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How to pass data from a activity to a recycler view adapter in android

I'm trying to design a page where address are stored in recycler view -> cardview.
When the user clicks the add address button from the Activity A the user is navigated to the add address page in Activity B. Here the user can input customer name, address line 1 and address line two.
And once save button is clicked in Activity B, a cardview should be created under the add address button in the Activity A.
This design is just like the amazon mobile app add address option.
Could anyone give me an example hoe to pass the saved data from activity to recycler adapter. I know how to pass data from recycler adapter to activity with putExtra etc..
Kindly help me. Million Thanks in advance!
Code In Activity A(Where the Add address button is available and where the recycler view is present)
public class ProfileManageAdressFragment extends AppCompatActivity {
RecyclerView recyclerView;
ProfileManageAddressRecyclerAdapter adapter;
ArrayList<ProfileManageAddressGetterSetter> reviews;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_profile_manage_adress);
Button addAddress = findViewById(R.id.addNewAddress);
reviews = new ArrayList<>();
addAddress.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(v.getContext(), "Clicked", Toast.LENGTH_SHORT).show();
Intent intent = new Intent(ProfileManageAdressFragment.this, AddNewAddress.class);
startActivity(intent);
}
});
}
}
Piece of Code that is responsible for adding a card view in Activity A. Kindly let me know how to invoke this below code on button click in Activity
reviews.add(new ProfileManageAddressGetterSetter("Customer Name", "address line 1", "address line 2"));
recyclerView = findViewById(R.id.addressRecyclerView);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(ProfileManageAdressFragment.this));
adapter = new ProfileManageAddressRecyclerAdapter(this, reviews);
recyclerView.setAdapter(adapter);
Code in the Recycler adapter
public class ProfileManageAddressRecyclerAdapter extends RecyclerView.Adapter<ProfileManageAddressRecyclerAdapter.ViewHolder> {
private ArrayList<ProfileManageAddressGetterSetter> mDataset = new ArrayList<>();
private Context context;
public static class ViewHolder extends RecyclerView.ViewHolder {
private TextView customer_name, address_one, address_two;
private Button edit, remove;
public ViewHolder(View v) {
super(v);
customer_name = (TextView) v.findViewById(R.id.customerName);
address_one = (TextView) v.findViewById(R.id.addressLineOne);
address_two = v.findViewById(R.id.addressLineTwo);
}
}
public ProfileManageAddressRecyclerAdapter(View.OnClickListener profileManageAdressFragment, ArrayList<ProfileManageAddressGetterSetter> dataset) {
mDataset.clear();
mDataset.addAll(dataset);
}
#Override
public ProfileManageAddressRecyclerAdapter.ViewHolder onCreateViewHolder(final ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.recycler_manage_address, parent, false);
ProfileManageAddressRecyclerAdapter.ViewHolder vh = new ProfileManageAddressRecyclerAdapter.ViewHolder(view);
return vh;
}
#Override
public void onBindViewHolder(#NonNull ProfileManageAddressRecyclerAdapter.ViewHolder holder, int position) {
ProfileManageAddressGetterSetter profileManageAddressGetterSetter = mDataset.get(position);
holder.address_one.setText(profileManageAddressGetterSetter.getAddress_line_1());
holder.address_two.setText(profileManageAddressGetterSetter.getGetAddress_line_2());
holder.customer_name.setText(profileManageAddressGetterSetter.getContractor_name());
}
#Override
public int getItemCount() {
return mDataset.size();
}
}
enter image description here - After trying the call from adapter using intent as mentioned above ended up with a 0.
Code in the Activity B
public class AddNewAddress extends AppCompatActivity {
private EditText customer_name, address_one, address_two;
private TextView cancel;
private Button add_address;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_add_new_address);
customer_name = findViewById(R.id.customerName);
address_one = findViewById(R.id.addressOne);
address_two = findViewById(R.id.addressTwo);
add_address = findViewById(R.id.addAddress);
cancel = findViewById(R.id.completeCancel);
String cancel_text = "Cancel";
SpannableString spanableObject = new SpannableString(cancel_text);
ClickableSpan clickableSpan = new ClickableSpan() {
#Override
public void onClick(View widget) {
Toast.makeText(AddNewAddress.this, "Clicked", Toast.LENGTH_SHORT).show();
}
#Override
public void updateDrawState(TextPaint ds) {
super.updateDrawState(ds);
ds.setColor(Color.BLUE);
}
};
spanableObject.setSpan(clickableSpan, 0, 6, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
cancel.setText(spanableObject);
cancel.setMovementMethod(LinkMovementMethod.getInstance());
final ProfileManageAdressFragment profileManageAdressFragment = new ProfileManageAdressFragment();
add_address.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(AddNewAddress.this, ProfileManageAdressFragment.class);
startActivity(intent);
}
});
}
private void setFragment(android.support.v4.app.Fragment fragment) {
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.main_frame, fragment).commit();
}
}
Update 1:
Kindly check my updated Recycler adapter. When I run this 0 is displayed in the text area as shown in the attached image. I'm new to android. Kindly help with example.

