Develop Reference

Is it possible to implement separate buttons onclickListener in both Activity and Fragment?

My MainActivity contain buttons which is used to switch to different fragments. Inside each fragment there are also has buttons. Activity button onClickListener work fine before implementing button onClickListener in fragments. I wonder if this is not supported by Android or my code is not correct.
Any pointer is appreciated. Thank you.
Fragment code:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
v = inflater.inflate(fragment1, container, false);
b2=(Button)v.findViewById(R.id.button2);
b2.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v){
button2Clicked(v);
}
});
return inflater.inflate(R.layout.fragment1, container, false);
}
public void button2Clicked(View view){
//do something
}
Activity code:
public class MainActivity extends FragmentActivity {
private Button btnHealth;
private Button btnSetting;
private Button btnSleep;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//Init component
btnHealth = (Button) findViewById(R.id.btnHealth);
btnSleep = (Button) findViewById(R.id.btnSleep);
btnSetting = (Button) findViewById(R.id.btnSetting);
replaceFragment(1);
btnHealth.setOnClickListener(new AdapterView.OnClickListener(){
#Override
//On click function
public void onClick(View view) {
replaceFragment(0);
}
});
btnSleep.setOnClickListener(new AdapterView.OnClickListener(){
#Override
//On click function
public void onClick(View view) {
replaceFragment(1);
}
});
btnSetting.setOnClickListener(new AdapterView.OnClickListener(){
#Override
//On click function
public void onClick(View view) {
replaceFragment(2);
}
});
}
//Create method replace fragment
private void replaceFragment(int pos) {
Fragment fragment = null;
switch (pos) {
case 0:
fragment = new Fragment1();
break;
case 1:
fragment = new Fragment2();
break;
case 2:
fragment = new Fragment3();
break;
default:
fragment = new Fragment2();
break;
}
if(null!=fragment) {
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.replace(R.id.main_content, fragment);
transaction.addToBackStack(null);
transaction.commit();
}
}
}

It is possible. If you want to handle the OnClick Event of the fragment inside the Activity class, you can do so by using FragmentInteractionListener (interface). Example: Android - handle fragment onClick from activity

Back to a fragment from fragmentActivity in Android

I'm trying to get back to a fragment from a fragmentActivity, but it is not working, I'm getting NullPointerException, When I hit cancel I need to update the previous fragment. How can I get back to a fragment and update it? don't know why this is happening.
public class AddEscolas extends FragmentActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.addescola);
mSessao = new SecurePreferences(AddEscolas.this, "sessao");
pesquisa = (EditText) findViewById(R.id.campo_pesquisa);
nomeEscola = (TextView) findViewById(R.id.nomeEscola);
logradouro = (TextView) findViewById(R.id.endereco);
cidade = (TextView) findViewById(R.id.cidade);
procura = pesquisa.getText();
InputMethodManager imm = (InputMethodManager) getSystemService(INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(pesquisa.getWindowToken(), 0);
getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
findViewById(R.id.btnProcurar).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
new Pesquisa().execute();
mFerramentas.hideKeyboard(AddEscolas.this, pesquisa);
}
});
findViewById(R.id.btnCancelar).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();
}
});
}
}
FragmentClass :
public class EscolasFragment extends Fragment {
#Override
public View onCreateView(final LayoutInflater inflater, final ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_escolas, container, false);
ImageView add = (ImageView) rootView.findViewById(R.id.add);
mSessao = new SecurePreferences(getActivity(), "sessao");
add.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent addIntent = new Intent(getActivity(), AddEscolas.class);
startActivity(addIntent);
}
});
return rootView;
}
}

Suppose you just need to call finish(), like this:
findViewById(R.id.btnCancelar).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
finish();
}
});
The reason for the NullPointerException maybe is that the layout id of R.id.content_frame could not be found in the AddEscolas activity.
If you need to update the EscolasFragment fragment after the AddEscolas activity exits, you may do as follow steps:
use startActivity() from the EscolarFragment fragment to call the AddEscolas activity.
use onActivityResult() in the activity containing the EscolarFragment fragment to extract result returned by the AddEscolas activity.
use onResume() in the EscolarFragment fragment to update the UI.

You have wrong idea about what FragmentActivity is. Activities host fragments. You cant go to fragment without having activity. Read the docs
Null pointer exception comes from
fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();
you need to give instance to 'fragment'. Somehing like:
Fragment fragment = new YourFragment();

Simply call onBackPressed(); in the FragmentActivity.

