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Execute method in fragment before ad it to backstack

I have multiple fragments and I can switch between them, my problem is on how can I execute a method in a fragment before it goes to backstack.
If I execute some method in fragment's OnPause() or OnStop() my activity is closing with all fragments instantly. The code to switch from one fragment to another is:
public void switchFrgFromFrg(Fragment fragment, String tag, boolean isAddedToBackStack, int idContainer) {
FragmentTransaction fragmentTransaction = getFragmentManager().beginTransaction();
fragmentTransaction.replace(idContainer, fragment, tag);
if (isAddedToBackStack) {
fragmentTransaction.addToBackStack(tag);
}
fragmentTransaction.commit();
}
Any help is apreciated.

Your fragment onResume() and onPause() will be called only when the Activity onResume() or onPause() that holds it is called. They are tightly coupled to the Activity, that's why your fragment is closing. I sugest you ti implement a back key listener as:
private void doBackActionListener(View view){
view.setFocusableInTouchMode(true);
view.requestFocus();
view.setOnKeyListener(new View.OnKeyListener() {
#Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
if (event.getAction() == KeyEvent.ACTION_DOWN) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
//execute code
//then do standart go back action
getActivity().onBackPressed();
return true;
}
}
return false;
}
});
}
You will cal this in your onCreateView() and pass inflated view as parameter.

how can I execute a method in a fragment before it goes to backstack
When you fragment is visible you can execute as many methods as you want
If I execute some method in fragment's OnPause() or OnStop() my activity is closing with all fragments instantly.
That's because some Exception is arising in your code. It is better to show your console (Log messages) in your question.

Remove only fragment when back pressed

I create sample app to show some data to user when user start specific activity and click on specific button the app start new fragment (only fragment added to activity for now ) my problem is when user click back the fragment and the activity removed and go to parent activity. using this code to do that
android.support.v4.app.FragmentManager fragmentManager = ((FragmentActivity) context).getSupportFragmentManager();
fragmentManager.popBackStack();
also I use the same code in another action when user click in specific button fragment and back correctly.
Can anyone help me to solve that

Add fragments to back stack when create them and override onBackPressed in your activity.
To add fragment
FragmentManager mFragmentManager = ((FragmentActivity) context).getSupportFragmentManager();
FragmentTransaction ft = mFragmentManager.beginTransaction();
ft.addToBackStack("tag of fragment");
ft.add("your container id", fragment);
ft.commit();
onBackPress
#Override
public void onBackPressed() {
if (mFragmentManager.getBackStackEntryCount() > 0)
mFragmentManager.popBackStackImmediate();
else super.onBackPressed();
}

To remove only fragment you have to add that fragment in addToBackStack(TAG) so that when you press back it popout only Fragment which are added to stack

override onBackPressed() and remove fragment. Back stack for fragments works differently as it stores transaction not fragments. So can not pop back a fragment but a transaction

This is work for me to handle backpressin a fragment in a fragment to remove backstack.
#Override
public void onResume() {
super.onResume();
if (getView() == null) {
return;
}
getView().setFocusableInTouchMode(true);
getView().requestFocus();
getView().setOnKeyListener(new View.OnKeyListener() {
#Override
public boolean onKey(View view, int keyCode, KeyEvent keyEvent) {
if (keyEvent.getAction() == KeyEvent.ACTION_UP && keyCode == KeyEvent.KEYCODE_BACK) {
Toast.makeText(getActivity(), "Clicked Back", Toast.LENGTH_SHORT).show();
getActivity().finish();
return true;
}
return false;
}
});
}

Backing out of an full-screen dialog

if I launch a full-screen dialog like such
FragmentManager fragmentManager = getActivity().getFragmentManager();
DialogStyleCreator editor = new DialogStyleCreator();
FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
transaction.add(android.R.id.content, editor).commit();
How can I make it so that if I hit the android back arrow (in the top left of the menu) or the back button it closes the dialog instead of going back to the previous activity like in alert dialogs?