I finally achieved my goal with the use of ActivityResult. Now I'm able to pass data from Activity to Cardview.
Solution: When button is clicked in Activity A, I start the activity with startResultActivity(). Later, when the Activity B i triggered. The end-user inputs the data and that data is passed with the use of putExtra() and once the save button is clicked in Activity B next setResult() in Activity B and finish().
Finally i define onActivityResult() in Activity A to get the result. Works well!!

I would create a global variable and then store all the data in that variable and simply just call that variable in adapter.
declare a global variable and assign null value to it:
public static String checking = null;
a then store data in when you need it:
checking = check.getText().toString();
then call it in your adapter class.

first make interface listener inside listener make function with parameter like this
interface YourRecycleViewClickListener {
fun onItemClickListener(param1:View, param2: String)
}
now extend your activity
class YourActivity:YourRecycleViewClickListener{
override fun onItemClickListener(param1:View, param2: String) {
//do any thing
}
}
third step make interface constract in your recycle adapter
class YourAdapter(
private val listener: YourRecycleViewClickListener){
holder.constraintLayout.setOnClickListener{
listener.onItemClickListener(param1,param2)
}
}
this is by kotlin lang
and by java is same but change syntax
that all to do

How to handle StackOveflowError: stack size 8MB using PhotoView in Viewpager with glidev4?

