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How to return multiple fragments from FragmentPagerAdapter

If I use a TabLayout with FragmentPagerAdapter, the overridden function getItem(int position) just return one fragment. In case of lager screen I would like to have 2 fragments to be returned.
How can I do it? should wrap these 2 fragments into one fragment and use that instead or is there any better solution?
FragmentPagerAdapter:
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0: //Ingredients
return IngredientsFragment.newInstance(mRecipe);
case 1: // Details
{
// TODO Here instead of DetailFragment I want to return
// two fragments called DetailFragment and StepFragment.
return DetailFragment.newInstance(mRecipe);
}
default:
throw new RuntimeException(this.toString() + " Wrong fragment!");
}
}
And then in my Activity onCreate:
#Override
protected void onCreate(Bundle savedInstanceState) {
// Initializing, etc.
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
mViewPager.setAdapter(mSectionsPagerAdapter);
TabLayout tabLayout = findViewById(R.id.tabs);
mViewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
tabLayout.addOnTabSelectedListener(new TabLayout.ViewPagerOnTabSelectedListener(mViewPager));
}

I do not see you have much of a wiggle room here.
These two options are exlusive:
You are returning one Fragment with two nested fragments (Wrapped fragment)
You are returning two fragments each anchored to his own tab.
If you would like two fragments to appear on singular page of ViewPager, you have no choice but to wrap them.
Otherwise swiping would go between these two fragments, which is the same as if they are completely different, that is non-correlated.

OK I managed to solve the problem using a Fragment consist of two other fragments as children.
Just do not forget in this case the FragmentManager object should be populated with getChildFragmentManager() to work properly.
For more info look at my BakingApp project DetailStepWideScreenFragment.java
GitHub Repos
Fragment Wrapper:
public class DetailStepWideScreenFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_detail_step_wide_screen, container, false);
// I added the fragments here. StepFragment can be replaced using
// replaceStepFragment function.
DetailFragment detailFragment = DetailFragment.newInstance(mRecipe);
StepFragment stepFragment = StepFragment.newInstance(mRecipe, mStepId);
FragmentTransaction transaction = getChildFragmentManager().beginTransaction();
transaction.add(R.id.fl_detail_fragment_wide_screen, detailFragment);
transaction.add(R.id.fl_step_fragment_wide_screen, stepFragment);
transaction.commit();
return view;
}
public void replaceStepFragment(String stepId) {
mStepId = stepId;
FragmentTransaction transaction = getChildFragmentManager().beginTransaction();
StepFragment stepFragment = StepFragment.newInstance(mRecipe, mStepId);
transaction.replace(R.id.fl_step_fragment_wide_screen, stepFragment);
transaction.commit();
}
}
PagerAdapter:
public class SectionsPagerAdapter extends FragmentPagerAdapter {
private DetailStepWideScreenFragment currentFragment;
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
currentFragment = null;
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0: //Ingredients
return IngredientsFragment.newInstance(mRecipe);
case 1: // Details
{
// Show base on screen size.
if (mIsLargeScreen) {
DetailStepWideScreenFragment detailStepWideScreenFragment = DetailStepWideScreenFragment.newInstance(mRecipe, "0");
currentFragment = detailStepWideScreenFragment;
return detailStepWideScreenFragment;
} else {
return DetailFragment.newInstance(mRecipe);
}
}
default:
throw new RuntimeException(this.toString() + " Wrong fragment!");
}
}
#Override
public int getCount() { return 2; }
public DetailStepWideScreenFragment getCurrentFragment() {
return currentFragment;
}
}

How to get the current fragment displayed in a specific tab of a viewpager?

