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Changing tabs of TabLayout programmatically but fragments of ViewPager is not updated

I am developing an Android app. In my app, I am using TabLayout with ViewPager. I need to update the Tabs of TabLayout and its fragments programmatically when an item at the bottom navigation bar is selected. I can update the tabs of TabLayout. But the fragments of pager are not updated.
This is the issue:
As you can see in the above, tabs are changed but its fragments are not changed. List Fragment is always displayed. All the fragments are just the same with the first tab selected. I mean fragments are not changing at all.
This is my XML file for the tabs and view pager:
<android.support.design.widget.AppBarLayout android:layout_height="wrap_content"
android:layout_width="match_parent" android:theme="#style/AppTheme.AppBarOverlay">
<android.support.design.widget.TabLayout
android:id="#+id/ma_tab_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabGravity="fill"
app:tabMode="fixed" />
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
app:layout_behavior="#string/appbar_scrolling_view_behavior"
android:id="#+id/ma_viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
This is my whole activity:
public class MainActivity extends AppCompatActivity {
private BottomBar bottomBar;
private TabLayout topTabLayout;
private ViewPager mainViewPager;
private MainPagerAdapter pagerAdapter;
private ArrayList<Fragment> pagerFragments;
private ArrayList<String> pagerTitleList;
protected TfrApplication app;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
app = (TfrApplication)getApplication();
setContentView(R.layout.activity_main);
initialize();
initViews();
setUpViews();
}
private void initialize()
{
pagerFragments = new ArrayList<Fragment>();
pagerTitleList = new ArrayList<String>();
}
private void initViews()
{
bottomBar = (BottomBar)findViewById(R.id.ma_bottom_action_bar);
mainViewPager = (ViewPager)findViewById(R.id.ma_viewpager);
topTabLayout = (TabLayout)findViewById(R.id.ma_tab_layout);
}
private void setUpViews()
{
pagerAdapter = new MainPagerAdapter(getSupportFragmentManager(),pagerFragments,pagerTitleList);
mainViewPager.setAdapter(pagerAdapter);
topTabLayout.setupWithViewPager(mainViewPager);
setUpBottomBar();
}
private void clearPagerFragments()
{
if(pagerAdapter!=null && pagerFragments!=null && pagerFragments.size()>0)
{
pagerFragments.removeAll(pagerFragments);
pagerTitleList.removeAll(pagerTitleList);
pagerAdapter.notifyDataSetChanged();
}
}
private void setUpNewsPagerFragments()
{
NewsFragment latestNewsFragment = new NewsFragment();
Bundle latestNewsBundle = new Bundle();
latestNewsBundle.putInt(NewsFragment.FIELD_CATEGORY_ID,0);
latestNewsBundle.putInt(NewsFragment.FIELD_LEAGUE_ID,0);
latestNewsBundle.putInt(NewsFragment.FIELD_COUNTRY_ID,0);
latestNewsBundle.putInt(NewsFragment.FIELD_TEAM_ID,0);
latestNewsFragment.setArguments(latestNewsBundle);
pagerTitleList.add("LATEST");
pagerFragments.add(latestNewsFragment);
PrioritizedTeamsFragment teamsFragment = new PrioritizedTeamsFragment();
pagerTitleList.add("TEAMS");
pagerFragments.add(teamsFragment);
NewsFragment articlesFragment = new NewsFragment();
Bundle articlesBundle = new Bundle();
articlesBundle.putInt(NewsFragment.FIELD_CATEGORY_ID, 0);
articlesBundle.putInt(NewsFragment.FIELD_LEAGUE_ID, 0);
articlesBundle.putInt(NewsFragment.FIELD_COUNTRY_ID, 0);
articlesBundle.putInt(NewsFragment.FIELD_TEAM_ID, 0);
articlesFragment.setArguments(articlesBundle);
pagerTitleList.add("ARTICLES");
pagerFragments.add(articlesFragment);
TopFragment topFragment = new TopFragment();
pagerTitleList.add("TOP 10");
pagerFragments.add(topFragment);
}
private void setUpMatchesPagerFragments()
{
MatchesFragment matchesFragment = new MatchesFragment();
pagerTitleList.add("MATCHES");
pagerFragments.add(matchesFragment);
StatisticsFragment statisticsFragment = new StatisticsFragment();
pagerTitleList.add("STATISTICS");
pagerFragments.add(statisticsFragment);
}
private void setUpBottomBar()
{
bottomBar.setOnTabSelectListener(new OnTabSelectListener() {
#Override
public void onTabSelected(int tabId) {
switch (tabId){
case R.id.bottom_tab_news:
clearPagerFragments();
setUpNewsPagerFragments();
pagerAdapter.notifyDataSetChanged();
break;
case R.id.bottom_tab_matches:
clearPagerFragments();
setUpMatchesPagerFragments();
pagerAdapter.notifyDataSetChanged();
topTabLayout.getTabAt(0).select();
break;
case R.id.bottom_tab_meme:
Toast.makeText(getBaseContext(),"MEME",Toast.LENGTH_SHORT).show();
break;
case R.id.bottom_tab_settings:
Toast.makeText(getBaseContext(),"Settings",Toast.LENGTH_SHORT).show();
break;
}
}
});
}
}
I showed the whole activity because code the whole activity dealing with that problem. Besides, the whole activity only contains code for creating tabs, view pager and bottom bar. All are connected.
This is my view pager adapter:
public class MainPagerAdapter extends FragmentPagerAdapter {
private ArrayList<Fragment> fragmentList;
private ArrayList<String> titleList;
public MainPagerAdapter(FragmentManager fragmentManager,ArrayList<Fragment> fragmentsParam,ArrayList<String> titlesParam)
{
super(fragmentManager);
this.fragmentList = fragmentsParam;
this.titleList = titlesParam;
}
#Override
public int getCount() {
return fragmentList.size();
}
#Override
public Fragment getItem(int position) {
return fragmentList.get(position);
}
#Override
public CharSequence getPageTitle(int position) {
return titleList.get(position);
}
}
Why is the content or fragments of view pager are not changed when tabs are changed? What is wrong with my code?
As you can see on bottom item selected listener I tried to set the selected fragment like this:
topTabLayout.getTabAt(0).select();
I tried this as well:
mainViewPager.setCurrentItem(0);
Both are not working.

