Develop Reference

Executing lifecycle method of backstack fragment problem in android

I have an activity with two fragment and want to be executed first fragment when its back from second fragment using back button. And i am using the add() when navigating first fragment to second fragment. Here is my scenario and code snippet:
First fragment:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.one_fragment, container, false);
final Button button = (Button) view.findViewById(R.id.buttonChange);
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
buttonClicked(v);
}
});
return view;
}
public void buttonClicked(View view) {
FragmentManager fragmentManager = getActivity().getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.add(R.id.fragment_Container, new TwoFragment());
fragmentTransaction.addToBackStack("sdfsf");
fragmentTransaction.commit();
}
Moving to Second fragment and here is the code:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.two_fragment, container, false);
return view;
}
The problem is that, When I am navigating from first to second fragment and then back again in the first fragment using back button first fragment lifecycle method is not executing. Instead of using add() if I use replace() then lifecycle method are executing properly. I know its the difference between add() and replace() but I want to use add() and also want to have navigation callback to handle some logic when I back in the first fragment using back button.
Also tried below code:
fragmentManager.addOnBackStackChangedListener(
new FragmentManager.OnBackStackChangedListener() {
public void onBackStackChanged() {
Log.e(TAG, "onBackStackChanged: ");
// Update your UI here.
}
});
But its also calling multiple times and creating anomalies.
How can I handle this? Specially handle some logic in first fragment when I back from second fragment.

The easiest way I can think of is to set result when you're done with the second fragment that essentially tells the first fragment to "resume" via its onActivityResult method.
When you create an instance of Fragment B, call #setTargetFragment() and pass in Fragment A as your target fragment. Then when Fragment B is done and going to return to Fragment A, before it exits, you will set the result of it for Fragment A by calling:
getTargetFragment().onActivityResult(getTargetRequestCode(), RESULT_FRAGMENT_B_FINISHED,null)
///// horizontal scroll padding
Note that RESULT_FRAGMENT_B_FINISHED would be some static integer you define somewhere, like
public static final int RESULT_FRAGMENT_B_FINISHED = 123123;
Now in Fragment A all you need to do is override onActivityResult and check that the request code matches the request code integer from setTargetFragment and the result code also matches RESULT_FRAGMENT_B_FINISHED, if so you can run the code that would have been fired from onResume().
#getTargetFragment()
#onActivityResult()
#getTargetRequestCode()

Instead of passing data between the two fragments I recommend you to use a SharedViewModel.
The idea is that the first fragment observe some data for changes and the second one edit this data.
Example:
Shared ViewModel
public class SharedViewModel extends ViewModel {
private final MutableLiveData<Item> selected = new
MutableLiveData<Item>();
public void select(Item item) {
selected.setValue(item);
}
public LiveData<Item> getSelected() {
return selected;
}
}
First fragment
public class FirstFragment extends Fragment {
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
SharedViewModel model =
ViewModelProviders.of(getActivity()).get(SharedViewModel.class);
model.getSelected().observe(this, { item ->
// Update the UI.
});
}
}
Second fragment
public class SecondFragment extends Fragment {
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
SharedViewModel model =
ViewModelProviders.of(getActivity()).get(SharedViewModel.class);
model.select(new Item("value 1","value 2");
}
}
You can read about ViewModels, LiveData and Architecture components starting from here: https://developer.android.com/topic/libraries/architecture/viewmodel#java
This answer is assuming that you want to execute some logic based on some data change. If it's not the case, you can explain what kind of logic do you want to execute and I will edit my answer.

Connecting Fragments using ImageButton in Android

I'm new Android programming. Earlier I was working with activities, where i could implement onClick on an ImageButton and go to a different activity.
Now I need to do the same but using Fragments. I have a prototype with a menu that always appear on screen and can show different activities to the user. The different lactivities would be inside this container.
Now I want to place an ImageButton inside a fragment and make that the screen shows the next fragment. But I'm confused how to do it.
I have the following components:
Activity_main(java)+activity_main.xml (with menu)
Fragment1(java)+fragment1.xml(working normal)
Inside this layout I have an ImageButton and want to show Fragment2
Fragment2(java)+fragment2.xml
How should look Fragment1 to can call Fragment2?
I will be glad if the answer could be the clearest possible because I'm new on it, and maybe I could forgot an obvious step. Thanks

Simply make a method in your activity which will always change/replace fragment when you invoke it. something like
public void updateFragment(Fragment fragment){
//add fragment replacing code here
}
in your fragment, invoke it some thing like this
((YourActivity)getActivity()).updateFragment(new YourFragment());
since, it is just an idea which works fine but still you can improve the logic.

