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Android Studio Null Pointer Exception on ArrayList using Intent

I am trying to create an intent with bundle extras but I am getting null pointer exception error on the Array List.
Here is the error:
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.util.ArrayList android.os.Bundle.getParcelableArrayList(java.lang.String)' on a null object reference
Am I implementing intents wrong?
Here is my application below for MP3 Player:
PlaylistSelector:
public class PlaylistSelector extends AppCompatActivity {
ListView listview;
String[] items;
#Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.playlist);
listview = findViewById(R.id.listViewSong);
runtimePermission();
}
public void runtimePermission()
{
Dexter.withContext(this).withPermission(Manifest.permission.READ_EXTERNAL_STORAGE)
.withListener(new PermissionListener() {
#Override
public void onPermissionGranted(PermissionGrantedResponse permissionGrantedResponse) {
displaySongs();
}
#Override
public void onPermissionDenied(PermissionDeniedResponse permissionDeniedResponse) {
}
#Override
public void onPermissionRationaleShouldBeShown(PermissionRequest permissionRequest, PermissionToken permissionToken) {
permissionToken.continuePermissionRequest();
}
}).check();
}
public ArrayList<File> findSong (File file)
{
ArrayList<File> arrayList = new ArrayList<>();
File[] files = file.listFiles();
for (File singlefile: files)
{
if (singlefile.isDirectory() && !singlefile.isHidden())
{
arrayList.addAll(findSong(singlefile));
}
else
{
if (singlefile.getName().endsWith(".mp3") || singlefile.getName().endsWith(".wav"))
{
arrayList.add(singlefile);
}
}
}
return arrayList;
}
void displaySongs()
{
final ArrayList<File> mySongs = findSong(Environment.getExternalStorageDirectory());
items = new String[mySongs.size()];
for(int i = 0; i<mySongs.size(); i++)
{
items[i] = mySongs.get(i).getName().toString().replace(".mp3","").replace(".wav","");
}
/*ArrayAdapter<String> myAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,songs);
listview.setAdapter(myAdapter);*/
customAdapter customAdapter = new customAdapter();
listview.setAdapter(customAdapter);
listview.setOnItemClickListener(new AdapterView.OnItemClickListener(){
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
String songName = (String) listview.getItemAtPosition(i);
startActivity(new Intent(getApplicationContext(), MainActivity.class)
.putExtra("songs", mySongs)
.putExtra("songname", songName)
.putExtra("pos", i));
}
});
}
class customAdapter extends BaseAdapter{
#Override
public int getCount() {
return items.length;
}
#Override
public Object getItem(int i) {
return null;
}
#Override
public long getItemId(int i) {
return 0;
}
#Override
public View getView(int i, View view, ViewGroup viewGroup) {
View myView = getLayoutInflater().inflate(R.layout.list_item, null);
TextView textsong = myView.findViewById(R.id.txtsongname);
textsong.setSelected(true);
textsong.setText(items[i]);
return myView;
}
}
}
MainActivity:
public class MainActivity extends AppCompatActivity {
private static final String TAG = "MainActivity";
private InputSource inputSource;
Button playbtn, btnnext,btnprev,btnff,btnrw;
TextView txtsn, txtsstop,txtsstart;
SeekBar seekmusic;
BarVisualizer visualizer;
String sname;
public static final String EXTRA_NAME = "song_name";
static MediaPlayer mediaPlayer;
int position;
ArrayList<File> mySongs;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
View frameLayoutMP = findViewById(R.id.preview_mp3_layout);
btnprev = findViewById(R.id.btnprev);
playbtn = findViewById(R.id.playbtn);
btnnext = findViewById(R.id.btnnext);
btnrw = findViewById(R.id.btnrw);
btnff = findViewById(R.id.btnff);
txtsn = findViewById(R.id.txtsn);
txtsstop = findViewById(R.id.txtsstop);
txtsstart = findViewById(R.id.txtsstart);
seekmusic = findViewById(R.id.seekbar);
visualizer = findViewById(R.id.blast);
if (mediaPlayer != null)
{
mediaPlayer.stop();
mediaPlayer.release();
}
Intent i = getIntent();
Bundle bundle = i.getExtras();
mySongs = (ArrayList) bundle.getParcelableArrayList("songs");
String songName = i.getStringExtra("songname");
position = bundle.getInt("pos",0);
txtsn.setSelected(true);
Uri uri = Uri.parse(mySongs.get(position).toString());
sname = mySongs.get(position).getName();
txtsn.setText(sname);
mediaPlayer = MediaPlayer.create(getApplicationContext(),uri);
mediaPlayer.start();
playbtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if(mediaPlayer.isPlaying())
{
playbtn.setBackgroundResource(R.drawable.ic_play);
mediaPlayer.pause();
}
else
{
playbtn.setBackgroundResource(R.drawable.ic_pause);
mediaPlayer.start();
}
}
});
}
}
I am trying to get this intent to grab song lists from playlists and put it into the player

Screen rotation - how to override the onSaveInstanceState and onRestoreInstanceState?