I get this error when trying to swipe in the ViewPager Activity using the photoView library, I use Glide for the image, and the url are from an Intent(url are array). I also in download data from a firebase database using a model class.
This is the log:
06-27 14:36:33.291 6520-6520/com.realty.drake.kunuk E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.realty.drake.kunuk, PID: 6520
java.lang.StackOverflowError: stack size 8MB
at android.support.v4.view.PagerAdapter.startUpdate(PagerAdapter.java:96)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1116)
at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:662)
at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:624)
at android.support.v4.view.ViewPager.dataSetChanged(ViewPager.java:1078)
at android.support.v4.view.ViewPager$PagerObserver.onChanged(ViewPager.java:3089)
at android.support.v4.view.PagerAdapter.notifyDataSetChanged(PagerAdapter.java:284)
at com.realty.drake.kunuk.ViewPagerActivity$SamplePagerAdapter.instantiateItem(ViewPagerActivity.java:45)
at com.realty.drake.kunuk.ViewPagerActivity$SamplePagerAdapter.instantiateItem(ViewPagerActivity.java:34)
at android.support.v4.view.ViewPager.addNewItem(ViewPager.java:1002)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1216)
at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:662)
at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:624)
at android.support.v4.view.ViewPager.dataSetChanged(ViewPager.java:1078)
at android.support.v4.view.ViewPager$PagerObserver.onChanged(ViewPager.java:3089)
at android.support.v4.view.PagerAdapter.notifyDataSetChanged(PagerAdapter.java:284)
at com.realty.drake.kunuk.ViewPagerActivity$SamplePagerAdapter.instantiateItem(ViewPagerActivity.java:45)
at com.realty.drake.kunuk.ViewPagerActivity$SamplePagerAdapter.instantiateItem(ViewPagerActivity.java:34)
at android.support.v4.view.ViewPager.addNewItem(ViewPager.java:1002)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1216)
at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:662)
at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:624)
at android.support.v4.view.ViewPager.dataSetChanged(ViewPager.java:1078)
at android.support.v4.view.ViewPager$PagerObserver.onChanged(ViewPager.java:3089)
at android.support.v4.view.PagerAdapter.notifyDataSetChanged(PagerAdapter.java:284)
at com.realty.drake.kunuk.ViewPagerActivity$SamplePagerAdapter.instantiateItem(ViewPagerActivity.java:45)
at com.realty.drake.kunuk.ViewPagerActivity$SamplePagerAdapter.instantiateItem(ViewPagerActivity.java:34)
at android.support.v4.view.ViewPager.addNewItem(ViewPager.java:1002)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1216)
at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:662)
at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:624)
at android.support.v4.view.ViewPager.dataSetChanged(ViewPager.java:1078)
at android.support.v4.view.ViewPager$PagerObserver.onChanged(ViewPager.java:3089)
at android.support.v4.view.PagerAdapter.notifyDataSetChanged(PagerAdapter.java:284)
at com.realty.drake.kunuk.ViewPagerActivity$SamplePagerAdapter.instantiateItem(ViewPagerActivity.java:45)
at com.realty.drake.kunuk.ViewPagerActivity$SamplePagerAdapter.instantiateItem(ViewPagerActivity.java:34)
at android.support.v4.view.ViewPager.addNewItem(ViewPager.java:1002)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1216)
at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:662)
at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:624)
at android.support.v4.view.ViewPager.dataSetChanged(ViewPager.java:1078)
at android.support.v4.view.ViewPager$PagerObserver.onChanged(ViewPager.java:3089)
at android.support.v4.view.PagerAdapter.notifyDataSetChanged(PagerAdapter.java:284)
at com.realty.drake.kunuk.ViewPagerActivity$SamplePagerAdapter.instantiateItem(ViewPagerActivity.java:45)
at com.realty.drake.kunuk.ViewPagerActivity$SamplePagerAdapter.instantiateItem(ViewPagerActivity.java:34)
at android.support.v4.view.ViewPager.addNewItem(ViewPager.java:1002)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1216)
at android.support.v4.vie
06-27 14:36:33.411 6520-6520/com.realty.drake.kunuk E/JavaBinder: !!! FAILED BINDER TRANSACTION !!! (parcel size = 1275500)
06-27 14:36:33.412 6520-6520/com.realty.drake.kunuk E/AndroidRuntime: Error reporting crash
android.os.TransactionTooLargeException: data parcel size 1275500 bytes
at android.os.BinderProxy.transactNative(Native Method)
at android.os.BinderProxy.transact(Binder.java:503)
at android.app.ActivityManagerProxy.handleApplicationCrash(ActivityManagerNative.java:4447)
at com.android.internal.os.RuntimeInit$UncaughtHandler.uncaughtException(RuntimeInit.java:90)
at com.crashlytics.android.core.CrashlyticsUncaughtExceptionHandler.uncaughtExcep tion(CrashlyticsUncaughtExceptionHandler.java:51)
at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:693)
at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:690)
The ViewPager activity, There I take the url from an intent, parse it to turn it into an array because it is multiple string concatenated. The glide use it to display the image. The first image display and doesn't crash, but when I swipe to the second image, it took a few seconds then crash(only the activity crash not the app), but If I swipe from second to the third image it crash suddenly before even display it.
public class ViewPagerActivity extends AppCompatActivity {
String imageList = null;
String[] propertyImageArray = {};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_view_pager);
//get imageList url from Intent
imageList = getIntent().getStringExtra("imageList");
propertyImageArray = imageList.split(",");
ViewPager viewPager = findViewById(R.id.view_pager);
viewPager.setAdapter(new SamplePagerAdapter());
}
class SamplePagerAdapter extends PagerAdapter {
#Override
public int getCount() {
return propertyImageArray.length;
}
#Override
public View instantiateItem(ViewGroup container, int position) {
//Must call notifyDataSetChanged before adding imageList to View
//otherwise it'll crash
notifyDataSetChanged();
PhotoView photoView = new PhotoView(ViewPagerActivity.this);
GlideApp.with(ViewPagerActivity.this)
.load(propertyImageArray[position])
.fitCenter()
.into(photoView);
// Now just add PhotoView to ViewPager and return it
container.addView(photoView,
ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
return photoView;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((View) object);
}
#Override
public boolean isViewFromObject(View view, Object object) {
return view == object;
}
This is the class that send the intent to ViewPagerActivity,
public class PropertyLotDetail extends AppCompatActivity implements Toolbar.OnMenuItemClickListener {
#Override
protected void onCreate( Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.property_lot_detail);
Toolbar myToolbar = (Toolbar) findViewById(R.id.kunuk_toolbar);
myToolbar.inflateMenu(R.menu.menu_detail);
setSupportActionBar(myToolbar);
myToolbar.setOnMenuItemClickListener(this);
//collect our intent
Intent intent = getIntent();
Property property = intent.getParcelableExtra("Property");
//collect all property values from Parcelable
int price = property.getPrice();
String address = property.getAddress();
final String propertyImage = property.getPropertyImage();
float lotDim = property.getLotDim();
String propertyDesc = property.getPropertyDesc();
String lotTerrainType = property.getLotTerrainType();
String lotTerrainDimExt = property.getLotTerrainDimExt();
String lotTerrainSteepness = property.getLotTerrainSteepness();
[...]
//Bind the data from the Parcelable to the Views
TextView addressDetail = findViewById(R.id.post_address);
addressDetail.setText(String.valueOf(address));
String currencyPrice = NumberFormat //Format the price variable in currency form
.getCurrencyInstance(Locale.US)
.format(price);
TextView priceDetail = findViewById(R.id.post_price);
priceDetail.setText(currencyPrice);
ImageView imageView = findViewById(R.id.post_propertyImage);
imageView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
startActivity(new Intent(getApplicationContext(),
ViewPagerActivity.class)
.putExtra("imageList", propertyImage)
.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK));
}
});
//take one long string containing multiple url and parse it
String propertyImageArray[] = propertyImage.split(",");
//TODO add loading icon for placeholder
// Download directly from StorageReference using Glide
// (See MyAppGlideModule for Loader registration)
GlideApp.with(getApplication())
.load(propertyImageArray[0])
.fitCenter()
.into(imageView);
That's the most relevant information. Please help

