Develop Reference

how to synchronise Between class controller contains AsyncTask and fragment

I am very very tired
I can't change visibility or an object in the fragment from the class controller
exmple addIteamsAutomatic.progressBar.setVisibility(View.GONE); return nullpointer
FragmentAddIteamsAutomatic :
public class FragmentAddIteamsAutomatic extends Fragment {
private EditText ssid, paswd;
public TextView afichage;
public Button parainage;
public Button validation;
public ProgressBar progressBar ;
public LinearLayout linearLayoutParm;
public static String sSSID,pWD;
private ControllerAddIteam controleAdd=null;
public FragmentAddIteamsAutomatic()
{
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.add_iteams_automatic, container, false);
controleAdd.getInstance(getActivity());
progressBar = (ProgressBar) view.findViewById(R.id.progressBar);
ssid = (EditText) view.findViewById(R.id.ssid);
paswd = (EditText) view.findViewById(R.id.password);
parainage = (Button) view.findViewById(R.id.btnParainage);
validation = (Button) view.findViewById(R.id.btnValid);
afichage = (TextView) view.findViewById(R.id.affichage);
linearLayoutParm = (LinearLayout) view.findViewById(R.id.linearLayParam);
progressBar.setVisibility(View.GONE);
afichage.setVisibility(View.GONE);
validation.setVisibility(View.GONE);
parainage.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
sSSID = ssid.getText().toString();
pWD = paswd.getText().toString();
if (sSSID.equals(""))
Toast.makeText(getActivity(), "Vous Dever Remplir Tous les champs", Toast.LENGTH_LONG).show();
else
parainer();
}
});
validation.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
controleAdd.addSwitchToBase();
Intent intent = new Intent(getActivity(), MainActivity.class);
startActivity(intent);
ControllerAddIteam.accesDistant.send("getIteams", new JSONArray());
// finish();
}
});
return view;
}
private void parainer(){
controleAdd.getInstanceExecuteHandle();
}
}
ControllerAddIteam :
public class ControllerAddIteam {
private static ControllerAddIteam instanceAdd = null;
private static Context context;
private static WifiUtils wifiUtils;
public static String SSID = null;
public static AccesDistant accesDistant;
public static Handler mHandler;
public static final ControllerAddIteam getInstance(Context context) {
if (context != null)
ControllerAddIteam.context = context;
if (ControllerAddIteam.instanceAdd == null) {
ControllerAddIteam.instanceAdd = new ControllerAddIteam();
accesDistant = new AccesDistant();
}
return ControllerAddIteam.instanceAdd;
}
public static void getInstanceExecuteHandle() {
new ParainageHandle().execute();
}
static class ParainageHandle extends AsyncTask<String, String, String> {
FragmentAddIteamsAutomatic addIteamsAutomatic=new FragmentAddIteamsAutomatic();
#Override
protected void onPreExecute() {
super.onPreExecute();
addIteamsAutomatic.progressBar.setVisibility(View.GONE);
addIteamsAutomatic.afichage.setVisibility(View.GONE);
}
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
addIteamsAutomatic.progressBar.setVisibility(View.GONE);
if(s.equals("valid"))
{
addIteamsAutomatic.linearLayoutParm.setVisibility(View.GONE);
addIteamsAutomatic.validation.setVisibility(View.VISIBLE);
addIteamsAutomatic.parainage.setVisibility(View.GONE);
}
else if(s.equals("notvalid"))
{
addIteamsAutomatic.parainage.setVisibility(View.VISIBLE);
}
}
#Override
protected void onProgressUpdate(String... values) {
addIteamsAutomatic.afichage.setVisibility(View.VISIBLE);
addIteamsAutomatic.progressBar.setVisibility(View.VISIBLE);
if (values[0].equals("actwifi")) {
if (values[1].equals("true"))
addIteamsAutomatic.afichage.setText("WIFI DEJA ACTIVEE");
else
addIteamsAutomatic.afichage.setText("ACTIVATION WIFI EN COURS...");
} else if (values[0].equals("scan"))
addIteamsAutomatic.afichage.setText("START SCAN FOR Iteams STiTo ... Please Wait");
else if (values[0].equals("find"))
addIteamsAutomatic.afichage.setText("STiTo : "+getTypeFromSsid(SSID)+" DETECTEE : "+SSID);
else if (values[0].equals("connect"))
addIteamsAutomatic.afichage.setText("CONNECTION WITH " + SSID + "En cours ...");
else if (values[0].equals("connectOk"))
addIteamsAutomatic.afichage.setText("CONNECTION WITH " + SSID + "ETABLISHED");
else if (values[0].equals("connectKo"))
addIteamsAutomatic.afichage.setText("PROBLEM OF CONNECTION WITH " + SSID);
else if (values[0].equals("config")) {
addIteamsAutomatic.afichage.setText("SENDING OF CONFIGURATION TO: "+getTypeFromSsid(SSID)+"AND SAVING DATA");
accesDistant.sendConfig(addIteamsAutomatic.sSSID,addIteamsAutomatic.pWD);
....