I need to keep and restore the results of a search while rotating the screen by override the onSaveInstanceState and onRestoreInstanceState... I don't know how to do this and where to use it.
someone got a clue about this ?
This is a part of the MainActivity:
public class MainActivity extends AppCompatActivity {
private static final String LOG_TAG = MainActivity.class.getName();
/**
* URL for book data from the Google books dataset
*/
private static final String G_BOOKS_REQUEST_URL =
"https://www.googleapis.com/books/v1/volumes?q=";
/**
* Adapter for the list of books
*/
private BookAdapter mAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
..............

Save the URL search result json/xml in savedInstanceState. When rotate screen test if result exist in savedInstanceState
savedInstanceState.putString("result", <serach result json/xml>);

final EditText searchTextView = (EditText) findViewById(R.id.search_bar);
Button searchButton = (Button) findViewById(R.id.search_button);
ListView bookListView = (ListView) findViewById(R.id.list);
mAdapter = new BookAdapter(this, new ArrayList<Book>());
bookListView.setAdapter(mAdapter);
bookListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) {
Book currentBook = mAdapter.getItem(position);
Uri bookUri = Uri.parse(currentBook.getmUrl());
Intent websiteIntent = new Intent(Intent.ACTION_VIEW, bookUri);
startActivity(websiteIntent);
}
});
searchButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String newQuery = searchTextView.getText().toString();
BookAsyncTask task = new BookAsyncTask();
task.execute(G_BOOKS_REQUEST_URL + newQuery);
}
});
}
#Override
protected List<Book> doInBackground(String... urls) {
// Don't perform the request if there are no URLs, or the first URL is null
if (urls.length < 1 || urls[0] == null) {
return null;
}
List<Book> result = QueryUtils.fetchBookData(urls[0]);
return result;
}
#Override
protected void onPostExecute(List<Book> data) {
mAdapter.clear();
if (data != null && !data.isEmpty()) {
mAdapter.addAll(data);
}
}
}
}

Fragment not Saving Instance State

I'm trying to save state data when you change the orientation of the android device, since I understand that's when it destroys activities and fragments. Does something special have to be done for fragments that are inside of other layouts (I have two fragments inside of my main activity xml). I thought I could simply handle saving data with saveInstanceState, but that seems to never be called, as the bundle that's passed into the onCreateView always is null. Any thoughts? I"m sure I'm missing something obvious here.
public class ControlFrag extends Fragment implements View.OnClickListener{
int hours, min, sec;
TextView text;
Button start;
Async async;
boolean clicked;
private static final String THREAD_STATUS = "thread status";
private static final String HOUR = "hour";
private static final String MINUTE = "minute";
private static final String SECOND = "second";
public ControlFrag() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View v = inflater.inflate(R.layout.fragment_control, container, false);
text = (TextView) v.findViewById(R.id.timer);
start = (Button) v.findViewById(R.id.start);
start.setOnClickListener(this);
if (savedInstanceState != null) {
text.setText("Test");
boolean isRunning = savedInstanceState.getBoolean(THREAD_STATUS);
if (isRunning) {
sec = savedInstanceState.getInt(SECOND);
text.setText("" + sec);
async = new Async();
async.execute(sec);
}
}
else {
async = new Async();
}
return v;
}
#Override
public void onClick(View view) {
if (async.getStatus() != AsyncTask.Status.RUNNING) {
async = new Async();
async.execute(0);
}
}
#Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
if (async != null && async.getStatus() == AsyncTask.Status.RUNNING) {
outState.putBoolean(THREAD_STATUS, true);
outState.putInt(SECOND, sec);
async.cancel(true);
}
else {
outState.putBoolean(THREAD_STATUS, false);
}
}
#Override
public void onDestroy() {
super.onDestroy();
if (async != null && async.getStatus() == AsyncTask.Status.RUNNING) {
async.cancel(true);
async = null;
}
}
private class Async extends AsyncTask<Integer, String, Void> {
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
}
#Override
protected void onProgressUpdate(String... values) {
super.onProgressUpdate(values);
text.setText(values[0] + values[1] + values[2]);
}
#Override
protected Void doInBackground(Integer... integers) {
sec = integers[0];
while (sec < 100) {
try {
sec++;
String second;
