Develop Reference

Tabs are not coming in layout of android studio

I am trying to create tabs in my layout. But instead of showing tab it is showing the below screen in design:
Below is the code:
**activity_mail.xml**
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_marginTop="200dp"
android:id="#+id/appBarLayout2">
<com.google.android.material.tabs.TabLayout
android:id="#+id/sliding_tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabMode="fixed"/>
</android.support.design.widget.AppBarLayout>
<androidx.viewpager.widget.ViewPager
android:id="#+id/viewPager"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:background="#android:color/white"/>
</LinearLayout>
MainActivity.java
import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.viewpager.widget.ViewPager;
import com.google.android.material.tabs.TabLayout;
public class MainActivity extends AppCompatActivity {
/* private TabAdapter adapter;
private TabLayout tabLayout;
private ViewPager viewPager;*/
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ViewPager viewPager = (ViewPager) findViewById(R.id.viewPager);
viewPager.setAdapter(new TabAdapter(getSupportFragmentManager(),
MainActivity.this));
TabLayout tabLayout = (TabLayout) findViewById(R.id.sliding_tabs);
tabLayout.setupWithViewPager(viewPager);
}
}
Tab1Fragment.java
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import androidx.fragment.app.Fragment;
public class Tab1Fragment extends Fragment {
public static final String ARG_PAGE = "ARG_PAGE";
private int mPage;
public static Tab1Fragment newInstance(int page) {
Bundle args = new Bundle();
args.putInt(ARG_PAGE, page);
Tab1Fragment fragment = new Tab1Fragment();
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mPage = getArguments().getInt(ARG_PAGE);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_main, container, false);
TextView textView = (TextView) view;
textView.setText("Fragment #" + mPage);
return view;
}
}
TabAdapter.Java
import android.content.Context;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentStatePagerAdapter;
public class TabAdapter extends FragmentStatePagerAdapter {
final int PAGE_COUNT = 3;
private String tabTitles[] = new String[] { "Tab1", "Tab2", "Tab3" };
private Context context;
public TabAdapter(FragmentManager fm, Context context) {
super(fm);
this.context = context;
}
#Override
public int getCount() {
return PAGE_COUNT;
}
#Override
public Fragment getItem(int position) {
return Tab1Fragment.newInstance(position + 1);
}
#Override
public CharSequence getPageTitle(int position) {
// Generate title based on item position
return tabTitles[position];
}
}
fragment_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/mainLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".ui.main.PlaceholderFragment">
<TextView
android:id="#+id/section_label"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="#dimen/activity_horizontal_margin"
android:layout_marginTop="#dimen/activity_vertical_margin"
android:layout_marginEnd="#dimen/activity_horizontal_margin"
android:layout_marginBottom="#dimen/activity_vertical_margin"
android:text="#string/sparta"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:layout_constraintLeft_creator="1"
tools:layout_constraintTop_creator="1" />
</androidx.constraintlayout.widget.ConstraintLayout>
Also when trying to run it in my mobile, it is showing error something like:
android.widget.RelativeLayout cannot be cast to android.widget.TextView
Please suggest the way to solve this issue.

After androidX, support library are removed,
so you need to use material design which help you.
Replace your appbar with below code
<com.google.android.material.appbar.AppBarLayout
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_marginTop="200dp"
android:id="#+id/appBarLayout2">
this will help you.