Actually, going from one fragment to another is almost similar to going from one activity to another. There are just a few extra lines of code.
First, add a new Java class named SingleFragmentActivity which would contain the following code-
public abstract class SingleFragmentActivity extends AppCompatActivity
{
protected abstract Fragment createFragment();
#LayoutRes
protected int getLayoutResId()
{
return R.layout.activity_fragment;
}
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(getLayoutResId());
FragmentManager fm = getSupportFragmentManager();
Fragment fragment = fm.findFragmentById(R.id.fragment_container);
if (fragment == null)
{
fragment = createFragment();
fm.beginTransaction().add(R.id.fragment_container, fragment).commit();
}
}
}
Make your activities in the following format-
public class SomeActivity extends SingleFragmentActivity
{
#Override
protected Fragment createFragment()
{
return SomeFragment.newInstance();
}
}
And your fragments like this-
public class SomeFragment extends Fragment
{
public static SomeFragment newInstance()
{
return new SomeFragment();
}
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
View v = inflater.inflate(R.layout.fragment_some, container, false);
return v;
}
}
After this everything has the same code as you have for activities except for one small detail which is your onCreateView(LayoutInflater, ViewGroup, Bundle) class. This is how you would write it-
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
View v = inflater.inflate(R.layout.fragment_some, container, false);
mTextView = (TextView)v.findViewById(R.id.some_text);
mButton = (Button)v.findViewById(R.id.some_button);
mTextView.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v)
{
check();
}
});
return v;
}
And that is it!

Hi i hope you are already aware about the fragments and their uses but still here is a brief. They are child to an activity and an activity can have more than one fragment so you can update your layout without changing activity just by changing fragments.
You can found more on fragment here : https://developer.android.com/training/basics/fragments/index.html
Back to the original problem, supposed you are in MainActivity.java and you want to load fragment in it, so you do this to load fragment first time.
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.frame, new Fragment1);
transaction.addToBackStack(null);
transaction.commit();
You will need this method to change fragment from another fragment, so add this in your MainActivity
public void changeFragment(Fragment fragment){
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.frame, new Fragment1);
transaction.addToBackStack(null);
transaction.commit();
}
Now from a button click in this fragment
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
((MainActivity)getActivity()).changeFragment(new Fragment2);
}
});
Hope it will help!

Reuse a fragment in Android

I have a fragment which has a TextView, an EditText and a Button. I also have 2 activities which include this fragment and at onClick of the button in one of the activities, the other is started. Via the intent, the text in the edittext is passed which becomes the text of the textview of the other activity.
I had two design decisions to choose from
Create two such fragments classes with appropriate methods that construct the appropriate intents. Access the UI elements from inside the respective fragment object and start the activities.
Create only one fragment class. onClick the, event is passed down to a particular method in the activities (both the activities have this method) and the activities have the logic to build the intent and start the other activity
Consider what would happen if there are 100 such activities. The first method would have us write 100 different fragment classes with custom methods, but in the second method, it is a single class and the activities have the custom logic in a particularly named method.
Therefore I chose to go with the second choice and I realized that the UI elements could not be instantiated in the onCreate method of activity as the fragment's layout is not inflated yet. I am doing the instantiation in onStart as a workaround.
Is that bad practice or is there a better design pattern to follow?