if(sec > 59){
sec = 0;
}
if (sec < 10) {
second = "0" + sec;
} else {
second = "" + sec;
}
publishProgress("" + sec, ":" + sec, ":" + second);
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
return null;
}
}
}
Code for Activity:
public class MainActivity extends AppCompatActivity implements View.OnClickListener{
public Button nextScreen;
public TextView timer;
public ControlFrag control;
public ListFrag list;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
control = new ControlFrag();
list = new ListFrag();
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
if (savedInstanceState == null) {
// transaction.replace(R.id.fragment_container, control, "portraitControl");
}
if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) {
transaction.replace(R.id.fragment_container1, list, "landscapeList");
}
else {
nextScreen = (Button) findViewById(R.id.nextScreen);
nextScreen.setOnClickListener(this);
}
transaction.commit();
}
#Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putString("Test", "GO");
}
#Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT) {
nextScreen.setText(savedInstanceState.getString("Test"));
}
}
#Override
protected void onDestroy() {
super.onDestroy();
}
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
if (newConfig.orientation == Configuration.ORIENTATION_LANDSCAPE) {
} else if (newConfig.orientation == Configuration.ORIENTATION_PORTRAIT) {
}
}
#Override
public void onClick(View view) {
if (getSupportFragmentManager().findFragmentByTag("portraitControl") != null) {
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.fragment_container, list, "portraitList");
transaction.commit();
}
else {
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.fragment_container, control, "portraitControl");
transaction.commit();
}
}
}

How to initialize interface instance to communicate with child fragment inside parent fragment

Good day, I have a fragment called MainFragment called from MainActivity. Inside MainFragment I have private OnProgressUpdateListener progressListener; this interface instance helps me talk to ProgressDialog Fragment.
I'm able to initialize interface instance inside my activities but I'm getting ClassCastException when I attempt to initialize the interface instance inside MainFragment
Below are my classes:
--------------------------------------------------------------------------------
Interface
--------------------------------------------------------------------------------
public interface OnProgressUpdateListener
{
void onProgressUpdate(String message);
void onDismissDialog();
}
--------------------------------------------------------------------------------
Child Fragment to MainFragment
--------------------------------------------------------------------------------
public class ProgressbarDialog extends DialogFragment implements OnProgressUpdateListener
{
TextView progressMessage;
ProgressBar progressBar;
View dialogView;
LayoutInflater inflater;
AlertDialog alertDialog;
AlertDialog.Builder dialogBuilder;
public ProgressbarDialog()
{
}
public static ProgressbarDialog newInstance(String title, String message)
{
ProgressbarDialog fragment = new ProgressbarDialog();
Bundle args = new Bundle();
args.putCharSequence("title", title);
args.putCharSequence("message", message);
fragment.setArguments(args);
return fragment;
}
#Override
public Dialog onCreateDialog(Bundle savedInstanceState)
{
dialogBuilder = new AlertDialog.Builder(getActivity());
inflater = getActivity().getLayoutInflater();
dialogView = inflater.inflate(R.layout.content_progressdialog,null);
dialogBuilder.setView(dialogView);
progressBar = dialogView.findViewById(R.id.pbProgressSpinner);
progressMessage = dialogView.findViewById(R.id.tvProgressMessage);
dialogBuilder.setTitle(getArguments().getString("title"));
progressBar.setIndeterminate(true);
progressMessage.setText(getArguments().getString("message"));
alertDialog = dialogBuilder.create();
alertDialog.setCanceledOnTouchOutside(false);
alertDialog.show();
return alertDialog;
}
#Override
public void onProgressUpdate(String message)
{
progressMessage.setText(message);
}
#Override
public void onDismissDialog()
{
alertDialog.dismiss();
}
}
--------------------------------------------------------------------------------
MainFragment - Parent Fragment To ProgressbarDialog
--------------------------------------------------------------------------------
public class MainFragment extends Fragment
{
private View mainView;