You're using deprecated design support AppBarLayout, You need to replace it with androidx library , so replace android.support.design.widget.AppBarLayout with com.google.android.material.appbar.AppBarLayout in your layout.
<?xml version="1.0" encoding="utf-8"?><?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<com.google.android.material.appbar.AppBarLayout
android:id="#+id/appBarLayout2"
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_marginTop="200dp">
<com.google.android.material.tabs.TabLayout
android:id="#+id/sliding_tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabMode="fixed" />
</com.google.android.material.appbar.AppBarLayout>
<androidx.viewpager.widget.ViewPager
android:id="#+id/viewPager"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:background="#android:color/white" />
</LinearLayout>
For the android.widget.RelativeLayout cannot be cast to android.widget.TextView, please post the entire stack trace.
UPDATE
tab names are not coming. only green background of the tablayout is shown.
this is odd behavior, as I you already override getPageTitle in the adapter.. I just suggest not to use a hard-coded array of Strings in the adapter, instead add the tab titles in the strings.xml
Strings.xml
<resources>
<string name="tab1">Tab1</string>
<string name="tab2">Tab2</string>
<string name="tab3">Tab3</string>
</resources>
Adapter
public class TabAdapter extends FragmentStatePagerAdapter {
final int PAGE_COUNT = 3;
// private String tabTitles[] = new String[] { "Tab1", "Tab2", "Tab3" };
private int[] tabTitles = new int[]{R.string.tab1, R.string.tab2, R.string.tab3};
private Context context;
public TabAdapter(FragmentManager fm, Context context) {
super(fm);
this.context = context;
}
#Override
public int getCount() {
return PAGE_COUNT;
}
#Override
public Fragment getItem(int position) {
return Tab1Fragment.newInstance(position + 1);
}
#Override
public CharSequence getPageTitle(int position) {
// Generate title based on item position
// return tabTitles[position];
return context.getString(tabTitles[position]);
}
}
Please have a look at this question that might be relevant.
UPDATE 2
Try to add those listeners
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ViewPager viewPager = (ViewPager) findViewById(R.id.viewPager);
viewPager.setAdapter(new TabAdapter(getSupportFragmentManager(),
MainActivity.this));
TabLayout tabLayout = (TabLayout) findViewById(R.id.sliding_tabs);
tabLayout.setupWithViewPager(viewPager);
// listeners
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
tabLayout.addOnTabSelectedListener(new TabLayout.ViewPagerOnTabSelectedListener(viewPager));
}
if not working , try to set the current item of the ViewPager
viewPager.setCurrentItem(itemPosition);

Change TextView values with method inside Fragment (NullPointerException)

I'm trying to make an app (for learning purposes) where I have a few tabs with scrollable content.
I have a collapsing app bar with a ViewPager for the main layout and three identical layouts with a TextView inside a NestedScrollView where the only difference is the image on top of the text. I also have three fragment classes with the same code inside. Everything worked fine.
But since I'm using the same layout in each tab, I thought that instead of a xml file and a java class for each tab, I could just have one of each and then somehow change the content for each tab inside my Adapter.
So I tried to just create a method to do that inside my tabFragment class. But I can't seem to find a way to modify the TextView. I keep getting a NullPointerException every time.
What am I missing?
Is my approach wrong? If so, what would be a better one? How do I solve this?
Thank you in advance :)
Here's my fragment class right now (the only one remaining ):
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import androidx.fragment.app.Fragment;
import com.example.tablayoutwithscrollview.R;
public class TabFragment extends Fragment {
private TextView textView;
private int text, image;
public TabFragment(){}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
View view = inflater.inflate(R.layout.tab1, container, false);
//textView = view.findViewById(R.id.textView);
return view;
}
#Override
public void onViewCreated(View view, Bundle savedInstanceState)
{
super.onViewCreated(view, savedInstanceState);
textView = getView().findViewById(R.id.textView);
}
public void setTabContent(int text, int image)
{
textView.setText(text);
textView.setCompoundDrawablesWithIntrinsicBounds(0,image,0,0);
}
}
My adapter class:
import android.content.Context;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentPagerAdapter;
import com.example.tablayoutwithscrollview.Tabs.TabFragment;
public class MyAdapter extends FragmentPagerAdapter {
private static int tabCount;
Context context;
public MyAdapter(FragmentManager fm, int tabCount, Context context){
super(fm);
this.tabCount = tabCount;
this.context = context;
}
#Override
public Fragment getItem(int position) {
TabFragment fragment;
switch (position)
{
case 0:
fragment = new TabFragment();
fragment.setTabContent(R.string.lorem_ipsum, R.drawable.jackfruit);
return fragment;
case 1:
fragment = new TabFragment();
fragment.setTabContent(R.string.lorem_ipsum, R.drawable.guava);
return fragment;
case 2:
fragment = new TabFragment();
fragment.setTabContent(R.string.lorem_ipsum, R.drawable.pomegranate);
return fragment;
default:
return null;
}
}
#Override
public CharSequence getPageTitle(int position)
{
switch (position)
{
case 0:
return context.getString(R.string.tab1_title);
case 1:
return context.getString(R.string.tab2_title);
case 2:
return context.getString(R.string.tab3_title);
default:
return null;
}
}
#Override
public int getCount() {
return tabCount;
}
}
MainActivity:
package com.example.tablayoutwithscrollview;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.widget.NestedScrollView;
import androidx.viewpager.widget.ViewPager;
import android.os.Bundle;
import com.google.android.material.tabs.TabLayout;
public class MainActivity extends AppCompatActivity {
private TabLayout tabLayout;
private ViewPager viewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tabLayout = findViewById(R.id.tabLayout);
viewPager = findViewById(R.id.viewPager);
populatesTabLayout(tabLayout);
MyAdapter myAdapter = new MyAdapter(getSupportFragmentManager(), tabLayout.getTabCount(), this);
viewPager.setAdapter(myAdapter);
tabLayout.setupWithViewPager(viewPager);
}
private void populatesTabLayout(TabLayout tabLayout)
{
for (int i = 0; i<3; i++)
{
tabLayout.addTab(tabLayout.newTab());
}
}
}
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/coordLayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.google.android.material.appbar.AppBarLayout
android:id="#+id/appBarLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<com.google.android.material.appbar.CollapsingToolbarLayout
android:id="#+id/collapseToolBar"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
app:contentScrim="?attr/colorPrimary"
app:layout_scrollFlags="scroll|exitUntilCollapsed"
app:toolbarId="#+id/toolbar">
<ImageView
android:id="#+id/imageView7"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:srcCompat="#drawable/strawberry" />
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"></androidx.appcompat.widget.Toolbar>
</com.google.android.material.appbar.CollapsingToolbarLayout>
<com.google.android.material.tabs.TabLayout
android:id="#+id/tabLayout"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:visibility="visible" />
</com.google.android.material.appbar.AppBarLayout>
<androidx.viewpager.widget.ViewPager
android:id="#+id/viewPager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
And my tab layout:
<?xml version="1.0" encoding="utf-8"?>
<androidx.core.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/tabNestedScrollView"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/textView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:drawableTop="#drawable/jackfruit"
android:text="#string/lorem_ipsum" />
</androidx.core.widget.NestedScrollView>
Here's how it's supposed to work (from before when each tab had a fragment class and a layout file):