try to add a method to swap the fragment-list and call notifyDataSetChanged() in your adapter like this:
public void notifyDataSetChanged(List<Fragment> list) {
fragmentList.removeAll();
fragmentList.addAll(list);
notifyDataSetChanged();
}
changing data in activity and call adapter.notifyDataSetChanged() may fail to update your view.You can log in getItem() to check if the adapter knows the data set has changed.

Just Check which layout you are inflating in MatchesFragment class.
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
v = inflater.inflate(R.layout.matches_fragment, container, false);
}

If your tab is set correctly, under the code where the tab is set, run this again:
mainViewPager.setAdapter(pagerAdapter);
Here is my code:
selectedTab = 0;
tabLayout.getTabAt(selectedTab).select();
viewPager.setAdapter(tabsAdapter);

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.

I want to add fragments to each corresponding actionbar tab at the same time

UPDATE : I don't understand why when tapping on each tab onTabSelected() doesn't show the correct fragment even though it's been added to the fragmentTransaction android.R.id.content.
I call this method before onTabSelected gets called to make sure fragments are not null.
protected void initTabs() {
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
if(mShowFragment3 == null) {
mShowFragment3 = EpisodeTileFragment.newInstance(getString(R.string.title_section4));
ft.add(android.R.id.content, mShowFragment3);
}
if(mShowFragment2 == null) {
mShowFragment2 = EpisodeTileFragment.newInstance(getString(R.string.title_section3));
ft.add(android.R.id.content, mShowFragment2);
}
}
#Override
public void onTabSelected(ActionBar.Tab tab,
FragmentTransaction ft) {
//this usually works, but if i try to mess with adding the tabs to the
//FragmentTransaction this won't work anymore
if(tab.getPosition() == 1) {
ft.show(mShowFragment2);
}
I have scoured the internet and this may not be possible but I wanted to give this a shot.
I currently have the app working fine, it has 4 tabs and 4 corresponding fragments. When a user opens the app onTabSelected is called and selects the first tab/fragment is added and we're all good.
A user clicks tab2 and the 2nd fragment is added and rendered. When a user clicks the 2nd tab there is an asynctask that gets data and renders this on a fragment. Etc.. this happens on tab 3 and 4 also. When a user clicks a tab the first time I instantiate the fragment and add it to the fragmentTransaction, the next time you click on the tab it's lightning fast because it's already added, and I'm hiding and showing fragments.
The question I have is , is there a way to load up all 4 tabs at the same time, vs. waiting for a user to click on a tab and then have onTabSelected firing and grabbing data etc. Please let me know if there is any questions, the code is working with no errors just not what I want, and I don't know how to instantiate all 4 fragments at the same time.
mSectionsPagerAdapter = new SectionsPagerAdapter(this.getSupportFragmentManager());
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
LayoutInflater inflater = LayoutInflater.from(getApplicationContext());
View tabView = inflater.inflate(R.layout.tab_title, null);
TextView titleTV = (TextView) tabView.findViewById(R.id.action_custom_title);
titleTV.setText(mSectionsPagerAdapter.getPageTitle(i));
titleTV.setTypeface(Typeface.createFromAsset(getAssets(), getString(R.string.tab_font)));
titleTV.setSingleLine();
titleTV.setTextSize(13);
Tab t = actionBar.newTab()
.setText(mSectionsPagerAdapter.getPageTitle(i))
.setTabListener(this);
t.setCustomView(tabView);
actionBar.addTab(t);