private CheckBox rememberMe;
private boolean stayLoggedIn;
private CountDownLatch latch;
private FragmentManager manager;
private OnMainListener mListener;
private EditText email, password;
private ProgressbarDialog progressDialog;
private OnProgressUpdateListener progressListener;
private final int REGISTER_CODE = 1, RESET_CODE = 2;
private FloatingActionButton fabRegister, fabLogin, fabReset;
public MainFragment()
{}
public static MainFragment newInstance()
{
MainFragment fragment = new MainFragment();
Bundle args = new Bundle();
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
if (getArguments() != null)
{}
manager = getChildFragmentManager();
progressDialog = ProgressbarDialog.newInstance("Authentication", "Connecting To Server, Please Wait...");
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState)
{
// Inflate the layout for this fragment
mainView = inflater.inflate(R.layout.main_fragment, container, false);
stayLoggedIn = false;
rememberMe = mainView.findViewById(R.id.cbRememberMe);
email = mainView.findViewById(R.id.edtLoginEmail);
password = mainView.findViewById(R.id.edtLoginPassword);
fabRegister = mainView.findViewById(R.id.fabRegister);
fabLogin = mainView.findViewById(R.id.fabLogin);
fabReset = mainView.findViewById(R.id.fabReset);
return mainView;
}
#Override
public void onViewCreated(View view, #Nullable Bundle savedInstanceState)
{
super.onViewCreated(view, savedInstanceState);
email.setTag("Account Email Required!");
password.setTag("Account Password Required!");
}
#Override
public void onStart()
{
super.onStart();
rememberMe.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
stayLoggedIn = b;
}
});
fabRegister.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View view)
{
mListener.onFABInteraction(REGISTER_CODE);
}
});
fabLogin.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view)
{
onLoginRequest();
}
});
fabReset.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view)
{
mListener.onFABInteraction(RESET_CODE);
}
});
}
#Override
public void onAttach(Context context)
{
super.onAttach(context);
try
{
if (context instanceof OnMainListener)
{
mListener = (OnMainListener) context;
}
else
{
throw new RuntimeException(context.toString()
+ " must implement OnMainListener");
}
}
catch (Exception e)
{
Log.e(MainFragment.class.getName(), e.getMessage());
}
}
**#Override
public void onAttachFragment(Fragment childFragment) {
super.onAttachFragment(childFragment);
if(childFragment instanceof OnProgressUpdateListener)
{
progressListener = (OnProgressUpdateListener) childFragment;
//This code is never executed
}
}**
#Override
public void onDetach()
{
super.onDetach();
mListener = null;
}
interface OnMainListener
{
void onLoginSuccess(BackendlessUser user);
void onFABInteraction(int option);
}
private class OnAuthentication extends AsyncTask<String, String, BackendlessUser>
{
#Override
protected void onPreExecute() {
super.onPreExecute();
latch = new CountDownLatch(1);
progressDialog.show(manager, MainFragment.class.getName());
Code Fails here, null pointer exception is thrown because progressListener interface instance is not initialised.
progressListener.onProgressUpdate("Authenticating User, Please Wait...");
}
#Override
protected void onProgressUpdate(String... values)
{
super.onProgressUpdate(values);
progressListener.onProgressUpdate(values[0]);
}
#Override
protected BackendlessUser doInBackground(String... strings)
{
try
{
Backendless.UserService.login(
Utility.getText(email),
Utility.getText(password),
onLoginCallback, stayLoggedIn);
publishProgress("Validating Credentials, Please Wait...");
latch.await();
}
catch (InterruptedException e)
{
publishProgress(e.getMessage());
}
return Utility.loginUser;
}
#Override
protected void onPostExecute(BackendlessUser user)
{
super.onPostExecute(user);
Utility.clearViews(email, password, rememberMe);
progressListener.onDismissDialog();
if(user != null)
{
if(((MainActivity)getActivity()).onRoleValidation(user))
{
mListener.onLoginSuccess(user);
}
else
{
//send a push notification to master channel
Utility.sendNotification(getActivity(),
"New Application User",
"New Registration",
"New User Awaiting Role Assignment", "Master",
"Role Assignment Pending For User :"
+ user.getEmail()
+ ":" + user.getProperty("name").toString()
+ " " + user.getProperty("surname").toString());
}
}
}
}
private void onLoginRequest()
{
if(Utility.hasText(email, password))
{
if(Utility.isEmailValid(Utility.getText(email)))
{
new OnAuthentication().
