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Sending data from Fragment to Fragment using Interface, by setting Fragment Layouts dynamically. Saved instance of Fragment NOT working

I am sending data from one fragment to another, using interface. This works absolutely fine. Now I am trying to use onSaveInstanceState() to save the value in
a Fragment and retrieving in onCreate(). however i'm getting null in Bundle of onCreate(). P.S. everything works fine when i set the Fragment directly into the activity layout in xml. but when i set the fragment through java code into the activity, the onSaveInstanceState is failing. It is not saving the last known value. Please help. Pasting the code below. You can try it out to know the exact issue.
Fragment_A :
public class Fragment_A extends Fragment implements View.OnClickListener {
Button btnAdd;
int counter = 0;
Communicator comm;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if(savedInstanceState != null){
counter = savedInstanceState.getInt("counter", 0);
}
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_a, container, false);
return view;
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
comm = (Communicator) getActivity();
btnAdd = (Button) getActivity().findViewById(R.id.btnAdd);
btnAdd.setOnClickListener(this);
}
#Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt("counter", counter);
}
#Override
public void onClick(View v) {
counter++;
comm.sendData(counter);
}
}
interface Communicator{
void sendData(int i);
}
=====
Activity :
public class Activity_InterComm extends Activity implements Communicator{
FragmentManager manager;
FragmentTransaction transaction;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_intercomm);
Fragment_A fragment_1 = new Fragment_A();
Fragment_B fragment_2 = new Fragment_B();
manager = getFragmentManager();
transaction = manager.beginTransaction();
transaction.add(R.id.frag_a, fragment_1, "Frag1");
transaction.add(R.id.frag_b, fragment_2, "Frag2");
transaction.commit();
}
#Override
public void sendData(int i) {
manager = getFragmentManager();
Fragment_B fragment_b = (Fragment_B) manager.findFragmentById(R.id.frag_b);
fragment_b.setData("Button has been clicked " + i + " times");
}
}
=====
Fragment_B :
public class Fragment_B extends Fragment {
TextView txtMessage;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_b, container, false);
return view;
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
txtMessage = (TextView) getActivity().findViewById(R.id.txtMessage);
}
public void setData(String message){
txtMessage.setText(message);
}
}
activity_intercomm.xml :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<!--<fragment
android:id="#+id/frag_a"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_marginBottom="8dp"
android:layout_weight="1"
android:name="android.learning.com.fragintercomm.Fragment_A"/>
<fragment
android:id="#+id/frag_b"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:name="android.learning.com.fragintercomm.Fragment_B"/>-->
<LinearLayout
android:id="#+id/frag_a"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_marginBottom="8dp"
android:layout_weight="1"
android:background="#color/colorAccent"
android:orientation="vertical"/>
<LinearLayout
android:id="#+id/frag_b"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_marginBottom="8dp"
android:layout_weight="1"
android:background="#color/colorPrimaryDark"
android:orientation="vertical"/>
</LinearLayout>

the soluion I found was using getView() instead of getActivity() while initializing the button in Fragment_A. use btnAdd = (Button) getView().findViewById(R.id.btnAdd); instead of btnAdd = (Button) getActivity().findViewById(R.id.btnAdd);.
However, you can't use getView() in Fragment_B. The Textview freezes and, onSaveInstanceStat() doesn't work. Please suggest a solution.

Can code inside a fragment access GUI of its activity?

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<fragment
android:id="#+id/fragment1"
android:name="ankit.fairmatrix.in.MyListFragment"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/mText"
android:text="Hello World!" />
</LinearLayout>
How can I access TextView inside the activity (here mText ) from Fragment class MyListFragment?