}
this is for adding the tabs. but need to add the fragments for each tab.

Set the offscreen page limit to your number of tabs, and then your ViewPager will render all the fragments when the parent activity is created.
mViewPager.setOffscreenPageLimit(4);
You should also check out the Class Overview of ViewPager, which has a really good example of using a custom FragmentPagerAdapter called TabsAdapter with a ViewPager (instead of using the ADT generated SectionsPagerAdapter). I added the code from the official Android docs below:
public class ActionBarTabsPager extends Activity {
ViewPager mViewPager;
TabsAdapter mTabsAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mViewPager = new ViewPager(this);
mViewPager.setId(R.id.pager);
setContentView(mViewPager);
final ActionBar bar = getActionBar();
bar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
bar.setDisplayOptions(0, ActionBar.DISPLAY_SHOW_TITLE);
mTabsAdapter = new TabsAdapter(this, mViewPager);
mTabsAdapter.addTab(bar.newTab().setText("Simple"),
CountingFragment.class, null);
mTabsAdapter.addTab(bar.newTab().setText("List"),
FragmentPagerSupport.ArrayListFragment.class, null);
mTabsAdapter.addTab(bar.newTab().setText("Cursor"),
CursorFragment.class, null);
if (savedInstanceState != null) {
bar.setSelectedNavigationItem(savedInstanceState.getInt("tab", 0));
}
}
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt("tab", getActionBar().getSelectedNavigationIndex());
}
/**
* This is a helper class that implements the management of tabs and all
* details of connecting a ViewPager with associated TabHost. It relies on a
* trick. Normally a tab host has a simple API for supplying a View or
* Intent that each tab will show. This is not sufficient for switching
* between pages. So instead we make the content part of the tab host
* 0dp high (it is not shown) and the TabsAdapter supplies its own dummy
* view to show as the tab content. It listens to changes in tabs, and takes
* care of switch to the correct paged in the ViewPager whenever the selected
* tab changes.
*/
public static class TabsAdapter extends FragmentPagerAdapter
implements ActionBar.TabListener, ViewPager.OnPageChangeListener {
private final Context mContext;
private final ActionBar mActionBar;
private final ViewPager mViewPager;
private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>();
static final class TabInfo {
private final Class<?> clss;
private final Bundle args;
TabInfo(Class<?> _class, Bundle _args) {
clss = _class;
args = _args;
}
}
public TabsAdapter(Activity activity, ViewPager pager) {
super(activity.getFragmentManager());
mContext = activity;
mActionBar = activity.getActionBar();
mViewPager = pager;
mViewPager.setAdapter(this);
mViewPager.setOnPageChangeListener(this);
}
public void addTab(ActionBar.Tab tab, Class<?> clss, Bundle args) {
TabInfo info = new TabInfo(clss, args);
tab.setTag(info);
tab.setTabListener(this);
mTabs.add(info);
mActionBar.addTab(tab);
notifyDataSetChanged();
}
#Override
public int getCount() {
return mTabs.size();
}
#Override
public Fragment getItem(int position) {
TabInfo info = mTabs.get(position);
return Fragment.instantiate(mContext, info.clss.getName(), info.args);
}
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
mActionBar.setSelectedNavigationItem(position);
}
#Override
public void onPageScrollStateChanged(int state) {
}
#Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
Object tag = tab.getTag();
for (int i=0; i<mTabs.size(); i++) {
if (mTabs.get(i) == tag) {
mViewPager.setCurrentItem(i);
}
}
}
#Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
}
#Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}
}
}