You may simply put your transaction in stack of fragment manager and override the function of back button
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (Integer.parseInt(android.os.Build.VERSION.SDK) > 5
&& keyCode == KeyEvent.KEYCODE_BACK
&& event.getRepeatCount() == 0) {
// Simply pop back your fragment stack here
return true;
}
return super.onKeyDown(keyCode, event);
}
#Override
public void onBackPressed() {
// Simply pop back your fragment stack here
}

Since you have added the DialogFragment as transaction.add(android.R.id.content, editor).commit(); you may not have option to listen the dismiss call back.
I suggest you to create the DialogFragment instance and start it like
fm.beginTransaction().add(sampleDialog, "Dialog").commit();
and set the call back interface for Activity Back Button Click and call dismiss();

webview fragment press back to return to

Hi I have an android app which a recycleview. When user click a button on a recycle viewholder. app will launch a webview (inside fragment). I want to handle when user click back button, webview will goback if there is a history, and if there is no history, the app will close the webview fragment and come back the recycleview.
I have successfull handle the back when there is a history (but webview can not come back to recycle view if there is no history
Here is my webview code
webView.setOnKeyListener(new View.OnKeyListener() {
public boolean onKey(View v, int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
if (webView.canGoBack()) {
webView.goBack();
}else {
getActivity().getSupportFragmentManager().popBackStack();
}
return true;
}
return false;
}
});
Anything wrong with these code? any help is much appreciate. Thanks
Edit i use these code inside recycleview adapter class to handle button click on ViewHolder class
url.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Bundle bundle = new Bundle();
bundle.putString("topStoryUrl", topStories.get(getLayoutPosition()).getUrl());
TopStoryWebView topStoryWebViewFragment = new TopStoryWebView();
topStoryWebViewFragment.setArguments(bundle);
if (ItemListActivity.mTwoPane) {
((FragmentActivity) context).getSupportFragmentManager()
.beginTransaction()
.add(R.id.item_detail_container, topStoryWebViewFragment)
.commit();
} else {
topStoryWebViewFragment.setArguments(bundle);
((FragmentActivity) context).getSupportFragmentManager()
.beginTransaction()
.add(R.id.frameLayout, topStoryWebViewFragment)
.commit();
}
}
});

addToBackStack will add your fragment to stack, and you can access this stack later
((FragmentActivity) context).getSupportFragmentManager()
.beginTransaction()
.add(R.id.item_detail_container, topStoryWebViewFragment)
// Add this transaction to the back stack (name is an optional name for this back stack state, or null).
.addToBackStack(null)
.commit();

how to go back to previous fragment on pressing manually back button of individual fragment?

I have only one activity and multiple fragments in my application.
Two main fragment A(left) and B(right).
Fragment A1 called from A
B1 called from B
B2 called from B1
All fragments have individual back buttons.
So when I press back button of fragment A1, it should go back to A, similarly when Back button from B2 is pressed, B1 appears and from B1 to B and so on.
How to implement this type of functionality?

public void onBackPressed()
{
FragmentManager fm = getActivity().getSupportFragmentManager();
fm.popBackStack();
}

I have implemented the similar Scenario just now.
Activity 'A' -> Calls a Fragment 'A1' and clicking on the menu item, it calls the Fragment 'A2' and if the user presses back button from 'A2', this goes back to 'A1' and if the user presses back from 'A1' after that, it finishes the Activity 'A' and goes back.
See the Following Code:
Activity 'A' - OnCreate() Method:
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activityA);
if (savedInstanceState == null) {
Fragment fragInstance;
//Calling the Fragment newInstance Static method
fragInstance = FragmentA1.newInstance();
getFragmentManager().beginTransaction()
.add(R.id.container, fragInstance)
.commit();
}
}
Fragment : 'A1'
I am replacing the existing fragment with the new Fragment when the menu item click action happens:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == R.id.action_edit_columns) {
//Open the Fragment A2 and add this to backstack
Fragment fragment = FragmentA2.newInstance();
this.getFragmentManager().beginTransaction()
.replace(R.id.container, fragment)
.addToBackStack(null)
.commit();
return true;
}
return super.onOptionsItemSelected(item);
}
Activity 'A' - onBackPressed() Method:
Since all the fragments have one parent Activity (which is 'A'), the onBackPressed() method lets you to pop fragments if any are there or just return to previous Activity.
#Override
public void onBackPressed() {
if(getFragmentManager().getBackStackEntryCount() == 0) {
super.onBackPressed();
}
else {
getFragmentManager().popBackStack();
}
}
If you are looking for Embedding Fragments inside Fragments, please refer the link: http://developer.android.com/about/versions/android-4.2.html#NestedFragments