You declare fragment in AsyncTask and doesn't call replace or add, it mean this fragment never show and it not call onCreateView
FragmentAddIteamsAutomatic addIteamsAutomatic=new FragmentAddIteamsAutomatic();
Maybe you should pass reference addIteamsAutomatic to class ControllerAddIteam. but please make sure it will be call on MainThread, because AsyncTask has method doInBackground in background Thread. best practice is wrap fragment reference by WeakReference

public class AddIteamActivity extends AppCompatActivity {
ViewPager pager;
TabLayout tab;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_add_iteam);
pager = findViewById(R.id.pager);
tab = findViewById(R.id.tab);
AddIteamsAdapter viewPagerAdapter = new AddIteamsAdapter(getSupportFragmentManager());
pager.setAdapter(viewPagerAdapter);
tab.setupWithViewPager(pager);
}
}

How to call a specific Fragment's getActivity()?

My problem is that i have a recyclerview implemented on a fragment that uses Room. RecyclerView, Adapter and Database need to be together in one class (i guess).
My problem is that if I put them into StudentActivity,
recyclerView = findViewById(R.id.SubjectRecyclerView);
will be null, because the Fragment won't be available by the time this function called.
If i put them into StudentSubjectsFragment,
everything would be good, but NewSubjectDialogFragment tells me that StudentActivity needs to implement NewSubjectDialogFragment because of this:
private NewSubjectDialogListener listener;
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
FragmentActivity activity = getActivity();
if (activity instanceof NewSubjectDialogListener) {
listener = (NewSubjectDialogListener) activity;
} else {
throw new RuntimeException("Activity must implement the NewSubjectDialogListener interface!");
}
}
If at the
FragmentActivity activity = getActivity();
line somehow I would be able to call the getActivity() function of StudentSubjectsFragment class, I think it would solve my problem, and then the class that would implement the NewSubjectDialogFragment would be the StudentSubjectsFragment instead of StudentActivity.
I tried this:
FragmentActivity activity = getActivity().getSupportFragmentManager().findFragmentByTag("StudentSubjectsFragment").getActivity();
But activity is null.
StudentSubjectsFragment class:
public class StudentSubjectsFragment extends Fragment
implements NewSubjectDialogFragment.NewSubjectDialogListener,
SubjectAdapter.SubjectClickListener {
public static final String TAG = "StudentSubjectsFragment";
private RecyclerView recyclerView;
private SubjectAdapter adapter;
private SubjectDatabase database;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container,
#Nullable Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.student_subjects, container, false);
FloatingActionButton fab = rootView.findViewById(R.id.fabbb);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
new NewSubjectDialogFragment().show(getActivity().getSupportFragmentManager(), NewSubjectDialogFragment.TAG);
}
});
database = Room.databaseBuilder(
getActivity(),
SubjectDatabase.class,
"subject-list"
).build();
recyclerView = rootView.findViewById(R.id.SubjectRecyclerView);
adapter = new SubjectAdapter(this);
loadItemsInBackground();