I want to get the last fragment in the backstack, or the current displayed it's the same for me, in the tab b_1. As you can see in the following image, I have a ViewPager, and another one inner tab b. Thus there are four current fragments displayed.
Question: How can I get the Fragment 2 instance?
I have seen another solutions, but none works for this scenario.
Annotation: The fragment to return is not necessary the hosted in the ViewPager. I can have opened two more fragments in a tab.
With this method I get all the current visible fragments, but not the one specific I want.
public ArrayList<Fragment> getVisibleFragment() {
List<Fragment> fragments = getSupportFragmentManager().getFragments();
ArrayList<Fragment> visibleFragments = new ArrayList<>();
if (fragments != null) {
for (Fragment fragment : fragments) {
if (fragment != null && fragment.isVisible())
visibleFragments.add(fragment);
}
}
return visibleFragments;
}
Some interesting code
activity_main.xml
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
<android.support.design.widget.TabLayout
android:id="#+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabMode="fixed"
app:tabGravity="fill"/>
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="#+id/viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"/>
</android.support.design.widget.CoordinatorLayout>
MainActivity.java
public class MainActivity extends AppCompatActivity {
private static ViewPagerAdapter adapter;
private static ViewPager viewPager;
private TabLayout tabLayout;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
viewPager = (ViewPager) findViewById(R.id.viewpager);
setupViewPager();
tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(viewPager);
setupTabIcons();
}
private void setupViewPager() {
adapter = new ViewPagerAdapter(getSupportFragmentManager());
// Wrap with HostFragment to get separate tabbed nagivation.
adapter.addFrag(HostFragment.newInstance(new Fragment1()), null);
adapter.addFrag(HostFragment.newInstance(new RootFragment2()), null);
adapter.addFrag(HostFragment.newInstance(new Fragment4()), null);
viewPager.setAdapter(adapter);
viewPager.setOffscreenPageLimit(2);
}
public void openNewFragment(Fragment fragment) {
HostFragment hostFragment = (HostFragment) adapter.getItem(viewPager.getCurrentItem());
hostFragment.replaceFragment(fragment, true);
}
}
fragment_host.xml
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/hosted_fragment"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
HostFragment.java
/**
* This class implements separate navigation for a tabbed viewpager.
*
* Based on https://medium.com/#nilan/separate-back-navigation-for-
* a-tabbed-view-pager-in-android-459859f607e4#.u96of4m4x
*/
public class HostFragment extends BackStackFragment {
private Fragment fragment;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
View view = inflater.inflate(R.layout.fragment_host, container, false);
if (fragment != null) {
replaceFragment(fragment, false);
}
return view;
}
public void replaceFragment(Fragment fragment, boolean addToBackstack) {
if (addToBackstack) {
getChildFragmentManager().beginTransaction().replace(R.id.hosted_fragment, fragment).addToBackStack(null).commit();
} else {
getChildFragmentManager().beginTransaction().replace(R.id.hosted_fragment, fragment).commit();
}
}
public static HostFragment newInstance(Fragment fragment) {
HostFragment hostFragment = new HostFragment();
hostFragment.fragment = fragment;
return hostFragment;
}
public Fragment getFragment() {
return fragment;
}
}
fragment2_root.xml
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/fragment2_root"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<android.support.design.widget.TabLayout
android:id="#+id/tab2_tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabMode="fixed"
app:tabGravity="fill"/>
<android.support.v4.view.ViewPager
android:id="#+id/tab2_viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"/>
</LinearLayout>
RootFragment2.java
public class RootFragment2 extends Fragment {
private ViewPagerAdapter adapter;
private ViewPager viewPager;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Inflate the layout for this fragment.
View root = inflater.inflate(R.layout.fragment2_root, container, false);
viewPager = (ViewPager) root.findViewById(R.id.tab2_viewpager);
setupViewPager(viewPager);
TabLayout tabLayout = (TabLayout) root.findViewById(R.id.tab2_tabs);
tabLayout.setupWithViewPager(viewPager);
return root;
}
private void setupViewPager(ViewPager viewPager) {
adapter = new ViewPagerAdapter(getActivity().getSupportFragmentManager());
// Wrap with HostFragment to get separate tabbed nagivation.
adapter.addFrag(HostFragment.newInstance(new Fragment2()), null);
adapter.addFrag(HostFragment.newInstance(new Fragment3()), null);
viewPager.setAdapter(adapter);
viewPager.setOffscreenPageLimit(1);
}
public ViewPagerAdapter getAdapter() {
return adapter;
}
public ViewPager getViewPager() {
return viewPager;
}
}

