Develop Reference

Reset RecyclerView adapter from another Fragment

I have a Fragment that contains a RecyclerView. I am trying to implement a filter on the RecyclerView. The filter UI opens a new Fragment Dialog where the user will input a value. Once the user hits the Search Button in the Fragment Dialog, the value should be returned to the RecyclerView Fragment and the existing data in the view should be cleared. I want to re-populate the RecyclerView with the new set of data that I will obtain from the server. My problem is that, I have a method called resetAdapterDetails() in the RecyclerView Fragment which works as expected if called from the RecyclerView Fragment itself. But, when I try to call the same method from the Fragment Dialog, I get an exception:
transactionList.clear(); --> is trying to clear a list which is null
Though the data is still visible in the RecyclerView.
The RecyclerView Fragment:
public class TransactionHistoryFragment extends Fragment implements SearchView.OnQueryTextListener, DateRangePickerFragment.OnDateRangeSelectedListener{
private RecyclerView recyclerview;
private TransactionHistoryAdapter adapter;
private List<Transaction> transactionList;
public TransactionHistoryFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_transaction_history, container, false);
recyclerview = (RecyclerView) view.findViewById(R.id.recyclerview);
LinearLayoutManager layoutManager = new LinearLayoutManager(getActivity());
recyclerview.setLayoutManager(layoutManager);
return view;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
setHasOptionsMenu(true);
getTransactionHistory("");
}
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.transactions_history_menu, menu);
final MenuItem searchItem = menu.findItem(R.id.action_search);
final SearchView searchView = (SearchView) MenuItemCompat.getActionView(searchItem);
searchView.setOnQueryTextListener(this);
super.onCreateOptionsMenu(menu, inflater);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.filter_date:
FragmentManager fmDate = getActivity().getFragmentManager();
DateRangePickerFragment dialogFragmentDate = DateRangePickerFragment.newInstance(this, true);
dialogFragmentDate.show(fmDate, "Sample Fragment");
return true;
case R.id.filter_mobile:
FragmentManager fmMobile = getActivity().getFragmentManager();
SearchMobileFragment dialogFragmentMobile = new SearchMobileFragment ();
dialogFragmentMobile.show(fmMobile, "Sample Fragment");
//resetAdapterDetails();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
#Override
public boolean onQueryTextChange(String newText) {
final List<Transaction> filteredModelList = filter(transactionList, newText);
adapter.setFilter(filteredModelList);
return true;
}
#Override
public boolean onQueryTextSubmit(String query) {
return false;
}
//for filtering the list
private List<Transaction> filter(List<Transaction> models, String query) {
query = query.toLowerCase();final List<Transaction> filteredModelList = new ArrayList<>();
for (Transaction model : models) {
final String text = model.getTxnStatus().toLowerCase();
if (text.contains(query)) {
filteredModelList.add(model);
}
}
return filteredModelList;
}
//for populating the list
private void getTransactionHistory(String agentId){
GetTransactionHistoryTask task = new GetTransactionHistoryTask("agent1", "password");
task.getTransactionsByAgent("OU23","OU230000000123456789").subscribe(transactionHistoryResponse -> {
if(transactionHistoryResponse != null && transactionHistoryResponse.getTransactions() != null && transactionHistoryResponse.getTransactions().size() > 0 && transactionHistoryResponse.getErrors().size() == 0){
transactionList = transactionHistoryResponse.getTransactions();
adapter = new TransactionHistoryAdapter(transactionList);
recyclerview.addItemDecoration(new DividerItemDecoration(getActivity(), LinearLayoutManager.VERTICAL));
recyclerview.setAdapter(adapter);
onClickListnerRecyclerView();
}
else{
}
}, e -> e.printStackTrace());
}
private void onClickListnerRecyclerView() {
recyclerview.addOnItemTouchListener(
new RecyclerItemClickListener(getActivity(), new RecyclerItemClickListener.OnItemClickListener() {
#Override
public void onItemClick(View view, int position) {
try {
final Transaction transactionModel= (Transaction) adapter.getObjectAt(position);
Intent i = new Intent(getActivity(), TransactionDetailsActivity.class);
i.putExtra("transaction_object",transactionModel);
startActivity(i);
}
catch (Exception e){
Log.e("List issue", e.toString());
}
}
})
);
}
#Override
public void onDateRangeSelected(int startDay, int startMonth, int startYear, int endDay, int endMonth, int endYear) {
}
public void fetchDateRange(String startDate, String endDate) {
Log.e("DateRange",startDate + "\n" + endDate);
}
public void fetchMobileNumber(String mobileNumber) {
Log.e("Mobile",mobileNumber);
resetAdapterDetails();
}
public boolean resetAdapterDetails(){
try {
transactionList.clear();
adapter.notifyDataSetChanged();
recyclerview.setAdapter(adapter);
} catch (Exception e) {
Log.e("Reset Error", ""+e.getMessage());
}
return true;
}
}
The Dialog Fragment:
public class SearchMobileFragment extends DialogFragment {
EditText mMobileNumberEditText;
Button search_button;
public SearchMobileFragment() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_search_mobile, container, false);
}
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
mMobileNumberEditText = (EditText) view.findViewById(R.id.mobile_number_editText);
search_button = (Button) view.findViewById(R.id.search_button);
search_button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
dismiss();
TransactionHistoryFragment obj = new TransactionHistoryFragment();
obj.fetchMobileNumber(mMobileNumberEditText.getText().toString());
}
});
}
}
The fetchMobileNumber() method in the TransactionHistoryFragment (RecyclerView Fragment) is called through the fetchMobileNumber() method which is called from the SearchMobileFragment (Dialog Fragment).
Where am I going wrong? Why the transactionList.clear(); is throwing the null pointer exception?