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
recyclerView.setAdapter(adapter);
return rootView;
}
private void loadItemsInBackground() {
new AsyncTask<Void, Void, List<Subject>>() {
#Override
protected List<Subject> doInBackground(Void... voids) {
return database.subjectDao().getAll();
}
#Override
protected void onPostExecute(List<Subject> subjects) {
adapter.update(subjects);
}
}.execute();
}
#Override
public void onItemChanged(final Subject item) {
new AsyncTask<Void, Void, Boolean>() {
#Override
protected Boolean doInBackground(Void... voids) {
database.subjectDao().update(item);
return true;
}
#Override
protected void onPostExecute(Boolean isSuccessful) {
Log.d("StudentActivity", "Subject update was successful");
}
}.execute();
}
#Override
public void onItemDeleted(final Subject item) {
new AsyncTask<Void, Void, Boolean>() {
#Override
protected Boolean doInBackground(Void... voids) {
database.subjectDao().deleteItem(item);
return true;
}
}.execute();
}
#Override
public void onSubjectCreated(final Subject newItem) {
new AsyncTask<Void, Void, Subject>() {
#Override
protected Subject doInBackground(Void... voids) {
newItem.id = database.subjectDao().insert(newItem);
return newItem;
}
#Override
protected void onPostExecute(Subject subject) {
adapter.addItem(subject);
}
}.execute();
}
}
StudentActivity class:
public class StudentActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_student);
ViewPager vpProfile = findViewById(R.id.vpStudent);
vpProfile.setAdapter(new StudentPagerAdapter(getSupportFragmentManager()));
}
}
NewSubjectDialogFragment class:
public class NewSubjectDialogFragment extends DialogFragment {
private EditText nameEditText;
public static final String TAG = "NewSubjectDialogFragment";
public interface NewSubjectDialogListener {
void onSubjectCreated(Subject newItem);
}
private NewSubjectDialogListener listener;
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
FragmentActivity activity = getActivity().getSupportFragmentManager().findFragmentByTag("StudentSubjectsFragment").getActivity();
if (activity instanceof NewSubjectDialogListener) {
listener = (NewSubjectDialogListener) activity;
} else {
throw new RuntimeException("Activity must implement the NewSubjectDialogListener interface!");
}
}
private boolean isValid() {
return nameEditText.getText().length() > 0;
}
private Subject getSubject() {
Subject subject = new Subject();
subject.name = nameEditText.getText().toString();
return subject;
}
#NonNull
#Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
return new AlertDialog.Builder(requireContext())
.setTitle(R.string.new_subject_item)
.setView(getContentView())
.setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialogInterface, int i) {
if (isValid()) {
listener.onSubjectCreated(getSubject());
}
}
})
.setNegativeButton(R.string.cancel, null)
.create();
}
private View getContentView() {
final View contentView = LayoutInflater.from(getContext()).inflate(R.layout.dialog_new_subject_item, null);
nameEditText = contentView.findViewById(R.id.SubjectNameEditText);
return contentView;
}
}
I think there is a way to change NewSubjectDialogFragment to work with StudentSubjectsFragment but I am a beginner in android developing and don't know how to do it.

