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Update Activity title from fragment in FragmentPagerAdapter

I have v4.ViewPager inside Activity and use SlidingTabLayout from google's examples SlidingTabBasics. The problem I encounter is that each fragment retrieved from getItem(position) in v4.FragmentPagerAdapter has to refresh activity title. I have already learnt the hard way that FragmentPagerAdapter causes fragments to have really weird life callbacks so I can't probably use onResume or onStart. I noticed though that onCreateOptionsMenu(menu,inflater) gets called exactly when I want to refresh activity title. Is there a callback to supply actions when ViewPager has settled the fragment and it should change activity title?
Setting callback on ViewPager.onPageSelected(position) is inconvenient because I want this information to be propagated from fragment, not to fragment.
Currently I 'steal' onCreateOptionsMenu(menu,inflater) to do the work for me but it causes optimisation issues when no menu should be inflated but I still want the fragment to be able to affect activity title.

Have you tried this code in your fragment:
if(getActivity() != null){
getActivity().setTitle("new title");
}
Take into consideration that getActivity() will be null if the fragment is not yet attached to the activity.
Godspeed.

You can do this in different ways.
You can use interfaces in fragments that can be implemented by activity. But the drawback is, if you do have large number of fragments you must implement all of them.

Where to put the Fragment functional code?

Just a general question about working with Fragments and Activitys for android development: where does the business end of the functional code go for Fragments loaded into an Activity dynamically? (i.e. a fragment's OnClickListeners, OnCheckedChangedListeners, button logic methods...)
Do they go in the Fragment class, or the Activity class?

All the GUI logic for views attached to a fragment should be contained inside the fragment itself.
Thus a fragment should be as self contained as possible.
You can, though, if necessary do callbacks to your activity based on fragment GUI interaction. This can easily be done like this inside the fragment:
#Override
public void onAttach(Activity activity) {
if (!(activity instanceof SherlockFragmentActivity)) {
throw new IllegalStateException(getClass().getSimpleName()
+ " must be attached to a SherlockFragmentActivity.");
}
mActivity = (SherlockFragmentActivity) activity;
super.onAttach(activity);
}
In this specific case the reason for gaining a reference to SherlockFragmentActivity is to gain access to the support menu inflater mActivity.getSupportMenuInflater(), hence the construction can of course also serve to gain information from the underlying activity.

This probably depends on how much the Fragment's functionalities have in common, and how many, let's say Buttons, have to be handled.
I personally (and it's probably most common practice) handle onClick(...) events separately for each Fragment, meaning that I let each Fragment implement it's own OnClickListener.
Furthermore, when handling everything through the Activity, probably not all the components that react to click-events are in memory at all times and can be reached via findViewById(...), depending on which Fragment is currently displayed and how your user-interface is built up in general.

they always in fragment class because fragment is one type of component in android which we can reuse it. if we put onclick and oncheckchanged in activity then what meaning of reusing that component??
for more information about please go through following step:
Link 1 for basic level of information about fragment and how to handle them
Link 2 for dealing with multi pane fragment
Standard site for fragment

It depends:
If fragment can handle logic which is self sufficient(complete) then that code can be handled by fragment. e.g. on click call phone number.
If fragment have UI whose action is activity specific, then you want to add listener in activity.
e.g. master detail view like email client, on tablet user click on title fragment1 which have list of email titles, then handler on click in activity can show detail fragment2 in activity.
In all you want to keep fragment reusable.

How to Migrate from activity to fragment

I'm migrating an activity to a fragment. The fragment will ultimately be placed in a tab page.
I have copied the "grouped list" from the Conference example. The listview was on an activity. I am now moving same to a fragment. The method OnViewModelSet() does not exist in the view. Where am I supposed to moved the code contained in OnViewModelSet() when using a fragment?

Here is a very good talk on this topic by Corey Latislaw. She gave it at DroidCon London 2012.

Extends your class from fragment instead of activity and call fragment class functions with the view.
I suggest you to please upload some piece of code.