You are getting the issue because you are creating new TransactionHistoryFragment instance search_button click in SearchMobileFragment. Which makes it's all variables null and initialize it again and here your transactionList becomes null.
You can achieve the same thing easily with different way also. As the place of SearchMobileFragment as a DialogFragment you can make it as Activity and start it as startActivityForResult from your TransactionHistoryFragment and implement onActivityResult callback to doing the fiteration.
But right now in your case you can manage it in different ways also:
First way:
As you are doing in your DialogFragment
search_button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
dismiss();
/*TransactionHistoryFragment obj = new TransactionHistoryFragment();
obj.fetchMobileNumber(mMobileNumberEditText.getText().toString());*/
}
});
Don't do the call for fetchMobileNumber here, in onResume of your TransactionHistoryFragment you should make a call for this. On the click of search_button save the filter data to SharedPreferences and use that in onResume of the TransactionHistoryFragment for filtering and after that clear this saved data from SharedPreferences onPause of this fragment.
You should remove
transactionList.clear();
of code from resetAdapterDetails() in TransactionHistoryFragment, because after search filter you will get updated transactionList which is already passed to adapter then forcefully no need to clear it. Or have a check before clearing it like:
if(transactionList!=null){
transactionList.clear();
}
Second way: Using BroadcastReceiver you can achieve the same thing.
Register a receiver in your TransactionHistoryFragment and sendBroadcast from SearchMobileFragment. In onReceive of the TransactionHistoryFragment do the filtration process.