Android FragmentManager for same Activity hide() doesnt work

Hi guys im working on my MainActivity and I am dealing with the following problem:
In my MainActivity I have 3 buttons(button1, button2, button3). With each I can add a Fragment(Fragment2, Fragment1, ProfileFragment) to my container. Everytime a button is pressed, it checks the Fragments if there is already anotherone visible.
If yes, FragmentManager().beginnTransaction().fragment.hide() should hide it.
Then it checks if the fragment bound to the button already exists.
If no, it adds it.
If yes, it should make the existing hidden fragment visible again with FragmentManager().beginnTransaction().fragment.show()
Now: If I press button2 as the first when I start my App everything works fine and I can infinitely switch between the fragments.
But: If I press button1 as the first, and then switch to button2 or button3, the fragment bound to button1 (m2fragment) can't be shown again. It just shows m1fragment (which should be hidden when I press button1)
The same happens if I press button3 as the first. Everytime I try to switch back to button3(profileFragment) it just shows m1fragment.
May be there a problem with the googleMap which I call from the xml from m2Fragment??
Anyone can see where I made (a) mistake(s) ? I would be really glad since I am dealing with this for several days now.
Thank you all !
Cut from my MainActivity:
public class MainActivity extends FragmentActivity implements ProfileFragment.OnFragmentInteractionListener,
OfferFragment.OnFragmentInteractionListener, MapsFragment.OnFragmentInteractionListener, OpenerFragment.OnFragmentInteractionListener, GoogleApiClient.ConnectionCallbacks,
GoogleApiClient.OnConnectionFailedListener {
private GoogleApiClient mGoogleApiClient;
protected int fragment1Open = 0;
protected int fragment2Open = 0;
protected int profileFragmentOpen = 0;
Fragment1 m1Fragment = new Fragment1();
Fragment2 m2Fragment = new Fragment2();
ProfileFragment mProfileFragment = new ProfileFragment();
OpenerFragment mOpenerFragment = new OpenerFragment();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if(savedInstanceState==null) {
getFragmentManager().beginTransaction().add(R.id.container,mOpenerFragment).commit();
}
final Button button1 = (Button) findViewById(R.id.button1);
button1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//check fragments
if(mOpenerFragment.isVisible()) {
getFragmentManager().beginTransaction().remove(mOpenerFragment).commit();
Log.d("button1", "remove OpenerFragment");
}
if(m1Fragment.isVisible()) {
getFragmentManager().beginTransaction().hide(m1Fragment).commit();
}
if(mProfileFragment.isVisible()) {
getFragmentManager().beginTransaction().hide(mProfileFragment).commit();
}
if(fragment2Open==0) {
fragment2Open=1;
getFragmentManager().beginTransaction().add(R.id.container, m2Fragment).commit();
} else {
getFragmentManager().beginTransaction().show(m2Fragment).commit();
}
}
});
final Button button2 = (Button) findViewById(R.id.button2);
button2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//hide other fragments
if(mOpenerFragment.isVisible()) {
getFragmentManager().beginTransaction().remove(mOpenerFragment).commit();
}
if(mProfileFragment.isVisible()) {
getFragmentManager().beginTransaction().hide(mProfileFragment).commit();
}
if(m2Fragment.isVisible()) {
getFragmentManager().beginTransaction().hide(m2Fragment).commit();
}
if(fragment1Open==0) {
fragment1Open=1;
getFragmentManager().beginTransaction().add(R.id.container, m1Fragment).commit();
} else {
getFragmentManager().beginTransaction().show(m1Fragment).commit();
}
}
});
final Button button3 = (Button) findViewById(R.id.button3);
button3.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//hide other fragments
if(mOpenerFragment.isVisible()) {
getFragmentManager().beginTransaction().remove(mOpenerFragment).commit();
}
if(m1Fragment.isVisible()) {
getFragmentManager().beginTransaction().hide(m1Fragment).commit();
}
if(m2Fragment.isVisible()) {
getFragmentManager().beginTransaction().hide(m2Fragment).commit();
}
//open fragment
if(profileFragmentOpen==0) {
profileFragmentOpen=1;
getFragmentManager().beginTransaction().add(R.id.container, mProfileFragment).commit();
} else {
getFragmentManager().beginTransaction().show(mProfileFragment).commit();
}
}
});
mProfileFragment and m2Fragment use identically onCreate and onCreateView methods:
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootview = inflater.inflate(R.layout.fragment_profile, container, false);
return rootview;
}
m1Fragment has the same methods, but gets a googleMaps fragment from its xml file.
m1Fragment:
public class Fragment1 extends Fragment implements OnMapReadyCallback {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
MapFragment mapFragment=(MapFragment) getFragmentManager().findFragmentById(mapid);
if (mapFragment==null) {
mapFragment = MapFragment.newInstance();
FragmentTransaction fragmentTransaction = getFragmentManager().beginTransaction();
fragmentTransaction.add(R.id.container, mapFragment);
fragmentTransaction.commit();
mapFragment.getMapAsync(this);
}
mapFragment.getMapAsync(this);
}
#Override
public void onMapReady(GoogleMap map) {
//right upper corner, location layer activated
map.setMyLocationEnabled(true);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_maps, container, false);
return rootView;
}
fragment_1.xml:
<fragment
android:id="#id/mapid"
class="com.google.android.gms.maps.MapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</FrameLayout>