The problem is that the created TabFragment instance has not been attached to the activity yet, therefore the textView does not inflated at that point.
You should pass the text to the TabFragment instance as an argument in the MyAdapter#getItem(..) method.
...
case 0:
fragment = new TabFragment();
Bundle args = new Bundle();
args.putString("key", textString);
fragment.setArguments(args);
return fragment
...
After that set the text for the TextView instance in the onViewCreated(...) method:
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
textView = getView().findViewById(R.id.textView);
textView.setText(getArguments().getString("key"));
}
Or you can see a nice example at the Android Reference.

Tablayout in Fragment not working in Navigation Drawer

I am creating a tabbed layout as home fragment of navigation drawer activity,
so i called fragment named 'test' as default in main activity. like
test home_fragment=new test();
android.support.v4.app.FragmentManager manager=getSupportFragmentManager();
manager.beginTransaction().replace(R.id.layout, home_fragment,home_fragment.getTag()).commit();
if i call this fragment again . like
if (id == R.id.nav_home) {
test home_fragment=new test();
android.support.v4.app.FragmentManager manager=getSupportFragmentManager();
manager.beginTransaction().replace(R.id.layout, home_fragment,home_fragment.getTag()).commit();
}
now the result is tab1 and tab2 are gone
See the screenshot for more reference
this is my test class( tabbed layout)
package com.hackerinside.jaisonjoseph.testapp;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import static android.R.attr.x;
/**
* A simple {#link Fragment} subclass.
*/
public class test extends Fragment {
public SectionsPagerAdapter mSectionsPagerAdapter;
public ViewPager mViewPager;
public test() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_test, container, false);
// View x = inflater.inflate(R.layout.fragment_test,null);
mSectionsPagerAdapter = new SectionsPagerAdapter (getFragmentManager());
mViewPager = (ViewPager) rootView.findViewById(R.id.container);
mViewPager.setAdapter(mSectionsPagerAdapter);
TabLayout tabLayout = (TabLayout) rootView.findViewById(R.id.tabs);
//Adding the tabs using addTab() method
tabLayout.addTab(tabLayout.newTab().setText("Tab Title 1"));
tabLayout.addTab(tabLayout.newTab().setText("Tab Title 2"));
tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
tabLayout.setupWithViewPager(mViewPager);
return rootView;
}
public class SectionsPagerAdapter extends FragmentPagerAdapter {
private SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
switch (position)
{
case 0:
tab1 tab1=new tab1();
return tab1;
case 1:
tab2 tab2=new tab2();
return tab2;
default:return null;
}
}
#Override
public int getCount() {
// Show 3 total pages.
return 2;
}
#Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0:
return "SECTION 1";
case 1:
return "SECTION 2";
}
return null;
}
}
}
this is my tabbed layout xml code
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/main_content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="com.hackerinside.jaisonjoseph.testapp.MainActivity"
android:orientation="vertical">
<android.support.design.widget.AppBarLayout
android:id="#+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/AppTheme.AppBarOverlay">
<android.support.design.widget.TabLayout
android:id="#+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
</LinearLayout>