I had resolved the above issue in a different way. In the Dialog Fragment I have implemented a View.OnClickListener and have created an Interface to initialize the same from the RecyclerView Fragment. I am posting the complete source codes below; the SearchMobileFragment now looks like:
public class SearchMobileFragment extends DialogFragment implements View.OnClickListener{
private OnMobileNumberSelectedListener onMobileNumberSelectedListener;
EditText mMobileNumberEditText;
Button mSearchButton;
public SearchMobileFragment() {
// Required empty public constructor
}
public static SearchMobileFragment newInstance(OnMobileNumberSelectedListener callback) {
SearchMobileFragment searchMobileFragment = new SearchMobileFragment();
searchMobileFragment.initialize(callback);
return searchMobileFragment;
}
public void initialize(OnMobileNumberSelectedListener callback) {
onMobileNumberSelectedListener = callback;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View root = inflater.inflate(R.layout.fragment_search_mobile, container, false);
getDialog().getWindow().requestFeature(Window.FEATURE_NO_TITLE);
mMobileNumberEditText = (EditText) root.findViewById(R.id.mobile_number_editText);
mSearchButton = (Button) root.findViewById(R.id.search_button);
mSearchButton.setOnClickListener(this);
return root;
}
#Override
public void onStart() {
super.onStart();
if (getDialog() == null)
return;
getDialog().getWindow().setLayout(WindowManager.LayoutParams.MATCH_PARENT, WindowManager.LayoutParams.WRAP_CONTENT);
}
public void setOnMobileNumberSelectedListener(OnMobileNumberSelectedListener callback) {
this.onMobileNumberSelectedListener = callback;
}
#Override
public void onClick(View v) {
dismiss();
onMobileNumberSelectedListener.onMobileNumberSelected(mMobileNumberEditText.getText().toString());
}
public interface OnMobileNumberSelectedListener {
void onMobileNumberSelected(String mobileNumber);
}
}
The RecyclerView Fragment modifications:
public class TransactionHistoryFragment extends Fragment implements SearchView.OnQueryTextListener,
DateRangePickerFragment.OnDateRangeSelectedListener, SearchMobileFragment.OnMobileNumberSelectedListener{
private RecyclerView recyclerview;
private TransactionHistoryAdapter adapter;
private List<Transaction> transactionList;
SearchView search;
public static final String TIMERANGEPICKER_TAG = "timerangepicker";
public TransactionHistoryFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_transaction_history, container, false);
recyclerview = (RecyclerView) view.findViewById(R.id.recyclerview);
LinearLayoutManager layoutManager = new LinearLayoutManager(getActivity());
recyclerview.setLayoutManager(layoutManager);
return view;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
setHasOptionsMenu(true);
getTransactionHistory();
}
#Override
public void onResume() {
Log.e("onResumeTHF","invoked");
super.onResume();
}
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.transactions_history_menu, menu);
search = (SearchView) menu.findItem(R.id.action_search).getActionView();
search.setOnQueryTextListener(this);
super.onCreateOptionsMenu(menu, inflater);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.filter_date:
FragmentManager fmDate = getActivity().getFragmentManager();
DateRangePickerFragment dialogFragmentDate = DateRangePickerFragment.newInstance(this, true);
dialogFragmentDate.show(fmDate, "Sample Fragment");
return true;
case R.id.filter_mobile:
FragmentManager fmMobile = getActivity().getFragmentManager();
SearchMobileFragment dialogFragmentMobile = SearchMobileFragment.newInstance(this);
dialogFragmentMobile.show(fmMobile, "Sample Fragment");
return true;
default:
return super.onOptionsItemSelected(item);
}
}
#Override
public boolean onQueryTextChange(String newText) {
Log.e("newText",newText);
final List<Transaction> filteredModelList = filter(transactionList, newText);
adapter.setFilter(filteredModelList);
return true;
}
#Override
public boolean onQueryTextSubmit(String query) {
return false;
}
#Override
public void onMobileNumberSelected(String mobileNumber) {
Log.e("mobileNumber",mobileNumber);
resetAdapterDetails();
}
public boolean resetAdapterDetails(){
try {
transactionList.clear();
adapter.notifyDataSetChanged();
recyclerview.setAdapter(adapter);
} catch (Exception e) {
Log.e("Reset Error", ""+e.getMessage());
}
return true;
}
}
Happy coding!