Android tabs implemented with Fragments and ViewPager

My application has 3 tabs, each represented by Fragments. There is a custom FragmentPagerAdapter which also implements ActionBar.TabListener. Initially my FragmentPagerAdapter was returning new instances of fragments in public Fragment getItem(int index) method. Also, my TabListener implementation was instantiating Fragments and showing/hiding them in the onTabSelected/onTabUnselected. Unfortunately this approach doesn't fit me well, because in this case each Fragment is actually created twice. What I want is to create it once and then just hide/show, when necessary.
For that I have instantiated my fragment earlier in the activity and passed them to the PagerAdapter:
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_tabs_layout);
List<Fragment> fragments = initTabFragments();
ViewPager viewPager = (ViewPager) findViewById(R.id.pager);
final ActionBar actionBar = getSupportActionBar();
TabsPagerAdapter pagerAdapter = new TabsPagerAdapter(this, getSupportFragmentManager(), fragments, viewPager);
viewPager.setAdapter(pagerAdapter);
actionBar.setHomeButtonEnabled(false);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
for (int tab_name : tabs) {
Tab tab = actionBar.newTab();
actionBar.addTab(tab.setText(tab_name).setTabListener(pagerAdapter));
}
...
}
private List<Fragment> initTabFragments() {
List<Fragment> fragments = new ArrayList<Fragment>(3);
fragments.add(SherlockFragment.instantiate(this, TabFragment1.class.getName()));
fragments.add(SherlockFragment.instantiate(this, TabFragment2.class.getName()));
fragments.add(SherlockFragment.instantiate(this, TabFragment3.class.getName()));
return fragments;
}
Then in the PagerAdapter I just return fragment:
#Override
public Fragment getItem(int index) {
return fragments.get(index);
}
To handle Tab selection there is the following code:
#Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
int position = tab.getPosition();
String tag = "android:switcher:" + viewPagerId + ":" + position;
Fragment fragment = context.getSupportFragmentManager().findFragmentByTag(tag);
switch (position) {
case 0:
if (fragment == null) {
ft.add(viewPagerId, fragments.get(0), tag);
} else {
// If it exists, simply attach it in order to show it
ft.show(fragments.get(0));
}
break;
}
case 1:
if (fragment == null) {
ft.add(viewPagerId, fragments.get(1), tag);
} else {
// If it exists, simply attach it in order to show it
ft.show(fragments.get(1));
}
break;
}
}
#Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
switch (tab.getPosition()) {
case 0:
ft.hide(fragments.get(0));
break;
case 1:
ft.hide(fragments.get(1));
break;
}
}
In this case each fragment is instantiated once. And the first tab is shown correctly, but when I switch between tabs second and third tabs are empty (just white background). Why?
I was trying to add fragment to a container android.R.id.content, but exception was thrown: Can't change container ID of fragment.... I found out that it is because when Fragment is returned in getItem method it is added to a viewPager container. That why I use viewPagerId when add fragment to a transaction.
Any help would be greatly appreciated.