The recommended pattern is to create a holder interface which any activity that wants to instantiate your fragment must implement. Also to set data for views in your new fragment then create a newInstance() factory method on your fragment.
I tend to approach it like this;
class FooFragment implements Fragment {
private static final String TEXT_FOR_TEXTVIEW = "textForTextView";
private FooFragmentHolder mHolder;
/*
* Rather than creating your fragment in your layout directly
* you should instead instantiate it using this class in your
* activity.
*/
public static FooFragment newInstance(String text) {
Bundle data = new Bundle();
data.putString(TEXT_FOR_TEXTVIEW, text);
FooFragment fooFragment = new FooFragment();
fooFragment.setArguments(data);
return fooFragment;
}
public interface FooFragmentHolder {
public void buttonPressed(String editTextContent);
}
/*
* When we create the fragment with the activity we use onAttach to get
* our holder implementation (the activity)
*/
#Override
public void onAttach(Activity activity) {
if (activity instanceof FooFragmentHolder) {
mHolder = (FooFragmentHolder) activity;
} else {
throw new IllegalStateException("Containing activity must implement FooFragmentHolder");
}
}
#Override
public void onCreateView(Inflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_foo, container, false);
final EditText editText = (EditText) view.findViewById(R.id.edit_text);
Button button = (Button) view.findViewById(R.id.button);
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(Button button) {
mHolder.buttonPressed(editText.getText());
}
})};
TextView textView = (TextView) view.findViewById(R.id.text_view);
Bundle args = getArguments();
if (args != null) {
textView.setText(args.getString(TEXT_FOR_TEXTVIEW));
}
return view;
}
}
Now in your activity you just need to implement the FooFragmentHolder interface and use the newInstance method we created;
class FooActivity extends Activity implements FooFragment.FooFragmentHolder {
private static final String TEXT_FOR_TEXTVIEW = "textForTextView";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentLayout(R.layout.activity_foo);
// Instead of creating your fragment in your layout, create a holder
// layout and attach a new instance of your fragment using a fragment
// transaction.
FooFragment fooFragment = FooFragment.newInstance(getIntent().getStringExtra(TEXT_FOR_TEXTVIEW));
getFragmentManager().beginTransaction()
.replace(R.id.content, fooFragment)
.commit();
}
#Override
public void buttonPressed(String editTextContent) {
// In this case just starting the next FooActivity, but logic could be
// applied for any other activity.
Intent intent = new Intent(this, FooActivity.class)
.putExtra(TEXT_FOR_TEXTVIEW, editTextContent);
startActivity(intent);
}
}

I decided to settle with the following patter --
Any activity which includes this fragment should implement an interface like
public interface ViewsCreatedListener {
public void onViewsCreated();
}
The activity would then look like
public class ExampleActivity extends Activity implements ViewsCreatedListener {
.
.
.
.
#Override
public void onViewsCreated() {
//Initiate the views here and do what gotta be done
}
}
The fragment should check that any activity that includes this fragment should implement that interface using the onAttach method and onActivityCreated, the activity is notified
public class ExampleFragment extends Fragment {
ViewsCreatedListener listener = null;
.
.
.
.
#Override
public onAttach(Activity activity) {
super.onAttach(activity);
try {
listener = (ViewsCreatedListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement ViewsCreatedListener");
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
listener.onViewsCreated();
}
}
Doing this way, the fragment just provides the UI and the including activities decide as to what should be done with the UI elements included via the fragment. This maximizes reusability.. DRY... :-D