The null pointer exception is because when you create a new TransactionHistoryFragment using new onViewCreated is not called and hence transactionList is never initialized. You can create a setter for the list or pass it as a constructor to the fragment to fix this

Modify Fragment's views from MainActivity

I am trying to implement swipe views with android. I am using a ViewPager with two tabs containing fragments. In my onCreate() method, I am trying to read from a sharedPrefferences and according to what i am getting, i want to change text and visibility to some child views of the parent view of the first fragment. Unfortunately i am always getting NullPointerException when i am trying to access fragments views.
My sample code from the one of the two fragments is given below. Could you please help me ? Is there a better way to do so?
MainActivity:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
actionBar = getActionBar();
context = getApplicationContext();
myTabPagerAdapter = new TabPagerAdapter(getSupportFragmentManager());
myViewPager = (ViewPager) findViewById(R.id.pager);
myViewPager.setAdapter(myTabPagerAdapter);
myViewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
Toast.makeText(MainActivity.this, "Selected page position: " + position, Toast.LENGTH_SHORT).show();
getActionBar().setSelectedNavigationItem(position);
}
#Override
public void onPageScrollStateChanged(int state) {
}
});
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
ActionBar.TabListener tabListener = new ActionBar.TabListener() {
#Override
public void onTabReselected(android.app.ActionBar.Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
}
#Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) {
myViewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(android.app.ActionBar.Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
}
};
actionBar.addTab(actionBar.newTab().setText("Spot Position").setTabListener(tabListener));
actionBar.addTab(actionBar.newTab().setText("Track Vehicle").setTabListener(tabListener));
//Get saved latitude and longitude from sharedPreferences
sharedPref = context.getSharedPreferences("net.ddns.drimou.bachelorthesis", Context.MODE_PRIVATE);
editor = sharedPref.edit();
}
#Override
protected void onStart() {
super.onStart();
getSharedPreferencesOnStart();
}
public void getSharedPreferencesOnStart() {
String s = myTabPagerAdapter.makeFragmentName(myViewPager.getId(),myViewPager.getCurrentItem());
SpotPosition sp = (SpotPosition) myTabPagerAdapter.getItem(0);
sp.setSettings();//In this call i am getting null pointer
...}
Fragment A
public class SpotPosition extends Fragment {
TextView locationTextView;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View spotPosition = inflater.inflate(R.layout.spot_position, container, false);
return spotPosition;
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
public void setSettings(){
locationTextView = (TextView) myView.findViewById(R.id.mainTextView);//NullPointerException here
locationTextView.setVisibility(View.VISIBLE);
locationTextView.setText("Hello");
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public void onDestroyView() {
super.onDestroyView();
}
TabPagerAdapter
public class TabPagerAdapter extends FragmentPagerAdapter {
SparseArray<Fragment> registeredFragments = new SparseArray<Fragment>();
private View mCurrentView;
private SpotPosition sp = null;
private static int NUM_ITEMS = 2;
public TabPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int i) {
switch (i) {
case 0:
//Fragment for SpotPosition myViewPager
return new SpotPosition();
case 1:
//Fragment for TrackVehicle myViewPager
return new TrackVehicle();
}
return null;
}
#Override
public int getCount() {
return NUM_ITEMS; //Number of Tabs
}
#Override
public Object instantiateItem(ViewGroup container, int position) {
Fragment fragment = (Fragment) super.instantiateItem(container, position);
registeredFragments.put(position, fragment);
return fragment;
}
#Override
public void setPrimaryItem(ViewGroup container, int position, Object object) {
sp = (SpotPosition)object;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
registeredFragments.remove(position);
super.destroyItem(container, position, object);
}
#Override
public CharSequence getPageTitle(int position) {
switch(position) {
case 0:
return "Spot Position";
case 1:
return "Track Vehicle";
default:
return null;
}
}
public String makeFragmentName(int viewId, int index) {
return "android:switcher:" + viewId + ":" + index;
}
public Fragment getRegisteredFragment(int position) {
return registeredFragments.get(position);
}
#Override
public int getItemPosition(Object object) {
return POSITION_NONE;
}
public View getCurrentView(){
return this.mCurrentView;
}
public SpotPosition getCurrentSpotPosition(){
return this.sp;
}
Feel free to ask if something is not understood. Thank you