(TextView) ((MyActivity)getActivity).findViewById(R.id.mText);
But better to do something like this:
public class MainActivity extends Activity implements OnTextChangeListener {
TextView textView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView = (TextView) findViewById(R.id. mText);
}
#Override
public void changeText(String text){
textView.setText(text);
}
}
Fragment code
public class MyListFragment extends Fragment {
interface OnTextChangeListener{
void changeText(String text);
}
private OnTextChangeListener onTextChangeListener;
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
if (activity instanceof OnTextChangeListener){
onTextChangeListener = (OnTextChangeListener)activity;
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.chat_list, container, false);
}
public void something(){
onTextChangeListener.change("Hello");
}
}

OnClickListener in Fragments does not work

I have a MainActivity and a Fragment called Frags that itself has a fragment called CardFrontFragment.
I register an OnClickListener on this fragment (the child fragment) and in this OnClickListener's OnClick method I replace this fragment(CardFrontFragment) by CardbackFragment fragment. Also I register an OnClickListener on this fragment(CardbackFragment) too, in order to switch again between this to child fragment.
OnClickListener in first fragment (CardfrontFragment) works and the second fragment is shown but now by clicking on the second fragment nothing happens, OnClickListener does not work with the second fragment, this is killing me, please help me!
Code:
MainActivity.java
public class MainActivity extends ActionBarActivity {
public static Frags frag=new Frags();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, frag)
.commit();
}
}
}
Frags.java
public class Frags extends Fragment{
CardBackFragment back=new CardBackFragment();
CardFrontFragment front=new CardFrontFragment();
View view;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view;
view=inflater.inflate(R.layout.frag_layout, container, false);
getChildFragmentManager().beginTransaction()
.add(R.id.frag_container, back)
.commit();
return view;
}
public void Onflip(boolean iSback)
{
if(iSback)
{
getChildFragmentManager().beginTransaction()
.setCustomAnimations(
R.animator.card_flip_right_in, R.animator.card_flip_right_out,
R.animator.card_flip_right_in, R.animator.card_flip_right_out)
.replace(R.id.frag_container, front)
.commit();
}
else
{
getChildFragmentManager().beginTransaction()
.setCustomAnimations(
R.animator.card_flip_right_in, R.animator.card_flip_right_out,
R.animator.card_flip_right_in, R.animator.card_flip_right_out)
.replace(R.id.frag_container, back)
.commit();
}
}
}
CardFrontFragment
public class CardFrontFragment extends Fragment {
public CardFrontFragment() {
}
View view;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
view=inflater.inflate(R.layout.fragment_card_front, container, false);
view.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View arg0) {
MainActivity.frag.Onflip(false);
Log.i("front","onclick");
}
});
return view;
}
}
CardBackFragment
public class CardBackFragment extends Fragment {
public CardBackFragment() {
}
View view;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
view=inflater.inflate(R.layout.fragment_card_back, container, false);
view.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View arg0) {
MainActivity.frag.Onflip(false);
Log.i("back","onclick");
}
});
return view;
}
}
xml:
fragment_card_front.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#0000ff" >
<Button
android:id="#+id/front_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button" />
</LinearLayout>
fragment_card_back.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#000000" >
<Button
android:id="#+id/back_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button" />
</LinearLayout>
frag_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:id="#+id/frag_container">
</LinearLayout>
activity_main.xml
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.demokhar.MainActivity"
tools:ignore="MergeRootFrame" />

