Develop Reference

FragmentTransaction in ViewPager

I have a Viewpager with two fragments.
I want to replace each of the fragment with 3 different fragments.
How can I do this?
Also, can I change whole ArrayList with the new list of fragments after button click in the current fragment?
Here is what I've done.
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View v = inflater.inflate(R.layout.fragment_healthy_mode, container, false);
swipeLeft = v.findViewById(R.id.leftSlide);
swipeRight = v.findViewById(R.id.rightSlide);
pageArray = new ArrayList<Fragment>();
pageArray.add(new Female());
pageArray.add(new Male());
healthyModeAdapter = new HealthyModeAdapter(getFragmentManager(), pageArray);
viewPager = (ViewPager) v.findViewById(R.id.healthyModeViewPager);
viewPager.setAdapter(healthyModeAdapter);
// I want to replace female n male fragment with
pageArray.add(new EctoBodyFemale());
pageArray.add(new EndoBodyFemale());
pageArray.add(new MesoBodyFemale());
pageArray.add(new EctoBodyMale());
pageArray.add(new EndoBodyMale());
pageArray.add(new MesoBodyMale());

ViewPager supports operation with Views or Fragments if I understand correctly you want each page each 3 sub components that are static, in such case you have 2 options:
Using nested fragments, create a Fragment for each page that will contain your sub-fragments. and use these parent fragments as the fragments your provide to the pager view
Note that nested fragments are not recommended, they have been proven to be buggy and might affect performances. So I suggest you to take the View approach, create an xml that defines the fragments, and after you inflate it provide it directly to the ViewPager.

ViewPager blocks Fragment's View's OnClickListeners

I currently have a view pager in a tab layout
//Get the ViewPager and set it's PagerAdapter so that it can display items
ViewPager viewPager = (ViewPager) findViewById(R.id.viewpager);
viewPager.setAdapter(new SettingsFragmentPagerAdapter(getSupportFragmentManager()));
//Give the TabLayout the ViewPager
TabLayout tabLayout = (TabLayout) findViewById(R.id.sliding_tabs);
tabLayout.setupWithViewPager(viewPager);
And then the fragments in the view pager have TextViews with OnClickListeners attached
final TextView zSemTxt = (TextView) getActivity().findViewById(R.id.zSemTxt);
zSemTxt.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
mSelectedTextView = zSemTxt;
showDialogToSelectClass();
}
});
My issue is the OnClickListeners are never called, it appears that all touches go to the ViewPager and never goes through to the TextViews. I've tried things like viewPager.requestDisallowInterceptTouchEvent(true); but none of it change anything.
Ideas?

Show more code.
Probably onClick dosen't work because your textview = null.
final TextView zSemTxt = (TextView) getActivity().findViewById(R.id.zSemTxt);
Are You sure about this?
I dont see your code but try
final TextView zSemTxt = (TextView) view.findViewById(R.id.zSemTxt);
where view is your fragment inflated view.

Turns out neither the onActivityCreated or onCreateView were being called on the fragment.
The solution was to go to the PageFragment class I was using to manage which fragment was displayed by the ViewPager and add the onClickListeners to there. The fragments were being inflated there which is why the other classes were never called.

ViewPager/FragmentPageAdapter, after recreation, does not call onCreate() of last selected view

I am currently working on an application with ActionBar tabs inside one of its fragments (main navigation is NavigationDrawer). The fragment's onCreate():
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
actionBar = activity.getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
Resources r = getResources();
//(…) tabNames initialization
adapter = new CustomTabAdapter(getFragmentManager());
}
and onCreateView():
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment, container, false);
viewPager = (ViewPager) rootView.findViewById(R.id.pager);
viewPager.setAdapter(adapter);
viewPager.addOnPageChangeListener(this);
for (String tabName : tabNames) {
actionBar.addTab(actionBar.newTab()
.setText(tabName)
.setTabListener(this));
}
return rootView;
}
There are 4 tabs, each of them with its own Fragment and layout. CustomTabAdapter returns new instance of proper fragment in its getItem(int). There are 4 tabs.
And now my problem is:
I start the application.
I choose this tab fragment from NavigationDrawer list. Everything is working just fine.
I choose another fragment from NavigationDrawer list which means that tab fragment is replaced with it.
I choose tab fragment again. And fragment related to tab that was selected before choosing another fragment from NavigationDrawer list, and one's adjacent to it are not recreated (blank screen under ActionBar tabs). I checked and onCreateView(…) methods of those fragment are not called. So after changing device orientation, or choosing tab not adjacent and this one again proper layout is shown.
How can I make it work as it should (showing proper layout on reentering tab fragment from NavigationDrawer list instead of blank space)? I run out of ideas.