Solution of Mike M. worked perfectly.
The working code parts are the following:
NewSubjectDialogFragment:
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Fragment fragment = getParentFragment();
if (fragment instanceof NewSubjectDialogListener) {
listener = (NewSubjectDialogListener) fragment;
} else {
throw new RuntimeException("Fragment must implement the NewSubjectDialogListener interface!");
}
}
StudentSubjectFragment:
FloatingActionButton fab = rootView.findViewById(R.id.fabbb);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
new NewSubjectDialogFragment().show(getChildFragmentManager(), NewSubjectDialogFragment.TAG);
}
});

Android viewpager AsyncTask finish when page changed

I have view pager. My viewpager contains 3 fragments. In the first fragment I have an AsyncTask class. I parsed JSON with AsyncTask and I can show it in listview. (everything is ok)
I have one problem AsyncTask which I have in the first fragment does not finish when I go to the next fragments. When I am in the second fragment my AsyncTask is also running. How can I write code to cancel my AsyncTask when viewpager's page changed?
This is my source (this is the first fragment source; another fragment source is the same but the only difference is the Server Url):
public class StradaChefs1 extends Fragment {
public static CustomerStatistic stat;
private ConnectionDetector con;
private AlertDialogManager alert = new AlertDialogManager();
#SuppressLint("ClickableViewAccessibility")
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.strada_chefs_1, container,
false);
stat = new CustomerStatistic();
con = new ConnectionDetector(getActivity());
if (!con.isConnectingToInternet()) {
alert.showAlertDialog(getActivity(),
"You have not internet connection");
} else {
stat.execute("my urlllllllll"); // geo
}
return rootView;
}
public class CustomerStatistic extends AsyncTask<String, Void, String> {
ProgressDialog pDialog;
#Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = ProgressDialog.show(getActivity(), "Please Wait... ",
"Loading... ");
pDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
pDialog.setCancelable(false);
pDialog.show();
}
#Override
protected String doInBackground(String... params) {
return Utils.getJSONString(params[0]);
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
try {
JSONArray mainJson = new JSONArray(result);
String first = mainJson.getString(0);
JSONObject jobject = new JSONObject(first);
String image = jobject.getString("image");
String String_title = jobject.getString("title");
String String_name = jobject.getString("name");
String String_desc = jobject.getString("description");
String second = mainJson.getString(1);
} catch (JSONException e) {
e.printStackTrace();
}
if (pDialog != null) {
pDialog.dismiss();
pDialog = null;
}
}
}
#Override
public void onResume() {
Log.e("DEBUG", "onResume of HomeFragment");
super.onResume();
}
#Override
public void onStop() {
super.onStop();
if (stat != null && stat.equals(AsyncTask.Status.RUNNING)) {
stat.cancel(true);
Toast.makeText(getActivity(), "finished", Toast.LENGTH_SHORT)
.show();
}
}
}
This is a viewpager java code
public class TabbedActivity1 extends Fragment {
private StradaChefs1 mfragment1;
private StradaChefs2 mfragment2;
private StradaChefs3 mfragment3;
private StradaChefs4 mfragment4;
SectionsPagerAdapter mSe;
public static final String TAG = TabbedActivity1.class.getSimpleName();
ViewPager mViewPager;
private ArrayList<Fragment> fragmentList;
public static TabbedActivity1 newInstance() {
return new TabbedActivity1();
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.activity_item_one_1, container, false);
mSe=new SectionsPagerAdapter(getChildFragmentManager());
mViewPager = (ViewPager) v.findViewById(R.id.pager1);
CirclePageIndicator circle=(CirclePageIndicator)v.findViewById(R.id.circleindicator1);
mViewPager.setAdapter(mSe);
circle.setViewPager(mViewPager);
mfragment1 = new StradaChefs1();
mfragment2 = new StradaChefs2();
mfragment3 = new StradaChefs3();
mfragment4 = new StradaChefs4();
fragmentList = new ArrayList<Fragment>();
fragmentList.add(mfragment1);
fragmentList.add(mfragment2);
fragmentList.add(mfragment3);
fragmentList.add(mfragment4);
mViewPager.setPageTransformer(false, new PageTransformer() {
#Override
public void transformPage(View page, float position) {
page.setRotationY(position * -40);
}
});
return v;
}
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
return fragmentList.get(position);
}
#Override
public int getCount() {
return 4;
}
#Override
public CharSequence getPageTitle(int position) {
return null;
}
}
}
How can I solve this problem?