Get view for button click on the Fragment of the ViewPager

I have successfully set up the a FragmentActivity with FragementPagerAdapter associated with ViewPager to implement two tabbed application .
One of the Tabs namely "Wave" has a text view and a button . All I want is call textview.setText method via the onClick method of button described by its xml attribute .
I do not know where should I initialize my TextView or Button , how can I get the context of Wave tab and where should I write onclick method-
public class InformationShow extends FragmentActivity {
XMLdata dataObject;
ViewPager viewPager;
PagerAdapter adpt;
Fragment temp;
TextView tv;
Button bt;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_main);
viewPager=(ViewPager)findViewById(R.id.pager);
adpt = new PagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(adpt);
// temp=adpt.fg.findFragmentById((int)adpt.getItemId(1));
tv=(TextView)findViewById(R.id.graphWaveTextView);
bt = (Button)findViewById(R.id.button1);
}
public void changeText(View v){
tv.setText("It worked ");
}
Adapter Class
public class PagerAdapter extends FragmentPagerAdapter {
int count = 2;
CharSequence namme[] = {"Temperature","Wave"};
XMLdata data;
FragmentManager fg;
public PagerAdapter(FragmentManager fragmentManager ){
super(fragmentManager);
this.fg = fragmentManager;
}
Context context;
#Override
public Fragment getItem(int arg0) {
switch (arg0){
case 0:{
TemperatureGraphFrag temp = new TemperatureGraphFrag();
return temp;
}
case 1:{WaveHeightGraphFrag wave = new WaveHeightGraphFrag();
return wave;
}
}
return null;
}
#Override
public int getCount() {
return 2;
}
#Override
public CharSequence getPageTitle(int position) {
return namme[position];
}
}
Fragments Class
public class TemperatureGraphFrag extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.graph_t, container, false);
return view;
}
}
public class WaveHeightGraphFrag extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.graph_sig_wave_height, container, false);
return view;
}
}
fragment_main XML implemented by FragmentActicity
<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<android.support.v4.view.PagerTabStrip
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="top"
android:paddingBottom="10dp"
android:paddingTop="10dp"
android:textColor="#65C2C9"
android:scrollbarSize="5dp"/>
</android.support.v4.view.ViewPager>
Tab 2 Fragment XML graph_sig_wave_height
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
>
<TextView
android:id="#+id/graphWaveTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Small Text"
android:textAppearance="?android:attr/textAppearanceSmall"
android:layout_gravity="center"
/>
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button"
android:layout_gravity="center"
android:onClick="changeText"/>
</LinearLayout>
Tab 1 fragment layout XML graph_t
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:id="#+id/linearTemp"
>
<TextView
android:id="#+id/graphTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Medium Text"
android:textAppearance="?android:attr/textAppearanceMedium"
android:layout_gravity="center"
/>
</LinearLayout>

Add the following method to your WaveHeightGraphFrag class:
#Override
public void onViewCreated(View view, Bundle savedInstanceState){
final TextView t = (TextView) view.findViewById(R.id.graphWaveTextView);
Button b = (Button) view.findViewById(R.id.button1);
b.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v){
t.setText("It worked ");
}
});
}
This is what you want.