I just got rid of the notifyDataChanged() method call. I presume it has been automatically called, I didn't need to do it, and that's why the stack trace leads to an endless recursion. It's just what I think.
public class ViewPagerActivity extends AppCompatActivity {
String imageList = null;
String[] propertyImageArray = {};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_view_pager);
//get imageList url from Intent
imageList = getIntent().getStringExtra("imageList");
propertyImageArray = imageList.split(",");
ViewPager viewPager = findViewById(R.id.view_pager);
viewPager.setAdapter(new SamplePagerAdapter());
}
class SamplePagerAdapter extends PagerAdapter {
#Override
public int getCount() {
return propertyImageArray.length;
}
#Override
public View instantiateItem(ViewGroup container, int position) {
//Must call notifyDataSetChanged before adding imageList to View
//otherwise it'll crash
notifyDataSetChanged();
PhotoView photoView = new PhotoView(ViewPagerActivity.this);
GlideApp.with(ViewPagerActivity.this)
.load(propertyImageArray[position])
.fitCenter()
.into(photoView);
// Now just add PhotoView to ViewPager and return it
container.addView(photoView,
ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
return photoView;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((View) object);
}
#Override
public boolean isViewFromObject(View view, Object object) {
return view == object;
}
Sorry for the bad formatting, don't know how to make striketrough in code

Different onClickListeners for dynamic buttons using RecyclerView

I am using RecyclerView (and GridLayout) to place dynamic buttons in a grid. What is the best way to set up a DIFFERENT onClickListener for each dynamic button as it is created using RecyclerView and placed in the Gridlayout?
My buttons are created randomly depending on a user action by passing a drawable to my RecyclerView in the method "createButton" below. Only one drawable gets passed to my gridLayout at a time, and each time a new onClickListener must be created. What is the best way to go about this?
private GridLayoutManager lLayout;
RecyclerViewAdapter rcAdapter;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
List<ItemObject> myList = new ArrayList<>();
rcAdapter = new RecyclerViewAdapter(getActivity(),myList);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.home_fragment, container, false);
lLayout = new GridLayoutManager(getActivity(), 3,
GridLayoutManager.HORIZONTAL, false);
RecyclerView rView = (RecyclerView)view.findViewById(R.id.recycler_view);
rView.setHasFixedSize(true);
rView.setLayoutManager(lLayout);
rView.setAdapter(rcAdapter);
return view;
}
public void createButton (Drawable d, String appName){
rcAdapter.addItem(new ItemObject(appName, d));
}

I don't think you need a new click listener every time you just need a click listener that is aware of the ItemObject. For that, I'll give you my usual approach for such a pattern:
Somewhere in your code you have an RecyclerView.ViewHolder, you should make that view holder implement OnClickListener and give pass the reference of ItemObject to the holder during OnBind, like following:
class MyHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
ItemObject itemObject;
public MyHolder(View itemView) {
super(itemView);
itemView.findViewById(your button Id).setOnClickListener(this); // make this holder receives the clicks
}
#Override
public void onClick(View view) {
// here you add logic that depending on the data from itemObject
}
}
and then during onBind you must properly set the ItemObject
#Override
public void onBindViewHolder (MyHolder holder, int position) {
ItemObject itemObject = list.get(position);
holder.itemObject = itemObject;
// the rest of your bind code....
}

How to update custom RecyclerView from FragmentDialog?