First define a SparseArray in your ViewPagers' adapters like below. In this array we'll hold the instance of fragments.
SparseArray<Fragment> registeredFragments = new SparseArray<>();
And Override your Adapters' instantiateItem method.
#Override
public Object instantiateItem(ViewGroup container, int position) {
Fragment fragment = (Fragment) super.instantiateItem(container, position);
registeredFragments.put(position, fragment);
return fragment;
}
Also Override destroyItem method of your ViewPagers
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
registeredFragments.remove(position);
super.destroyItem(container, position, object);
}
And define a new method to get your ViewPager Fragments instance.
public Fragment getRegisteredFragment(int position) {
return registeredFragments.get(position);
}
And finally set add a PageChangeListener to your ViewPagers:
viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
// Here's your instance
YourFragment fragment =(YourFragment)yourPagerAdapter.getRegisteredFragment(position);
}
#Override
public void onPageScrollStateChanged(int state) {
}
});
I hope this'll help you. Good luck.
Edit: I'm sorry i cannot understand exactly what you're planning to do but if you need to keep sub fragment (b_1, b_2) instance you can define a method to your activity such as
public void setCurrentFragment(Fragment fragment){
this.currentFragment = fragment;
}
and in your sub view pager's adapter you can call this method like below:
subViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
// Here's your instance
YourFragment fragment =(YourFragment)yourSubPagerAdapter.getRegisteredFragment(position);
((MyActivity)getActivity).setCurrentFragment(fragment);
}
#Override
public void onPageScrollStateChanged(int state) {
}
});
With this way you can keep one instance and your top fragment.

After some comments with DEADMC, I decided to implement it with extra memory, saving in a list the open fragments.
I explain my solution. I hve two types of special fragments, host and root. Host Fragments are those which are the init of a tab. Root Fragments are those which hold a ViewPager. In this scenario, tab_b has a Root Fragment with an inner ViewPager.
For each tab, this is, for each HostFragment, I have added a list fragments to save the fragments opened in this tab. Also a method getCurrentFragment to get the last displayed in this tab.
public class HostFragment extends BackStackFragment {
private ArrayList<Fragment> fragments = new ArrayList<>();
public Fragment getCurrentFragment() {
return fragments.get(fragments.size() - 1);
}
Also a method to remove the last fragment displayed in this tab is needed, to maintain a true state. Back button needs to be redirect to this method.
public void removeCurrentFragment() {
getChildFragmentManager().popBackStack();
fragments.remove(fragments.size() - 1);
}
Also previous methods need to be changed, to insert the new fragments opened into the list.
public void replaceFragment(Fragment fragment, boolean addToBackstack) {
// NEW: Add new fragment to the list.
fragments.add(fragment);
if (addToBackstack) {
getChildFragmentManager().beginTransaction().replace(R.id.hosted_fragment, fragment).addToBackStack(null).commit();
} else {
getChildFragmentManager().beginTransaction().replace(R.id.hosted_fragment, fragment).commit();
}
}
public static HostFragment newInstance(Fragment fragment) {
HostFragment hostFragment = new HostFragment();
// NEW: Add first fragment to the list.
hostFragment.fragments.add(fragment);
return hostFragment;
}
} // HostFragment.
RootFragment is an interface implemented by those fragments which holds a ViewPager.
public interface RootFragment {
/**
* Opens a new Fragment in the current page of the ViewPager held by this Fragment.
*
* #param fragment - new Fragment to be opened.
*/
void openNewFragment(Fragment fragment);
/**
* Returns the fragment displayed in the current tab of the ViewPager held by this Fragment.
*/
Fragment getCurrentFragment();
}
And then, the implementation would be:
MainActivity is not a Fragment, but I implement RootFragment interface for meaning.
public class MainActivity extends AppCompatActivity implements RootFragment {
private void setupViewPager() {
adapter = new ViewPagerAdapter(getSupportFragmentManager());
// Wrap with HostFragment to get separate tabbed nagivation.
adapter.addFrag(HostFragment.newInstance(new Fragment1()), null);
adapter.addFrag(new RootFragment2(), null); // This is a Root, not a Host.
adapter.addFrag(HostFragment.newInstance(new Fragment4()), null);
viewPager.setAdapter(adapter);
// 2 because TabLayout has 3 tabs.
viewPager.setOffscreenPageLimit(2);
}
#Override
public void openNewFragment(Fragment fragment) {
Fragment hosted = adapter.getItem(viewPager.getCurrentItem());
// Replace the fragment of current tab to [fragment].
if (hosted instanceof HostFragment) {
((HostFragment) hosted).replaceFragment(fragment, true);
// Spread action to next ViewPager.
} else {
((RootFragment) hosted).openNewFragment(fragment);
}
}
#Override
public Fragment getCurrentFragment() {
Fragment hosted = adapter.getItem(viewPager.getCurrentItem());
// Return current tab's fragment.
if (hosted instanceof HostFragment) {
return ((HostFragment) hosted).getCurrentFragment();
// Spread action to next ViewPager.
} else {
return ((RootFragment) hosted).getCurrentFragment();
}
}
}
and RootFragment2
public class RootFragment2 extends Fragment implements RootFragment {
private void setupViewPager(ViewPager viewPager) {
adapter = new ViewPagerAdapter(getActivity().getSupportFragmentManager());
// Wrap with HostFragment to get separate tabbed nagivation.
adapter.addFrag(HostFragment.newInstance(new Fragment2()), null);
adapter.addFrag(HostFragment.newInstance(new Fragment3()), null);
viewPager.setAdapter(adapter);
// 1 because TabLayout has 2 tabs.
viewPager.setOffscreenPageLimit(1);
}
#Override
public void openNewFragment(Fragment fragment) {
((HostFragment) adapter.getItem(viewPager.getCurrentItem())).replaceFragment(fragment, true);
}
#Override
public Fragment getCurrentFragment() {
return ((HostFragment) adapter.getItem(viewPager.getCurrentItem())).getCurrentFragment();
}
}
And then, I just need to call:
((MainActivity) getActivity()).getCurrentFragment();