As far as I understand you call setSettings from you activity, to change views in you fragment. You did not provide stacktrace and i assume you problem - attempt to change view after onPause was called in offcreen fragment. There are several ways to deal with it.
First of all dont call to views dirrectly.
On activity
public void getSharedPreferencesOnStart() {
String s = myTabPagerAdapter.makeFragmentName(myViewPager.getId(),myViewPager.getCurrentItem());
SpotPosition sp = (SpotPosition) myTabPagerAdapter.getItem(0);
// sp.setSettings();//In this call i am getting null pointer
SharedPreferences prefs = getSharedPreferences("message",MODE_PRIVATE);
Editor editor = prefs.edit();
editor.putBoolean("say_hello",true")
editor.commit();
...}
in fragments
#Override
public void onResume(){
super.onResume();
SharedPreferences prefs =
getActivity().getSharedPreferences("message", Context.MODE_PRIVATE);
{
//this block is used for offsreen fragment, it will get update, when it go to forescreen
boolean sayHello = prefs.getBoolean("say_hello", false);
if(sayHello){
locationTextView =
(TextView) myView.findViewById(R.id.mainTextView);//NullPointerException here
locationTextView.setVisibility(View.VISIBLE);
locationTextView.setText("Hello");
}else{
// say something elese
}
}
{
//this listener is for forescreen fragment, as soon as shared preferences will be updated,
// listerner willbe called and you can update your view depending on changed parameters
prefs.registerOnSharedPreferenceChangeListener(
new OnSharedPreferenceChangeListener(){
#Override
public void onSharedPreferenceChanged(
SharedPreferences sharedPreferences, String key
){
if(key.equals("say_hello")){
boolean sayHello = sharedPreferences.getBoolean("say_hello", false);
if(sayHello){
locationTextView =
(TextView) myView.findViewById(R.id.mainTextView);//NullPointerException here
locationTextView.setVisibility(View.VISIBLE);
locationTextView.setText("Hello");
}else{
// say something elese
}
}
}
}
);
}
}
You also can use Otto bus it is still unsutable for activity to fragment communication, as fragment can be in !isResumed state, but it is usefull fro fragment -activity comunication.
If you need some complex state tracking for each fragment and activity separatly, I'd recomment to use sqlDatabase and CursorLoaders. It will give you good controll over states and instan comunication.
Edit:
Its not that you cannot pass view from fragment to activity with getters.
Problem - you cannot garanty, that you completly aware of state of the fragment and a view. You try to update views on onStart of activity, which is call earlier, then fragmentsonStart, because fragment have to be generated by adapter and go through attachement process. (to find yout if fragment is attached to activity, you have to set listener in activity and call it ononActivityAttached` of fragment. See android studio activity with fragment template). Thus, when you call to change views, fragment and views probably did not exist.
Futhermore you should read about fragment and activity lifecycle and read about context ( espesialy why strong referencing views in unrelated context holder lead to sever memmory leaks and lificle errors

SeekBar does not show text in Fragment

Here's my code:
public class ScoreFragment extends Fragment {
public static final String TAG ="ScoreFragment";
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
Log.d(TAG, "onAttach");
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if(savedInstanceState==null)
{
Log.d(TAG,"onCreate FIRST TIME");
}
else
{
Log.d(TAG,"onCreate SUBSEQUENT TIME");
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
super.onCreateView(inflater,container,savedInstanceState);
final View v = inflater.inflate(R.layout.score_collection, container, false);
final TextView sliderText = (TextView) v.findViewById(R.id.score_number);
sliderText.setTextSize(48);
//TODO: Find solution to find known bug in Android
/* ActionBar actionBar = ((ActionBarActivity) getActivity()).getSupportActionBar();
actionBar.hide();*/
SeekBar seekbar = (SeekBar) v.findViewById(R.id.seekBar);
seekbar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
#Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
sliderText.setText("" + progress);
}
#Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
#Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
});
Log.d(TAG,"onCreateView");
return inflater.inflate(R.layout.score_collection, container, false);
}
The seekBar is displayed but it does not increment or show any text in my view.
Here's how I set it up in my view (inside a RelativeLayout):
<SeekBar
android:layout_width="300sp"
android:layout_height="wrap_content"
android:id="#+id/seekBar"
android:progress="0"
android:max="10"
android:minHeight="30sp"
android:maxHeight="30sp"
android:layout_below="#+id/score_number"
android:layout_centerHorizontal="true"/>
It actually worked before I placed it into Fragment, so I think it has to do with it being inside a Fragment but I'm not entirely sure.
It's suppose to increment by 1, on a scale of 0 to 10.