Finally, I found a solution. My CustomTabAdapter was extension of FragmentPagerAdapter. I changed it to be extension of FragmentStatePageAdapter, and now fragments are recreated.
More details in this answer by #Louth.

It takes fragments from cache without recreation

Fragment view in ViewPager is not restored when resuming

I have ActionBar Tabs setup. It consists of 4 tabs. Everything is fine until I navigate away from TabbedFragment and returning back.
I create tabs like this:
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
final ActionBar actionBar = getActionBar();
tabs = Lists.newArrayList();
tabs.add(new TabDefinition<>("Tab 1"));
tabs.add(new TabDefinition<>("Tab 2"));
tabs.add(new TabDefinition<>("Tab 3"));
tabs.add(new TabDefinition<>("Tab 4"));
for (TabDefinition tab : tabs) {
actionBar.addTab(actionBar.newTab()
.setText(tab.text)
.setTag(tab.tag)
.setTabListener(this));
}
}
And initialize adapter like this:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.paging_tab_container, container, false);
}
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
viewPager = (ViewPager) view.findViewById(R.id.pager);
viewPager.setAdapter(new FragmentStatePagerAdapter(getFragmentManager()) {
#Override
public Fragment getItem(int position) {
return tabs.get(position).fragment;
}
#Override
public int getCount() {
return tabs.size();
}
});
viewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
#Override
public void onPageSelected(int position) {
getActionBar().setSelectedNavigationItem(position);
}
});
viewPager.setCurrentItem(getActionBar().getSelectedNavigationIndex(), true);
}
When returning back to TabbedFragment selected tab and 1 next to it would not have any content. Just empty view. But if I select current + 2 fragment content is loaded. And then returning to that first fragment content is reloaded.
For example I have A, B, C, D tabs. Before leaving TabbedFragment I had selected tab A.
When returning to TabbedFragment I still am at tab A, but it's empty. So is tab B.
But when selecting tab C it is created and loaded. Returning to tab A it is recreated.
What could be the problem here?

After a while ran into the same problem again, so updating this question.
If you're using FragmentStatePagerAdapter you should provide FragmentManager via getChildFragmentManager() instead of getFragmentManager(). See Issue 55068: ViewPager doesn't refresh child fragments when back navigation via backstack

Okay so When using a FragmentStatePagerAdapter your fragments will be destroyed when you navigate anymore than one fragment Away since by default offScreenPageLimit is set to 1 by default just as mentioned above.
Typically this Class is used for an activity that has a very large set of Fragments, i.e have to scroll through a large amount of views. If your application does not need more than say 3-4 tabs I would suggest using FragmentPagerAdapter instead, and then specifying your offScreenPageLimit to something like 3, so if you get to the 4th Tab, all 3 tabs before will still be in memory.
Here is some Sample Code for a project on github that i created illustrating how to dynamically load the fragments if you don't want to add this offScreenPageLimit.
https://github.com/lt-tibs1984/InterfaceDemo/blob/master/src/com/divshark/interfacedemo/InterfaceDemoMain.java
Walk through all this code in this Class, and you will see how I'm dynamically loading the fragments, each time my ViewPager is slid over. Most notably at the bottom.
You can download this code, and use it as a test base for what you want to do.
Try adding the setOffScreenPageLimit(2) in the onCreate() method for the viewPager and notice the different behavior. To check the behavior, edit the text in fragment 1. Navigate Away and navigate back, with this set or not. You will see when it is set, the fragment's text remains what you change it to, since the fragment is never recreated.
Please provide additional questions if you have them.
GoodLuck
UPDATE
private static final String [] fragmentClasses = {"com.example.project.YourFragment1","com.example.project.YourFragment2","com.example.project.YourFragment3"};
viewPager.setAdapter(new FragmentStatePagerAdapter(getFragmentManager()) {
#Override
public Fragment getItem(int position) {
Fragment fragmentAtPosition = null;
// $$$$ This is the Important Part $$$$$
// Check to make sure that your array is not null, size is greater than 0 , current position is greater than equal to 0, and position is less than length
if((fragmentClasses != null) && (fragmentClasses.length > 0)&&(position >= 0)&& (position < fragmentClasses.length))
{
// Instantiate the Fragment at the current position of the Adapter
fragmentAtPosition = Fragment.instantiate(getBaseContext(), fragmentClasses[position]);
fragmentAtPosition.setRetainInstance(true);
}
return fragmentAtPosition;
}
#Override
public int getCount() {
return fragmentClasses.length;
}
});