The FragmentPagerAdapter keeps additional fragments, besides the one shown, in resumed state, so you can't use onPause and onResume for starting/stopping the AsyncTask. The solution is to implement a custom OnPageChangeListener and create a new method for when the fragment is shown.
1) Create LifecycleManager Interface The interface will have two methods and each ViewPager’s Fragment will implement it. These methods Are as follows:
public interface FragmentLifecycle {
public void onPauseFragment();
public void onResumeFragment();
}
2) Let each Fragment implement the interface
3) Implement interface methods in each fragment - in onPauseFragment stop the AsyncTask, in onResumeFragment start it
4) Call interface methods on ViewPager page change You can set OnPageChangeListener on ViewPager and get callback each time when ViewPager shows another page
5) Implement OnPageChangeListener to call your custom Lifecycle methods
Listener knows the new position and can call the interface method on new Fragment with the help of PagerAdapter. I can here call onResumeFragment() for new fragment and onPauseFragment() on the current one.
I need to store also the current fragment’s position (initially the current position is equal to 0), since I don’t know whether the user scrolled from left to right or from right to left. See what I mean in code:
private OnPageChangeListener pageChangeListener = new OnPageChangeListener() {
int currentPosition = 0;
#Override
public void onPageSelected(int newPosition) {
FragmentLifecycle fragmentToShow = (FragmentLifecycle)pageAdapter.getItem(newPosition);
fragmentToShow.onResumeFragment();
FragmentLifecycle fragmentToHide = (FragmentLifecycle)pageAdapter.getItem(currentPosition);
fragmentToHide.onPauseFragment();
currentPosition = newPosition;
}
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) { }
public void onPageScrollStateChanged(int arg0) { }
};
I didn't write the code. Full tutorial here

When you start the asynctask set the flag isRunning=true
when you are trying to jump from one fragment to other it mean
as per fragment lifecycle your are pausing and stoping your current fragment
so in onStop method of fragment you can check isRunning flag of asynctask is true if yes the
cancel the asyntask
its my logic hope it will help you to achieve your requirement

How to update a textview in a dialog fragment from an activity?

It may be a silly question but I didn't find a good way to update a dialogfragment's textview from an activity in my android app.
What I'd like to do is to update the textview every second with a counter value and once the time elapsed, a Runnable closes the dialog fragment.
The dialog is closed once the time is elapsed, no problem but I cannot update the textview I want.
Here's my code for the dialog:
public class AlertDialog extends DialogFragment {
private String message = null;
private String title = null;
private ImageView imgV = null;
private TextView msgTv = null;
private TextView counterTv = null;
private Button okBtn = null;
private int imageId = 0;
public static int AUTOMATIC_CLOSE = 100001;
private AlertDialogListener mDialogListener;
public void setImage(int i){
imageId = i;
}
public void setContent(String ttl, String msg){
message = msg;
title = ttl;
}
public boolean hasContent(){
return message != null && title != null;
}
public AlertDialog(){
}
public void performClick(){
okBtn.performClick();
}
public void updateField(String text){
counterTv.setText(text);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.dialog, container);
msgTv = (TextView)v.findViewById(R.id.textDialog);
imgV = (ImageView)v.findViewById(R.id.imageDialog);
counterTv = (TextView)v.findViewById(R.id.timeCounterDialog);
if(imageId != 0)
imgV.setImageResource(imageId);
else
imgV.setImageResource(R.drawable.error_icon);
if(hasContent()){
msgTv.setText(message);
getDialog().setTitle(title);
}
else{
getDialog().setTitle("ERROR");
msgTv.setText("An unexcepted error occured");
}
okBtn = (Button)v.findViewById(R.id.validateButton);
okBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(mDialogListener != null){
mDialogListener.onFinishedDialog();
}
}
});
return v;
}
#Override
public void onStart() {
mDialogListener.onStartedDialog();
super.onStart();
}
#Override
public void onAttach(Activity activity) {
mDialogListener = (AlertDialogListener) activity;
super.onAttach(activity);
}
#Override
public void onDetach() {
mDialogListener = null;
super.onDetach();
}
public interface AlertDialogListener{
void onStartedDialog();
void onFinishedDialog();
}
}
And this is how I launch it:
class myActivity extends Activity implements AlertDialogListener{
protected void onCreate(Bundle savedInstanceState){
"""some init stuff"""
button.setOnClickListener(new View.OnClickListener() {
showAlertDialog();
}
}
#Override
public void onStartedDialog() {
AutoCloseRunnable mAutoClose = new AutoCloseRunnable();
mHandler.postDelayed(mAutoClose, 1000);
}
#Override
public void onFinishedDialog() {
this.finish();
}
private void showAlertDialog(){
FragmentManager fm = getFragmentManager();
mAlertDialog = new AlertDialog();
mAlertDialog.setContent("No Connection available", "Please enable your internet connection.");
mAlertDialog.setImage(R.drawable.error_icon);
mAlertDialog.show(fm, "fragment_alert");
}
private void updateAlertDialog(String text){
mAlertDialog.updateField(text);
}
private void autoCloseAlertDialog(){
mAlertDialog.performClick();
}
public class AutoCloseRunnable implements Runnable{
#Override
public void run() {
int closeCpt = 10;
while(closeCpt >= 0){
try {
Thread.sleep(1000);
updateAlertDialog("Will close automatically in " + closeCpt + " seconds.");
closeCpt--;
} catch (InterruptedException e) {
e.printStackTrace();
}
}
autoCloseAlertDialog();
}
}
}
Does anyone know how to proceed?