Communication fragments/activities

In my existing app I am porting two activities to fragments. The case is the classic dual panel mode with a list on the left and the content on the right.
The doc says that I should avoid to manipulate fragments within fragments, passing instead through the host activity. Said that I am using callbacks to the activity.
The first doubt (maybe banal) I have is:
How to avoid to duplicate the same code in the activity that hosts the
2 fragments and into the activity that wraps the fragment when not in
dual mode?
I'll try to explain. So I have:
ListFragment and ListFragmentActivity
ContentFragment and ContentFragmentActivity
because both fragments can live independently from each other, then:
HostActivity
that implements a listener invoked from ListFragment for adding/replacing the ContentFragment
My question is: when ListFragment is instead hosted from ListFragmentActivity, how to avoid to duplicate the code present in the HostActivity into ListFragmentActivity.
Guess I am missing something, thanks in advance.

Get rid of ListFragmentActivity. Have HostActivity handle the case where there is either one or both fragments. Then, by definition, there is no code duplication. See: https://github.com/commonsguy/cw-omnibus/tree/master/LargeScreen/EU4You

Android: How to call function of Activity inside of tab from the tabhost

I have a tabhost with three tabs. Each is an activity. I would like to have a button which is in the action bar, the bar along the top with common buttons, call functions of the tab which is active.
For example, an add function which could add something different to each tab depending on what tab was present when you clicked the button.
So, I am aksing how to call a function in Activity A from the tabHost.
And if that wont work, perhaps I can update the database from the tabhost and then refresh the tab content. Would that be easier?
Thank you all for you time and support.

I used the following code within my TabActivity class to switch tab then call a public method defined in the activity of the tab:
getTabHost().setCurrentTab(0);
Activity MyActivity = this.getCurrentActivity();
MyActivity.myMethod();
Hopefully helpful to someone looking for the answer to this question.

Hi Just stumbled across this, not sure if you already found a solution?
I solved this myself recently. I was previously getting around the problem by raising a intent broadcast from the tabhost activity and receiving the broadcast within the sub tab activity. This worked for me but i was sure there is a "better" way.
A cleaner way is to achieve it with something like this:
might have something like this:
parentActivity - my "container"
activity which holds the TabHost
childActivity - my tab activity
which holds tab content and the
public method i want to call from
parentActivity
within parentActivity:
// a method used for onclick callback or whatever you need. within parentActivity (tabhost)
// this will get call huzzah() in the first tab - getChildAt(0)
onClick () {
childActivity childAct = (childActivity) getTabHost().getChildAt(0).getContext();
childAct.huzzah();
}
within childActivity:
// a public method for the parent activity to access
public void huzzah() {
Log.d("stuff", "huzzah() called");
}
Note: Another alternative i believe is to redesign to use views instead of activities in your tabs. This is a better overall alternative because IIRC memory wise you are only storing 1 activity on the stack rather than (n * tabs) number of activities
Hope that helps

Edited as per Peter O request:
I am on API 10, and this problem gave me a huge headache. I have 3 tabs, I want all of them to be aware of changes on the other. The problem I had was that once the activity for a tab is started, there seemed to be no call back so the activity understood the user switched to a different tab, and thus needed to do work to be sure its state was correct.
I found lots of answers to this problem, but none seemed to work.
The one that I finally got to work was the solution offered as #3 for this thread --but it too is confusing. I found that the getTabHost().setCurrentTab(0); does nothing; I implemented OnTabChangeListener() to call a function that used getTabHost().setCurrentTab(0); however, I found the getTabHost().setCurrentTab(0); caused the app to crash for any tab other than 0--e.g, If I chose tab B (index=1) then called getTabHost().setCurrentTab(1); the app crashed.
Using the Debugger, I found the call this.getCurrentActivity(); always returns the activity associated with the tab which the user clicked on--calling getTabHost().setCurrentTab(); did not change that fact, and caused the app to crash.
So I got rid of it and I can now call this.getCurrentActivity(), then call a method in the Actvitity class returned by that call --this lets the activity know it has to update it's state--in my case it does this using the application object.

The above way of calling the method will not work,
Here is the quick answer for the above problem:
getTabHost().setCurrentTab(0);
Activity myActivity=getCurrentActivity();
String name=((Tab1) myActivity).et1.getText().toString();
Here the above code is given in the onclick() method of the activity which has TahHost
where Tab1 is the secondactivity and et1 is the identity of the edittext in the Tab1 activity so you can get all the value of the different fields like this individually.