The problem exists in the Fragments you use as tabs, I think. They seem to not show anything when they are resumed (see Fragment lifecycle). The "weird" issue that only the currently selected +/-1 tab is empty, is because the offScreenPageLimit of your ViewPager is 1 by default. All tabs above this threshold are re-created.
Therefore, increasing the value will -- in your case -- cause all your tabs to appear empty after resuming. Check in your Fragment code which lifecycle methods you use to inflate your layout, set adapters and so forth, because that's what's causing your trouble.

I guess this happens because while loading fragment android loads current and current+1, if you debug you would not see onPause getting called for the immediate next fragment.
You can reload content programmatically in onTabChanged() method of TabHost.OnTabChangeListener.

After doing much research, this worked for me.
I have a complex layout with 3 tabs in a fragment, that gets switched out for other fragments. I realized that the ViewpagerAdapter will retain state, even if you press the home button. My problem was switching back and forth would null out the child fragment UI view elements and crash. The key is to not new out your ViewPagerAdapter. Adding the null check for the Adapter worked for me. Also, be sure to allocate setOffscreenPageLimit() for your needs. Also, from what I understand setRetainInstance(true); should not be used for fragments that have UI, it is designed for headless fragments.
In the fragment that holds your Tabs:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_tab, container, false);
tabLayout = (TabLayout) view.findViewById(R.id.tablayout);
viewPager = (ViewPager) view.findViewById(R.id.viewPager);
//Important!!! Do not fire the existing adapter!!
if (viewPagerAdapter == null) {
viewPagerAdapter = new ViewPagerAdapter(getChildFragmentManager());
viewPagerAdapter.addFragments(new AFragment(), "A");
viewPagerAdapter.addFragments(new BFragment(), "B");
viewPagerAdapter.addFragments(new CFragment(), "C");
}
//Allocate retention buffers for three tabs, mandatory
viewPager.setOffscreenPageLimit(3);
tabLayout.setupWithViewPager(viewPager);
viewPager.setAdapter(viewPagerAdapter);
return view;
}

Or more simply when navigating back to tabbedfragment (assuming you use an intent and the fragment is within an activity) use:
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
This keeps the original activity and moves it to the top of the stack rather than recreating it, thus you never need to recreate the viewPager.

View Pager in Fragment

Once again, I am so annoyed by the AndroidSDK . Why does this have to be so complicated?
I have a ViewPager that I want to populate with my Fragment. I implemented this on an Activity and it works. But when its in another Fragment the whole thing crashes and the erros messages tells me nothing:
07-01 12:58:20.210: E/AndroidRuntime(10146): java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.
Here is my code:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_tabwrapper, container);
List<Fragment> fragments = getFragments();
pageAdapter = new MyPageAdapter(getActivity()
.getSupportFragmentManager(), fragments);
pager = (ViewPager) v.findViewById(R.id.viewpager);
pager.setAdapter(pageAdapter); // <- CRASH!
return v;
}
BTW: The whole thing is based on this tutorial: http://architects.dzone.com/articles/android-tutorial-using

This error occurs beacuse you have to remove all views before set adapter in view pager so get right way..... So check this:
MyPageAdapter pageAdapter ;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_tabwrapper, container);
List<Fragment> fragments = getFragments();
pageAdapter = new MyPageAdapter(getActivity()
.getSupportFragmentManager(), fragments);
pager = (ViewPager) v.findViewById(R.id.viewpager);
pager.removeallviews();
pager.setAdapter(pageAdapter); // <- CRASH!
return v;
}

you should not use the ViewGroup that onCreateView provides as container to put your inflated view:
Change
View v = inflater.inflate(R.layout.fragment_tabwrapper, container);
to
View v = inflater.inflate(R.layout.fragment_tabwrapper, null);

This might shed a little light on the topic: http://developer.android.com/about/versions/android-4.2.html#NestedFragments
IMHO: I don't understand why developers put up with these tools. I find them impossible to work with. No wonder there are so many low-quality apps on the Play store. I'm looking forward to the day this project is done. Won't be working with this OS anytime soon again ...