I solved it, simply use asynctask it's easier to handle UI updates like this.

Call method of interface implements with child fragment From container activity Android

I'm stuck with communication between activity and fragment using interface. I have created activity with child fragment. I wanna do some stuff with continuous thread defined in activity and during that thread when I'm getting some result at that time I wanna trigger to child fragment to do something.
My Container Activity
public class MySpaceActivity extends BaseDrawerActivity {
private OnSetLastSeenListener mListner;
public static Thread mThread = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
super.setHeaders(Const.MY_SPACE);
super.setSubmenus(Const.MY_SPACE,
Utils.getSubmenuList(Const.MY_SPACE, MySpaceActivity.this),
submenuBean);
// super.attachFragment(submenuBean);
}
#Override
public void setHeaderSubMenu(SubmenuBean subMenuBean) {
// txt_submenu.setText(subMenuBean.getSubmenu_name());
this.submenuBean = subMenuBean;
Log.print("::::: setHeaderSubMenu ::::");
super.attachFragment(submenuBean);
}
public void setsubFragment(SubmenuBean subMenuBean) {
this.submenuBean = subMenuBean;
super.attachSubFragment(submenuBean);
}
#Override
public void onBackPressed() {
super.onBackPressed();
popLastFragment();
}
private void popLastFragment() {
if (super.getNumberOfChilds() > 1) {
super.popSubFragment();
} else {
finish();
}
}
#Override
protected Fragment getFragement() {
StudentsFragment fragment = new StudentsFragment(Const.MY_SPACE,
getSubmenubean());
return fragment;
}
public SubmenuBean getSubmenubean() {
return submenuBean;
}
#Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
mThread = new Thread(new CountDownTimer(MySpaceActivity.this));
mThread.start();
}
#Override
protected void onStop() {
// TODO Auto-generated method stub
super.onStop();
if (mThread.isAlive()) {
mThread.interrupt();
mThread = null;
}
}
public void updateLastSeen(){
Log.print("::::::Call Interface::::::");
mListner.updateLastSeen();
}
class CountDownTimer implements Runnable {
private Context mContext;
private JSONObject mJsonObject;
private JSONArray mJsonArray;
public CountDownTimer(Context mContext) {
this.mContext = mContext;
}
// #Override
public void run() {
while (!Thread.currentThread().isInterrupted()) {
try {
HttpChatLastSeen mChat = new HttpChatLastSeen();
mJsonObject = mChat.Http_ChatLastSeen(mContext);
String mResult = mJsonObject.getString("Result");
if (mResult.equalsIgnoreCase(String
.valueOf(Const.RESULT_OK))) {
mJsonArray = mJsonObject.getJSONArray("UserData");
for (int i = 0; i < mJsonArray.length(); i++) {
mJsonObject = mJsonArray.getJSONObject(i);
new DbStudentMasterBll(mContext).update(
"last_seen", mJsonObject
.getString("LastSeen"), Integer
.parseInt(mJsonObject
.getString("UserId")));
}
} else {
Log.print("MY LAST SEEN Response : "
+ mJsonObject.toString());
}
updateLastSeen();
Thread.sleep(15000);
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