I have an Activity A with a fragment frag2. Inside the fragment I have a RecyclerView and Adapter to show a list of custom class objects. Adding objects to the adapter is handled programmatically. I have a button inside TwoFragment that opens a FragmentDialog. I'd like to add an object to my Adapter by confirming this dialog, but it seems that the adapter is null when called from the FragmentDialog.
The same adapter is not null, and works if I call it from the fragment OnClick.
Moreover the adapter is null only after screen rotation, it works fine before rotating.
To communicate between the two Fragments I implement a communicator class in activity A.
Activity A
public void respond(String type) {
frag2.addSupport(type);
}
frag2
public RecyclerView rv;
public ArrayList<support> supports;
public myAdapter adapter;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
supports = new ArrayList<>();
adapter = new myAdapter(supports);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View layout = inflater.inflate( R.layout.fragment_two, container, false);
layout.setId(R.id.frag2);
if (savedInstanceState!=null)
{
supports = savedInstanceState.getParcelableArrayList("supports");
}
rv = (RecyclerView) layout.findViewById(R.id.rv);
adapter = new myAdapter(supports);
rv.setAdapter(myAdapter);
rv.setLayoutManager(new LinearLayoutManager(getActivity()));
rv.setItemAnimator(new DefaultItemAnimator());
#Override
public void onClick(View v) {
int id = v.getId();
switch (id){
case R.id.button1:
addSupport(type); // THIS WORKS ALWAYS, even after screen rotate
break;
case R.id.button2:
showDialog();
break;
}
}
public void showDialog(){
FragmentManager manager = getFragmentManager();
myDialog dialog = new myDialog();
dialog.show(manager, "dialog");
}
public void addSupport(String type){
adapter.addItem(new support(type)); // this line gives null pointer on adapter, but only if called after screen rotate and only if called from the dialog
}
dialog
communicator comm;
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.dialog, null);
comm = (myCommunicator) getActivity();
create = (Button) view.findViewById(R.id.button_ok);
create.setOnClickListener(this);
return view;
}
#Override
public void onClick(View v) {
if(v.getId()==R.id.button_ok)
{
// some controls to set type
comm.respond(type)
dismiss();
}
else {
dismiss();
}
myAdapter
public class myAdapter extends RecyclerView.Adapter<myAdapter.VH> {
private LayoutInflater inflater;
private ArrayList<support> data = new ArrayList<>();
// settings for viewholder
public myAdapter (ArrayList<support> data)
{
this.data=data;
}
public void addItem(support dataObj) {
data.add(dataObj);
notifyItemInserted(data.size());
}
}
logcat
FATAL EXCEPTION: main
java.lang.NullPointerException: Attempt to invoke virtual method 'myAdapter.addItem(myObject)' on a null object reference
I hope there are no mistakes, I shortened the code for better understanding. Keep in mind that everything works if I never rotate the screen.
I'm a beginner with android and I'm stuck with this for several days now. Please, help.

To understand the problem, it's as you say:
.. everything works if I never rotate the screen
So firstly to understand what happens on rotation, this is a quote from the Android Developer website:
Caution: Your activity will be destroyed and recreated each time the user rotates the screen. When the screen changes orientation, the system destroys and recreates the foreground activity because the screen configuration has changed and your activity might need to load alternative resources (such as the layout).
Ok, now to understand the error:
FATAL EXCEPTION: main
java.lang.NullPointerException: Attempt to invoke virtual method 'myAdapter.addItem(myObject)' on a null object reference
Essentially, in your dialog class, you have created a strong dependency by declaring :
comm = (myCommunicator) getActivity();
because comm references objects which would have been destroyed on rotation, hence the NullPointerException.
To further understand runtime changes, such as orientation changes, I'd recommend going through Handling Runtime Changes.
Update
Thank you for your answer, what would you recommend instead of comm = (myCommunicator) getActivity(); ?
The solution comes in 3 parts:
Make sure the onCreate of Activity A has the following:
#Override
public void onCreate(Bundle savedInstanceState) {
......
// find the retained fragment on activity restarts
FragmentManager fm = getFragmentManager();
frag2 = (Frag2) fm.findFragmentByTag(“frag2”);
// create frag2 only for the first time
if (frag2 == null) {
// add the fragment
frag2 = new Frag2();
fm.beginTransaction().add(frag2 , “frag2”).commit();
}
......
}
Add setRetainInstance(true) to the onCreate of frag2.
Remove the implicit referencing i.e. comm = (myCommunicator) getActivity();, and implement something more loosely coupled for dialog.
dialog
public interface Communicator {
void respond(String type);
}
Communicator comm;
....
public void addCommunicator(Communicator communicator) {
comm = communicator;
}
public void removeCommunicator() {
comm = null;
}
#Override
public void onClick(View v) {
if((v.getId()==R.id.button_ok) && (comm!=null))
{
// some controls to set type
comm.respond(type);
}
// Regardless of what button is pressed, the dialog will dismiss
dismiss();
}
This allows you do the following in frag2 (or any other class for that matter):
frag2
<pre><code>
public class Frag2 extends Fragment implements dialog.Communicator {
........
public void showDialog() {
FragmentManager manager = getFragmentManager();
myDialog dialog = new myDialog();
dialog.addCommunicator(this);
dialog.show(manager, "dialog");
}
#Override
public void respond(String type){
adapter.addItem(new support(type));
}
}