Passing data into multiple fragments that uses one container

First time posting here and also a new developer for Android Apps.
Desire Function of Example App:
1) Activity starts in fullscreen A
2) Fragment B then populates/inflates container of A fullscreen
3) Fragment B has a button, button is press
4) Fragment B is now replaced with Fragment C
5) Fragment C is now full screen and has data that is inputted by users, user then hits button to send to next Fragment
6) Fragment C is replaced with Fragment D and presents data to view which was inputted from Fragment C
Summary Functionality:
I am trying to keep everything on one screen going from
A (Activity) -> B (Fragment replace) -> C (Fragment replace to type data) -> D (Fragment replace and see last fragment data)
Problem/Issue
My code crashes when I try to populate the last screen with data obviously. It seems to throw an error in MainActivity at this specific line when I debug it
CartFragmentCode addCartInfoTextFragment = (CartFragmentCode) getSupportFragmentManager().findFragmentById(R.id.maincontainer);
I am definitely passing the values correctly through the interface I created, but during the debug process, I found out that my current program is trying to populate information into the same container since it seems like it didn't commit yet to replace the fragment to assign the variables to the right UI.
I was checking if I was able to replace the Fragment C with D, and I was able to only if I remove that above line of code.
Code Below
Main
public class MainActivity extends FragmentActivity implements OrderFragmentCode.FragUIListeners{
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Fragment AllMenu = new AllMenuFragmentCode();
FragmentManager fragManager = getSupportFragmentManager(); //getSupportFragmentManager setup
FragmentTransaction ft = fragManager.beginTransaction(); //setup fragmentTranscation = ft
ft.add(R.id.maincontainer, AllMenu);
ft.commit();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public void onCartButtonClicked(String editFood, String editType, String editName){
CartFragmentCode addCartInfoTextFragment = (CartFragmentCode) getSupportFragmentManager().findFragmentById(R.id.maincontainer);
addCartInfoTextFragment.UpdateCartTexts(editFood, editType, editName);
}}
Fragment A
public class AllMenuFragmentCode extends Fragment implements OnClickListener {
private Button Order;
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
View view = inflater.inflate(R.layout.all_menu_fragment, container, false);
Order = (Button) view.findViewById(R.id.orderButton);
Order.setOnClickListener(this);
return view;
}
#Override
public void onClick(View v) {
Fragment OrderFragmentCode = new OrderFragmentCode();
FragmentManager fragManager = getFragmentManager(); //getSupportFragmentManager setup
FragmentTransaction ft = fragManager.beginTransaction(); //setup fragmentTranscation = ft
ft.replace(R.id.maincontainer, OrderFragmentCode);
ft.addToBackStack(null);
ft.commit();
}}
Fragment C
public class OrderFragmentCode extends Fragment implements OnClickListener {
FragUIListeners activityCallback;
public interface FragUIListeners {
public void onCartButtonClicked(String foodText, String typeText, String nameText);
}
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
activityCallback = (FragUIListeners) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement FragUIListeners");
}
}
private EditText editTextFood;
private EditText editTextType;
private EditText editTextName;
private Button AddToCartButton;
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
View view = inflater.inflate(R.layout.order_fragment, container, false);
editTextFood = (EditText) view.findViewById(R.id.editText);
editTextType = (EditText) view.findViewById(R.id.editText2);
editTextName = (EditText) view.findViewById(R.id.editText3);
AddToCartButton = (Button) view.findViewById(R.id.addToCart);
AddToCartButton.setOnClickListener(this);
return view;
}
#Override
public void onClick(View v) {
Fragment Cart = new CartFragmentCode();
FragmentManager fragManager = getFragmentManager();
FragmentTransaction ft = fragManager.beginTransaction();
ft.replace(R.id.maincontainer, Cart);
ft.addToBackStack(null);
ft.commit();
activityCallback.onCartButtonClicked(editTextFood.getText().toString(), editTextType.getText().toString(), editTextName.getText().toString());
}}
Fragment D
public class CartFragmentCode extends Fragment{
private TextView foodView;
private TextView typeView;
private TextView nameView;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.cart_fragment, container, false);
foodView = (TextView) view.findViewById(R.id.foodView);
typeView = (TextView) view.findViewById(R.id.typeView);
nameView = (TextView) view.findViewById(R.id.nameView);
return view;
}
public void UpdateCartTexts(String editfood, String edittype, String editname)
{
foodView.setText(editfood);
typeView.setText(edittype);
nameView.setText(editname);
}}
--Final Say--
Sorry for the long post, this has been bugging me for HOURS and I even tried to use bundles and setting the arguements but I wasnt able to get that working either (I thought if i were able to obtain values correctly I could work around and use this to assign values to my textviews through getArguments on my last Fragment).
Please help!!!! Thanks!!!

In the line CartFragmentCode addCartInfoTextFragment = (CartFragmentCode) getSupportFragmentManager().findFragmentById(R.id.maincontainer);
findFragmentById sholule be passed that you use as 2nd argument in add while adding fragment to container for e.g. ft.add(R.id.maincontainer, AllMenu); if you want to get this fragment then you use findFragmentById(AllMenu) which is the tag that is associated with the fragment. R.id.maincontainer is the container in which that fragment is being displayed.

I guess the problem is you call onCartButtonClicked inside fragment C (where fragment C still exist) so the fragment D isn't created and take C place yet.
Try to call onCartButtonClicked by a Handler in your MainActivity

This is was one of my resource at the time to mimic a solution (he was using two fragments in one activity, while my app is trying to use one activity and replacing the main framelayout): http://www.techotopia.com/index.php/Using_Fragments_in_Android_-_A_Worked_Example
After playing around with example codes and using the available documentations. I cannot use these two lines to transfer the information as suggested in my MainActivity:
CartFragmentCode addCartInfoTextFragment = (CartFragmentCode) getSupportFragmentManager().findFragmentById(R.id.maincontainer);
addCartInfoTextFragment.UpdateCartTexts(editFood, editType, editName);
I think I finally found a workaround or a solution? I am not sure if this is the correct way of passing information to fragments or other classes, but here it is...
I basically Took away those two lines and rework my MainActivity's Click method and changed it to this...
public void onCartButtonClicked(String editFood, String editType, String editName){
CartFragmentCode.passFood = editFood;
CartFragmentCode.passType = editType;
CartFragmentCode.passName = editName;
}
I then went to my last fragment Code which was OrderFragmentCode.java and declared my Strings to retrieve them at the top of the Class and they were...
public static String passFood;
public static String passType;
public static String passName;
I then took the those values and setText them to my textViews. Wallah! It works as intented, however I am not sure if this is the right way to do things... If you guys are able to find a more professional way to handle data across multiple fragments, please let me know!