You can create something like CustomFragment class which contains getClassName method and extends from Fragment class. Then extend all your fragments such as RootFragment2 from CustomFragment class instead of just Fragment.
So you can get fragment like this:
public CustomFragment getNeededFragment(String fragmentName) {
List<Fragment> fragments = getSupportFragmentManager().getFragments();
CustomFragment result = null;
if (fragments != null) {
for (Fragment fragment : fragments) {
if (fragment != null && fragment.isVisible()) {
try {
CustomFragment customFragment = (CustomFragment) customFragment;
if (customFragment.getClassName().equals(fragmentName)))
result = customFragment;
} catch (ClassCastException e) {
}
}
}
}
return result ;
}

I would do something like that:
1. Create a interface like this.
public interface ReturnMyself {
Fragment returnMyself();
}
2. All fragments inside ViewPagers should implements this one.
3. Add OnPageChangeListener to your main VP. So You will always know current position.
4. Add OnPageChangeListener your inner(s) VP so you will know which one is there on screen.
5. Add method to your adapter (both main and inner) which returns your fragment from list passed to it.
public ReturnMyself getReturnMyselfAtPosition()
6. All Fragments should return this in returnMyself()
7. Fragment that has inner fragments should return in returnMyself something like.
Fragment returnMyself() {
return this.myInnerFragmentAdapter.getReturnMyselfAtPosition().returnMyself();
}
8. From main fragment/activity you just call.
this.adapter.getReturnMyselfAtPosition().returnMyself();
And you got your current fragment.