So I figured out what I was doing wrong. It's really a silly mistake. I apologize.
Here's the solution for those interested:
Original code:
return inflater.inflate(R.layout.score_collection, container, false);
I was returning the view all over again when I should have just returned v (View v).
So I changed the return statement above to
return v;
instead and it works. Silly me.

Tabs with Fragment life cycle

in my app i have a Tabs with fragment classes. i trying to refresh listView in "fragment a" with the new data i insert.
In "fragment b" i have EditText and Button ,that inserting text to the database.
in "fragment a" i have the ListView with the dataBase rows. when "fragment a" is "OnCreateView" i just put the dataBase on a "ArrayList" and past it to my baseAdapter.
but "onCreateView" not refreshing my new data every time i get into the "fragment a" else i goes to "fragment c" and "onDestroy" call on "fragment a".
so my result it was to call : "setUserVisibleHint" override method, and check if it is visible and refreshing the list.
but i dont think it is the good practice .
what should i do?
Class a
public class ListFragment extends Fragment{
basAdapterCustom adapter;
ListView lv;
ArrayList<Clock> list;
private DbHandler hand;
Context context;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.list_fragment, container, false);
context = getActivity();
Log.d(TAG, "onCreateView");
hand = new DbHandler(context);
list = new ArrayList<Clock>();
lv = (ListView) v.findViewById(R.id.listOfShifts);
adapter = new basAdapterCustom(list, getActivity());
lv.setAdapter(adapter);
refreshList();
return v;
}
//like on "resume":
#Override
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);
// Make sure that we are currently visible
if (this.isVisible()) {
refreshList();
if (!isVisibleToUser) {
// TODO stop
}
}
}
private void refreshList() {
list = hand.getByWorkName();
adapter = new basAdapterCustom(list,getActivity());
lv.setAdapter(adapter);
}
class b:
public class ClockFragment extends Fragment{
DbHandler hand;
Context context;
#Override
public View onCreateView(LayoutInflater inflater,
#Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.clock, container,false);
context = getActivity();
hand = new DbHandler(context);
return v;
}
// ADD to .Db
public void addToDb(View v){
hand.add(new Clock(0, dateDay));
}
}
class mainActivity:
public class MainActivity extends FragmentActivity implements ActionBar.TabListener, OnPageChangeListener{
public static final String TAG = "myClock";
String[] tabMenu = {"FRAG A","FRAG B","FRAG C"};
private ViewPager viewPager;
private TabPagerAdapter mAdapter;
private ActionBar actionBar;
#SuppressLint("NewApi")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Log.d(MainActivity.TAG, "OnCreate = MainActivity (Pager");
viewPager = (ViewPager) findViewById(R.id.pager );
actionBar = getActionBar();
mAdapter = new TabPagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(mAdapter);
actionBar.setHomeButtonEnabled(false);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
for (String tabsNames : tabMenu) {
actionBar.addTab(actionBar.newTab().setText(tabsNames).setTabListener(this));
}
viewPager.setOnPageChangeListener(this);
}
// public void transDialog(){
// Dialog mDialog = new Dialog(this, android.R.style.Theme_Translucent_NoTitleBar_Fullscreen);
// }
#Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
}
#Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}
#Override
public void onPageScrollStateChanged(int arg0) {
}
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
#Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
}
PagetAdapter.class
public class TabPagerAdapter extends FragmentPagerAdapter {
private static final String TAG = "myClock";
public TabPagerAdapter(FragmentManager fm) {
super(fm);
// TODO Auto-generated constructor stub
}
#Override
public Fragment getItem(int index) {
Log.d(TAG, " CLASS : TabPagerAdapter");
switch (index) {
case 0:
return new ListFragment();
case 1:
return new ClockFragment();
case 2:
return new SettingFragment();
default:
break;
}
Log.d(TAG, " CLASS : TabPagerAdapter = "+index);
return null;
}
#Override
public int getCount() {
return 3;
}
}
Please help me i hope you are understand my problem...