Try this two solution:
Solution 1
instead of
public class SectionsPagerAdapter extends FragmentPagerAdapter {
use
public class SectionsPagerAdapter extends FragmentStatePagerAdapter {
Solution 2
use getChildFragmentManager() instead of getFragmentManager()
mSectionsPagerAdapter = new SectionsPagerAdapter (getChildFragmentManager());

android.support.design.widget.TabLayout not working properly with ViewPager

android.support.design.widget.TabLayout not working properly with ViewPager
If I set tabLayout.setupWithViewPager(viewPager); then tablayout view not showing please find attached screen shots.
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:fitsSystemWindows="false"
android:orientation="vertical"
tools:context=".home.HomeActivity"
tools:showIn="#layout/activity_home">
<android.support.design.widget.TabLayout
android:id="#+id/tab_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?attr/colorPrimary"
android:elevation="6dp"
android:minHeight="?attr/actionBarSize"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"/>
<android.support.v4.view.ViewPager
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="fill_parent"
android:layout_below="#id/tab_layout"/>
Fragment Code :
TabLayout tabLayout = (TabLayout) view.findViewById(R.id.tab_layout); tabLayout.addTab(tabLayout.newTab().setText(getActivity().getResources().getText(R.string.feeds))); tabLayout.addTab(tabLayout.newTab().setText(getActivity().getResources().getText(R.string.following))); tabLayout.addTab(tabLayout.newTab().setText(getActivity().getResources().getText(R.string.you)));
tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
final ViewPager viewPager = (ViewPager) view.findViewById(R.id.pager);
final PageAdapter adapter = new PageAdapter(getChildFragmentManager(), 3);
viewPager.setOffscreenPageLimit(3);
viewPager.setAdapter(adapter);
tabLayout.setupWithViewPager(viewPager);
When remove "tabLayout.setupWithViewPager(viewPager);" the view is working fine. But I need navigate respective fragment when click on respective tab.

In my case I solved this by replacing,
tabLayout.setupWithViewPager(viewPager);
By,
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(
tabLayout));
tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
#Override
public void onTabSelected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(TabLayout.Tab tab) {
}
#Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
I hope this will help you out.

Incase if you are using tabLayout inside fragment try this answer
Possible mistake
you need to pass getChildFragmentManager() to FragmentPagerAdapter
not getSupportFragmentManager() or getFragmentManager()
//wrong one
ViewPagerAdapter adapter = new ViewPagerAdapter(getActivity().getSupportFragmentManager());
//correct one
ViewPagerAdapter adapter = new ViewPagerAdapter(getChildFragmentManager());
ViewPagerAdapter is FragmentPagerAdapter
public class ViewPagerAdapter extends FragmentPagerAdapter {
}

Short version of solution (Naveen Kumar M):
viewPager.addOnPageChangeListener(
new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
tabLayout.addOnTabSelectedListener(
new TabLayout.ViewPagerOnTabSelectedListener(viewPager));

try this
add this to viewpager.
app:layout_behavior="#string/appbar_scrolling_view_behavior"
Also keep to parent as Coordinator layout then only scrolling will work fine
Refer here:http://coderzpassion.com/working-appbarlayout-like-whatsapp/

Check the getCount().
DON'T RETURN IT TO NULL! RETURN TO blankFragment.
package my.package;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;
public class tabPagers extends FragmentStatePagerAdapter {
String[] titles = new String[]{"Home", "Campus", "Course"};
public tabPagers(FragmentManager fm) {
super(fm);
}
#Nullable
#Override
public CharSequence getPageTitle(int position) {
return titles[position];
}
#Override
public Fragment getItem(int position) {
BlankFragment blankFragment = new BlankFragment();
Blank2Fragment blank2Fragment = new Blank2Fragment();
Blank3Fragment blank3Fragment = new Blank3Fragment();
switch (position) {
case 0:
return blankFragment;
case 1:
return blank2Fragment;
case 3:
return blank3Fragment;
}
return blankFragment; //This one is important
}
#Override
public int getCount() {
return titles.length; //This one is important too
}
}

https://developer.android.com/reference/com/google/android/material/tabs/TabLayout#viewpager-integration
<androidx.viewpager.widget.ViewPager
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.google.android.material.tabs.TabLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="top" />
</androidx.viewpager.widget.ViewPager>