swipe back from a viewpager causes the app to crash

I wrote an app that has an action bar and 3 view pagers, now I finished the first pager, which is a Google map, and for the other 2, I currently just inflate them with a layout that has only a text view. The problem is that whenever I swipe to the 3rd view pager, and then swipe back, the app crashes, but switching between the first two is okay, except that the UI of the second pager seems to be affected by the google map UI. The code for the main activity is here:
public class LobbyActivity extends ActionBarActivity implements ActionBar.TabListener {
SectionsPagerAdapter mSectionsPagerAdapter;
ViewPager mViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_lobby);
// Set up the action bar
final ActionBar actionBar = getSupportActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
initializePager();
mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener(){
#Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
});
for(int i=0; i<mSectionsPagerAdapter.getCount(); i++){
actionBar.addTab(
actionBar.newTab()
.setText(mSectionsPagerAdapter.getPageTitle(i))
.setTabListener(this));
}
}
private void initializePager() {
List<Fragment> fragments = new Vector<Fragment>();
fragments.add(Fragment.instantiate(this, MapFragment.class.getName()));
fragments.add(Fragment.instantiate(this, ListFragment.class.getName()));
fragments.add(Fragment.instantiate(this, SavedFragment.class.getName()));
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager(), fragments);
mViewPager = (ViewPager) findViewById(R.id.lobby_pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
}
#Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) {
mViewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction ft) {
}
#Override
public void onTabReselected(ActionBar.Tab tab, FragmentTransaction ft) {
}
public class SectionsPagerAdapter extends FragmentPagerAdapter {
private List<Fragment> fragments;
public SectionsPagerAdapter(FragmentManager fm, List<Fragment> fragments) {
super(fm);
this.fragments = fragments;
}
#Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a fragment in the fragment container
return this.fragments.get(position);
}
#Override
public int getCount() {
// Show 3 total pages.
return this.fragments.size();
}
#Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return "MAP VIEW";
case 1:
return "YANK LIST";
case 2:
return "SAVED YANKS";
}
return null;
}
}
}
and I have 3 fragment classes, they're almost the same, so I just show the map fragment:
public class MapFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle saveInstanceState) {
if (container == null)
return null;
return inflater.inflate(R.layout.fragment_lobby_map, container, false);
}
}
And below is the layout for the main activity:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.view.ViewPager
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/lobby_pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
layout for map fragment:
<?xml version="1.0" encoding="utf-8"?>
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:name="com.google.android.gms.maps.MapFragment"/>
The other two layouts for the remaining 2 fragments are just a linearLayout containing a textview.
When the app crashes, I get
05-12 12:05:18.963 147-227/? W/MemoryDealer﹕ madvise(0x423c3000, 16384, MADV_REMOVE) returned Operation not supported on transport endpoint
05-12 12:05:18.963 9173-9173/com.yankteam.yank.app W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0x40cf2390)
Thanks a lot for reading this.

I found this answer to call viewPager.setOffscreenPageLimit(3); and its working for me nicely.

Android: "Navigation Type: Fixed Tabs + Swipe"

I'm trying to use Tabs + Swipe in an App and want to use the Navigation Type "Fixed Tabs + Swipe" which the ADT provides me when creating an Activity.
Sooo now the ADT spits out nice Code, which I slightly modified...
I completely understand the code and what's going on... But how can I teach the App to use my three Fragments instead of the stupid Dummy Frag? :(
I cannot find any tutorial which deals with the ADTs "Navigation Types"...
Thanks for your help!
public class MainActivity extends FragmentActivity implements ActionBar.TabListener {
SectionsPagerAdapter mSectionsPagerAdapter;
ViewPager mViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Set up the action bar.
final ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Create the adapter that will return a fragment for each of the three
// primary sections of the app.
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
// When swiping between different sections, select the corresponding
// tab. We can also use ActionBar.Tab#select() to do this if we have
// a reference to the Tab.
mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
#Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
});
//Adding Tabs
actionBar.addTab(actionBar.newTab().setText("Tab 1").setTabListener(this));
actionBar.addTab(actionBar.newTab().setText("Tab 2").setTabListener(this));
actionBar.addTab(actionBar.newTab().setText("Tab 3").setTabListener(this));
}
#Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
// When the given tab is selected, switch to the corresponding page in
// the ViewPager.
mViewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(ActionBar.Tab tab,FragmentTransaction fragmentTransaction) {
}
#Override
public void onTabReselected(ActionBar.Tab tab,FragmentTransaction fragmentTransaction) {
}
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a DummySectionFragment (defined as a static inner class
// below) with the page number as its lone argument.
Fragment fragment = new DummySectionFragment();
Bundle args = new Bundle();
args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
fragment.setArguments(args);
return fragment;
}
#Override
public int getCount() {
// Show 3 total pages.
return 3;
}
}
public static class DummySectionFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
public static final String ARG_SECTION_NUMBER = "section_number";
public DummySectionFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main_dummy,container, false);
TextView dummyTextView = (TextView) rootView.findViewById(R.id.section_label);
dummyTextView.setText(Integer.toString(getArguments().getInt(ARG_SECTION_NUMBER)));
return rootView;
}
}
}

a switch-case to set the fragments is easy and makes it really clear. Let each of your fragment inflate the root view in your xml
#Override
public Fragment getItem(int index) {
Fragment fragment = null;
switch(index){
case 0:
fragment = new Fragment1();
break;
case 1:
fragment = new Fragment2();
break;
case 2:
fragment = new Fragment3();
break;
default:
break;
}
//set args if necessary (which it isn't?)
Bundle args = new Bundle();
args.putInt(ObjectFragment.ARG_OBJECT, index + 1);
fragment.setArguments(args);
//return fragment
return fragment;
}

But how can I teach the App to use my three Fragments instead of the stupid Dummy Frag?
You will notice that DummySectionFragment is referenced in getItem() of the SectionsPagerAdapter:
#Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a DummySectionFragment (defined as a static inner class
// below) with the page number as its lone argument.
Fragment fragment = new DummySectionFragment();
Bundle args = new Bundle();
args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
fragment.setArguments(args);
return fragment;
}
If you want to use different fragments, modify getItem() to return the fragment you want, given the supplied position (0-based page number).