#trueblue's answer got me going with one minor but annoying issue. When there is only one fragment on the backstack and you press back button, that frame is removed and the app remains active with a blank screen. User needed to press back button one more time to exit the app. I modified the original code to the following in order to handle this situation
#Override
public void onBackPressed() {
if(getFragmentManager().getBackStackEntryCount() == 0) {
super.onBackPressed();
}
else if(getFragmentManager().getBackStackEntryCount() == 1) {
moveTaskToBack(false);
}
else {
getFragmentManager().popBackStack();
}
}
When there is only 1 fragment in the backstack, we are basically telling android to move the whole app to back.
Update (and probably a better answer)
So after doing some more reading around this, I found out that you can add fragment manager transactions to back stack and then android handles back presses automatically and in a desired way. The below code snippet shows how to do that
Fragment fragment; //Create and instance of your fragment class here
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.fragment_container, fragment).addToBackStack(null);
fragmentTransaction.commit();
fragmentTransaction.addToBackStack(null);
The last line shows how you add a transaction to back stack. This solves back press issue for fragments in most situations except for one. If you go on pressing back button, then eventually you will reach a point when there is only one fragment in the back stack. At this point, you will want to do one of the two things
Remove the activity housing the fragment from the back stack of the task in which activity is running. This is because you do not want to end up with a blank activity
If the activity is the only activity in the back stack of the task, then push the task in background.
In my case, it was the later, so I modified the overridden onBackPressed method from my previous answer to look like below
#Override
public void onBackPressed() {
if(getFragmentManager().getBackStackEntryCount() == 1) {
moveTaskToBack(false);
}
else {
super.onBackPressed();
}
}
This code is simpler because it has less logic and it relies on framework than on our custom code. Unfortunately I did not manage to implement code for first situation as I did not need to.

You have to implement your own backstack implementation as explained here.
You can call the popFragments() whenever you click the back button in a fragment and call pushFragments() whenever you navigate from one Fragment to other.

Just Do
getActivity().getFragmentManager().popBackStack();

Try this, Its Work for me.
public void onBackPressed() {
if (mainLayout.isMenuShown()) {
mainLayout.toggleMenu();
} else {
FragmentManager fm = getSupportFragmentManager();
Log.print("back stack entry", fm.getBackStackEntryCount() + "");
if (fm.getBackStackEntryCount() > 1) {
fm.popBackStack();
// super.onBackPressed();
// return;
} else {
if (doubleBackToExitPressedOnce) {
fm.popBackStack();
super.onBackPressed();
return;
}
this.doubleBackToExitPressedOnce = true;
Toast.makeText(this, "Press one more time to exit",
Toast.LENGTH_SHORT).show();
new Handler().postDelayed(new Runnable() {
#Override
public void run() {
doubleBackToExitPressedOnce = false;
}
}, 3000);
}
}
}

Back button will traverse in the order, in which Fragments were added to backstack. This is provided as a navigation function by default. Now if you want to go to specific Fragment, you can show it from backstack.

You can handle it by adding tag in the backStack. Check my answer here :
https://stackoverflow.com/a/19477957/1572408
hope it helps

#Override
public void onResume() {
super.onResume();
getView().setFocusableInTouchMode(true);
getView().requestFocus();
getView().setOnKeyListener(new View.OnKeyListener() {
#Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
if (event.getAction() == KeyEvent.ACTION_UP && keyCode == KeyEvent.KEYCODE_BACK){
// replace your fragment here
return true;
}
return false;
}
});
}
// Happy Coding

If you press back image you have to create method first like this
private void Backpresses() {
getActivity().getSupportFragmentManager().beginTransaction().replace(R.id.contant_main, new Home()).commit();
}
then you have to call like this when you press back image..
back.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Backpresses();
}
});
It work fine for me.