Have a ExampleFragment class defined that extends Fragment. Something like shown below
public class ExampleFragment extends Fragment {
private View categoryView;
private ViewPager mViewPager;
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
categoryView = inflater.inflate(R.layout.viewpager, container, false);
mViewPager = (ViewPager) categoryView.findViewById(R.id.pager);
return categoryView;
}
public ViewPager returnViewPager() {
return mViewPager;
}
}
main_fragment.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
tools:context=".ExampleFragmentActivity" >
<fragment
android:id="#+id/main_fragment"
android:name="somepackage.ExampleFragment"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
</RelativeLayout>
And then add this in the onCreate() of ExampleFragmentActivity
ExampleFragment fragment = (ExampleFragment) getSupportFragmentManager().findFragmentById(R.id.main_fragment);
mViewPager = fragment.returnViewPager();
fragmentManager = getSupportFragmentManager();

How to use SherlockFragmentActivity with SlidingMenu?

Am using SlidingMenu which uses different types of Fragment/SherlockFragment as menu.
Am in need of SherlockFragmentActivity, as I am using Tabs inside menu.
How to use SherlockFragmentActivity with SlidingMenu?
If it's not possible, is there any other library through which I can have sliding menu & tabs inside sliding menu? Am not sure if it can be achieved using android-menudrawer
Edit : want to achieve the below. ie, Tabs inside Menu
when menu button is clicked, menu Fragment is opened, inside Menufragment I want to add tabs.
   

EDIT:
I wanted to take this design as a challenge and see what is the result:
As I suggested in the comments, I used PagerSlidingTabStrip andViewPager.
I did not include the ActionBarSherlock, but if needed that will be easy to modify: the MainActivity will be required to extend from SherlockFragmentActivity, and the theme #style/Theme.Sherlock.Light added to manifest file, and that is all.
(Just to be sure you got the idea, PagerSlidingTabStrip is the one who creates the tabs at the bottom)
Here are the steps I took to integrate PagerSlidingTabStrip and ViewPager with SlidingMenu:
1 - Import SlidingMenu library into Eclipse workspace
2 - Import PagerSlidingTabStrip library into Eclipse workspace
3 - Add Android Support Library to your project (and copy the same .jar into SlidingMenu and PagerSlidingTabString libraries, otherwise eclipse might complain)
4 - A minimal example of MainActivity:
public class MainActivity extends FragmentActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
SlidingMenu menu = new SlidingMenu(this);
menu.setTouchModeAbove(SlidingMenu.TOUCHMODE_FULLSCREEN);
menu.setBehindOffset(50);
menu.setFadeDegree(0.35f);
menu.attachToActivity(this, SlidingMenu.SLIDING_CONTENT);
menu.setMenu(R.layout.left_menu);
ViewPager pager = (ViewPager) findViewById(R.id.pager);
pager.setAdapter(new ViewPagerAdapter(getSupportFragmentManager()));
PagerSlidingTabStrip tabs = (PagerSlidingTabStrip) findViewById(R.id.tabs);
tabs.setViewPager(pager);
}
}
5 - The layout of sliding menu, R.layout.left_menu:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/left_menu"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#CCC"
android:orientation="vertical" xmlns:app="http://schemas.android.com/apk/res/org.grec">
<com.astuetz.viewpager.extensions.PagerSlidingTabStrip
android:id="#+id/tabs"
app:shouldExpand="true"
android:layout_width="match_parent"
android:layout_alignParentBottom="true"
android:layout_height="48dip" />
<android.support.v4.view.ViewPager
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="#id/tabs" />
</RelativeLayout>
6 - The ViewPagerAdapter:
public class ViewPagerAdapter extends FragmentStatePagerAdapter {
private final int PAGES = 3;
private String[] titles={"Tab 1", "Tab 2", "Tab 3"};
public ViewPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return new TabFragment1();
case 1:
return new TabFragment2();
case 2:
return new TabFragment3();
default:
throw new IllegalArgumentException("The item position should be less or equal to:" + PAGES);
}
}
#Override
public CharSequence getPageTitle(int position) {
return titles[position];
}
#Override
public int getCount() {
return PAGES;
}
}
7 - And an example of fragment, TabFragment1.java (the other 2 are similar):
public class TabFragment1 extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_tab_1, container, false);
}
}
8 - And the layout of the fragment R.layout.fragment_tab_1 which is pretty simple, it contains a single TextView, so I won't include it here.
I hope this example addresses your issue and will help you getting started on the right track.
Full source on github: https://github.com/vgrec/SlidingMenuWithViewpager