(ActionBar) Tabs + Pager + detail Fragments inside ViewPager container

For ActionBarSherlock I would like to have (Action Bar) Tabs + Pager. I use Fragments inside that pager container. I already got the examples of http://actionbarsherlock.com/ working, but I can't manage to get a details fragment inside that pager container when I would click on let's say a listitem in the first fragment.
Is it impossible to have something like this:
Activity with Tabs and pager container
Fragment A inside pager container under Tab1
Click on something in Fragment A and show Fragment B in same pager container under Tab1.
Fragment A is then not visible, only Fragment B is visible, but also all the Tabs.
At the moment I think only a new activity (which would hold Fragment B inside it) can be started after clicking something in Fragment A.

Here is my solution for the (Tabs + Fragment + ViewPager) it is works for me as i wanted,
hope that works for you as well
here is the xml file
<LinearLayout
android:id="#+id/linearLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" >
<android.support.v4.view.ViewPager
android:id="#+id/pager"
android:layout_width="0dip"
android:layout_height="match_parent"
android:layout_weight="5" />
<FrameLayout
android:id="#+id/fragment_details"
android:layout_width="0px"
android:layout_height="match_parent"
android:layout_weight="4.3" />
</LinearLayout>
here is the code for MainActivity.java I'll post relevant code only so you'll have to manage it
public class MainActivity extends FragmentActivity implements
DialogInterface.OnDismissListener, TabDataResponder {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
getSupportActionBar().setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
artistTab = getSupportActionBar().newTab().setText(
R.string.tab_name_artist);
albumTab = getSupportActionBar().newTab().setText(
R.string.tab_name_album);
songTab = getSupportActionBar().newTab().setText(
R.string.tab_name_songs);
map = new HashMap<String, Integer>();
mViewPager = (ViewPager) findViewById(R.id.pager);
FrameLayout deatil = (FrameLayout) findViewById(R.id.fragment_details);
mDualPane = (deatil != null) && (deatil.getVisibility() == View.VISIBLE);
mTabsAdapter = new TabsAdapter(this, getSupportActionBar(), mViewPager);
if (savedInstanceState != null) {
flag = true;
index = savedInstanceState.getInt("index");
}
setUpTabView();
}
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt("index", getSupportActionBar()
.getSelectedNavigationIndex());
}
private void setUpTabView() {
mTabsAdapter.addTab(artistTab, ArtistFragment.class, null);
mTabsAdapter.addTab(albumTab, AlbumFragment.class, null);
mTabsAdapter.addTab(songTab, SongFragment.class, null);
getSupportActionBar().setSelectedNavigationItem(index);
}
public static class TabsAdapter extends FragmentPagerAdapter implements
ViewPager.OnPageChangeListener, ActionBar.TabListener {
private FragmentActivity mContext;
private ActionBar mActionBar;
private final ViewPager mViewPager;
private final ArrayList<String> mTabs = new ArrayList<String>();
private TabDataResponder responder;
public TabsAdapter(FragmentActivity activity, ActionBar actionBar,
ViewPager pager) {
super(activity.getSupportFragmentManager());
mContext = activity;
mActionBar = actionBar;
mViewPager = pager;
// TabDataResponder is an interface which is implemented in MainActivity
// You can find implementation # the last
responder = (TabDataResponder) activity;