You want to update listView in fragment A, after insert data in fragment b? Then  you have a few solutions to choose:
1. Implement communications between fragments via activity. Then B insert date, it send message to activity, that data need to be updated. Then fragment A started, it's ask activity to need update data. For details on implementing this communication check link.
2. Use some bus library, EventBus for example. Then fragment B insert data, it post 'data changed' event to bus. Fragment A checks on start if this event occurs.
3. Use Loaders which "monitor the source of their data and deliver new results when the content changes."

Why is my android.R.id.home not called in my fragment?

I'm currently using FragmentStatePagerAdapter and I would like it to have a "navigate up" feature (DisplayHomeAsUpEnabled). When I set the following code it shows up as a correct navigate back button. But nothing happens when I click on it, can you guys see anything that I', doing wrong in my code, I get no error while pressing the "navigate up" button and I get no compiler errors.
Here is the code, its in the "public boolean onOptionsItemSelected(MenuItem item) {" it gets interesting at the bottom.
public class ShareholdingDetailFragment extends FragmentActivity {
final int NUM_ITEMS = Portfolio.getPortfolio().count();
MyAdapter mAdapter;
ViewPager mPager;
Bundle extras;
#Override
protected void onCreate(Bundle savedInstanceState) {
System.out.println(NUM_ITEMS + "e");
super.onCreate(savedInstanceState);
setContentView(R.layout.shareholdingdetailview_fragment_wrapper);
mAdapter = new MyAdapter(getSupportFragmentManager());
mPager = (ViewPager)findViewById(R.id.pager);
mPager.setAdapter(mAdapter);
}
public class MyAdapter extends FragmentStatePagerAdapter {
public MyAdapter(FragmentManager fm) {
super(fm);
}
public int getCount() {
return NUM_ITEMS;
}
public Fragment getItem(int position) {
return ShareholdingFragment.newInstance(position);
}
}
public static class ShareholdingFragment extends Fragment {
int mNum;
static ShareholdingFragment newInstance(int num) {
ShareholdingFragment f = new ShareholdingFragment();
// Supply num input as an argument.
Bundle args = new Bundle();
args.putInt("num", num);
f.setArguments(args);
return f;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mNum = getArguments() != null ? getArguments().getInt("num") : 1;
}
#SuppressLint({ "NewApi", "NewApi" })
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.shareholdingdetailview_fragment, container, false);
/****************Setting the Display as home and it shows*******************/
ActionBar bar = getActivity().getActionBar();
bar.setDisplayHomeAsUpEnabled(true);
/**********************************/
return view;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home://Not working
System.out.println("test");//This isn't printed out
Intent upIntent = new Intent(getActivity(), DetailShareHoldingActivity.class);
if (NavUtils.shouldUpRecreateTask(getActivity(), upIntent)) {
getActivity().finish();
} else {
NavUtils.navigateUpTo(getActivity(), upIntent);
}
return true;
}
return super.onOptionsItemSelected(item);
}
}
}

Try adding: setHasOptionsMenu(true); in your onCreate() in ShareholdingFragment.

Add setHomeButtonEnabled(true) on API Level 14 and higher when you configure your action bar. On API Level 11-13, the home button is enabled automatically.

If you're using the new Toolbar and ActionbarDrawerToggle. You can assign clickHandler directly. For my activities that have this drawer toolbar I implemented an interface to enable drawer if at root,
#Override
public void enableDrawer(boolean enable) {
mDrawerToggle.setDrawerIndicatorEnabled(enable);
mDrawerToggle.setToolbarNavigationClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// Pop fragment back stack or pass in a custom click handler from the fragment.
}
});
}