Android - ActionBarActivity with ViewPager

i have a problem with ActionBarActivity and ViewPager.
On my "main-activity" which is a ActionBarActivity i have some tabs, which are fragments.
I want to implement the "swipe-feature" between these tabs.
I've already read the following tutorial:
http://developer.android.com/training/implementing-navigation/lateral.html
Actually i have implemented the whole code, but my app wont work. :(
There is no "swipe-feature" between the tabs.
Here is my code of the main-activity:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_hauptmenue_extended);
try {
actionBar = getSupportActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// ViewPager ...
pagerAdapter = new CollectionPagerAdapter(
getSupportFragmentManager());
viewPager = (ViewPager) findViewById(R.id.viewpager);
viewPager.setAdapter(pagerAdapter);
viewPager.setCurrentItem(1);
viewPager
.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
#Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
});
// Add all tabs to the actionbar...
Tab tabB = actionBar.newTab();
tabB.setText("Home");
tabB.setIcon(R.drawable.icon_home);
tabB.setTabListener(new TabListener<Startmenue_activity>(this,
"Start", Startmenue_activity.class, viewPager));
actionBar.addTab(tabB);
Tab tabA = actionBar.newTab();
tabA.setText("");
tabA.setIcon(R.drawable.icon_nachrichten_sel);
tabA.setTabListener(new TabListener<Nachrichten_activity>(this,
"News", Nachrichten_activity.class, viewPager));
actionBar.addTab(tabA);
Tab tabC = actionBar.newTab();
tabC.setText("");
tabC.setIcon(R.drawable.icon_favoriten);
tabC.setTabListener(new TabListener<Favoriten_activity>(this,
"Favs", Favoriten_activity.class, viewPager));
actionBar.addTab(tabC);
And my adapter looks like this:
public class CollectionPagerAdapter extends FragmentPagerAdapter {
final int NUM_ITEMS = 3; // number of tabs
List<Fragment> fragments = new ArrayList<Fragment>();
public Fragment getItem(int pos) {
return fragments.get(pos);
}
public void addFragment(Fragment f) {
fragments.add(f);
}
public CollectionPagerAdapter(FragmentManager fm) {
super(fm);
Fragment home_Fragment = new Startmenue_activity();
addFragment(home_Fragment);
Fragment news_Fragment = new Nachrichten_activity();
addFragment(news_Fragment);
Fragment favoriten_Fragment = new Favoriten_activity();
addFragment(favoriten_Fragment);
}
#Override
public int getCount() {
return NUM_ITEMS;
}
}
Oh and my XML of the main-activity looks like this:
<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/fragView"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".Hauptmenue_extended" >
<!-- The ViewPager -->
<android.support.v4.view.ViewPager
android:id="#+id/viewpager"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<!-- The main content view -->
<FrameLayout
android:id="#+id/main"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</FrameLayout>
<!-- The navigation drawer -->
<ListView
android:id="#+id/left_drawer"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
android:background="#fff"
android:choiceMode="singleChoice"
android:divider="#android:color/transparent"
android:dividerHeight="0dp" />
</android.support.v4.view.ViewPager>
</android.support.v4.widget.DrawerLayout>

There's a bunch of things that I don't fully understand about your code, for example, why are you putting a ListView inside the ViewPager?. Anyways if you want to implement some tabs with the swipe feature. Here is how do it:
First the xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<android.support.v4.view.PagerTabStrip
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="top" />
</android.support.v4.view.ViewPager>
Now the activity:
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;
public class MainActivity extends FragmentActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ViewPager pager = (ViewPager) findViewById(R.id.pager);
pager.setAdapter(new SampleAdapter(this, getSupportFragmentManager()));
}
}
The adapter:
import android.content.Context;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;
public class SampleAdapter extends FragmentStatePagerAdapter {
Context ctxt = null;
public SampleAdapter(Context ctxt, FragmentManager mgr) {
super(mgr);
this.ctxt = ctxt;
}
#Override
public int getCount() {
return 3;
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return new SimpleFragment("Hi");
case 1:
return new SimpleFragment("There");
case 2:
return new SimpleFragment("Fella");
}
return null;
}
#Override
public String getPageTitle(int position) {
switch (position) {
case 0:
return "First Tab";
case 1:
return "Second Tab";
case 2:
return "Third Tab";
}
return null;
}
}
And the SimpleFragment:
import android.annotation.SuppressLint;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
#SuppressLint("ValidFragment")
public class SimpleFragment extends Fragment {
String text;
public SimpleFragment(String string) {
text = string;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View root = inflater.inflate(R.layout.fragment, container, false);
TextView textview = (TextView) root.findViewById(R.id.textView1);
textview.setText(text);
return root;
}
}
And the fragment.xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:text="Large Text"
android:textAppearance="?android:attr/textAppearanceLarge" />
</RelativeLayout>
Hope this helps :)

Try this out. But I've not tested it.
http://wptrafficanalyzer.in/blog/swipable-navigation-tabs-using-actionbarcompat-library/