mViewPager.setAdapter(this);
mViewPager.setOnPageChangeListener(this);
//I have used map to save state of the fragment
map.put(SongFragment.TYPE_FRAGMENT.trim(), 0);
map.put(AlbumFragment.TYPE_FRAGMENT.trim(), 0);
map.put(ArtistFragment.TYPE_FRAGMENT.trim(), 0);
}
public void addTab(ActionBar.Tab tab, Class<?> clss, Bundle args) {
mTabs.add(clss.getName());
// mArgs.add(args);
mActionBar.addTab(tab.setTabListener(this));
notifyDataSetChanged();
}
#Override
public int getCount() {
return mTabs.size();
}
#Override
public Fragment getItem(int position) {
return Fragment
.instantiate(mContext, mTabs.get(position), /*
* mArgs.get(
* position)
*/null);
}
#Override
public void onPageScrolled(int position, float positionOffset,
int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
Log.i(TAG, "PageSelected....");
mActionBar.setSelectedNavigationItem(position);
}
#Override
public void onPageScrollStateChanged(int state) {
Log.i(TAG, "ScrollSateChanged....");
}
#Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}
#Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
mViewPager.setCurrentItem(tab.getPosition());
String a = null;
if (mDualPane) {
a = mTabs.get(tab.getPosition());
responder.loadData(a, map.get(a));
}
}
#Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
Log.i(TAG, "Tab is released now....");
}
}
#Override
public void onDismiss(DialogInterface dialog) {
setUpTabView();
}
//This interface must be call from fragment class
//# the time of event you want to show detail
// pass the class name in the type argument using class.getName() method
#Override
public void loadData(String type, int index) {
DetailFragment viewer = (DetailFragment) getSupportFragmentManager()
.findFragmentById(R.id.fragment_details);
if (mDualPane) {
if (viewer == null || viewer.getShownIndex() != index
|| viewer.getTypeFragment() != type) {
DetailFragment df = DetailFragment.newInstance(index, type);
getSupportFragmentManager()
.beginTransaction()
.replace(R.id.fragment_details, df)
.setTransition(
FragmentTransaction.TRANSIT_FRAGMENT_FADE)
.commit();
map.put(type.trim(), index);
}
} else {
Intent intent = new Intent();
intent.setClass(MainActivity.this, DetailActivity.class);
intent.putExtra("index", index);
intent.putExtra("type", type);
startActivity(intent);
}
}
}
and here is how i deal with detail fragment not very efficient but kind of working
public class DetailFragment extends Fragment{
public static DetailFragment newInstance(int index, String TYPE_FRAGMENT) {
DetailFragment f = new DetailFragment();
// Supply index input as an argument.
Bundle args = new Bundle();
args.putInt("index", index);
args.putString("type", TYPE_FRAGMENT);
f.setArguments(args);
return f;
}
public int getShownIndex() {
return getArguments().getInt("index", 0);
}
public String getTypeFragment(){
String a = getArguments().getString("type");
return a;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
//template is blank layout
View view = inflater.inflate(R.layout.template, container, false);
if(getTypeFragment().equals(ArtistFragment.TYPE_FRAGMENT)){
view = null;
view = inflater.inflate(R.layout.artist_details, container, false);
//....
}
else if(getTypeFragment().equals(AlbumFragment.TYPE_FRAGMENT)){
//do's for album fragment
}
else if(getTypeFragment().equals(SongFragment.TYPE_FRAGMENT)){
//do's for song fragment
}
return view;
}
}
do not save the state of tab in their individual fragment it will conflict, we are already doing it here