RecyclerView leaks in FragmentPagerAdapter

I've figured out that in defined concatenation of circumstances RecyclerView leads to memory leak. To archive such effect, I have created FragmentPagerAdapter that contains fragment with RecyclerView as child.
In case of going application to background or finishing, leak canary fires memory leak alert. Here's my activity class
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
ViewPager mViewPager = (ViewPager) findViewById(R.id.view_pager);
List<Fragment> fragments = new LinkedList<>();
for (int i = 0; i < 10; i++) {
fragments.add(CustomFragment.newInstance(i));
}
mViewPager.setAdapter(new CustomPagerAdapter(getFragmentManager(), fragments));
mViewPager.setCurrentItem(0, false);
}
public class CustomPagerAdapter extends FragmentPagerAdapter {
private List<Fragment> fragments;
public CustomPagerAdapter(FragmentManager fragmentManager, List<Fragment> fragments) {
super(fragmentManager);
this.fragments = fragments;
}
#Override
public Fragment getItem(int position) {
return fragments.get(position);
}
#Override
public int getCount() {
return fragments.size();
}
}
}
To get the leak, RecyclerView even doesn't need to be initialized. If I comment it in xml file, the leak isn't fired
public class CustomFragment extends Fragment {
public static final String POSITION = "position";
public static CustomFragment newInstance(int position) {
Bundle b = new Bundle();
b.putInt(POSITION, position);
CustomFragment fragment = new CustomFragment();
fragment.setArguments(b);
return fragment;
}
private int position;
private RecyclerView recyclerView;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
position = getArguments().getInt(POSITION);
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_custom, container, false);
TextView textView = (TextView) v.findViewById(R.id.text);
textView.setText("Position: "+position);
recyclerView = (RecyclerView) v.findViewById(R.id.pulse_recyclerview);
return v;
}
#Override
public void onDestroy() {
super.onDestroy();
RefWatcher refWatcher = CustomApplication.getRefWatcher(getActivity());
refWatcher.watch(this);
}
}
Here's leak trace. RecyclerView version 23.1.1
In com.example.gabin.sampleapplication:1.0:1.
* LEAK CAN BE IGNORED.
* com.example.gabin.sampleapplication.MainActivity has leaked:
* GC ROOT static android.view.inputmethod.InputMethodManager.sInstance
* references android.view.inputmethod.InputMethodManager.mCurRootView
* references com.android.internal.policy.impl.PhoneWindow$DecorView.mContext
* leaks com.example.gabin.sampleapplication.MainActivity instance
* Retaining: 3,9 КБ.
* Reference Key: 67c5e9f4-464e-40c3-b21d-d802fe64a84b
* Device: LGE google Nexus 4 occam
* Android Version: 5.1.1 API: 22 LeakCanary: 1.4-beta1 02804f3
* Durations: watch=5035ms, gc=190ms, heap dump=5948ms, analysis=46384ms
May it be an Android bug?
Please, give any idea how to fix the leak, or help me figure out the reason of its firing by leakcanary.

Your stack trace shows at least two things:
It is not RecyclerView who leaks activity. It is the ImputMethodManager.
LEAK CAN BE IGNORED. According to Leak Canary docs it is a known sdk problem. But I don't think its really an activity leak. If you check your memory dump you will not see several activity instances. Code looks pretty safe at now.