Calling method of Fragment has no effect

And first of all thank you anyway for your help.
This is a difficult question for me.
Please I have an activity that contains 5 Fragments; on user interaction the Fragments get swapped.
I am using the ACL.
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
stackArray =new ArrayList<Integer>();
favQ =new ArrayList<Stock>();
tablet=true;
mBound = false;
fragmentActivity = this;
setContentView(R.layout.splashmain);
splashfragment =new splashFragment();
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.add(R.id.splashview,splashfragment);
fragmentTransaction.commit();
/*
other stuff....
*/
fragmentlista = new listafragment();
fragmentfavourites= new favouritesFragment() ;
worstbest = new WorstBest();
searchfragment = new searchFragment();
/*
other stuff....
*/
lt = mService.ritira();
worst=mService.ritiraWorst();
best=mService.ritiraBest();
favQ.clear();
favQ.addAll(mService.ritiraFav());
fragmentlista.prendiLista(lt);
worstbest.prendiListaWorst(worst);
worstbest.prendiListaBest(best);
if(favQ.size()>0)fragmentfavourites.prendiLista(favQ);
// --->>>>HERE THE SAME METHOD enableAll() WORKS!!! <---
// --->>>>HERE THE SAME METHOD enableAll() WORKS!!! <---
splashfragment.enableAll();
// --->>>>HERE THE SAME METHOD enableAll() WORKS!!! <---
// --->>>>HERE THE SAME METHOD enableAll() WORKS!!! <---
/*
other stuff....
*/
}
//Method invoked to setup the configuration of the screen is layoutSchermo(int conf)
public static void layoutSchermo(int conf){
//Check if it is a Tablet in Landscape mode or not
//if it finds v2 than we are on a LARGE screen, then we check ORIENTATIO
fragmentActivity.setContentView(R.layout.main);
View v2 =(View)fragmentActivity.findViewById(R.id.view2);
if(v2==null
&
fragmentActivity.getResources().getConfiguration().orientation==
Configuration.ORIENTATION_PORTRAIT)
tablet=false;
//Calls the screen configuration LIST
if(conf==LIST){
fragmentActivity.setContentView(R.layout.main);
FragmentManager fragmentManager = fragmentActivity.getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.remove(splashfragment);
fragmentTransaction.commit();
fragmentManager.executePendingTransactions();
//Remove old Fragment splashfragment
//At this point I expect the fragment splashfragment is destroyed
//OR NOT???
fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.setCustomAnimations(R.anim.slide_in_left, R.anim.slide_out_right);
if(!tablet){fragmentTransaction.replace(R.id.view1, fragmentlista);}
if(tablet){
fragmentTransaction.replace(R.id.view1, splashfragment);
fragmentTransaction.replace(R.id.view2,fragmentlista );
} fragmentTransaction.addToBackStack(null);
stack= fragmentTransaction.commit();
stackArray.add(stack);
//Brand new fragments added
// --->>>>HERE THE SAME METHOD enableAll() NOT WORKING!!! <---
// --->>>>HERE THE SAME METHOD enableAll() NOT WORKING!!! <---
splashfragment.enableAll();
}
------------
So basically what happens and where the problem is:
The problem is in the method
layoutSchermo(int conf)
In the method layoutSchermo(int conf),
I detach a Fragment (splashfragment) and reattach it (together with another one).
It is not clear to me if when I call
remove(splashfragment)
Actually the Fragment is destroyed or not?
Additionally, whenever the Fragment freshly added is a new one or the old one,
why the call to
splashfragment.enableAll();
Has no effect ?
I expect it to work either it is the new or old Fragment!
Please enlighten me!
Thanks
maurizio
----------
EDIT EDIT EDIT EDIT EDIT EDIT
Here is the code of the fragment (I do not think it helps much)
ublic class splashFragment extends Fragment {
public View v;
public Button buttonfav;
public Button buttonBW;
public Button buttonSe;
public Button buttonLi;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
v=inflater.inflate(R.layout.splashnew, container, false);
RelativeLayout box1 = (RelativeLayout)v.findViewById(R.id.box1);
//box1.setBackgroundColor(Color.BLUE);
buttonfav=(Button)v.findViewById(R.id.heart);
buttonBW=(Button)v.findViewById(R.id.star);
buttonSe=(Button)v.findViewById(R.id.search);
buttonLi=(Button)v.findViewById(R.id.lista);
buttonfav.setBackgroundResource(R.drawable.hearth_gray_tansp);
buttonBW.setBackgroundResource(R.drawable.star_gray_trans);
buttonSe.setBackgroundResource(R.drawable.search_gray_transp);
buttonLi.setBackgroundResource(R.drawable.list_gray_trans);
buttonfav.setEnabled(false);
buttonBW.setEnabled(false);
buttonSe.setEnabled(false);
buttonLi.setEnabled(false);
buttonfav.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
Quotes.layoutSchermo(Quotes.FAVOURITES);
}});
buttonBW.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
Quotes.layoutSchermo(Quotes.BESTWORST);
}});
buttonSe.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
Quotes.layoutSchermo(Quotes.SEARCH);
}});
buttonLi.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
Quotes.layoutSchermo(Quotes.LIST);
}});
return v;
}
#Override
public void onSaveInstanceState(Bundle outState) { }
public void enableAll(){
buttonfav.setEnabled(true);
buttonfav.setBackgroundResource(R.drawable.hearth);
buttonBW.setEnabled(true);
buttonBW.setBackgroundResource(R.drawable.star);
buttonLi.setEnabled(true);
buttonLi.setBackgroundResource(R.drawable.list);
buttonSe.setEnabled(true);
buttonSe.setBackgroundResource(R.drawable.search);
}
}