Passing data between two fragments in two different activities

I am trying to do a very basic example with Fragments.
Structure : Fragment1 -> Fragment1Activity, Fragment2 -> Fragment2Activity.
Both activities have a STATIC Fragment in it.
Here are the XMLs:
activity_for_fragment_1.xml
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/fragment_1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:name="com.xx.fragmentstutorial1.Fragment1"
tools:context="com.xx.fragmentstutorial1.Fragment1Activity"/>
fragment1.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/textview_fragment_1"
android:layout_width="match_parent"
android:layout_height="0dip"
android:layout_weight="0.60"
android:text="This is Fragment 1"
android:gravity="center"
android:textAppearance="?android:attr/textAppearanceLarge" />
<EditText
android:id="#+id/edittext_fragment_1_text"
android:layout_width="match_parent"
android:layout_height="0dip"
android:layout_weight="0.20"
android:text="Type your message here..." >
<requestFocus />
</EditText>
<Button
android:id="#+id/button_fragment_1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Click Me" />
</LinearLayout>
activity_for_fragment_2.xml
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/fragment_2"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:name="com.xx.fragmentstutorial1.Fragment2"
tools:context="com.xx.fragmentstutorial1.Fragment2Activity"/>
fragment_2.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/textview_fragment_2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:text="This is Fragment 2"
android:textAppearance="?android:attr/textAppearanceLarge" />
<TextView
android:id="#+id/textview_fragment_2_result"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:text="I will display text from \nFragment 1"
android:textAppearance="?android:attr/textAppearanceLarge" />
</LinearLayout>
Now, I have an Edittext and button in the fragment_1. When I click on the button, I want to get the text entered in EditText and set it to the textview(textview_fragment_2_result) in fragment_2
I was able to achieve this, but, I am not very convinced, that the approach I took was good enough. Please look at the java code below..
Fragment1Activity.java
public class Fragment1Activity extends SherlockFragmentActivity implements Fragment1.ButtonClickListener{
Fragment1 fragment1;
#Override
protected void onCreate(Bundle bundle) {
super.onCreate(bundle);
setContentView(R.layout.activity_for_fragment_1);
System.out.println("onCreate Fragment1Activity");
fragment1 = (Fragment1) getSupportFragmentManager().findFragmentById(R.id.fragment_1);
}
#Override
public void onButtonClick(String message) {
System.out.println("onButtonClick Fragment1Activity");
startActivity(new Intent(this, Fragment2Activity.class).putExtra("message", message));
}
}
Fragment1.java
public class Fragment1 extends SherlockFragment {
EditText message;
Button clickme;
ButtonClickListener listener;
public interface ButtonClickListener{
public void onButtonClick(String message);
}
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
if (activity instanceof ButtonClickListener)
listener = (ButtonClickListener) activity;
else {
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
System.out.println("onCreateView Fragment1");
View view = inflater.inflate(R.layout.fragment_1, container, false);
message = (EditText) view.findViewById(R.id.edittext_fragment_1_text);
clickme = (Button) view.findViewById(R.id.button_fragment_1);
clickme.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
if (!message.getText().toString().equalsIgnoreCase("")) {
System.out.println("Message in Fragment1 = "+message.getText().toString());
listener.onButtonClick(message.getText().toString());
} else {
Toast.makeText(getActivity(),
"Please enter some message...", Toast.LENGTH_LONG)
.show();
}
}
});
return view;
}
}
Fragment2Activity.java
public class Fragment2Activity extends SherlockFragmentActivity {
Fragment2 fragment2;
#Override
protected void onCreate(Bundle bundle) {
super.onCreate(bundle);
setContentView(R.layout.activity_for_fragment_2);
fragment2 = (Fragment2) getSupportFragmentManager().findFragmentById(R.id.fragment_2);
fragment2.setMessage(getIntent().getExtras().getString("message").toString());
}
}
Fragment2.java
public class Fragment2 extends SherlockFragment {
String msg;
TextView textview;
public Fragment2() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_2, container, false);
textview = (TextView) view
.findViewById(R.id.textview_fragment_2_result);
textview.setText(msg);
return view;
}
public void setMessage(String message) {
msg = message;
textview.setText(msg);
}
}
I have set the text for textview in setMessage() of Fragment2.java, which I think is not a good approach. If i comment that out, I don't see any text in the textview of Fragment2.
Can someone help me out, on how to pass values between two static fragments correctly.

You should go with interface
Follow the Diagram Here :
Communication Between Two Fragment is Done Via Activity using Interface
Fragment A-------------------------->Activity-------------------->Fragment B
(defines Interface) (Implement interface) (pass it other Fragment B)
Hope this could help
Check This Out

What you have is mostly good. The part of transferring the data from Fragment1 to Activity1 is good. Once the data gets to Activity2, you are setting it in Fragment2. I would change this part a little.
In Activity2:
#Override
protected void onCreate(Bundle bundle) {
super.onCreate(bundle);
setContentView(R.layout.activity_for_fragment_2);
fragment2 = (Fragment2) getSupportFragmentManager().findFragmentById(R.id.fragment_2);
fragment2.setArguments(getIntent().getExtras());
}
and in Fragment2.
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
Bundle bundle = getArguments();
String message = bundle.getString("message");
View view = inflater.inflate(R.layout.fragment_2, container, false);
textview = (TextView) view
.findViewById(R.id.textview_fragment_2_result);
textview.setText(message);
return view;
}

Your approach seems correct. The connection between your Fragment1 and Activity1 is just like in the fragments guideline. Your fragment1 shouldn't know about fragment2 therefore it's OK to pass the responsibility to the fragment's container/parent - activity1 - that knows what to do with the data. This time again your approach is correct - activity1 starts it's slave/child etc. and is responsible to start it with correct data (passed through the intent extras). And then again you have a correct approach - when your activity2 is created you populate it's views with the appropriate content/data (the message) that was meant to be displayed in this activity and given to it by the "parent" activity.