execute(Utility.getText(email),
Utility.getText(password));
}
else
{
Utility.showToast(getActivity(), "Invalid Email");
Utility.clearViews(email);
}
}
}
private AsyncCallback<BackendlessUser> onLoginCallback = new AsyncCallback<BackendlessUser>()
{
#Override
public void handleResponse(BackendlessUser backendlessUser)
{
latch.countDown();
Utility.loginUser = backendlessUser;
Log.i(MainFragment.class.getName(), "Login Successful!\n" + backendlessUser.getUserId());
}
#Override
public void handleFault(BackendlessFault backendlessFault)
{
latch.countDown();
progressListener.onProgressUpdate("Login Unsuccessful!");
Log.e(MainFragment.class.getName(), "Login Failed!\n" + backendlessFault.getMessage());
}
};
}

How can I find memory leak in android app

I'm developing an android kind-of-gallery-app with Firebase, so I will have plenty of images. I know that I need to be careful about memory management.
When I was searching how to find memory leak in android apps, I came across with LeakCanary. It looks really great, so I used in my app.
Basically my app has 3 fragments, which are Drawer, ProductGrid and ProductDetail. Sometimes LeakCanary says that I have a memory leak in ProductGrid, but I couldn't find it! Usually, adapters or static methods or listeners could cause memory leak because of Context object, but my knowledge is not sufficient to say 'aah that's because of here'
Here are the classes. Where is the leak?(If you suggest me anything that I can improve my code or approach, I would be appreciated!)
Because of body character limit, I put the link leak canary log file.
How I suspect there is a memory leak
First of all, LeakCanary shows a dialog and logs the dump. Second thing is, when I click on an item in drawer, in grid and in detail like 15 times(respectively), memory usage increases. It starts with 18M, increases 22M-23M after showing 3 images(normal). Then it heads up to 29M-30M after clicking on 15 times. If you click on around 30-40, memory usage increases 34M-35M
Edit: I've just figured out that, if I open and close drawer, memory usage increases 0.05M everytime, so one time opening and closing drawer costs 0.1M! What am i missing?
Main.java
public class Main extends ActionBarActivity implements DrawerListener {
private Toolbar mToolbar;
private Drawer drawerFragment;
private HomePage homeFragment;
private FragmentHelper fh = new FragmentHelper();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
if (homeFragment == null)
homeFragment = new HomePage();
if (savedInstanceState == null) {
mToolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(mToolbar);
getSupportActionBar().setDisplayShowHomeEnabled(true);
drawerFragment = (Drawer)
getSupportFragmentManager().findFragmentById(R.id.navigation_drawer);
drawerFragment.setUp(R.id.navigation_drawer,
(DrawerLayout) findViewById(R.id.drawer_layout), mToolbar);
drawerFragment.setDrawerListener(this);
drawerFragment.setRetainInstance(true);
displayView(null);
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_home) {
getSupportActionBar().setTitle(getString(R.string.app_name));
fh.replace(getSupportFragmentManager(), homeFragment, R.id.container_body);
return true;
}
if (id == R.id.action_settings) {
return true;
}
if (id == R.id.action_search) {
Toast.makeText(getApplicationContext(), "Search action is selected!", Toast.LENGTH_SHORT).show();
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
public void onDrawerItemSelected(View view, int position, Category category) {
displayView(category);
}
private void displayView(Category category) {
if (category != null) {
getSupportActionBar().setTitle(category.getName());
ProductGrid gridFragment = new ProductGrid();
Bundle args = new Bundle();
args.putString(Product.CATEGORY_ID, category.getId());
gridFragment.setArguments(args);
fh.replace(getSupportFragmentManager(), gridFragment, R.id.container_body);
} else {
getSupportActionBar().setTitle(getString(R.string.app_name));
fh.replace(getSupportFragmentManager(), homeFragment, R.id.container_body);
}
}
}
Drawer.java
public class Drawer extends Fragment {
private Firebase mFirebase;
private Alert alert;
private RecyclerView recyclerView;
private View containerView;
private DrawerLayout mDrawerLayout;
private ActionBarDrawerToggle mDrawerToggle;
private DrawerListener drawerListener;
private DrawerAdapter mAdapter;
private List<Category> mCategories;
public Drawer() {
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