When exactly fragments are destroyed can't be known with any certainty. All you know is that it's called after onStop() and before onDetach().
As for your splashFragment.enableAll(), you haven't showed us what that method is so how can we know why it isn't working... Also, you haven't showed us the more general context of this layoutSchermo method. I say this because I suspect you're doing this all wrong. You have a static method, referencing activities somehow...(not clear how that's happening), setting the contentview on that activity reference..the whole thing just sets off some red flags.
SplashFragment.enableAll is most likely something that needs to be called inside of that Fragment's onAttach or onResume, but again it's impossible to know without some explanation from you.
EDIT
Ok, so I think you're going about this incorrectly. What you are effectively trying to accomplish is to "configure" your Fragment in a certain way (depending on some state) when you display it again. The issue here is that you don't know exactly when the View hierarchy of a Fragment is inflated or when exactly it's attached to the Activity, etc. In other words, trying to call methods that affect the UI of your fragment simply on the basis of having a reference to the object of a Fragment is a mistake. You need to hook into the lifecycle of your Fragment and do things "the correct way."
Here's what I recommend: create a static constructor for your Fragment that makes it easy to create the properly configured Fragment that you want. Here's what that might look like:
public class SplashFragment extends Fragment {
public static SplashFragment newInstance(Bundle bundle) {
SplashFragment splashFragment = new SplashFragment()
splashFragment.setArguments(bundle);
return splashFragment;
}
// or alternatively
public static SplashFragment newInstance(int favResource, int bwResource, int liResource, int seResource,
boolean favEnabled, boolean bwEnabled, boolean liEnabled, boolean seEnabled) {
SplashFragment splashFragment = new SplashFragment()
Bundle bundle = new Bundle();
bundle.putInt("fav_res", favResource);
bundle.putInt("bw_res", bwResource);
bundle.putInt"li_res", liResource);
bundle.putInt("se_res", seResource);
bundle.putBoolean("fav_enabled", favEnabled);
//...And so on
splashFragment.setArguments(bundle);
return splashFragment;
}
//Then....
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
//setup your view as normal...then
buttonFav.setBackgroundResource(getArguments().getInt("fave_res"));
//.....etc
}
}
Now if you really need to be able to manipulate a Fragment without creating a new instance, then the only way I can think to do this is to add the fragment with a tag, as in the
replace(int containerViewId, Fragment fragment, String tag)
and
add (Fragment fragment, String tag)
varieties.
Then, later you can try to ask the fragment manager to find those fragment for you, i.e.
SplashFragment splashFragment = (SplashFragment) getFragmentManager().findFragmentByTag("some tag here");
Check that it's not null and then call your method on it...