} catch (Exception e) {
Log.print("ChatLastSeenThread : ", e.getMessage());
}
}
}
}
}
My Child Fragment With Interface :
public class StudentsFragment extends Fragment implements OnSetLastSeenListener{
TextView txt_submenu;
ListView list_students;
SubmenuBean submenuBean;
int Mainmenu;
MySpaceActivity mMySpaceActivity;
ArrayList<DbStudentMasterBean> studentsList;
StudentsAdapter mAdapter = null;
OnSetLastSeenListener mListner;
public StudentsFragment() {
super();
}
public StudentsFragment(int Mainmenu, SubmenuBean submenuBean) {
this.submenuBean = submenuBean;
this.Mainmenu = Mainmenu;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_students, container,
false);
mMySpaceActivity = (MySpaceActivity) getActivity();
txt_submenu = (TextView) view.findViewById(R.id.txt_submenu);
txt_submenu.setText(submenuBean.getSubmenu_name());
txt_submenu.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
mMySpaceActivity.openDrawer();
}
});
list_students = (ListView) view.findViewById(R.id.list_colleagues);
studentsList = new DbStudentMasterBll(getActivity()).getAllRecords();
mAdapter = new StudentsAdapter(getActivity(), studentsList, handler);
list_students.setAdapter(mAdapter);
list_students.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
DbStudentMasterBean bean = (DbStudentMasterBean) parent
.getAdapter().getItem(position);
Message msg = new Message();
msg.what = CHAT;
msg.obj = bean;
handler.sendMessage(msg);
}
});
return view;
}
Handler handler = new Handler() {
public void handleMessage(android.os.Message msg) {
switch (msg.what) {
case CHAT:
submenuBean.setTag(VIEWCHATSTUDENT);
DbStudentMasterBean bean = (DbStudentMasterBean) msg.obj;
mMySpaceActivity.setsubFragment(submenuBean);
break;
}
};
};
#Override
public void updateLastSeen() {
// TODO Auto-generated method stub
Log.print("!!!!!!!!!Refresh Adapter!!!!!!!!!!!");
mAdapter.notifyDataSetChanged();
}
}
My Interface :
public interface OnSetLastSeenListener {
public void updateLastSeen();
}
So I have implemented interface OnSetLastSeenListener with my child fragment StudentsFragment . Now I'm calling method of tht interface updateLastSeen() from my container activity with thread. But it is not getting trigger to child fragment where I have implemented interface. So I don't know whether it is good way to communicate or not? Let me take your help to suggest on this solution or best way to communicate from child fragment to parent activity.
Thanks,

It is better to use interface when you want to communicate something from Fragment to Activity and not vice versa.
In your case, you can directly call the method in Fragment from Activity through fragment object. No need to use interface.
Something like this (For static fragments)
StudentsFragment fragment = (StudentsFragment) getFragmentManager()
.findFragmentById(R.id.fragmentid);
if (fragment != null && fragment.isInLayout()) {
fragment.updateLastSeen();
}
For dynamic fragment you can use the fragment object directly.