MapFragment mapFragment=(MapFragment) getFragmentManager().findFragmentById(mapid);
in this line your actually tring to get the parent's fragmentManager (in your case the activity),and fail to find the fragment.
and then in this line:
FragmentTransaction fragmentTransaction = getFragmentManager().beginTransaction();
fragmentTransaction.add(R.id.container, mapFragment);
fragmentTransaction.commit();
you are adding to the parent FragmentManager.
a quick to solution is to replace getFragmentManger() with getChildFragmentManager, which refers to the fragment's FragmentManager.

Maybe you should try to use :
// Create new fragment and transaction
Fragment newFragment = new ExampleFragment();
FragmentTransaction transaction = getFragmentManager().beginTransaction();
// Replace whatever is in the fragment_container view with this fragment,
// and add the transaction to the back stack if needed
transaction.replace(R.id.fragment_container, newFragment);
transaction.addToBackStack(null);
// Commit the transaction
transaction.commit();
With fragment_container as FrameLayout in your activity?
I'm not 100% sure, but i think it'll avoid such issues

I just solved it:
Withing my MapsFragment class I instantiated a googleMaps fragment "twice". Trying to hide the mapFragment I just hid one of them, leaving the other one visible in front.
For people having similar issues here my solution:
I erased the
<fragment
android:id="#id/mapid"
class="com.google.android.gms.maps.MapFragment"/>
from the xml layout file.
And inside the MapsFragment class I changed
MapFragment mapFragment=(MapFragment) getChildFragmentManager().findFragmentById(mapid);
to
MapFragment mapFragment = MapFragment.newInstance();
getChildFragmentManager().beginTransaction().add(R.id.framLay, mapFragment).commit();
Now I put one clean Instance of MapFragment into my FrameLayout and it works properly.

How to stop running thread of Fragment safely on android?

I want to know how to stop running thread and asyncTask of fragment safely on android.
here is my code:
public class MainActivity extends FragmentActivity {
public Fragment mFragment;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_main);
Button btn_next = (Button) findViewById(R.id.button_next);
btn_next.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
((FragmentOne)mFragment).infoThread.interrupt();
}
});
Intent intent = getIntent();
String start_fragment = intent.getStringExtra("start_fragment");
onShowFragment(start_fragment);
}
public void onShowFragment(String select_fragment) {
Fragment fr = null;
switch (select_fragment) {
case "fragment1":
fr = new FragmentOne();
break;
case "gragment2":
fr = new FragmentTwo();
break;
}
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.replace(R.id.fragment_place, fr);
ft.commit();
}
}
public class FragmentOne extends Fragment {
public Thread infoThread;
public View view_one;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
view_one = inflater.inflate(R.layout.fragment_one, container, false);
onGetInfo();
return view_one;
}
public void onGetInfo() {
infoThread= new Thread(new Runnable() {
#Override
public void run() {
String response_info = HTTPUtils.HTTPPost(Global.USER_URL,
"name", "abc",
"password", "1234");
processGetInfo(response_info);
}
});
infoThread.start();
}
}
in here, when click btn_next button, FATAL EXCEPTION ERROR occur.
please help me.

try to use:
infoThread.stop()
instead of:
infoThread.interrupt();

You are never initialising mFragment with a value.
Add mFragment = fr; to onShowFragment
But, you're going to have a whole load of different issues if you carry on down this path. You should consider a more robust framework than performing http requests in threads spawned from a Fragment's onCreateView method.

switching from a fragment to an activty and back to the fragment

i created an activity that contains 5 fragments and one of the fragments contains a profile page and i created another activity to edit the profile page but when i click the save button to return to the Edit (fragment) . The app crashes..
i need help or suggestions
this is my Fragment code below :
public class MeFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// TODO Auto-generated method stub
View view = inflater.inflate(R.layout.me, container, false);
Button bt = (Button) view.findViewById(R.id.btedit);
bt.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent i = new Intent(getActivity(), Editme.class);
startActivity(i);
}
});
return view;
}
and this is the Editme Class:
Button btnLoad = (Button) findViewById(R.id.btsave);
OnClickListener listener = new OnClickListener() {
#Override
public void onClick(View v) {
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager
.beginTransaction();
MeFragment save = new MeFragment();
fragmentTransaction.add(R.id.fragment_content, save);
fragmentTransaction.commit();
}
};
btnLoad.setOnClickListener(listener);

If you opened another activity and after making some changes you'd like to go back to previous activity(with 5 fragments) simply call finish method instead of doing fragment transaction.
OnClickListener listener = new OnClickListener() {
#Override
public void onClick(View v) {
finish();
}
}