlist, in your onPageChangeListener. int position in onPageScrolled is the index of the first displayed item.
As a side note, all caps should be reserved for constants. Any variable that can be changed in code should start with a lower case letter.