1) Add SherlockActionBar library to SlidingMenu
2) Change SlidingFragmentActivity extends FragmentActivity to SlidingFragmentActivity extends SherlockFragmentActivity
3) Then add SlidingMenu library to your project and your project should use MyProjectActivity extends SlidingFragmentActivity
You can use SherlockActionBar to create sliding menu with tabs inside
Here sample code to create Tab with view pager
For sliding, you can look at their documentation
public static class TabsAdapter extends FragmentPagerAdapter implements ActionBar.TabListener, ViewPager.OnPageChangeListener {
private final Context mContext;
private final ActionBar mActionBar;
private final ViewPager mViewPager;
private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>();
static final class TabInfo {
private final Class<?> clss;
private final Bundle args;
TabInfo(Class<?> _class, Bundle _args) {
clss = _class;
args = _args;
}
}
public TabsAdapter(SherlockFragmentActivity activity, ViewPager pager) {
super(activity.getSupportFragmentManager());
mContext = activity;
mActionBar = activity.getSupportActionBar();
mViewPager = pager;
mViewPager.setAdapter(this);
mViewPager.setOnPageChangeListener(this);
}
public void addTab(ActionBar.Tab tab, Class<?> clss, Bundle args) {
TabInfo info = new TabInfo(clss, args);
tab.setTag(info);
tab.setTabListener(this);
mTabs.add(info);
mActionBar.addTab(tab);
notifyDataSetChanged();
}
#Override
public int getCount() {
return mTabs.size();
}
#Override
public Fragment getItem(int position) {
TabInfo info = mTabs.get(position);
return Fragment.instantiate(mContext, info.clss.getName(), info.args);
}
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
mActionBar.setSelectedNavigationItem(position);
}
#Override
public void onPageScrollStateChanged(int state) {
}
public void onTabSelected(Tab tab, FragmentTransaction ft) {
Object tag = tab.getTag();
for (int i = 0; i < mTabs.size(); i++) {
if (mTabs.get(i) == tag) {
mViewPager.setCurrentItem(i);
}
}
}
#Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
}
#Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}
}
mViewPager = new ViewPager(this);
mViewPager.setId(R.id.pager);
setContentView(mViewPager);
ab.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
mTabsAdapter = new TabsAdapter(this, mViewPager);
mTabsAdapter.addTab(ab.newTab().setText("tab1"), FirstFragment.class, null);
mTabsAdapter.addTab(ab.newTab().setText("tab2"), SecondFragment.class, null);
mTabsAdapter.addTab(ab.newTab().setText("tab3"), ThirdFragment.class, null);

As what you have said the SlidingMenu uses fragments and you want to to have Tabs inside a Menu. For me, using Tabs inside a Menu needs nested fragments which means that you can't use SherlockFragmentActivity since it is like the Main Activity. You can't contain an Activity inside a fragment.
I have not implemented this kind of approach but maybe you can try implementing TabListener inside a fragment.
I am using this code for my activity not the fragment,
class MainActivity extends SherlockFragmentActivity implements ActionBar.TabListener
{
}
maybe you can have,
class FragmentA extends SherlockFragment implements TabListener{
#Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
}
#Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
}
#Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
}
}