EDIT:
Cheered too soon. Now the details_container is not a viewpager and I cannot use it to 'swipe tabs'.
Found it! Just had to define two FrameLayouts, with in the first one the ViewPager and in the second the details fragments can be 'loaded'. This is done by adding fragments dynamically and replace them.
First the two FrameLayouts:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:fadingEdge="none" >
<FrameLayout
android:id="#+id/main_container"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<android.support.v4.view.ViewPager
android:id="#+id/pager"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />
</FrameLayout>
<FrameLayout
android:id="#+id/details_container"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</RelativeLayout>
Then replace a fragment dynamically:
// Create new fragment and transaction
Fragment detailsFragment = 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
transaction.replace(R.id.details_container, detailsFragment);
transaction.addToBackStack(null);
// Commit the transaction
transaction.commit();
Very simple and I don't understand why it took me hours to figure this out..

I still did not find a possibility to have a Pager container where fragments should be loaded in and also keep the (ActionBar) Tabs. I have however found a really dirty solution to acomplish this, with starting intens (Main Activity with the Tabs) and finishing the previous ones when the backbutton doesn't need it anymore.
I adapted the code from ABS: Support Demos - Tabs and Pager. But again it's really dirty:
LoaderCursorSupport.CursorLoaderListFragment under Tab2
#Override public void onListItemClick(ListView l, View v, int position, long id) {
Intent intent = new Intent();
intent.setClass(getActivity(), ActionBarTabsPager.class);
intent.putExtra("index", position);
intent.putExtra("fragment", "details");
intent.putExtra("tab", 1);
ActionBarTabsPager.mPreviousActivity = getActivity();
startActivity(intent);
ActionBarTabsPager (Main Activity with Tabs)
public class ActionBarTabsPager extends FragmentActivity {
ViewPager mViewPager;
TabsAdapter mTabsAdapter;
static Activity mPreviousActivity;
static Activity mActivity;
static int mTabPosition = -1;
static Boolean mTabRefreshed = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.actionbar_tabs_pager);
getSupportActionBar().setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
ActionBar.Tab tab1 = getSupportActionBar().newTab().setText("Tab 1");
ActionBar.Tab tab2 = getSupportActionBar().newTab().setText("Tab 2");
ActionBar.Tab tab3 = getSupportActionBar().newTab().setText("Tab 3");
ActionBar.Tab tab4 = getSupportActionBar().newTab().setText("Tab 4");
String fragment = "";
try {
Bundle bundle = this.getIntent().getExtras();
fragment = bundle.getString("fragment");
mTabPosition = bundle.getInt("tab");
} catch (Exception ex) {
}
mViewPager = (ViewPager) findViewById(R.id.pager);
mTabsAdapter = new TabsAdapter(this, getSupportActionBar(), mViewPager);
mTabsAdapter.addTab(tab1, FragmentStackSupport.CountingFragment.class);
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.ECLAIR) {
mTabsAdapter.addTab(tab2, FragmentStackSupport.CountingFragment.class);
mTabsAdapter.addTab(tab3, FragmentStackSupport.CountingFragment.class);
mTabsAdapter.addTab(tab4, FragmentStackSupport.CountingFragment.class);
} else {
if (!fragment.contains("details")) {
mTabsAdapter.addTab(tab2, LoaderCursorSupport.CursorLoaderListFragment.class);
} else {
mTabsAdapter.addTab(tab2, ExampleFragment.class);
}
mTabsAdapter.addTab(tab3, LoaderCustomSupport.AppListFragment.class);
mTabsAdapter.addTab(tab4, LoaderThrottleSupport.ThrottledLoaderListFragment.class);
}
if (savedInstanceState != null) {
getSupportActionBar().setSelectedNavigationItem(savedInstanceState.getInt("index"));
}
if (mTabPosition > -1) {
mTabsAdapter.setPrimaryItem(mTabPosition);
mActivity = this;
}
}
Inside this Class there's a TabsAdapter
public static class TabsAdapter extends FragmentPagerAdapter implements ViewPager.OnPageChangeListener, ActionBar.TabListener {
private final Context mContext;
private final ActionBar mActionBar;
private final ViewPager mViewPager;
private final ArrayList<String> mTabs = new ArrayList<String>();
#Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
if (mTabPosition > -1 && mTabRefreshed) {
int tabPosition = tab.getPosition();
if (mTabPosition != tabPosition) {
if (mPreviousActivity != null) {
mPreviousActivity.finish();
mTabRefreshed = false;
mPreviousActivity = null;
mTabPosition = -1;
Intent intent = new Intent();
intent.setClass(mContext, ActionBarTabsPager.class);
intent.putExtra("fragment", "home");
intent.putExtra("tab", tabPosition);
mActivity.startActivity(intent);
mActivity.finish();
}
}
}
mViewPager.setCurrentItem(tab.getPosition());
}
Can this be done simpler? Or should I just give up on having Tabs together with fragment history? This was done before Android 3.0 with ActivityGroups and Activities, but it seems this can't be done with fragments.

I found the other good example of the same implementation in hear... https://github.com/UweTrottmann/SeriesGuide
In this example under package com.battlelancer.seriesguide.ui
you can find UpcomingRecentActivity.java, and UpcomingFragment.java
and layout upcoming_multipan.xml
this example works for me...
I got one problem while adding different content for detail-fragment the different tabs, it gives me class-cast-exception
so i implemented a common detalFragment class and created separate layout in onCreateView method
but the only one problem i found is layout is not changing on tab switched, may be need to do it by implementing some listener
I'll tell you when i found the answer.