alert = new Alert(getActivity().getApplicationContext());
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View layout = inflater.inflate(R.layout.drawer, container, false);
mCategories = new ArrayList<>();
mAdapter = new DrawerAdapter(mCategories);
recyclerView = (RecyclerView) layout.findViewById(R.id.drawer_list);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity().getApplicationContext()));
recyclerView.setItemAnimator(new SlideInOutLeftItemAnimator(recyclerView));
recyclerView.setAdapter(mAdapter);
mFirebase = new Firebase(getActivity().getResources().getString(R.string.firebase_ref))
.child(FirebaseRoots.CATEGORY);
Query query = mFirebase.orderByChild(Category.PRIO);
query.addChildEventListener(new ChildEventListener() {
#Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
Category model = dataSnapshot.getValue(Category.class);
model.setId(dataSnapshot.getKey());
mCategories.add(model);
recyclerView.scrollToPosition(mCategories.size() - 1);
mAdapter.notifyItemInserted(mCategories.size() - 1);
}
#Override
public void onChildChanged(DataSnapshot dataSnapshot, String s) {
Category model = dataSnapshot.getValue(Category.class);
model.setId(dataSnapshot.getKey());
int index = -1;
for (int i = 0; i < mCategories.size(); i++) {
if (mCategories.get(i).getId().equals(model.getId())) {
index = i;
break;
}
}
mCategories.set(index, model);
recyclerView.scrollToPosition(0);
mAdapter.notifyItemChanged(index);
}
#Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
Category model = dataSnapshot.getValue(Category.class);
model.setId(dataSnapshot.getKey());
int index = -1;
for (int i = 0; i < mCategories.size(); i++) {
if (mCategories.get(i).getId().equals(model.getId())) {
index = i;
break;
}
}
mCategories.remove(index);
recyclerView.scrollToPosition(0);
mAdapter.notifyItemRemoved(index);
}
#Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {
}
#Override
public void onCancelled(FirebaseError firebaseError) {
alert.show(firebaseError.toString());
}
});
recyclerView.addOnItemTouchListener(new RecyclerTouchListener(getActivity().getApplicationContext(),
recyclerView, new ClickListener() {
#Override
public void onClick(View view, int position) {
Category category = mCategories.get(position);
drawerListener.onDrawerItemSelected(view, position, category);
mDrawerLayout.closeDrawer(containerView);
}
#Override
public void onLongClick(View view, int position) {
}
}));
return layout;
}
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) {
super.onDrawerOpened(drawerView);
getActivity().invalidateOptionsMenu();
}
#Override
public void onDrawerClosed(View drawerView) {
super.onDrawerClosed(drawerView);
getActivity().invalidateOptionsMenu();
}
#Override
public void onDrawerSlide(View drawerView, float slideOffset) {
super.onDrawerSlide(drawerView, slideOffset);
toolbar.setAlpha(1 - slideOffset / 2);
}
};
mDrawerLayout.setDrawerListener(mDrawerToggle);
mDrawerLayout.post(new Runnable() {
#Override
public void run() {
mDrawerToggle.syncState();
}
});
}
public void setDrawerListener(DrawerListener listener) {
this.drawerListener = listener;
}
}
ProductGrid.java
public class ProductGrid extends Fragment implements ChildEventListener{
private Firebase mFirebaseRef;
private Alert alert;
private RecyclerView recyclerView;
private GridAdapter mAdapter;
private String categoryId;
private ArrayList<Product> mProducts;
private FileSystem fs;
public ProductGrid() {
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.categoryId = getArguments().getString(Product.CATEGORY_ID);
this.alert = new Alert(getActivity().getApplicationContext());
this.fs = new FileSystem(getActivity().getApplicationContext());
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View layout = inflater.inflate(R.layout.grid, container, false);
fieldInitialize(layout);
mProducts = new ArrayList<>();
mAdapter = new GridAdapter(mProducts, getActivity().getApplicationContext());
recyclerView.addItemDecoration(new MarginDecoration(getActivity()));
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new GridLayoutManager(getActivity(), 2));
recyclerView.setAdapter(mAdapter);
mFirebaseRef = new Firebase(getActivity().getResources().getString(R.string.firebase_ref))
.child(FirebaseRoots.PRODUCT);
Query query = mFirebaseRef.orderByChild(Product.CATEGORY_ID).equalTo(categoryId);
query.addChildEventListener(this);
recyclerView.addOnItemTouchListener(new RecyclerTouchListener(getActivity(), recyclerView, new ClickListener() {
#Override
public void onClick(View view, int position) {
ProductDetail detailFragment = new ProductDetail();
Bundle args = new Bundle();
args.putSerializable("product", mProducts);
args.putInt("position", position);
detailFragment.setArguments(args);
FragmentTransaction transaction = getFragmentManager().beginTransaction();
transaction.replace(R.id.container_body, detailFragment);
transaction.addToBackStack(null);
transaction.commit();
}
#Override
public void onLongClick(View view, int position) {
}
}));
return layout;
}
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
}
#Override
public void onDetach() {
super.onDetach();
}
public void fieldInitialize(View layout) {
recyclerView = (RecyclerView) layout.findViewById(R.id.product_grid_layout);
}
#Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
Product model = dataSnapshot.getValue(Product.class);
model.setId(dataSnapshot.getKey());
mProducts.add(model);
if (!fs.getFileNames().contains(model.getName() + FileExt.JPG.get())) {
fs.writeImage(model.getName(), ImageUtil.base64ToBitmap(
StringUtil.getBase64FromUrl(model.getImageData().getDataUrl())));
}
Collections.sort(mProducts);
recyclerView.scrollToPosition(0);
mAdapter.notifyItemInserted(mProducts.size() - 1);
}
#Override
public void onChildChanged(DataSnapshot dataSnapshot, String s) {
Product model = dataSnapshot.getValue(Product.class);
model.setId(dataSnapshot.getKey());
fs.writeImage(model.getName(), ImageUtil.base64ToBitmap(
StringUtil.getBase64FromUrl(model.getImageData().getDataUrl())));
int index = -1;
for (int i = 0; i < mProducts.size(); i++) {
if (mProducts.get(i).getId().equals(model.getId())) {
index = i;
break;
}
}
mProducts.set(index, model);
recyclerView.scrollToPosition(0);
mAdapter.notifyItemChanged(index);
}
#Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
Product model = dataSnapshot.getValue(Product.class);
model.setId(dataSnapshot.getKey());
fs.deleteImage(model.getName());
int index = -1;
for (int i = 0; i < mProducts.size(); i++) {
if (mProducts.get(i).getId().equals(model.getId())) {
index = i;
break;
}
}
mProducts.remove(index);
recyclerView.scrollToPosition(0);
mAdapter.notifyItemRemoved(index);
}
#Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {
}
#Override
public void onCancelled(FirebaseError firebaseError) {
alert.show(firebaseError.toString());
}
#Override public void onDestroy() {
super.onDestroy();
RefWatcher refWatcher = AcarsanApp.getRefWatcher(getActivity());
refWatcher.watch(this);
}
}
ProductDetail.java
public class ProductDetail extends Fragment {
private FullScreenImageAdapter adapter;
private ViewPager viewPager;
private ArrayList<Product> products;
private int position;
public ProductDetail() {
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
products = (ArrayList<Product>) getArguments().getSerializable("product");
position = getArguments().getInt("position");
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.product_detail, container, false);
viewPager = (ViewPager) view.findViewById(R.id.product_gallery);
adapter = new FullScreenImageAdapter(getActivity().getApplicationContext(), products);
viewPager.setAdapter(adapter);
viewPager.setCurrentItem(position);
return view;
}
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
}
#Override
public void onDetach() {
super.onDetach();
}
}
FileSystem
public class FileSystem {
private Context mContext;
public static final String PHOTOS_FOLDER = "photos";
public FileSystem(Context mContext) {
this.mContext = mContext;
}
public void writeImage(String name, Bitmap bitmap) {
String filename = name + FileExt.JPG.get();
File dir = mContext.getDir(PHOTOS_FOLDER, Context.MODE_PRIVATE);
File fileWithinDir = new File(dir, filename);
FileOutputStream outputStream;
try {
outputStream = new FileOutputStream(fileWithinDir);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, outputStream);
outputStream.close();
} catch (Exception e) {
e.printStackTrace();
}
}
public List<String> getFileNames() {
List<String> fileNames = new ArrayList<>();
File file = mContext.getDir(PHOTOS_FOLDER, Context.MODE_PRIVATE);
File[] files = file.listFiles();
for (File f : files) {
fileNames.add(f.getName());
}
return fileNames;
}
}
ImageUtil
public class ImageUtil {
public static Bitmap base64ToBitmap(String encodedImage) {
if (encodedImage == null)
return null;
byte[] decodedString = Base64.decode(encodedImage, Base64.DEFAULT);
return BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length);
}
}